Bike pump problem?

I was using my bike pump today to fill a pneumatic launcher, and finally I just got fed up with the leaking around the pump base. On every stroke, the first 3/4 of air would be leaked out of the base, and it would only compress the remaining 1/4 of air remaining, and that would only compress if you pushed down very hard, and quickly, otherwise it all leaked out. And no matter what pressure the launcher was pressureized to, the pump handle/piston would slide down slowly, getting pushed down under it's own weight, meaning that there was almost no resistance to it. I think the leak is occuring where the tube meets the pump base, and you can feel air rush out with your legs as you pump. I'm pretty sure there is a one way valve in the gauge portion of the pump, which connects to the base with a hose,  and the filling hose is coming out of it, which is allowing me to compress at least a little air before the rest leaks out. I disassembled  the pump, starting with the base. Turns out, the leak was from an oring on the tube which was not tightened down enough by a screw on ring around the base of the tube. Put it back together, and voila, pushing my finger against the schrader valve connector and pushing down on the pump handle created pressure against my finger and no leaking. As soon as I hooked it up to my launcher, i realized something was up, I could pump down once, but the pump handle just got pushed upwards as soon as i let go. This is what I can't figure out how to fix. It seems the one way valve in the gauge portion is locked in the open position. Anybody know how to fix this? EDIT: Okay I took pictures of the pieces. I now cannot figure out if the valve is in the base, or the gauge portion, so i have included pics of both. Hopefully someone can help me figure this out. EDIT 2: Turns out the valve is in the base, and the ball just fell out when i first disassembled it, i have now found the ball and it is working fine.

Question by LiquidLightning 7 years ago  |  last reply 7 years ago


Fixing a leak in a bike pump

Hi All,  I have a floor bicycle pump like this (http://www.halfords.com/cycling/bike-maintenance/bike-pumps/topeak-joe-blow-sport-ii-bike-pump) which lately developed a leak in the center tube at the bottom. It is apparently caused by bad positioning while pumping air. I have located the hole which is beneath the pump and the material is plastic. It is small 1mm or smaller hole. Is there any recommendation on what type of glue should I use to fix it ? I was thinking of epoxy, but would like to know what you guys think. Thanks

Question by YousufS2 2 years ago  |  last reply 2 years ago



How do you make a bike pump from scratch?

Need a pump

Question by GEEK1 10 years ago  |  last reply 4 years ago


how to inflate a bike tire with out a pump

Hello everybody, I have recently built a no weld rebumbant bike. And during the course have discovered that I do not own an bike pump. since I live in a extremely rural area borrowing is out of the question if some one could please help me I would greatly appreciate it. sincerely, fidgety

Topic by fidgety2 10 years ago  |  last reply 10 years ago


Vacuum pump voltage?

Today I was dumpster diving and i found an old vacuum so i decided to take the pump out but i made the mistake of not checking what voltage the vacuum runs on, because it also had a spinning component at the mouth of the vacuum. I think the pump works fine because i noticed that tube connecting the mouth of the vacuum and the pump was broke. Is there anyway to find out what voltage it runs on? would standard 120 be ok?The markings on it say 81 b-9 ECP 6500-240 HPU+ 60hz HD10 120 vac 07:07 does that mean it will work off a standard 120 outlet?update: What I am going to do with this motor has been decided. I will be attaching it to the back wheel of my bike with a car battery, i will install some type of switch on the handlebar or add something like a dimmer switch, this would allow me to have the motor on if i want, and i can adjust the speed. Please help fine tune this idea.

Topic by astrozombies138 11 years ago  |  last reply 7 years ago


Where is the manuel tire pump vaccumn sealer that used to be on this site?

The manuel floor tire pump for bikes etc was shown to be altered to suck air out instead of forcing air in. It could be used to seal jarsof dry seeds etc. I could not download it the other day and now I cqn't find it.

Question by zenniagirl 10 years ago  |  last reply 10 years ago


Schrader Valve use with liquid?

I am working on making a compressed liquid system and i need a valve that can take both a bike pump and have liquid put through it...Can a Schrader Valve take a liquid (clean) and then have the bike pump still attached after?

Question by trf 9 years ago  |  last reply 9 years ago


how to use bike gears to control speed of vertical axis windmill for pumping water?

I would like to use bike gears to switch gears eighter clockwise, or counterclockwise on a vertical axis windmill for pumping water. The purpose is to slow down the speed of the spinging rotor or switch it intoa idler gear, to allow the rotor to keep spinging, and to disconnect the water pump, so it wont' be damaged in high winds; Also not to slam the rotor to a sudden stop, by ingageing a brake. I am building this not only for myself, but also my church for them to give away free to needly people around the world. Thank you for any and all help in this matter.

Question by robertbarfield 9 years ago  |  last reply 9 years ago


Having problems on building A bike generator

First, I have problem on choosing suitable generator. my choices are washing machine motor , alternator or water pump (1hp) what should i use ?! second, how can i calculated the power i will take from the generator theoretically. third, i had read that if i put a high gear ratio the motor will be destroyed because it can't hold it so how can i fit it with maximum allowable ?

Topic by loradwan 1 year ago  |  last reply 1 year ago


Solution to turning on/off gas: new pump design.

I've been working a couple weeks now on solving the problem I posted here on how to improve my pump design by alternating the feed of ethanol vapour. I got good feedback but ultimately all the solutions involved mechanisms which were going to be somewhat tricky to build and source, which is against the brief of the project I'm working on; being an open source solar tracker concentrator makeable from scrap. In the end I solved the problem by largely redesigning the whole pump. Since it's driven by boiling ethanol, rather than add an extra mechanism for turning the feed of vapour off and on, I reduced the amount of ethanol being boiled, so that it boils itself out after an appropriate period. The vapour is then able to collapse fully, which sucks in more liquid ethanol and refills the system. 1. At the bottom right is the boiler, which holds about 2-3 ml ethanol. 2. This boils and the vapour enters the 'chamber' (the half blue, half white (liquid and gas)), forcing out the liquid, which pours into the wheel, ending up in the main reservoir. 3. This continues until the eths in the boiler has boiled away to the extent that it can no longer overcome the rate of re-condensation in the chamber, which starts to suck, so to speak. 4. This draws liquid from the reservoir, which passes through the boiler, shutting off the boil, the pressure drops quickly and the chamber and boiler refill with liquid. 5. Two valves (the only moving parts, besides the wheel) keep all this going in the right direction. 6. Repeat. The wheel provides the motion for the solar tracker. It's not in by any means powerful or efficient, but the whole thing can be made from a bit of metal tube, some thin pipe, a glass jar and two valves from bike inner tubes (plus a paint tin, bike wheel bearing and some drinks cans for the wheel). I haven't had a chance to try it in the field yet, but powered by a candle it seems to work fairly well. Blog entry here, will post photos and videos when available.

Topic by SolarFlower_org 8 years ago


Can someone help me with my fatal flaw in my spudgun design?

So i have built spudguns in the past and with every new gun i make it gets bigger and better. So i just found pressure rated 3" pvc and im going to use it for a new air chamber. Its a simple end around gun with a piloted sprinkler valve so yea the design is good. Except for one thing. I am enthusiastic enough of a spudgunner to use an air compressor to power it when im at home. but when im at a park or some open feild i bring along a bike pump to pump it up. But with each size up for the air chamber it takes longer and longer and longer to pump. Im not enthusiastic enough to buy a compressed air tank for $60. so what should i do to power it up. i dont have enough room at my house for a distance or height shot and it will take forever to use a bike pump so what should i do. PLESE HELP ME  i will try to post pics of it soon  HELP ME

Question by ostomesto 8 years ago  |  last reply 8 years ago


Has anyone used/made a Schrader-valve (tire stem) adapter for a Coleman mattress pump?

I'm getting too old (or out of shape) to use a manual tire pump on mine and my wife's bicycles. We own a Coleman air mattress with their wall-plug inflation pump. The latter comes with their custom "air lock" adapter for the mattress, and a "pinch valve" adapter.Before I go out and buy a compressor/electric pump for the bikes, I wanted to try using this one that I already own. Has aynone ever used this pump with a valve-stem adapter (Schrader valve) to inflate tires? If so, where did you get the adapter? Or did you make one?

Topic by kelseymh 10 years ago  |  last reply 10 years ago


Everytime i air up my tires they blow. Why?

Okay, when i air up my tires on my bike, the tire comes off the rim, the tube comes out and pops, even at 55-65 PSI exactly what they are supposed to be at. How do stop this? Please!! It is getting expensive!!

Question by Yerboogieman 9 years ago  |  last reply 9 years ago


Too many volts from a bike generator

I took a treadmill motor and hooked it up to an excersize bike in order to charge a 12v battery and power an audio system.  Unfortunately, it worked far better than I ever hoped and is pumping out 75v at a max pedal, 45v on an easy ride.  I've looked into various charge controllers, but they only charge batteries close to the input voltage, and step-down voltage changers take it directly down to 12v, too low to charge a 12v battery.  Any suggestions?  Thanks.

Topic by EastsidePrep 7 years ago  |  last reply 6 years ago


I can't buy a generator from Amazon or ebay so what should i choose ?

I'm working on Bike power Generation and i have problem in choosing the generator. my options are motors then transform them into generators. options are ( Water pump (1hp) - Washing Machine motor - treadmill motor - car Alternator ) What should i use and what modification i should do ?! 

Question by loradwan 1 year ago  |  last reply 1 year ago


What lubricant to refill a fridge compressor with?

Hey all, I just grabbed a compressor from a fridge that had been badly mangled by a bulldozer at a demolition site, planning to make a vacuum pump or airbrush compressor (or both!) Trouble is, I thought the liquid it contained was leftover refrigerant, and drained it all out. I didn't really have a choice, as leftover freon was gassing out of the compressor (thought it had lost pressure, but there was still a little in the compressor) and it was sputtering the oil everywhere. I held it upside down while carrying it home, and when I got it here, it was apparently empty. Then I found out that what I poured out wasn't liquid freon, but actually vital oil that keeps it alive. The compressor runs fine, but I only tried it for a few seconds for fear of destruction. I have many lubricants here, motor oil, 2-stroke oil, bike chain oil, etc. If I'm to dump an oil into my compressor, any ideas on which is the best call, and roughly how much should it take?

Topic by Rectifier 11 years ago  |  last reply 2 years ago


Need way to fill small air canisters (4-8oz) w/ bike pump

I've got a couple of older small CO2 canisters that I haven't used in a few years. I figured a good way to reuse them was to make a refillable canned air. The only problem is I don't have an air compressor. What I do have is a bike pump. Does anyone have any good ideas on how to (1) get air into the cylinder with the pump and (2) make some sort of release system, trigger or otherwise, to release it like canned air. I'm looking to use it to blow out electronics and the like. Yes I know about the moisture issue but not terribly concerned with it.

Topic by MrBippers 12 years ago  |  last reply 12 years ago


Best way to lift a liquid using heat? (SImple pump designs)

I'm overhauling the design of my solar concentrator and now need a good way of lifting a fluid, so as to pour it into a waterwheel and provide rotation. I have a little solar concentrator and boiler to generate heat or steam. What's the best configuration to give as high a rate of flow as possible? I'm hoping for something in the range of 500 ml per minute, rising about 30 cm. I've briefly played around with the attached setup, which is a very basic bubble or airlift pump,  The black is my wheel, the blue a reservoir for the fluid (ethanol), the white is the boiler putting out steam (ethanol vapour) and the light blue is a mix of the liquid and bubbles of vapour which rise up the pipe and re-enter the wheel. It actually works ok, but even optimally only gives a third the rate I'm after. If necessary I can grab some valves from old bike innertubes, or other basic materials if they'll help. My previous design was to have the bubbles of steam going directly into the wheel, which was filled with ethanol. This works but requires heating 3 litres of ethanol to just under boiling. Not impossible but a bit of a hassle. I'm hoping lifting a liquid instead will be a bit easier.

Topic by SolarFlower_org 9 years ago  |  last reply 9 years ago


Net Gun

Hey instructables, I haven't been on in a while but I am back and looking for someone to give me some advice. In my class, we are playing a castle crashers type game where we have to design a device that will remove all of the foam blocks from the area provided. I came up with an idea that utilizes air pressure to propel the net forward with a decent amount of force. However, I am running into an issue in finding a feasible way to store the pressure provided from me pumping a bike pump, and releasing it to propel the net. I was interested in using a rubber bladder to contain the air pumped into it, and releasing the air on command (start button). I can't use an actual compressor unit as it must be human or battery powered, and it must fit in a 2'x2' space and can't reach more than 5' tall. Any ideas as to where or how I might create a bladder would be greatly appreciated!

Topic by piddle01 6 years ago  |  last reply 6 years ago


disc/disk brake squeal rear brake? Answered

After a rainy day riding my bike, i had wiped it down and forgot the rear brake and now it squeals when I try to use it. More like an elephant noise. Help please!

Question by knektek 8 years ago  |  last reply 8 years ago


potato cannons

Hey, just wanted to see everyone's potato cannon designs. please post yours and I will post mine. a great instructional book on how to make these can be found at your local library, called backyard ballistics.

Topic by nerfer 10 years ago


How to straighten copper tubing? Answered

I'm making an air "cannon", but my tubing is bent. It is 3/8 copper tubing, and is very bendy. Is there a way to get it straight, or am I better off buying a small steel tube? (I did try googling this, with no helpful results)

Question by Bartboy 9 years ago  |  last reply 9 years ago


cooling water mister fabrication, with hand pump, for carry or backpack use? Answered

I noticed that there are a lot more part suppliers for mister type cooling systems. i am thinking of fabricating one . i was thinking of using the same parts used in the air zound bicycle air horn. i could use a small bike pump and schrader valve to turn a 2 liter soda bottle into the pressure chamber , i think i would have to wrap it in gorilla tape for the added pressure.. i am not sure if i could also put water into it.  i did a search and didn't  see any instructables on building cooling misting systems.any ideas?

Question by escapefromyonkers 7 years ago  |  last reply 7 years ago


nerf gun airtech 2000 and 3000 mod!

Alright... so i hooked a soda bottle up to a nerf airtech 2000 (when i get the stuff for the 3000 i will do that one too) and so now i have a big resivoir and i have a way of hooking it up to a bike pump so i can pump it up to a reasonable pressure and run around and cause pain without tired arms. but the guns pump still works (and gets it up to about 40 psi after 2 minutes of pumping) you use a 4 way coupler WITH HOSE CLAMPS! and use tubing rated for pressure! you have a schrader valve (or similar) and plug the pump on the 4 way along with the out line. (this was done on a 2000, the 3000 may or may not work) DONT HOLD DOWN THE TRIGGER! if you do then much of the pressure will be lost. now you can shoot easily and not be found out by pumping noises) im sorry i dont have a diagram. so when your done... the soda bottle (2 litre is the best! it lasts longer), schader valve, output, and input from the onboard pump should all be on the 4 way coupler and be hose clamped (if not the hoses will fly off and youll hear a loud hiss and be angry) the 2 litre bottle can be consealed in your backpack or be heald under your armpit, glued or taped to the gun, whatever!

Topic by mrbob1000 10 years ago  |  last reply 10 years ago


I want a good reliable Airsoft pistol, any suggestions? Answered

I love playing airsoft but its so damn expensive, especially in canada.  I've been looking at a few different methods of building a spring or elastic-powered airsoft pistol to be used when my main gun is out of ammo. I've made a couple from K'nex but they dont hold up when i put alot of elastics on them.  im not interested in using the aerosol or bike-pump pvc models, i've built those too but they take too long for each shot. Help me out Please :)

Question by mr.break_it 9 years ago  |  last reply 7 years ago


Will this launcher design work?

Concept - A hybrid-launcher (combustion and pneumatics) with interchangeable barrels for various projectile types So the design is pretty simple, in the back of the gun launcher thing (we’ll call it ‘the weapon’ for now) will be a propellant chamber measuring 2.5” wide and 1.5’ long. On one end of the propellant chamber will be an unscrewable coupler. On the other end, a 2.5” ball valve. Attached to the ball valve will be the female end of a 2.5” coupler (without cap) From here will be the interchangeable barrels, which are simple. The barrels would consist of the male end of the 2.5” coupler and a 2.5” width converter, converting the width from 2.5" to various different sizes for the different projectile sizes (this would have to be one piece for durability, idk if such a piece exists, I hope it does, if not, i can make one) the barrel itself would measure 3’ in length A Shrater valve (bike tire valve) will be installed on the propellant chamber (for pneumatic power). A bike pump would be mounted on the weapon (like a shotgun kinda) An ignitor will be installed on the back of the chamber, mounted on the unscrewable coupler.  

Question by ishmal1103 8 years ago  |  last reply 8 years ago


Air cannon

After wanting to make an air rifle for awhile I have finally decided to do it.  I plan to use 80-100 psi from a bike pump to power it.  I plan to use a 1/2 or 3/4 inch QEV (something like this https://www.amazon.com/uxcell-Pneumatic-QE-04-Inlet-Exhaust/dp/B01MYRC509/ref=sr_1_12?ie=UTF8&qid;=1495573897&sr;=8-12&keywords;=3%2F4in+quick+exhaust+valve).  Do you guys know if a 2L soda bottle would be a good air tank or should I spend the money to make a pvc or galvanized steel one?  Would an air gun connected to the QEV work well?  Thank you for your time and help                        -James

Topic by TypeNameHere 1 year ago  |  last reply 1 year ago


what do yall think?

Btw what happend to not liable any ways OK i was bored today. It acutaly rained in so cal so I made this thing its about 5 feet tall and its a pnumatic blow gun thing with a electronic scope i coulnd find the presure rated pvc thing nor the co2 tanks so i used the next best thing A COKE BOTTLE AND A BIKE PUMP WOOOOOOT. i Know people are going to say why the (*(& are u using a coke bottle its because i only need 25-30 psi with a paper dart tiped with a paperclip and foil it went about well outa my houses yard passed my neighbors yard to my 3rd row down neighbors yard (thak god!)

Topic by gotja 11 years ago  |  last reply 10 years ago


pumatic airsoft gun help ? Answered

Ok so heres my situation. About 6 months ago I made my own pneumatic airlift sniper but even though I could get about 80 lbs of pressure stored up before I pulled my trigger my sniper only shot as far as my 300 fps gun. My question is why cuz I had a lot more force in my pneumatic sniper then my other gun and it doesn't seem to matter. My sniper was made of a metal nipple about 9 inches long and 2 inches in diameter. I then put a cap on one end and a reducing coupler on the other. I drilled a hole in the cap and inserted a valve that allowed me to attach the chamber to a bike pump. On the end with the reducer I then added a ball valve that worked as my trigger. After the ball valve was another reducing coupler that brought the size down from an inch to 1/2 an inch. Into this coupler I screwed a break line about 50 cm long(sorry about the unit change I don't remeber its length in inches) and it fit the bb very nicely. I also added a little contraption I made from paper clips that allowed the gun to be tired downward without the bb falling out. However I don't believe this was the problem as I fired the gun when their was just a wire across the back of my breakline ,to keep the bb from falling into the gun ,and the distance seemed the same. I made sure every connection before the ball valve was sealed well except that the gun did leak at a rate of 20 lbs for minute because of a bad connection with the valve that connected with the bike pump. If you need more info just say so in the comments but I don't have the gun with me right now so all i have to go off of is my memory. Thanks for your help I really appreciate it. : )

Question by inconceivable1 2 years ago  |  last reply 2 years ago


[newsletter] Best Shoe Knot, Tank Cake, Comfy Chair Recumbent...

Sign-up for our newsletter here. May 1, 2008 Welcome back! New contest! The days are longer and the weather is warmer so we're celebrating with Bike Month! Share your bike mods, upkeep tips, riding advice, and any other bike-themed Instructable to inspire others and win some cool prizes! The Cake Contest is over and the winners have been announced. See who won here! Check out these cool Instructables! Moving Tank Birthday Cake Not only is it really a tasty cake, but the turret rotates and the barrel moves up and down. Get ready for cake warfare! posted by dave spencer on Apr 25, 2008 How to Start A Flash Mob Do you and a few hundred friends have some time on your hands? Then follow these simple guidelines for creating a Flash Mob and have some fun! posted by w1n5t0n on Apr 28, 2008 Add a third LCD to your portable screen DVD player Need more LCD screens to entertain the family on road trips? Then hook up new AV outs to your DVD player and you're good to go. posted by okieinAZ on Apr 28, 2008 Make Your Own Biodiesel Processor Get a source of waste vegetable oil and put together this biodiesel processor and you'll be able to skip the regular pump. posted by drinkmorecoffee on Apr 26, 2008 How to make a Moleskine Notebook Want a Moleskine, but don't feel like paying the high price? Follow these simple instructions and you'll be turning out custom sketch pads in no time. posted by laminterious on Apr 24, 2008 Tesla turbine from old hard drives and minimal tools Those old hard drives can't handle your music collection any more, but they're perfect for creating a Tesla turbine with the help of some simple tools! posted by gerrit_hoekstra on Apr 25, 2008 Show us your flowers! May is Bike Month! Green Science Fair! The Comfy Chair Recumbent Add a recumbent bike to your comfy chair and you'll be riding in style. Bike riding has never been so plush! posted by oxania on Apr 29, 2008 Animated GPS Batmobile Icon Holy satellite triangulation, Batman! A little scanning of the Batmobile and now it's on the virtual map! posted by aarrgghh on Apr 30, 2008 DY-NO-MITE!!! birthday cake There's only one way to defuse this bomb -- it must be eaten. Start with the licorice "wires" and move on to the cake dynamite sticks. posted by mmmicha on Apr 28, 2008 Film Canister LED Flashlight Get comfy with basic wiring and LEDs with this great beginner project, and build a sweet $4 flashlight. posted by comodore on Apr 21, 2008 World's Best Shoe Knot Get loopy with it and tie the world's best shoe knot. Disagree? Then leave a comment and share your favorite knot. posted by shoemaker on Apr 28, 2008 Now go make something awesome, and I'll see you next week! - Eric

Topic by fungus amungus 11 years ago  |  last reply 11 years ago


How to ride DH safely

1. Always wear a helmet, wear body armor as well when needed (how much depends on course, and what you find to be suitable) at all times. 2. Look ahead of you. The faster you are going the further ahead you should look. 3. Stay focused and try not to concentrate or think while you are going at high speed, this tends to slow you down and/or cause accidents...practice alot and everything should come naturally with flow! - Before a run get a song or something that gets you "in the mood" in the back of your mind,and go for it - before you know it you'll be through the track/race no problem...you should all ready know the track turn for turn before doing this. 4. Make sure your tires have appropriate tread on them and are not cracking/damaged 5. Check your bike over in the parking lot before going up the lift. Ride it around and check the brakes and tire pressures. 6. Get enough sleep before riding and especially before racing. 7. Don't drink or get high before racing or riding (you can do it, and seen it done, but if you want to win or want to be safe...don't) 8. Stay relaxed and dialed in on the bike, be as relaxed as possible mentally before you start a race but be pumped physically at the same time. 9. Know the track as well as you can before racing it (the later steps will go into greater detail on how to do this). 10.Learn to 'pump through the ruff stuff'-pull up on the face and push down on the back side of bumps/rocks/landing trannys, etc... 11. Stay light on the back brake as much as you can and try to lock it as rarely as possible if at all...it may cause you to wash out. Only lock the brake on extremely sharp turns or to get into a turn if a cuttie won't be efficient enuff. 12. Try to go as fast as you can when you can-->PEDAL PEDAL PEDAL like a bat out of hell in the open or out of turns when/where ever you can. 13. Practice "cutties". 14. Buy the "Fundamentals" DVD available here on pinkbike.com or at most bike shops and study it...take notes if you have to. You will find how to do "cutties" on the DVD as well as many many more "fundamentals" for DH riding-----> BUY IT, you will be glad you did. 15.Off camber: make sure you weight your outside foot and stand the bike on the egde of the tire, that way it will stick 16. Rock gardens: the faster the better- you will bobble across the top and be on you way before you know it, rather than getting packed down and ending up with major arm pump. 17. Braking: only ever do real braking in straight lines, you can brake on corners but do it conservatively and only to slide around sharp turns better as it may cause you to wash out as mentioned above. The less you brake the faster you go and fast riding is a winning formula- think about that. 18. >>>Don't Crash It can have you out for the rest of the season and that can prevent you from winning races----obviously. Just dont ride like an idiot and attempt things that will probably end in you getting hurt. Ride within your limits! 19. (Words of Pro Down hiller Steve Peat from the "fundamentals" DVD mentioned above) "Stay as light as you can on the bike and pump through the back side of rocks or rough sections as a skateboarder pumps a vert ramp" to gain or maintain speed and momentum. 20. Trust your tires throughout the course. If you believe and have faith in your tires grip, chances are they will have grip fine. If you don't trust your tires and BELEIVE that they wont grip and you will probably fall, chances are they won't grip and as a result you will indeed fall. 21. Walk the track and look for new lines or which lines are best to take and are the fastest 22. Tuck when ever possible to conserve energy. Pedal hard in the open spots before the ruff stuff then tuck and pump and repeat. 23. True your wheels to increase your speed and pedalling efficiency 24. Don't use big fat mud bog tiresfor DH(i.e. 2.6"-3.0") EVER...unless your DH course happens to be a downhill mud swamp 25. Learn to brake with out losing traction , this helps in straight line braking before turns. 26.Push yourself in the warmups, (not stupidly) and give 95% of what your maximum was when you were pushing yourself, in the actual race. This way you wont fall, but you are still hauling a$$. 27.Practice shift points, it is very important to be in the right gear at the right time or youll be sucking wind trying to pedal a flat stretch in too high of a gear. On a fast stretch where you need to begin pedaling to maintain that speed, youll be spinning out. Know what gear to start in and what gear you need to be in at every point in the track. 28. If all else fails look fast across the finish line where everyones watching. 29.When learning, set your fork/and or shock harder than you would normally, this will teach you to use to body rather than relying upon the bike. 30. Try to pick memory markers for your self; tree stump, odd looking rock, etc... and break the course down in your head so you can become very quick overall. 31. Practice simple skills such as manuals (good for roots), Hops, roots/rocks) and of course cutties 32. Commit to berms, brake on a berm and it will end it tears, aim to "rail the berm" to do this - hit the berm at a speed that isnt too fast (this will cause you to slip up it) and not to slow (you will slip down and is slower duh) The ideal speed should carry you round as g forces will push you into the berm. 34.Take a couple of the "Learn to race" clinics offered before many of the sanctioned races. 35.Play with your set up, everything from seat angle, to brake postioning- it can all make a big difference. The more comfortable you are on the bike the faster youll go, the steepness can be different for each course(for instance) so tweak it a little each time but dont EVER change your entire setup before a race. 36.When walking the course, look back up at it. You will find new lines looking up rather then down. 37. While riding (including in the air) never squeeze the seat with your knees. This makes it impossible to flow smoothly, and makes you a ridged weight to be tossed around at the mercy of the trail. It may feel safer, but it will cause you to wreck and lose speed when you would not otherwise. In the air also, it you pinch your seat then you can not compress the lip and extend for landing. Also you can not whip and prepare for upcoming turns and bumps. The ONLY time that pinching your seat would be appropriate is when doing a suicide no hander which, if you can do it without loosing speed, is a cool way to entertain the crowd. 38.Learn to crash,it is an important skill to have that will save you alot of trouble in the long run. 39. Work your way up to the big stuff. Even if you are a good rider always warm up on an easier trail then go for the harder stuff you set out to conquer. Same for riding in general- dont go tackle the hardest trail on the mountain without first being able to do the easy ones---this may sound somewhat obvious but alot of people just cant get this bit of logic into their skulls without being told directly. 40. If the drop doesn't have a great tranny, hit it with more speed. this will cause you to have increased foreward momentum and less downward ( static ) momentum and make the landing smoother. let your bike go off the drop first. 41. If you are in the air ( off a jump drop or whatever... ) and your back end starts to dip too much, tap your back brake, this will cause the front end to dip forward. ( this is used all the time in Motocross) WARNING: Use this with caution and only when its a neccesity. 42. XC riding will make you faster. I always love watching the out of shape downhillers crossing the finish line and nearly having a hear attack. The more tired you are the more mistakes you make and the more likely you are to get hurt. Pedal! Then pedal more! 43. Train like a mofo. During my DH racing times I would spend the summer mornings doing 5-8 runs on local dh trails then dirt jumping and XC riding in the afternoon= Legs that were strong/fast as hell. Dont forget to train in the off season too. 44. Develop a training schedule not just for biking and racing but to keep in shape in general. The more you ride the better you will be. Like Ito was saying, do as much of each mountain biking discipline as possible with emphasis on Down hill. Cedric Gracia wins because he is a great all around rider as is Minaar. 45.Commit to the front end of your bike in corners. Watch Sam Hill, no-one does it better. NOTE: BEFORE DOING THIS, make sure you have practiced it and know how to do this technique at speed (Note is courtesy of Iceboy) 46. Don't pedal like a mad man out of the gate. Pedal, but let your bike gather speed and focus on keeping it. Racing comes down to one thing - exit speed , in particular your speed out of corners. Wait until you feel the flow before you start pushing it harder. If you pedal too hard from the start you'll flip in 60 seconds and get back on your bike a go harder to make up the time. Then you'll flip again. Speaking from experience on this one! It's all about being 'zen'. At least that's what all the dudes who keep beating me are telling me. Learn how to go as fast as you can through turns and sections to know your limits. 47. Make your riding FEEL slow when you are going fast! If you feel fast it's because the trail is catching up with you too quickly for you to process all the info in a comfortable time frame. Probably because you are too busy worrying about going fast and not feeling the flow. Look out, you are about to flip. It's that zen thing you're missing. 48. Practice having FLOW in all your riding, down hill (speed as well as flow), Dirt jumps (flow), XC(speed and flow), what ever (FLOW)... 49.Dont be intimidated by other riders, stay focused on what you have to do not what they are doing, if they crash pay atention to why, and try not to make the same mistake. 50. Learn to go over jumps at as high a speed as possible with out overshooting or losing speed by going too high. Jumps and learning to land them without thinking is a VERY beneficial skill to have... (if you want to stay low coming of jumps learn to soak up the lip...you will go just as far but you'll stay lower) 51. When doing a j-hop, bunny hop or going up the face of a jump don't forget to push into the ground and then come up to get more air. 53. The rougher the place you are riding the more ralaxed and flowy you should be trying to go . 54. Spend time at the track and just watch other riders(especially how they are going through the tricky sections that you are having trouble with), see what they are doing wrong and try to not make the same mistakes, also watch for where the speed spots of the section are. 55.Read Brian Lopes's & Lee McCormick's book " Mastering Mountain Biking Skills", this book covers everything you need to know in great detail from top to bottom, it is with out a doubt the most comprehensive guide for how to ride/race mountain bikes and how to handle and practice everything involved in riding. I HIGHLY RECCOMEND IT, and would say that it is the BIBLE for Mountain Biking! 56.Look where you want to go not at what you are trying to avoid. if you stare at the tree you are trying to go around instead of the trail around it you will more often than not hit the tree. 57. As mentioned previously-The faster you are going the further ahead you should look, always look at what lies further ahead when riding downhill AND avoid staring at your front wheel--staring at your front wheel will slow you down drastically and often will lead to crashing. 58.To re-inerate what Harding.Thomas was saying; do not focus on obstacles like stumps logs and rocks, because thats were you will go instead of where you want to go. In essence, keep an eye on where you want to go and you will go there. Do not look down at what your riding over, let your bike deal with the terrain, thats what its for. This is a very important tip to increasing speed and improving flow. 59. Before you go riding, I find that a simple 10 minute warm up on flat land and practicing tight turns and j-hops helps loosen you up and calms you down If you have any other tips, tell me! ill post them in the list.

Topic by struckbyanarrow 7 years ago


Brushed DC motor HP requirements for Longboard? Answered

So I have 2 brand new tilt/trim pump motors and thought about making a set of matching electric longboards since products like Boosted Boards seem to have become fairly popular.  I am not too sure whether the tilt/trim motor would be strong enough though, they are a decent size motor though.  But it got me thinking what size is required for an electric longboard? The main problem with the tilt/trim pump motors is that I can't find specs on them anywhere, just specs for tilt/trim pump assemblies they are off of, but nothing about the motor itself other then SAE J1171 Marine rating.  Because of this I thought of buying another DC motor to do the job.  (Picture of tilt/trim motor) The constraints for me is that I have a couple 12 - 24v 100A motor controllers already, for brushed motors only.  As well, I want to just pick up a couple cheap $40 12v, 24AH Sealed led-acid (SLA) batteries from the local Ace Hardware and run either a 12v or 24v motor.   Options on eBay for affordability purposes range from 12v, 24v, 90v and 180v dc, obviously 90v and 180v are out of the question.  Looking through the 12vdc and 24vdc motors, there are many fractional HP motors available.  I was looking at something like this; http://www.ebay.com/itm/172252712203?_trksid=p2055119.m1438.l2649&ssPageName;=STRK%3AMEBIDX%3AIT Running 1/4 HP at 24v, would 1/4HP be enough though?  I know electric motors HP ratings are lower then petrol engines, a 6.5HP petrol go kart runs about the same as an identical kart with a 1HP electric motor. If that isn't enough I am thinking a 2/3HP motor from Holley might be better? http://www.ebay.com/itm/361524972024?_trksid=p2055119.m1438.l2649&ssPageName;=STRK%3AMEBIDX%3AIT Wondering if someone has an idea for sizing.  I know lots of eBikes and Chinese electric mini bikes and things have 500W motors, so roughly 2/3HP, so I can't imagine I need more then that.  As well I don't want it to go too fast (fear of speed wobbles) but if anyone would have an idea of sizing that would be super helpful!

Question by Electric Spectre1 2 years ago  |  last reply 2 years ago


DIY Scuba Tank (breath underwater)

I need some advice. I have a great idea that would be amazing if it worked. I want a small scuba/air tank whatever you want to call it (like a scuba secondary tank or a paintball co2 tank) that i can use to mess around with in a pool. I dont want to be constantly breathing, just enough to take a deep breath, go underwater and hold it for a minute, release air from the tank-take a breath, hold it, take another breath from the tank, hold it, and so on. Just enough to get a few breaths and be under water to last me for 5 or 10 minutes. The only thing is i dont want to have to fill it at a dive shop or from a tank that has to be filled at a dive shop like scuba secondary tanks. i want to rig it to fit a bike pump (which probably will not have enough psi to get the amount of air i want) or my air compressor. So i would like advice and also would i need an air regulator since im not constantly breathing? what could i use as a regulator if i need one at all? 

Topic by wdemarche 4 years ago  |  last reply 5 months ago


Just 24 more hours..

And this week is over.. I'm about to whine about life, so back out now if you like. What a hell of a week, I started going to UCF monday. Now, admittedly, I'm happy about that, even though it's terribly stressful. But that's not the problem, really. No, would you believe that monday I bit into a brownie at work and cracked a molar on a nut? So my first day of school was accompanied by horrible pain. Followed by a dental crown on tuesday. Yeah that's not that bad, so I'll add in that my wife's truck needed a new differential on thursday (somewhat more expensive than a calculus book). And today?The washing machine broke. Spent three hours tearing it down, it's a goner. Leaking pump, with horrible grinding noise, broken balance strut, and no power to the motor. Only six years old too. And worst of all i didn't win the explicative deleted bike. That's an almost $2500 outlay this week for broken things.. Oh yeah one more really irritating thing, I finished up my A.A. and received my diploma this week, in a big flat envelope stamped all over "Do not bend", which the mailman folded in half and stuffed in the mailbox. I'll probably read this in the morning and decide I'm a self absorbed SOB and delete it. ;-)

Topic by Tool Using Animal 11 years ago  |  last reply 11 years ago


Joule Thief w/ 555 timer

Hello, I have a question about using a 555 timer with a joule thief. I'm trying to build a circuit for some solar powered bike lights but I have a couple of questions... 1. Am I correct in assuming that it's a bad idea to try to run a TLC555 timer chip from the output of the joule thief? Without a load, it seemed to be pumping out at almost 80 volts. 2. I tried building the circuit so that the two rechargeable 1.2V batteries would power the 555 directly, and then the output would sink and source two transistors alternately, which in turn would switch the LEDs alternately, using the output from the joule thief, which was also powered directly from the battery. That resulted in no LEDs lit and some very hot transistors... Bad idea. The TLC555 chip is supposed to run on a supply voltage of 2-18V, but when I tested it with the 2.4V coming from the batteries, it would source, but not sink... Is there any way to build this circuit so the 555 could blink 2 LEDs alternately while the LEDs are powered by the joule thief? The only alternative I can see that might work would be to power the joule thief from the output of the 555 and just blink all of the LEDs at the same time from the joule thief's output. Any help would be appreciated!

Topic by amklose 8 years ago  |  last reply 8 years ago


(newsletter) Hidden Compartment, Watermelon Keg, Ferret Wheelchair...

Sign-up for this newsletter: Welcome back! NEW CONTEST: Converse Back to School in Style Contest - Make or customize anything school-related and win a gift card so you can make your own Converse shoes!SINGER Kids Crafts Contest - Create something crafty with or for a kid and win a sweet new serger or sewing machine from SINGER!Forbes Teach Me Fast Contest - Make a 30-second how-to video and win an awesome Flip MinoHD video camera! Winning videos will be featured on Forbes.com.Gorilla Glue Cardboard Contest - Build anything using cardboard, and win a huge package of Gorilla Glue supplies and gear!Ends August 23: Low & Slow BBQ Contest - Cook up something tasty and win a Weber Smokey Mountain Cooker, and autographed copies of the new Low & Slow BBQ book! Bike Dog Walker The Wild Pig Smoker Make a Magnetic Fish Tank Cleaner Hidden Cabinet Behind Fake DVDs Make or customize anything school-related! FerretMobile: DIY Ferret Wheelchair Make a Resistor Reference Card Listen to Shortwave on an AM Radio Home Made Tonic Water Concentrate Share something cool quickly! Get crafty! Make a Sekkaboku Rubbing Crayon CIR Sand Casting System Air Pumped Patio Fireplace Homebrew Cold Smoke Generator Submit a cardboard creation and win a prize pack from Gorilla Glue! Cook up something tasty today! Ends August 23 Pulled Pork on a Weber Kettle Grill Smart Power Strip for Your PC Stone Tile Lamp Make a Watermelon Keg Sign-up for this newsletter:

Topic by fungus amungus 9 years ago


"Taller de Inventos", Jameco Build Night @ Buenos Aires

On Saturday August 24th we held our very first “Instructables Build Night”, which we baptized “Taller de Inventos” (Inventions Workshop). It was a free event aimed for anyone older than 10 ys old. We had around 15 participants that joined us on the quest for technological reappropiation. We knew beforehand that most of them had never touched a soldering iron, so the first activity that we held was an improvised desoldering workshop where people cheerily removed components from electronic garbage. Most of them became immediately enchanted with the mighty desoldering pump ;) After the participants had settled in their preferred spots, we opened the event by talking about what we (Wazzabi) do as a group and what this event sponsored by Instructables and Jameco was all about. We were thrilled of having so many new faces around. What the Build Night meant to us was the opportunity of holding a free event without having to care about components. Since we received 100USD worth of goods by Jameco, we decided to keep it free. We offered the participants various projects to work on: a "Wazzabi Punk" Light Theremin (a light theremin based on our take on the classic Atari Punk console), an audio switch for choosing between two inputs, a LED Blinking Light for bike and a classic Wazzabi Punk console. Every one of them was incredibly eager of soldering components to the PCBs that we gave away and getting their hands on their own creations. They left not only having learned that they were capable of some awesome things, but also with some pretty cool devices made by themselves :) Check the pictures after the jump. They were taken by Cristian Reynaga and Amina Luveaux.

Topic by wazzabi 5 years ago  |  last reply 5 years ago


Technology Makes Cheap Drinking Water from Air

INTRODUCTION:   How can we best apply basic technology to help the underprivileged and/or disaster-hit countries like Haiti? Daily hygiene and nourishment are among the top needs for disaster ridden regions!  Simply put, no water means no hygiene. The Romans understood that over two millennia ago and created their complexly beautiful aqueduct networks for handling both fresh and wastewater! Other ingenious water systems like “air wells” have been found in the city of Theodosia (cf: discovered in 1900 by Zibold, see Zibold’s Collectors/Dehumidifiers) dating back to Greco-Roman times during the Byzantine Empire. These were strictly passive systems that naturally dehumidified air, collecting its potable water in underground basins. All air, even in relatively dry desert regions, will precipitate or release its natural water content (initially in the form of vapor) through condensation when it hits its dew-point temperature and below. That means you “chill” it to an appropriate level that is anywhere from 5F to 50F below its current air temperature, depending upon how much water content (relative humidity) it has locally absorbed. The condensation of the water vapor releases its internal latent heat (reheating the cooled air) which must be constantly dissipated (absorbed by something) in order for water formation to steadily continue. So how do we dissipate this resultant vapor-heat and chill our air without any infrastructure or electricity, in an underprivileged or disaster-ridden region? We simply bury a long cast-iron or any metallic drain-pipe sufficiently underground where the temperature of the earth is naturally held to a constant at around 45F to 55F. That’s our “free” chiller gift from nature. One end of the pipe, Figure-1,  sticks out of the ground to suck-in local outside hot air, and the other end dumps cooled dry air and water into an underground cistern where it gets collected and is piped to the surface to both exhaust the cooled dry air and connect to a water pump. We need a hand operated water pump to lift up the water above ground, and we need an electric fan to constantly pump air through the ground-chilled piping system. We can even force the cooled piped air to exhaust into a tent-like structure where it provides air conditioning as an added bonus, but this adds the penalty of both power and the increased fan size necessary to drive our required airflow further into an enclosure! While this concept is not “passive” (requiring electricity to work) like those clever Byzantine air-wells, it will produce much more potable water and within a smaller volume than those elegantly passive historic devices. The electricity for our fan power requirements can be produced by any one of four ways using either “active” or “passive” techniques: 1) An active playground or bike-pedaling-person or oxen-driven mechanism-generator, 2) A passive windmill generator, 3) A passive solar energy collection system that directly generates electricity, or 4) A passive thermo-electric system that directly generates electricity using the Peltier effect, operating solely on temperature differences between the cell’s top and bottom surface (we jury-rig the cool pipe and hot ambient air to contact separate sides of the cell). Depending upon how much water is needed, the required air volume plus pipe length and diameter, together with the fan will be sized accordingly. We can also configure groups of parallel fan-driven air pipes that are radially fed into the cistern. The sizing of this underground network depends upon the ambient air’s local average temperature and relative humidity (how much water gets absorbed into the air) plus buried pipe depth and effective underground temperatures achieved. The basic concept is one where we “wring” water from air at some given humidity content. The higher its relative humidity the more water is recovered from the air. The air-wringing process simply chills the air as it scrubs along the cooled internal pipe surface until it starts to rain inside the pipe from condensation onto its surface. The condensation is like the dew that forms on car windows, grass or any cooled surface in the early morning, before the sun comes out and evaporates the dew back into the heating air. A further bonus is that our dew-formed water is naturally distilled and very clean. It is potable water ready to drink without the need for additional sterilizing agents. Of course, we must make sure that the interior piping and cistern network is biologically cleansed before burying it underground. The hand pump with its 10 to 15 foot extended piping to reach the underground cistern must also be cleansed. The beauty of this constantly replenishable water supply is its convenient underground installation anywhere! After the in-ground installation, we have a virtual, partially passive, no moving parts, non-breakdown system containing above ground total access to all moving parts that could breakdown, namely the water pump and electric fan. Also, it is easily maintained, with few moving parts (water hand-pump and electric fan) and basically lacking any technical complexity which makes it ideal for technologically backward regions. The example below uses a relatively small industrial fan moving air at 1500 CFM (Cubic Feet per Minute) with a DC motor rated at 1kW. This fan together with our underground piping system will conservatively generate 12 GPH (Gallons Per Hour) of potable drinking water without need for any purification chemistry. Based on an average electrical cost of 14-cents per kWh (kilo-Watt hour), the typical commercial distillation of one gallon of drinking water costs roughly 35-cents as compared to our cost of only 1.2-cents. Furthermore, if we decide to go green and use solar energy for generating our water, it would effectively cost us nothing beyond the initial installation! USING A PSYCHROMETRIC CHART TO SIZE OUR WATER SUPPLY: The following gets a little technical and is only provided for those die-hards who are truly interested in how the science works. Those non-technically schooled may skip this part and not miss the basic concept. Figure-2 shows a Psychrometric Chart for air. This chart summarizes some of the basic thermodynamic properties of air throughout its typical range of operating temperature. The chart uses six basic air properties that defines the physical chemistry of water evaporation into air:  (1) the enthalpy or total energy contained within a unit of air which is a combination of its internal and external energy, expressed as the amount of BTU-energy per unit mass of reference dry-air, (2) the specific volume or the ratio of a unit volume of local air to its mass of reference dry-air, (3) the humidity ratio or the amount (mass) of moisture in a local unit of air divided by its reference mass of dry-air, (4) the percent relative humidity per unit of local air, or the mass ratio (expressed in percentage form) of the partial pressure of water vapor in the air-water mixture to the saturated vapor pressure of water at those conditions (the relative humidity depends not only on air temperature but also on the pressure of the system of interest),  (5) the dry-bulb temperature or the locally measured air temperature, and (6) the wet-bulb temperature or saturation temperature which is the local air temperature experienced during constant water evaporation (a wet-bulb thermometer is typically used:   a thermometer that measures resultant temperature while wrapped in a water wet-gauze and spun to generate local air movement and max-evaporation)  1.0   The Process and A Sample Calculation Our Psychrometric Chart uses six thermodynamic properties that help to determine the amount of water available for extraction from the local ambient air as a function of its temperature, pressure and relative humidity.  Let’s assume the following local ambient conditions for the region we plan to construct our water system at:  (1) Typical daily air temperature Td = 106F and one atmosphere pressure assumed at sea-level, (2) Relative Humidity, RH = 55%, and (3) Typical underground temperature down at six feet is measured at Tu=55F (at 12ft. it drops to ~45F). This yields the following calculated results for obtaining a steady-state supply (changes at night) of water to fill the cistern:      1)      In our example, the “local” air (dry-bulb) temperature is Td=106F, at a relative humidity of RH= 55%.  Fig-2 indicates that the resultant Humidity Ratio is HR= 0.0253 Lbs-water/Lb-Dry-Air (intersection of Td=106F line and RH=55% line, then horizontal to HR value).  We then determine the “gulp” of air volume containing the HR Lbs-water which corresponds to the point of intersection of Td and RH. Interpolating on specific volume “mv” yields mv=14.7 ft3/Lb-Dry-Air (this value sets the optimum unit airflow for our given ambient conditions, and creates a ballpark pipe length to diameter ratio needed later). It represents the basic unit of air volume that will enter our underground pipe per given time, and ultimately defines the size of our fan and piping network. For increased water creation, multiples of this unit volume will scale up the additional amounts of water that can be collected. 2)      As the inlet air cools down to a temperature of Tu=55F, from contact with the relatively cold underground pipe, we follow the constant enthalpy line (red upward left-diagonal) from the intersection of Td and RH to its saturated air temperature condition of Ts= ~88F, which is its dew-point temperature where the corresponding local RH=100%.  At this temperature or under, the air precipitates and releases its moisture content, resulting in water condensation onto the pipe walls.  Since our air will chill to a final pipe temperature of Tu=~55F, we follow the RH=100% saturated curve (green) down to yield an HR=~0.009 Lbs-water/Lb-Dry-Air. This is how much water is left in the air when it gets to 55F.  Therefore for every pound of local outside air that enters the pipe, mw=0.0253 – 0.009 = 0.0163 pounds of absolute pure, distilled potable water precipitates onto the inside pipe wall (per pound of dry air that is cooled and dehydrated) to gravity-flow out the pipe exit and into the cistern. 3)      We now convert pounds of air per unit time into a unitized volumetric airflow that yields gallons of hygienically pure potable water production per unit time. For every Va=100 ft3 of local volumetric air movement per minute (CFM) through the pipe, which translates into ma=Va/mv= 100/14.7 = 6.8 lbs. of dry air per minute or 6.8 * 60 = 408 lbs. per hour (PPH), to yield a water-flow of mwf=ma * mw = 408 * 0.0163 = 6.65 PPH or 6.65/8.345 = 0.8 GPH of water.  An industrial fan rated at 1kW DC will typically move 1500 CFM at a pressure of 8-iwc, to continuously produce 15 * 0.8 = 12 GPH of pristine potable water. 4)      Not shown here are the design details of sizing our pipe, fan and solar collection system for electric power requirements using heat transfer principles coupled with a thermodynamic heat balance, and aerodynamic fan performance assessment. These details help to size the electric power generation requirements plus margin used to properly size a solar collector containing further margins for overcast days. The engineering involved here is straight forward but beyond the scope of the current project.

Topic by RT-101 6 years ago  |  last reply 1 year ago


Two Hands Two Legs and lots of walking in SF

And we're off! The documentary tour of hacker spaces in America starts off in Boston with an early breakfast:At 3:30 on September 8 I began making the WOD's [waffles of departure] and gathered my friends. This was it, I was having my goodbye breakfast. We sat around a giant LED display that was playing tetris on autopilot like we were at a sports bar and called the AI engine out on it's bad plays. Choice is the name of the game in AI, how do you make the optimal choices with limited knowledge about the present and doubt about the future?I drank my cocoa considering the choices I've made to hit the skies and shoot a documentary on hackerspaces, and it filled me with exhilaration. What could be more critical than doing something that gives you the energy to do the thing you want to be doing? There has to be this ignition point to push the chooser into action, creating this snowball of awesome gathering steam as it goes downhill. Rather than chilling with Sysiphus on his uphill downhill journey. Feeling energized, feeling pumped, I called my friends around me and we ate to good health and poured generous libations of yogurt smoothie [Spilled the contents of the blender on the floor]. **************Later that very evening I found myself SSFed :: Suddenly in San Francisco:Walking down 17th street passing bodega after fruit market after bodega and suddenly we intersected. The assembly of the Two Hands Project was complete as we fortuitously intersected directly at the gates to NoiseBridge nouveau. An odd bunch from Chicago/Alaska, Michigan/Boston, and Florida/notsureyet we were meeting for the first time since the inception of the project, and we were ready to rock. Having almost no equipment after meeting up with Mitch and experiencing excellence and consensus in action we go to Sadies house (what a great lady), stay up late, and work all night. Starting the tradition that will continue to this day. Hopping on Paul's tiny folding bike I run across town gathering Mic's, video cameras and miracle fruit. Meeting up with the crew dazed and confused walking around town with tons of gear on their back we were glad to have a brief breakfast with SkyT, Mitch and FBZ before checking out the reMakeLounge.At the reMakeLounge we met up with Inna who saved our lives, 300 times. With her help we were able to talk with the folks at the Internet Archive where we met up with Mang. She drove us over to Oakland, back to SF, and finally back to the Airport. If there's one lady that made the SF leg of this trip possible it was Inna.Mang and his roommate Mike have an awesome Hacker Space appended to their home. We were given a rare peek into Radish Research which they opened up to us. It's been amazing how much people have opened up to us this trip! I'd like to take this moment to thank you all for your kindness, generosity and ability to withstand the rush that is The Two Hands Project. Hee!Posting would happen more frequently if it weren't for the emergency nature of this trip. But keep an eye out, I'll be posting shorter things more regularly I hope._Bilal GhalibAnd now, a brief video of the first leg of our trip:

Topic by lamedust 9 years ago  |  last reply 9 years ago


Aircon or fridge compressor to solar?

Sometimes I get weird ideas that I can't shake off :)When I was looking into options for a 12 compressor fridge freezer combo I was stunned.You a get a fullsized frrezer for far less!A further check revealed that it is mainly the linear compressor that makes the price plus the usual mark ups.Efficiency and especially start up is far better with thes compressors than out standard rotary and piston drive models.But why would it be so impossible to replace the motor from a standard compressor with a brushless DC one?I focussed on three things for the start:Lubrication, cooling and sealing.There is no such thing like a simple compressor with a piston system that does have some leaking.So apart from the noise the enclosure really needs to be welded and sealed again.Everything moving inside is lubricated by the drive shaft - it acts like a little pump.Same for the cooling of these vital parts.The oil flow exchanges heat through the big metal housing.A replacement motor would need to be suited to run in such a messy enviroment.Of course something to provide a proper oil flow needs to be created too if the drive shaft is replaced.With some basic enineering this might be possible, same for the motor mount and wiring to the outside.But what to do about the full load starting conditions that can happen?Even with no load from the cooling system the motor needs massive torque to get the piston moving.A bypass valve that closes once the motor is at proper speeds might work but hard to implement in a tight space.Any ideas?Did you ever try something that stupid?Could you make it work?What about a rotary compressor with external drive?We use ice blenders that have a magnetic base and the actual connection is made through the magnetic forces alone.A scroll compressor has lots of space without the original motor inside.Plus, a round pipe is easier to work with when it comes to adding or removing things.Small scroll compressors from an airconditioner or small industrial freezer wouldn't have to do much work in a small setup.Best thing is that with a variable speed the cooling power can be adjusted.How feasable would it be to use some polycarbonate end plate and a magnetically coupled drive ?Modern BLDC motors offer great performance and suitable gear systems are readily available.N52 neodymium magnets of the block type provide several kg of force if close enough to each other - should be enough to make a compressor spin...In return it could mean to have a nice freezer or even airconditioner that runs directly on solar power.No massive losses from inverters, no need for huge battery banks either.As long as the sun is out you have free power, once down you can still switch to a power supply for the motor or use battery power.Just imagine you come home after long day of work and the house is already cool.And you did not have to pay a cent to get it cool or wait for hours for it to reach this temperature!We love to add solar panels to our houses in the hope to get a few cents back from our energy providers.The sad reality often is that you might be able to power all your needs during the day but the excess that goes back to the grid often pays next to nothing.But if you could power a lot more things like a compressor directly with the electricity from your panels....Then these kWh would not appear on your usage bill either.Means you neither use what the power provider compensates you for nor is it "wasted" thorugh this bogus compensation.The normal solar setup can then provide you with this little extra money while an additional set powers the motors for your big freezer or little airconditioner - little being relative to what you make of the idea ;)If you really dare than you could even use your bike and legs to power your fridge directly ;)Use your imagination :)

Topic by Downunder35m 2 months ago  |  last reply 2 months ago


South By Southwest (SXSW) 2009 Interactive Review - It's a Party Masquerading as a Conference

It's no secret that SXSW is more about the parties than the conference, but when you have so many smart people who run interesting businesses together, it's a pretty significant lost opportunity that the conference isn't better. Christy and I attended the 2008 SXSW Interactive conference, and decided it wasn't worth coming back. However, Instructables was a finalist in the Web Awards "Classic" category at the 2009 SXSW Interactive conference, which netted us two free passes. So, we attended again this year. This is my review of the interactive portion of the conference.High level - I'm glad we didn't pay. If you go, admit that you're going for entertainment, not to learn something about the interactive industry. The keynotes were excellent -- even if I didn't come away from them with anything actionable to do --, while the rest of the panels and talks were terrible. Having the resources to get to Austin doesn't mean that most conference attendees will have done their homework -- otherwise interesting panels with smart people were nearly always hijacked by stupid questions, and unfortunately it was rare that a moderator would shut down the stupid questions and get back to anything engaging. For example, at How Safe is Your Domain Name? someone actually asked "What does ICANN stand for?" If you're the type of person who reads reviews, and tries to determine if a conference has value for your business, SXSW does not. It's a party masquerading as a conference. If you go, think of it as a vacation, enjoy the evening events and keynotes, and when you learn one or two interesting things by accident, you won't be disappointed. Longer Review:Plan B: Can an Ad Guy Bring Bike Sharing to America?The story of how an advertising agency exec. was able to start up a bicycle sharing venture. Worth checking out just to understand how Crispin Porter+Bogusky works, and to see how they keep their thinking fresh about advertising.Spying 2.0: Can America Compete With Web-Savvy Enemies?Quickly devolved into an I-use-Twitter-so-should-you panel. Yawn. Is Privacy Dead or Just Very Confused?Academics talking about websites they use, and privacy issues they think might apply. A discussion of "experiences"; nobody on the panel is actually doing anything real, nor do they have any insight into major players' privacy policies or how those policies affect users. How did they get a panel?Change v2Lawrence Lessig's non-keynote-scheduled keynote on how money reduces our faith in politics. Excellent. Find a video of this and watch it.Opening Remarks: Tony HsiehTony Hsieh has given this identical talk at other conferences, but the message is so good, it's worth seeing twice. Slides available here.Feed Me: Bite Size Info for a Hungry InternetThis had an interesting set of people on the panel, but it nonetheless turned into a why-Facebook's-new-homepage-sucks-because-it-copied-friendfeed fest. Then, the panelists started openly wondering why they hadn't invited anyone from Twitter to be on the panel.Collaborative Filters: The Evolution of Recommendation EnginesThis was one of the biggest disappointments. Anton Kast of Digg is clearly top notch, and has spent deep hours thinking about recommendations and the math behind them; and, the people making up the rest of the panel were no slouches either. Unfortunately, they spent more than half of the time describing in layman's terms how each of their websites work, and we never got to anything juicy. "On Digg, users rate up a story they find interesting by clicking the Digg button..."! Edupunk: Open Source EducationThe description of this panel really got me pumping: DIY teachers around the world are using open source course management systems, open access textbooks, and other open source tools to buck the chains and limitations of corporate education software. What the panel really turned out to be was a bunch of ineffectual academics having a cat fight over who was more ineffectual. They all tried to outdo one another with stories of how management at their university prevented them from having any impact, and the winner seemed to be the panelist who accomplished the least. Seriously.This was only topped by the first question from the audience, which opened with: "I've learned a new word at this conference, and I'm going to use it here: monetize..." Seriously? I now have a new rule for conferences: Stay away from all education topics. The ratio of people with opinions to people who can/are having impact is way too high. How to Create a Great Company CultureThis is a tough topic, and one in which there's no right answer or overarching theory. The only way to get data is to listen to anecdotes, and this session gave me a few more. Although to be fair, I probably could have spent the same hour reading blogs written by company founders and gotten more out of it. Sunday Keynote: Stephen Baker / Nate Silver InterviewInterviews with really passionate people are always a treat. Nate Silver fits the bill.From Flickr and Beyond: Lessons in Community ManagementI was baffled why Metafilter was invited to be on this panel. In a discussion of privacy policies, the director of operations from Metafilter said "We don't have one. We're not there yet." Despite obviously having the most to contribute, the representative from Youtube didn't share anything; his lawyer must have told him to keep his mouth shut. Overall this was let down.New Think for Old PublishersThis panel was deceptively described, and the audience was annoyed to find a group of publishers simply looking to scribble down suggestions rather than having a conversation about the industry. Fortunately, Clay Shirky was animated enough to heat things back up.Presenting Straight to the BrainRunning a panel on better ways to use slides and graphics where each panelist presents slides might seem a bit hubristic, not they pulled it off. Take home: Use your slides to tell a story.How to Protect Your Brand Without Being a Jerk!This powerhouse panel was interrupted a mere 15 minutes in by a self-described-artist-from-Europe who raised (and shook) his hand for 5 minutes until the moderator eventually gave in. His question: "Do I need to copyright my songs? No really, do I need to copyright each one?" This softball opened a pandora's box of stupid questions from audience members clearly unable to format their questions into that tricky search engine text box. Monday Keynote: Virginia Heffernan / James Powderly InterviewJames Powderly is a friend and deeply fascinating individual. I wish this interview had been longer so they could have gotten deeper into his motivations and experiences. Advertising is Entertaining - Who's Selling Out?I came out of this session thinking it was pretty good. However, on further reflection, since it was more conversation than lecture, and lots of people had the opportunity to speak their mind, I was just happy no one said anything particularly stupid. This should give you a sense of my expectations at this stage at SXSW.New Threats to New Media: Fair Use On TrialThis was an excellent panel, particularly because Jason Schultz ran a very tight ship, kept things moving, and prevented questions from derailing the session. In my opinion, all three videos shown were clear examples of fair use, and I would have appreciated one that was a little closer to the line, but the session overall was still both enjoyable and useful. Building Strong Online CommunitiesWhile too general to have any actionable items, this was still pretty good. It's also fun to hear Drew Curtis's irreverent opinion on community. Tuesday Keynote: Chris Anderson / Guy Kawasaki ConversationThis made me really look forward to Chris Anderson's coming book Free. Guy Kawasaki did a fantastic job moderating, especially with respect to mocking people who ask questions just to insert a pitch for themselves, and limiting meaningless follow-up "questions."Nom Nom Nom: The Secrets of Successful FoodbloggingGet a DSLR, all other rules of successful blogging apply.The parties and evening events were good. I enjoyed Dorkbot Austin and Plutopia, and still think often of the food at The Salt Lick. The Web Awards were surprisingly fun. We were up against some much bigger names, and Flickr won (which in my opinion, was the expected value; I use Flickr at least weekly, if not more). Baratunde Thurston emceed, and he kept it spirited and fast-paced. His interludes were funny, and when no one from Flickr showed up to claim their award, he claimed it for them. "I remember really wanting to share some photos online..." I've been to other conferences where the parties are fun, the talks are engaging, and you come away with a laundry list of actionable items that will make measurable improvements in your business (or life). The SXSW interactive conference has all the ingredients to make that happen, which is why it's so disappointing when it doesn't come together.

Topic by ewilhelm 10 years ago  |  last reply 10 years ago


Looking for a cheap compressor with a high pressure rating or for airbrush use?

Today a friend of mine asked me if I know a way to reduce the noise level of his compressor in the work shed. With the current heat he prefers to work in the evening and nights, which does not make his neighbours too happy. His main use for several airbrush guns and sometimes for mormal airtools or the big spray gun for an undercoat or similar. So his main concern is oil in the airline and the actual flow rate is of second concern as he has an old 25kg propane cyclinder as an additional air tank. For relative low air volumes I would suggest an old fridge compressor. With a thicker pipe at the outlet that is filled with stainless steel wool most of the oil stays in the compressor. That is if this pipe is a) long enough b) upright c) of sufficient diameter so there is enough for the oil to avoid it being pushed up A second, standard oil seperator will be enough for the oil level required for airbrush stuff - and most other things too. If there is no pressure regulator on the airbrush system it is best to add a small air tank and shut off valve for it. In our case however a fridge compressor would be just enough to keep the bigger airbrush gun running but not to fill the tank at the same time. Not to mention the problem of fluctuating pressure levels. Since we already had a tank and pressure shut off connected to the loud compressor it was only a matter of finding something that keeps the neighbours happy. The first thing we did was to check how often the compressor comes on and how long it runs till the tank is back to pressure. With that and the stated air volume on the compressor we guesstimated that something a bit bigger than the compressor of a window airconditioner should be sufficient. The search begins.... If you don't know what to look for I give you a few hints: Older airconditioners often run on R22 or R12 - both use quite high system pressures which is a bonus, but more on that later. As a rule of thumb for these compressors you cans say: the bigger the higher the flow rate. At the local wreckers and scrap yards we found a few units but noticed the bigger ones often used three phases and not just one :( So we opted for the R22 compressor of a 4.5kW unit. Keep in mind the 4.5kW is for the entire system, so the quite massive fans can be removed from the sum. Usually the compressor alone is the 2.5 - 3kW range. Ok, we found the big thing but how does this help us? First things first ;) The oil was removed as the housing stating the original oil amount. This allowed us to use an oil rated for air use that has little to no water absorption qualities - you don't want water in your compressor. With the usual heat the water should be no problem anyway. Next was a pressure test to make sure the thing actually still works, so we added some plumping in the form of standard connectors to the inlet and outlet. We got well above 200PSI and abondoned the test at this stage as it was more than enough already. The air volume seemd to be well more than expected too so let'S move to the next stage. A fridge or aircon compressor always needs to have a certain amount of oil in it as it will otherwise seize and overheat quickly. But they are also designed so that the oil mixes with the refrigerant to cool all moving parts. So the biggest hurdle is to make sure the oil stays where it should stay and won't enter or get lost in the tank. Only real option for this to use something to catch the oil that is capable of releasing it into the compressor once it shuts off. Now there are several options for this so I start with the most basic: A "catch can" will get most of the oil, especially if filled with stainless steel wool or similar. Downside is that you have to find a way to get it back into the compressor. A step better is a thicker pipe filled with stainless steel wool to catch the oil. If placed upright and the outgoing pipe can be bend a bit upwards you have a good chance that most of the oil will sweep through the valves and get back down into the compressor housing. But only too often the cheap or even free compressor is better than expected and the oil won't get back into the housing as the vlaves are just too good. The last and IMHO best option is a pressurised return system. Most compressors for bigger aircons have a seperate filling port or sealed off piece of pipe. In this case you can do a simple check to see if they are usable for our purposes. Open the port of pipe and use a simple bike bump or similar to get some pressure in it. With a dedicated oil filling port you are best off but they are hard to find. The air you pump in should come out of the high pressure side - you might need a little pressure to overcome the valves. If you hear any bubbling in the housing (use a pipe on your ear or a sensitive microphone) it means you are going through the oil inside the compressor - perfect! You might not hear any bubbling but the port or pipe is still usable. Get ready with your fingers and start the compressor. The fill pipe should be sucking air in, same for the service port if there is one. A dedicated oil port should not suck but instead force some oil up if you cover the high pressure outlet. I assume all is good and no oil is splashing out of the open pipe or port. Add a small amount of oil with a syringe or similar into the port/pipe. If you see an oil mist coming out of the high side it is bad news. Clean outlet air is good. To get the oil back from the catch pipe or can we have to add a hose or pipe with a needle valve. It needs to be adjusted so that there is only a very little airflow (or oil mist) coming out. This regulated outlet is now being connect to the port/pipe with a bit of suction that we found earlier. Now every time the compressor runs the collected oil is forced back into the compressor :) Please double check the port/pipe used is not directly connected to the intake port! The last thing you want is a puddle of oil going into the cylinder and damaging it! They are designed to move gas but not liquid! If in doubt use a hardened sttel nail or similar to create a small puncture in the top of the compressor housing if there is nothing else to use. Check first if the material sound very thick, if so it might help to drill with a 5 or 6mm drill first - only about 1mm to make sure you won't enter the housing and conimate it with metal shavings! Once you have a small puncture hole of about 2mm in diameter get some 2 component metal repair glue mix and add a suitable connection for the collecting pipe/can. If you feel up to it you can of course use a blow torch and solder the connection on. Now we have the compressor working with a oil return system that also gives up very little to no oil at all in our system. You might now think you are good to go but you should at least add a decent and fine filter to the air inlet ;) The compressor noise of a bigger system can still be an issue if thicker pipes are used that allow the noise to travel out. Keep in mind they usually run in a fully closed system.... As we only need to match the noise level of the compressor itself a solid steel can like an old fire extinguisher in the 1kg rage is a good way out. Fill it with filter wool and a fine filter pad after adding some hose connectors either end. You can misuse the trigger nozzle and keep it to seal the top if you braze a connector on it. If the intake here is about 5 times larger than the pipe connection to the compressor itself the air flow going into the thing is low enough for a cheap paper air filter can or box if you have a quite dusty enviroment to work with. The real trick is to have a hose or pipe on the inside of the fire extinguisher connected to the compressor pipe connection. A garden hose is great here as is reduces the noise quite good and is dirt cheap. Make a lot of about 2mm sized holes in this pipe and close the other end of it off. Now the compressor will suck it through the small holes and the soft garden hose reduces the noise, the surrounding padding brings it down to basically nothing. The special case of clean air for airbrush.... If you read this for the sole purpose of airbrush use then this chapter is just for you, all other might want to skip it. The two things you don't want to enter your gun is oil or water. Both are a common thing in normal compressors due to lubrication and pressure difference resulting in condensation of the humidity in the intake air. Oil free compressors of good quality can cost quite a few bucks and often require ongoing replacement of membranes or piston seals. A refrigeration compressor with the above modifications already provides clean enough air for most airbrush users if a proper tank is used to store enough of the compressed air. So you might just want to add a basic oil filter or very fine paper filter close to the regulator. For very detailed work with very sensitive paints you might want to build a filter box containing of several layers of oil absorbent paper. This stuff is often used in the industry to clean up minor oil spills and bind oil very well. A PVC pipe (pressure rated please) with 5-8 layers of filter screens should last about a lifetime before the filters need changing if the diameter is in the 10-15cm range. That leaves us with the dreaded problem of condensation and water contamination. Depending on the type of paint and gun used a small amount of water vapour is usually no problem. Solvent based paints usally show their disliking by unwanted drops or run offs caused by water droplets. Of course you just go and buy a professional dehumidifier and accept the ongoing replacement costs for the cartridges... But if you are in a climated that has above 30% humidity for most of the year than you will have to remove the water one way or the other. A big enough storage tank for the air that is upright usually helps to release any condensated water prior to usage. But if you use a homemade tank you might want to avoid this problem completely and forget about water in the system altogehter. Silaca gel is the answer here, specifically the indicating variety that changes color once "full". A spaghetti glas or similar should be big enough unless you are in a very humid climate - is so just use multiple in a row. The air intake side for the compressor has to go through the silica gel to be effictive. This mean we need two holes in the lid. One with a pipe or hose going all the way to the botom - that is the air intake side. The other right on the lid - this is the air outlet side which continues to the compressor intake. With the color change in the silica gel we can estimate how much usage we have left until we have to heat it up to remove the water. If this color change happens quite fast from the bottom to the top, let's say within three days or less than you really need to use more jars with silica gel in a row or a longer one - like using a long and clear acrylic pipe instead. Of course you can always just cut holes and "viewing glasses" along the length to a PVC pipe.... No matter how wet your climate is you want to get at least 100 hours of compressor run time before you need to recharge the silica gel. This brings us to the recharging.... Once the color changes and you only have about one quarter left to the top you want to get the water out of the gel and re-use it. To do this you simply heat it up in your oven to around 120-150°C - the supplier should state the max temp for this. If you use a gas oven or one with limited accuracy here it is best to stay within the 120° range. You need to stir and mix the gel or use something big enough like an oven tray. But be aware that these little balls are like glass! The roll and bounce like no tomorrow! IMHO it best to use an old cooking pot that has no plastic handles for this and not to overfill it. This allows for easy mixing without making a mess that might cause a bad trpping hazard on your kitchen floor tiles! Once the gel is back to original colr it is time to let it cool of to a safe temperature and to fill it back into our canister or pipe. Tanks and shut off systems.... We have a refrigeration compressor working for us, and since it was for R22 we can use much higher pressures as a simple compressor from the hardware store. The low pressure side is used to 70PSI or around 5Bar of pressure in normal working conditions. The high side often works at pressure in the range of 200-300PSI or 14-20Bar! The tank we used is a big propane tank that was restamped at some stage in his life for the use of LPG - so it was tested to quite high pressures. The lower pressure limit is what keeps the stored gas liquid at the given temperature. For Propane at an imaginary 30°C this would around 155PSI or 10Bar. The stamped test pressure, although outdated, showed 600PSI or around 40Bar of pressure with no problems - and the thing was thick in the walls... The old shut off switch from an old air compressor was adjustable after removing the safety cap with a bit of force and the help of few cold beer. With a little tank attached we adjusted it to turn the compressor off at 250PSI or around 17Bar of pressure. If your tank is old or has no test pressure stamped on do your own test in a safe location. Make sure the area is secured so there is no chance of debris from a brusting tank can go anywhere - this includes to chain down the tank itself ;) Use the aircon compressor to fill it up to 300PSI or 20Bar of pressure - this should be tolerated with ease by any propane or LPG tank. Shut the valves and let it rest for a day or so. It is best to do this in the early morning so the heat from the day will slightly increase the pressure. At the end you still want to have a working tank and no major pressure losses. All of our mods on this tank were done without actually harming the tank. This was possible as the original valve had a release port for filling purposes - as it standard on most refillable ones. Here we removed the valve and added a pressure guage instead - better to know what is happening than to assume things. As this "port" had a seperate connection to the bottom of the brass valve we added as T-connection to allow for the connection to the compressor. Just be be really sure a thin piece of copper tubing was brazed to the exit hole of this port so all incoming air will be going down and away from the outlet connection with the big shut off valve on top - which we use to actually isolate and close the tank when not it use. Last thing required was something to connect the pressure shut off switch and regulator to. That was the only major expense on this project as we had no old BBQ hose or similar to get a suitable connector to the tank. We bought a simple adapter for the use of smaller hoses and cut the unwanted bits off we there was only the bottle conntector with the nut left. After removing the rubber ring we brazed piece of copper pipe onto it. Here we drilled holes and fitted severy connectors. First for the pressure switch, then for the connection to the pressure regulator and two standard ones with a ball valve for air hose connections. One air hose connection female, the other male so a standard compressor can be connected as well or "backfilled" for additional and mobile storage use. As we wanted to avoid any reduction in the safety and burst pressure no release valve was added at the bottom on the tank. The added silica gel filter stage was used instead so no water will get into the system to begin with. Additionally, and painfully for me and me friend, the inside of the tank was coated with a layer of acrylic paint to prevent and rust as it was free from it when we checked it at the beginning. This involved filling a suitable amount of paint into it, closing the top while keeping the thread clean and then to move the tank around to cover the inside evenly. If you do this be prepared for some weird movements with your friends LOL Once we were sure all ust be covered by paint at least three times we released the exxess paint and allowed the inside to dry with the assistance of some air forced to go in with a length of pipe. This was repeated 3 times... Then another two just for the bottom third of it where there might be some moisture after all... Now you don't want to remove the brass valve with everything connected to it just to turn the tank over to releae the collected water. Instead we made sure the added pipe on the former relese port would go all the way to the bottom of the tank. If any water collection is suspected only the connection to the compressor needs an additional valve for the disconnection so the water will be force back out here. To make this easy and fast we used standard quick connectors and a piece of flexible airhose rated to 20bar of pressure for the connection to the compressor. We checked the performance of the moisture removal and oil removal only for a few hours of running time while priming some surface for later use. The compressor oil used was very smelly to say it nice but nothing coul be smelled in the first paper filter after the pressure regulator. To check for remaining moisture levels (65% humidity in the house) we used a 10m length of clear PVC tubing going through an ice bath. After 30 minutes of moderate air release there was no condensation on the inside of the tubing visible. Of course if you only need it for air supply and don't care about a bit of moisture and oil you can keep it simple ;) Benefits of doing such a stupid thing: For starters noise and the peace of mind that you can do a lot of airbrushing until the compressor needs to kick in again. Then of course the benefit of an almost silent system compared to a standard compressor - something you can actually tolerate while doing art. But the real deal is knowing YOU did it and you did it for cheap. Warnings and some advise... I know, it should be at the very beginning but I just hope you read till the end ;) If the compressor fails from overheating you are up for a new one. This means the tan size should be within the limits of what the compressor can handle - same for what you actually use on air. You want an empty tank to be filled before the compressor feels hot to touch - quite warm is fine but if you can't leave your hand on it then it is too hot. Same story for the usage. There is no point in using a tiny 10 liter storage tank if you need that capacity every few minutes. The compressor would only have little pauses and overheat quickly. You want a good balance of usage time before the tank goes below supply pressure and running time of the compressor to get it to full pressure again. This brings us to the safety of high pressures. Where possible only copper tubing or sufficiently rate hoses should be used, the later as short as possible to avoid them acting like a whip if something goes wrong. When it comes to the safety of the tank you want to make sure to stay withing it's rated limits. All benefits of a compressor capable of producing over 500PSI otr close to 35Bar is wasted if your tank and pressure regulator can't handle it. This must not mean that you try to use a gas cylinder of unknow age and pressure rating and assume it will work! If in doubt use a lower shut off pressure and stay within the limits of normal air compressors - which is around 120PSI or 8Bar. Never, ever use a tank that is compromised by inside rust or bad corrosion on the outside! If you don't know how to braze copper tubing, pipes and connectors then check out some of the great Instructables about it! Whenever you know you won't use any compressed air for more than a few hours close all valves especially the ones going back to the compressor on the high pressure side! Some compressors really don't like a huge pressure difference constantly pushing on the reed valves. If your tank is big enough to allow for more than one hour of operation before the compressor has to top it up you might want to consider a one way valve right on the compressor outlet. This will prevent any massive pressures going onto the valves - especially helpful for modern compressors that only rely on the sealing capabilities of the clyinders or rotary system used. One thing you should always consider is a pressure relief valve rated for about 50PSI more than your tank pressure - it can be added to the pipe ;) If the shut off valve ever fails the relief valve gives you the ease of mind that it will blow before your tank does. Maintenance... If modded correctly the compressor should stay in the compressor and the compressor itself should not overheat from use. Having said that your compressor might force out a little more than your best catch system can handle. If that becomes a problem it might help to use an oil with a lower viscosity. If all fails it just means you need to top up oil once the last last paper filter is filthy or use slightly more to begin with so the intervals are longer. The silica gel, if used should be recharged before all of it is wasted - no point in adding it if you use it once full of water. If no gel is used there will be water in the storage tank. Even with the added paint and a good air filter it is possible that nasty things grow in there. Making sure the tank is emptied of any water after long uses and again before the next use is good practise. If no pressure gauge is used on the tank you must make sure the shut off valve is always working fine and within set parameters. I strongly recommend using a gauge and if not to perform a pressure check of the system every now and then to confirm all is within parameters of normal operation. A compressor constantly running means you either use far too much air or you have a leak - same story if the compressos kicks in after some of forgetting to shut it off and close the valves. If you keep the above in mind the salvaged compressor should work just fine for many years to come. Troubleshooting and alternatives.... You put everything together the right way, double checked and something is till not right? Maybe my crystal ball helps me to find something... 1. Always oil coming through the catch system. It usually means you use too much of it. A salvaged compressor, if the refrigent was removed legally from the system should still have a "correct" level of oil inside. Too much oil would mean is being pumped through the system at an excessive rate. Very thin compressor oils tend to do that in the compressor is misude like we do. Changing to standard mineral oil can help here. As a last resort you can use a pressure gauge or good judgement to allow more flow through the needle valve from the catch system back to the compressor. Too much backflow here would mean we loose system pressure to the set level of this needle valve! 2. The R22 rated compressor seems to be unable to produce enough pressure. First do a leak test using soapy water to rule out any leaks. Do a back pressure test on the ports. If you can push air through them in the reverse way with ease it means the valves are damaged making the compressor useless. You need to replace it. A regular cause with our type of usage is a constand back pressure from the storage tank to the compressor. To prevent this it might help to mount an electric solenoid between the compressor and storage tank. Such valve should be off when the pressure switch is engaged and on when the pressure switch is disengaged. This prevents the coil from overheating but requires a "normally off" type of valve. A good source at the wreckers are cars with LPG systems installed, they usually have suitable 12V valves somewhere on or near the tank and filler cap. 3. I am using several kg of silica gel but still get a lot of water in my storage tank. Going overboard in a humid climate can be a good thing here but if moisture makes it into the tank even with great amounts of silica gel there are only two causes: a) the tube or cylinder used is not long enough or not wide enough to allow the absorption of all the moisture going through. b) the flow rate is too high and the temperatures are too. For the first the solution is obvious enough. The second is related to the first for the diameter and lenght but temperatures constantly above the 30°C while operating somehow limits what the gel can do. Using a cooling coil on the intake side or simply putting the gel containers in icy water will help to a great deal here. If that is not an option than I suggest to layer the gel and to seperate it with fine paper filter screens. This will slow and even out the airflow allowing for more contact time with the gel. 4. The compressor gets very noisy after some time. If "some time" means more than 30-45 minutes you simply have it running too much and it overheats. If the noise increases too much when reaching the shut off pressure it can mean the pressure is too high for it. 5. Can I use multiple compressors from smaller units or refrigerators to get enough air volume? Of course you can but it might mean you have to lower your pressure expectations. Consider that each individual compressor would get the back pressure from all other compressors running while it's outlet valve is closed. To avoid premature failure you want to make sure the compressors are shut off at a lowver pressure. 6. I don't want to use a big tank but require a good airflow for airbrush. Two or three fridge compressors working one after the other with a small tank to keep the output pressure even can allow for about 30 minutes runtime per compressor. With three it gives one hour for the the first to cool off and should be enough for ongoing work. Downside is you need to make some sort of automatic switch to "rotate" to compressor working. Last words.... Is you find any spelling mistakes you can keep them. However, if you use them in any way to make a profit with them I kindly ask for 10% of your earning from it ;) Why did I not make an Instructable out of all this? Well the day was very hot, the beer very cold and my mobile phone at home, so I did not take any pics. To top it up the whole thing is now in a seperate box for additional noise reduction so it can be used in the same room where the guy is working. Of course he just used a nailgun for the job without any regard of access or at least easy view of the two pressure gauges. Typical if you have a great idea and the cold beer tells you to forget all about screws or hinges ROFL Only comment was: You created it and it works fine, why would need more than the pipe connections for the gel and regulator? Maybe he will reconsider when the service is due....

Topic by Downunder35m 2 years ago  |  last reply 2 years ago