knex gear box?

hey everyone i need help on my current procect it is very large and a part the swings around and if i turn off the moter it clicks alot and sometimes breaks so i need a gearbox that has a nuteral (where it can spin on its own) and a 1st gear and 1st gear needs to be slow.

Question by knexsuperbuilderfreak   |  last reply


will this gear setup work for an RC car? Answered

For a while now i have been working on an rc car from almost scratch. i picked up a nice car for this on the clearance rack for $10, it already had a gearbox, but no gears. This was a pushtoy, after all. abyways, i found gears and filled the gearbox. will this setup of gears work well for speed in my car? or will there be more torque? for the best speed, what does my setup have to be like? (im using a high rpm motor, but not the one in the picture, the one in the picture absorbs way too much current)

Question by zack247   |  last reply


Motors, gear boxes and pulleys, OH MY!

We are making a time lapse dolley with an arduino. We need to move a 5 lb camera across a metal frame smoothly to produce a great shot. How can we do this?

Topic by ladymechanika   |  last reply



cuold somone make a knex 3 speed gear box?

Plz i really want a cool and owsome one

Question by rik3098   |  last reply


How do you build a gear box for a motor to make a small car?

The gear box has to be made - no prefab gearboxes.

Question by jsheaney   |  last reply



Machined Spring Powered Car

OK, I think after posting in some of the other forums that maybe this is the best place. I have asked for some help in the Tech, Science, and Burning Questions Forum (Not sure if I should have started a new thread in each one for this project so if I should delete the other's please let me know). I am new to the forums and just signed up for a 2 year pro membership to help contribute as I have been viewing on and off here and there for the past few years. If anyone can help me make this, it would be much appreciated! I came across the object shown in the link below and shown in the attached pictures. It is the  "Toy Car" by the designer "Wouter Scheublin". It is a spring powered toy car made in the limited edition of 20. It does not look very complex, but does look elegant. It can be purchased for close to $3,500.00 US on the justification that it is art, but that is not something I will ever be able to afford for this type of object. I am not insinuating that it is not worth it (last year I actually contacted the designer as well as the people selling it for him to see if I could pick one up for substantially less).  In any case, please check out the link below for pictures and let me know where a good place to start making the components might be or just where to start in the design and build process period would be. I guess I would need to know the actual parts needed before I could start to assemble even something remotely similar and I figured the geniuses that use the forums here could help me (being that its December and in the spirit of giving and sharing and all) or maybe someone here might even be interested in possible making with me. Thanks in advance for your consideration and reply. See Link Below.  http://www.wouterscheublin.com/projects/toy-car/ On another note, I really really love this kind of gadget. Metal (or wood), Mechanical, Simple, Elegant. I have searched everywhere and have trouble finding a site specific to these types of objects. small precision desktop machines like a well machined Stirling engine or the like. (no need to be powered. Can anyone point me to a place that has such things. Another example of something I like (and did purchase) is the super precision gyroscope from gyroscope.com. http://gyroscope.com/d.asp?product=SUPER2 Another example of a mechanical gadget I would love to have or like to read about is. http://www.ohgizmo.com/2011/11/28/hypnotizing-video-of-the-worlds-smallest-v-12-engine-being-assembled/

Topic by onyx77 


Want to build a useless box but can't find the gear motor...

Want to build a useless box but can't find the gear motor... Solarbotics is sold out and can't find it on makers shed... any advise ?

Question by dandanski   |  last reply


What should I be oiling my rc car gear box with? Answered

I hear alot of people saying that grease is not the way to go because it will slow youre rc car down and that they reccomend oil but what oil should I be useing.

Question by coolpizzadude   |  last reply



how do i make a gear box with a 6to1 ratio so i can build a wind up power supply for emergency?

I want to build a generator that doesn't use gas but will turn fast enough to turn an alternator with a gear box system once i have the gear box built which will meet my requirements I will use three battery's two alternators. having this done ill use an invert er.    

Question by Lonnie W pagle Jr   |  last reply


Hi im new . hello to all.. I need help with a reverse gear box . Answered

I need a reverse gear box for my go kart and I ask if I can modifiy a lower gear case from an out board motor ( from a mercury 20 )? thanks

Question by mardokk   |  last reply


What is the easiest/simplest way to run this "220V 30rpm gear motor box"?

Hello, so my electrotechnical (is that a word?) knowledge is about zero point zero, but ALL I want to do is make this motor do its work and rotate his fine ass. That's the only thing, nothing more, nothing less. What is the easiest way to do that for a clueless hopeless piece of scrap like me? Note: it's important that the motor goes 30 rpm. I added pics of the motor for clearification.  PS. I saw this awesome motor pack thing with clear instructions which would have been ideal for me, but the site doesn't send its products to the Netherlands :( link: http://www.monsterguts.com/store/product.php?productid=17760&cat;=3&page;=1   

Question by Dyonv   |  last reply


​HELP! Looking for mechanical engineering advice in building a multiplier/compounding gearbox for a hand crank siren project

HELP! I have a project I'm working on that involves making a hand cranked mini air-raid siren utilizing a 12v generator and a 12v siren. I've done a proof of concept rig where I direct wired the siren to the generator and then used a drill to generate enough RPM on the shaft to get the noise I want. Problem is, I'd like to make this entirely manual and will be adding a crank handle once I get the housing built...which means, I need a way to seriously up my RPM. I've done research into building multiplier gear boxes and compound gear trains and pinions and everything in between, but am going to confess that while I'm obsessed with DIY projects, this one is exceeding my engineering knowledge. I am at a loss for how best to approach this build. What ratio would you suggest? 40:1? 50:1? Does anyone have experience building gear boxes that would be ok emailing me with their advice? The input for my generator is a 20 tooth gear (please don't laugh if I'm totally messing up all the nomenclature...most of my life experience comes from writing and baking and a very short (failed) stint as an EE...this is a totally new world for me.) and I got this information from another sub: it’s a 3600 rpm motor so 60/sec. I think the fastest I would want to crank is 2/sec, so, 30:1 gear box sounds about right. With a nice long crank handle a 50:1 should also work nicely. 10:1 is too slow. Ideally (and this might be where it gets really tricky) I'd like it to all fit into a space that's about 5"X3"X3, not including the siren (I can run that further out, using the leads).I'm attaching a photo of the original proof of concept wire up that I did...and don't worry, I know there are exposed wires, I fully plan on isolating the wires, insulating the whole thing and installing the proper resistors. https://imgur.com/a/MaAR2PQ Here is a link to the generator: https://ebay.us/zgAoDQHere is a link to the siren: https://ebay.us/fEgahDThank you in advance!

Question by Tye Rannosaurus   |  last reply


Can I use the screen of a Mattel Juice Box for anything?

Okay, I found these http://www.geeks.com/details.asp?invtid=CM203CA&cat;=VID and i want to use them with a small display. I was planning to use a replacement headset for the Wild Planet Spy Gear RC car camera, but I can't seem to find one. Then I remembered the juice box. Is the juice box screen compatible with the output of this camera? Can I just solder the camera wires and hook up some power? Thanks in advance.

Topic by Trace II 


random motion gearbox

I have been exploring wast of creating a random motion from a gearbox, i need this for a segment of a kinetic work i have been doing for some time now. random motion seems somewhat difficult to achieve so i came to the conclusion of using magnets! the gearbox i am working on at the moment works by orbiting one magnet around the other, the central magnet spins the output shaft while the orbiting magnet performs many rotations around the central magnet tugging it to different positions giving an almost random movement (patterns can be found). i was wondering if there were other maybe more effective methods of achieving random patterns of movement without the use of electronics.

Topic by rustlabs   |  last reply


How to find the rotating shaft rpm?

I have used AC motor of 750 rpm... motor then transmit its power to gear box then to shaft... on shaft rope drum is connected to do the required work i-e lifting or lowering of load

Question by waseemhaider.syed   |  last reply


Gearbox Sharpener for knex

NOTE THIS IS A MODIFIED VERSION OF THE ONE I MADE LOOKING AT THE VIDEO ON YOUTUBE! IT WAS INTENDED AS A GEAR BOX BUT I ALSO TURNED IT INTO A SHARPENER AND A CHAIN SAW!!! It is hand cranked so... yeahThis is a knex sharpener tool that uses gear ratios to spin the rod at high speeds faster then a large yellow gear to small blue or grey gear ratio which is a 1/5 rotation ratio, for this gearbox though you achieve a magnificent 1/32 rotation ratio. One spin of the cog or yellow gear or starting gear whatever = end rotationWhen spinning at high speeds use a knife or sand paper to refine the sharpness of your rod to a dangerous needle if needed, or you just want to clean up a bad cut job from a pencil sharpener or knife cutter? This gearbox will smoothen out our refine your knex rod... NOTE THIS CAN SHARPEN THE ROD SO SHARP THAT IT IS DEADLY... NEVER EVER FIRE THIS ROD EVER TRUST ME NEVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER EVER SHOOT THE SHARPENED ROD AT YOURSELF OR SOMEONE OR ON AN UNRELIABLE KNEX GUN OR A STUPID KNEX GUN ETC THIS THING CAN MAKE YOUR RODS DEADLY TRUST ME IT HAPPENED TO ME BEFORE!!Anyway enjoy!

Topic by mrbox   |  last reply


How do I make a marble elevator with a small DC motor?

One inch marble, raised 48", elevator comes back down and picks up another marble..using small DC motor, breadboard and homemade gear box

Question by jseeley   |  last reply


Motor for ceiling mounted cargo box storage lift?

Hi there, A year or so ago, I purchased a Thule 571 Roof Mount Cargo Box Storage Lift and installed it on the ceiling in my garage.  The ceiling in the garage has a fairly high ceiling though and using the crank that came with the lift is a bit cumbersome to say the least.  I usually have to stand up on a tire of the car in order to reach the crank to turn it efficiently. So the idea popped into my head that wouldn't it be really cool to connect a reversible electric motor to the lift so I could just flip a switch to lift it and then toggle the switch down to lower it.   Here's a link to the specific product I'm using, which I think Thule has discontinued because I couldn't find it on their website tonight:  http://www.overheadgaragestoragesolutions.org/thule-571-roof-mount-cargo-box-garage-storage-solution/ My questions: 1) What size/spec motor should I get? 2) Where can I get the motor from? 3) I'm assuming that any electric motor can be reversible just by swapping polarity in the switch? 4) Do I need a belt to ensure that the motor doesn't spin the worm gear too fast or should it just be a direct connection? 5) Any other thoughts/ideas? There's an open 110v outlet in the ceiling of the garage where the garage door opener is installed, so I could run a power cord to that outlet and then I presume I'll need to run a wired switch down to the wall of the garage where I want to be able to control the lift. Thanks in advance for your time and consideration.  This would certainly make my life a bit easier to be able to quickly and easily raise and lower my ski box onto and off the roof of my car.   Regards, David

Topic by dtepper 


How much knex do you have?

I was wondering how much knex people have. i have about 6500 knex pieces including: rods, connectors, wheels, motors, gears, tubes etc... the buckets of rods and connectors are full to the top. ive sorted them into four boxes which are: (1) rods (2) connectors (3) small parts - wheels, gears, small motors etc... (4) big parts - tubes, large motors, books etc... now, show me your knex colletion!

Topic by ~KGB~   |  last reply


knex vulcan mini gat

Ok this will be the best thing out of knex,but i need some help.I have an idea for the gear box and twisting pivoting stand,but thats about it i want it to be like a real one with a mag 4-8 barrels that cock themselfs using a rail system so if you have any ideas(especialy knex masters like mepain mykhailo or killerk or any other person)please post soon i think i have an idea for a way to make it have only one mag wat will happen is at the end of the mag there will be a ledge that holds them in place then when the barrel comes around it can grab it with a special tooth attachment and then gravity will pull it down into the barrel(no idea on how to build yet) pic 1 real thing pic 2-3 gear box

Topic by darth acexxacer   |  last reply


brushed to brushless!

If you have been flying your RC planes a lot and have found them getting a bit boring, go brushless and get lithium polymer cells. brushless motors are lighter and twice as powerful as brushed. lithium polymer batteries hold the most electricity to weight ratio compared to standard Nicd and Nmh. Dont believe me look at your cell phone open the battery hatch and take out battery its probably a Lithium polymer or lithium ion notice how light it is and small it is now look at the volts/ mAH pretty amazing hu? Got a laptop it probably got a lipo to. you want to make the switch but dont know what motor, battery, ESC (ESC-electronic speed control) to get, just ask and ill give you a hand! i will need to know the motor and battery that came with the plane/ or that u are using. Are you flying glow (gas powered) and wana go electric? i can help u out their too! Their are 2 kinds of brushless motors outrunner and inrunner whats the difference? well outrunners spin slower with more power so it acts like it has a gear box (this eliminates the need for a gear box reducing weight and noise) it also has a different design (look at pics). inrunners have a brushed appearance but their much lighter and more powerful u might need a gear box through. update 2/20/08 new image added (not all comment boxes are working)

Topic by i make shooting things   |  last reply


Dual energy generation with magnetic Seesaw system and gravity with the help of 3 volt toy motor

This technology is based on  a Seesaw system and magnetic repelling principle Linear motion  .We can generate electricity with very little force with the help of this technology.This will be a radical step in the field of energy generation. In this technology there will be a balance system and two heavy weight magnets(high strength NEODYMIUM MAGNETS) will be attached with each side of this balance system as per diagram. As per diagram there will be two moving weights and these moving weights will move on tracks.These tracks will be fixed at the angle of 8 to 10 degree. Two magnets will be attached on the front side of these moving weights and these magnets will have similar polarity with the magnets of balance system. These moving weights will be attached with two gear boxes and these gear boxes will be attached with two generators. HOW THIS TECH WILL WORK? When one side heavy weight magnet of balance system will be pressed with the help of any kind of external force then this side will come down and repel its side moving weight due to equal polarity of magnets.due to repelling the moving weight will move forward .but when the heavy weight magnet will move upward then this moving weight will move backward due to gravity to get its position back. in this way this moving weight will work to run a gear box and this gear box will work to start a generator to generate energy. This balance system will also work to pass through their side copper coil due to linear movement and in this way this technology will generate Dual energy. WE will take very high strength NEODYMIUM magnets  for balance system. I would like to insist on some following points (1) The balance system will be attached with 'L' form crank with external PRESSING source. (2) The moving weights will also be attached with 'L' form crank with gear boxes. (3) Each side magnet of balance system will work one by one .When one side magnet will come down the another side magnet will move up .These magnets will come down and move up one by one to repel their side moving weight. (4) We can take as much weight as we can of these magnets of balance system .(500 kilogram to 1000 Kilogram or more) to pass through the heavy coils having 100000 turns or more.  (5) External source of pressing this balance system could be anything such as pressing with foot  or solar cell. WE WILL NEED ONLY 3 VOLT EXTERNAL ENERGY TO PRESS THIS BALANCE SYSTEM  AND GENERATE MORE AND MORE ENERGY.

Topic by vikram_gupta11 


how do i make a gearbox for a 12 v dc motor? it is already fitted with a metallic worm.

I have four rs 385 ph motors manufactured by mabuchi..i need to make gear boxes for them to make them spin around 150 rpm and its already fitted with a metallic worm...any idea?

Question by shaondip   |  last reply


whats the best way to sharpen a knex rod?

I want to sharpen a knex rod but it never ends up looking like for example gorkems rod in his video i tried sanding it down with a gear box and a drill to make it spin fast but the rod melts when it spins to fast so how can i sharpen a knex rod more effectivley

Question by iundonei   |  last reply


Small RC Car drive system help?

I have been looking online all day and i haven't found anything.  I am looking to turn a iPod touch case into a small rc car using a canabalized rc toy that I got from a friend.  I am using it for mainly its transmitter/receiver and motor controller.  All would be well and good but one gear in on of the gearboxes is shot.  I have many other hobby motors and two that are the same that I want to use instead but I don't know if I can without putting a gear box on them first or if I can, like I want, attach the axle right to the motor spindle with a jery rigged shaft collar.  Just for reference I DO know about building things like this I am on my schools robotics team which I founded but in vex not only are the hookups male instead of female the motors are like servos and they have built in gearboxes (they come as a module).  Any ideas or advice would be greatly appreciated and if I could get help asap I would love it. Thanks in advance.

Question by ahleagle   |  last reply


Does anybody want these?

So heres the deal, Jack In The Box was having a GameStop sweepstake which I entered and won the following items from: Gears of War 3 free in-game weapon skin 5-pack Assassin's Creed Revelations outfit Gears of War 3 free in-game weapon skin 5-pack (I won this twice  which is why it is listed twice) Now seeing as to how I don't play those games and further more do not have an Xbox I was wondering if anyone wants them. If you do write a number in a comment in the next few days. I will randomly choose three numbers and send the link and the code that I was sent by Jack in the box to the three people who wrote those numbers. I will not be held responsible under any circumstances if including but not limited to: the code does not work for you they charge you shipping you do not have the games they arrive damaged etc. etc. etc.

Question by ElvenChild   |  last reply


How to make cylinders move in a serpintine pattern

I am creating a sculpture that has a very complicated movement that I am struggling with.  I have a shadow box containing 2 rows of two foot long one inch diameter cylinders. I want them to "weave" back and forth in the shadow box. I thought about cutting out a track from a 1/4" plate and mounting it on the top and bottom of the box. Than placing a motor  inside one of the cylinders connected to a shaft and a gear that would ride in the track. I like this idea but, I do not know how to overcome the problem of where the track crosses itself. (the track would look like multiple figure 8's) Any ideas on this or better ideas? Thanks for your help!

Topic by cramnager   |  last reply


DIY Steering Wheel

Hello, I'm new here. So, lately, I've been thinking about making a steering wheel for my PC, with a simple up-and-down gear box and 2 pedals for acceleration and brake. Steering Wheel. I'm using a polystyrene sheet, to cut out a wheel from it, and in the center, there's space for installing a phone holder. I'm planning to use my phone's gyroscope and simulate it to the PC. Pedals. I've figured by using foams underneath, we can place a nail and a foil separated and when we press the pedal, the foil touches the nail and circuit gets completed. I've a general idea, but I'm stuck on how to give that signal to PC as to simulate as a button (say for acceleration and brakes.) Gearbox. For the gearbox, I figured it might be easier to make an up-down box (as in pulling the level shifts the gear up and vice-versa.) Here too, The part where I'm stuck is giving the signal to the PC. Anyone who can help me, please?

Topic by RohitR78   |  last reply


Is there a way to search Answers for answers? Answered

Is there some way to find specific answers? Whenever I put a search in (e.g. "gears"), it only comes up with results in the Instructables category. And I can't find any dialog boxes to change the search category to "Answers". It just seems to me that a system as awesome as the "Answers" section is needs accessibility to get the full potential out of it. (It's forgivable at this point because it's still new).

Question by victus_maestro   |  last reply


HEMI no programing required !

Hello  I am interested in build a simple mini line following robot  like HEMI dome shape design, has any one here built this robot ! or ones like it, and information on where to get parts mini or micro gear box, and motor and mini wheels to fit as well as mini circuit boards or I will make one via you tube . . Thanks any help appreciated  David  

Topic by beginner 1    |  last reply


sketch for arduino obstacle robot using seed motor shield v2.0?

Hi everybody, im barely started writing sletch so i need help, i build a obstacle robot and i used  arduino uno r3 seeed motor shield v2.0 one servo tamiya twin motor gear box hc-sr04 sensor  so i dont really know how to start writind the sketch.....

Question by salvador.lopez1   |  last reply


another full auto machine gun mechanism

Right this is just the mech of the machine gun you will have to make the mag/clip/barrel/everything.You may have seen this already on the comment on https://www.instructables.com/id/8-SHOT-KNEX-HAND-GUN-REVOLVER/?&sort;=NEWEST&limit;=50&offset;=50The comment with it was posted May 7, 2008. 12:25 PM.Basicaly the hammer is attached to a small cog, a motor or handle is attached to a cog with only 4 teeth(on each half) the 4 teeth will crank the hammer back then when it runs out of teeth it will snap back, it actually works(I would have posted but my sister destroyed it D= ) te only problem I had was the mag, I attempted to build a box mag, oh and the fact you need a metal rod for the handle/motor and for the hammer with gear on(I lost 3 red rods because it just twisted the hell out of them, it was impossible to use them again)So you can only make it with some sort of renforced rod, but overall it actually works.this is just a small step by step type thingStep 1sand down 3/4 of a small cog.Step 2to speed up rate of fire add speed up gears (optional)Step 3make hammer, lock canibalised cog onto a rod with hammerStep 4connect it to speed up gear/sStep 5add elastic band to hammerStep 6add mag, clip or belt. note: if you make belt the add timmed gears to the speed up gear.

Topic by CrazyCHRIS!!   |  last reply


SELLING MY K'NEX

To mark my retirement of making knex guns, From Tuesday the 24th of november, my whole set of K'nex will be up for sale on eBay, which is made up of the power tower crane, space tower, 2 cyber K'nex sets and countless other sets, and includes 4 boxes full of wheels, gears and motors (8 electric motors to be exact), i will ship internationally if requested and if you state that you are a K'nex gunner i will include the orginal semi-auto prototype that i created, a splodies grenade and launcher loaded and ready to fire and a large box of rubber bands free (this will be broken down if a non knex guner buys it) i will post a link  to the sale after it has been listed and good luck! pictures uploaded...

Topic by bedbugg2   |  last reply


How can I build a 4 wheeled device on which a harley sportster can be loaded and transported?

The device would be operated by one or more 12v dc motors.  Power for the motors will be obtained from a pickup truck battery. I want to use the device to load a harley sportster, which weighs 500 lbs., onto the box of a pickup truck.   Loading will be enabled by a platform, angled from ground surface to truck box.  Presently, I'm able to use a 12v winch, attached to the front end of the truck box,  to pull the bike up a ramp onto the truck box. To hold the bike erect while it is being pulled up the ramp, I use two 8 inch air filled wheels attached to the bike,( by a very makeshift wooden settup) one wheel on each side of the bike.  However, the bike must be pulled backwards onto the truck box so that it can be more safely offloaded by riding the bike, in its forward position, off the truck and down the ramp .   In order to keep the front wheel straight, this method still requires more than one person to hold the bike while it is being loaded.  The bike's transmission must be in neutral, but the back wheel, drive belt and xmission gears still turn and provide some resistance.  A 4 wheeled device loaded with a motorcycle, and operated by seperate electric motors would have free turning wheels and could be used to move the motorcycle around without its need to be pushed manually.  Perhaps it could be controlled remotely. 

Question by p2otoole   |  last reply


Your opinion on this DOWNGRADE of and airsoft gun ?!?

Hi ... as usual my another airsoft rifle is to powerful for the site rules. Because it's NEW, iw ould like to avoid open it and the gear box as well and change the spring. Or to clip the spring. What about to make a small hole in the valve that is pushing the BB in the barrel ??? With those small/fine drill bits (0.3 - 0.6 mm) ??? That should make the pressure smaller, you wouldn't have to fight with the spring and it would be cheaper to replace it ?!?! Do I see it to optimistic or do you think it could work ??? Thanks ...

Question by zholy   |  last reply


Choosing drive motors for kids riding toy

I'm building  "robot horse" for my daughter, and have the metal frame mostly complete.  The plan for locomotion is to mount reversible powered 6" wheels to the outside of each hoof, and steer tank-style. My biggest challenge is finding reasonably priced, reasonably powerful drive motors for each wheel.  My issues are  1)  I'm inexperienced at specing dc motors.       A) I'm not real sure how to translate published specs into real world motion.  I don't know exactly how much power it takes to get this reliably moving over rough ground to a top speed of around 1 mph.  I also don't have a good sense of much voltage you can pump into a DC motors.  (IOW, should I be able to push 2 x the rated voltage for a quarter second to get it moving? Will the motors naturally increase their amperage at a constant voltage (and thus power) as they are resisted by torque?)  How much power will starting from a stop take?  What about a slight uphill slope?     B)  I'm not sure what form-factor is best:  Gear motor?  Gear motor with final drive belt?  I would like to use worm-gear motors, as I think it would be safest if the wheels didn't move when unpowered. 2)  Hunting around supplier web-sites, I see lots of $20ish gear motors that use 5-20W of power.  Great price, but would 4 of them make enough power?  (See #1A above)  Also, I see lots of fractional HP motors for >$100 that would unquestionably be strong enough, but would cost more than the project justifies.  I found very little in between.  Are there motors and gear boxes that could power this at a reasonable price?   Relevant clarifications and details: 1)  The horse is about 40" high at it's withers (shoulder) 2)  Frame is made of 1/2" square tube steel. 3)  Normal rider + vehicle will be about 150 lbs.  However, unquestionably, larger kids (or multiple small kids) will at some point hop on it and try to ride it.  At 250 lbs. rider+vehicle weight it doesn't have to go fast, but shouldn't burn up the motors. 4)  It'll be powered by a lipo battery pack that shouldn't have any issues with 20A+ max currents and can be sized as needed for voltage. 5)  I'd like to keep the motors and gears <$200 total, if possible. 6)  "Rough ground" = flat grassy turf or reasonably smooth gravel. 7)  Motors need to be reversible. Can anyone lend some perspective on what type of motors to buy for this?  How much power/torque should I look for?  Any advantages/disadvantages of any particular gearing style for this application? I am assuming that motors on each wheel are the way to go, but if there are any other power transmission schemes that would work better, I'm all ears.

Topic by SvdSinner   |  last reply


Knex ball machine.

I was wondering if somebody could make a new knex ball machine, with 4 paths, and with 3000 - 5000 pieces. what you can use: any connectors or rods anything from the big ball air tower set any gears any motor what you cant use: orange tubing over 10ft of chains (unless its some kind of other lift) these are other ball machines i made. i broke them because there were not many paths, the ball kept falling off, or that they just werent good enough. project box project immeuble project nano project dos project aggresor (the famous knex big ball factory below)

Topic by ~KGB~   |  last reply


DVD, VCR, DVR Parts

Dream Box of Goodies? I have a box full of circuit boards, motors, gears, lasers, power supplies, LED displays from several VCRs and DVD players, as well as internal parts from a DirecTV DVR with Tivo (not including the hard drive). All circuit boards contain chips, resisters, capacitors, etc intact on the boards. If you have interest in this or can point me to a place where I can get some value out of this lot, please let me know. Would most like to sell all together, but will consider selling piece-by-piece. Or maybe someone could direct me as to what parts to salvage. At this point, I have removed the boards and mechanics from the the enclosures in order to save space. I have recycled the steel/plastic enclosures. I am in the Dallas, TX metropolitan area. I would appreciate any offers or constructive advice.

Topic by aw0 


Heavy aerial lift quadcopter?

Hi, I am in a local competition where they are asking for a quadcopter that can lift a box of lead. The box weigh's 25kg. Yes, you read that right 25 kg. The rules state that it must be a quadcopter and it must fit in a meter by meter by meter cube. This limits the prop size to 500mm diameter unless the height of the blades is different so they overlap. I would prefer not to do this. each rotor must lift 7000 grams (payload + weight of quad). I have been using this thrust calculator : http://personal.osi.hu/fuzesisz/strc_eng/ and according to it a 500mm (20") at 4.5" pitch (I just put that as standard) will need to spin at 6000 RPM to produce 7.12 kg of thrust. It also says it will need an 800 Watt motor. I plan on using these motors http://www.hobbyking.com/hobbyking/store/__24433__NTM_Rotor_Drive_450_Series_1700KV_930W.html. They are 930 watts and 1700kv. they run on a 6s lipo. A 6s lipo is 22.2 volts. 22.2 X 1700 = 37,740. 37,740 RPM is the theoretical speed of the motor. I only need 6000 RPM. 37,740 / 6000 = about 6. so the motor has an 8 tooth gear on it and the prop has a 42 tooth gear on it. This makes a roughly 6:1 ratio to slow down and power up the rotor. The motor is 30A constant current, 42A burst. The ESC will be this one http://www.hobbyking.com/hobbyking/store/__25366__Turnigy_Multistar_45_Amp_Multi_rotor_Brushless_ESC_2_6S.html and the battery will be this two of these: http://www.hobbyking.com/hobbyking/store/__9176__Turnigy_5000mAh_6S_20C_Lipo_Pack.html.          When I started writing this I had a question that I answered myself but now I just want to know if you see any faults with this. PS, the winner of the competition is the one who can hover the longest. I also want to do it for as cheap as possible

Question by monty324   |  last reply


LCD Screens and motors for projects

Hi, guys. I have acquired a whole bunch of defunct printers that don't work for one reason or another. I have box of working LCD touch screens. Printer motors, stepper driver boards for the motors, belts drives, gears, shafts, scanner lights, power boards, cables, printer heads, power supplies and screws. I can't use them all and I was wondering if any was interested in some of this stuff for projects. I have picked out a few things for my self, but I can't use it all. If any one is interested in buying anything let me know. If enough people ask I can make a list of parts and prices for the parts.

Topic by gigashadow   |  last reply


Geting wheels of a axle?

I have a 2345 peerless transmission that i need to get the wheels off of.. ive removed the lock ring and washer but it wont budge, it does have a keyway but i wouldnt think that would be my issue.. here is a complete guide on how to take the tranny apart but not too much help (the transmission i have starts on page 81) http://www.smallenginesuppliers.com/html/engine-specs/tecumseh/Tecumseh_Transaxle_Service_Information.pdf and heres a blown apart picture and shows my type of axle it says 47 and 48 but i think i have 47b and 48b because of the key http://www.mymowerparts.com/pdf/Peerless-Tecumseh-Transmissions-Transaxles-Differentials-Gear-Boxs/2300-2345.pdf and the image is of the end of the axle with washer and lock ring off

Question by knexsuperbuilderfreak   |  last reply


How to Build "The Extra Investigator" aka "The Ed Box" Device. Will be featured on new Amazon Prime show. Will Pay for Build!!

Hey Im looking for someone that can help me build an older paranormal device called "The Extra Investigator" aka "The Ed Box". I can't find the right build for it ANYWHERE and only have one pic and the device details, this device is not used by "television paranormal investigators" any longer so its impossible to find any for sale or even other pics of this devices other than the one posted below... it has EMF detection, IR detection and detects "physical events', which i don't understand (BS basically) but it basically is an EMF detector that connects to the compass and points to the em field. Also, Im not sure how the IR detection is utilized. I have not seen this device in action, so this is what i'm assuming because of other gadgets with similar applications. I have found ways to build an EMF detector and an IR detector, I also have tons of parts, bread-boards.. everything needed for the build (have the enclosure and compass on the way via mail) but I need guidance in the build or it built for me. I understand that most serious builders don't believe in the applications of these devices but this is for a serious project and want to show this device on an episode of our new show, also they (the builder/helper) would get a shout out on an up-coming Amazon Prime show, along with payment for the labor and any parts i cant supply (paranormal engineering position for our team may open up if things work out. We are searching for a smaller company/engineer). But! ANY help would be appreciated! No need to make jokes and point out what i've obviously stated, if you cant or don't want to help, pls keep your negative comments to yourself. This device is also going to be a teaching tool for kids ages 12-16 who are interested in the paranormal and want to learn the basics. I wanted to show them some devices they wont see on TV. I'm under no illusions that these devices are 100 percent accurate and will not waste time with non-believers. This is a business situation, the build shouldn't matter. Thanks science peers

Question by langdoncobbb   |  last reply


20th Anniversary!

So for any of you wondering it's 20 years since K'nex was released...  ...and I've had it for 13 of those years (o_O)  To celebrate, K'nex are making a Remake of the Screaming Serpent, called 'Son of Serpent' this month. But at $999 it's pretty expensive.  To Celebrate, share your stories of any mishaps/interesting things you've done with this great Construction toy when you were younger! (not just Gunz)  Also: When did all of you get your first K'nex set?! And which one was it?  My First Set: 10 Model Box set (the one with the Surfer on it) Age: 5 Been hooked ever since, I still have the original Instructions!  Random Moment: Age 9, I made a 'Podcopter' as I liked to call it. I doughnut-shaped Helicopter with Gears to make the Props spin. 

Topic by TheFoofinator   |  last reply


Cable tester? xlr, jack, phono etc

It looks pretty simple: http://www.studiospares.com/test-gear/studiospares-ultimate-cable-tester/invt/458260/ i was wondering whether anyone could help me with how i would go about building one of these from scratch within a hobby box? i have components (sockets and plugs, veriboard etc) but i've never designed a circuit before so any idea would be great! im thinking two rows of LEDs that match pins 1 to 1, 2 to 2, and 3 to 3 at each end of the cable being tested (maybe 4 and 5 too) refering to tip, ring sleeve on jacks, centre pin and ground sheath on phono, and pins 1, 2, 3 on xlrs. any schematics/idea please! take a look at the link for a better idea. LEDs to indicate shorts and phase switch would be cool too.

Question by jamesjamesjames   |  last reply


Sensor and Quick Release for Monster Trap Christmas Gift

I'm building a Christmas present for my 2 year old nephew... The goal is to build a monster trap for his room. My current plan calls for a large 2-3 ft. net, framed with a lightweight material, this would be attached to the ceiling of his bedroom by dad. In the apparatus that attached the net to the ceiling there is some form of 'quick release' mechanism that is triggered by some form of sensor hidden in a pillow, platform, cardboard box... a big stuffed banana -something that resembles monster bait. The physical parts of simple enough but I'm wondering what options I have for the sensor and quick release... I'm pretty handy with radio gear and fly quadcoptors so I'm pretty sure I can rassle up something.. Any ideas? Parts for Monster Trap: - one lg net, preferrably framed - radio controlled quick release - light sensor w/ radio transmitter - pillow or something to mount the light sensor in - screws to ceiling mount the net

Question by mrmartin79   |  last reply


What would you recommend for an Arduino starter kit? Answered

I have €60 =~ $79 / £50 to spend on an arduino and stuff to use with it as an introduction to electronics. I've looked around at other starter kits and so far, I plan to get: An arduino Deumillanove, A breadboard Jumper wire a few piezo elements, 5 x blue, 5x red, 5 x green LEDs, 2 x RGB LEDs. LOGIC, SHIFT REGISTER 8-BIT, 16DIP (how many of these will I need) So far that costs about €50 from ie.farnell.com. Are there any better places to buy from in Ireland? I have some motors with gear boxes and potentiometers that I used for school projects which I can recycle. I know that I'll need resistors but I don't know how many of which resistances. Is there anything else like sensors etc. that I might need or you think would be fun or good to learn with? I dont mind extending the budget if I have to. Thanks a lot in advance :D

Question by Technologic   |  last reply


1992 Toyota Paseo (5-speed manual transmission) with difficulty shifting into 1st, 2nd, 5th & reverse?

I have a 1992 Toyota Paseo that's recently started shifting hard into all gears except 3rd & 4th.  We've tried it even when the car's off and it's still having difficulty, so it doesn't seem like it would have anything to do with the clutch.  Weirdly, it doesn't seem to do it all the time. It almost seems like it does it right after it's rained. When it's being difficult, the hardest to shift into is definitely reverse, although 5th isn't always a picnic either. 1st and 2nd are a little tough, but not that bad. 3rd and 4th are smooth as butter. Is it possible for the shift assembly box (or whatever it's technically called) to have some sort of difficulty that could be causing it to stick or be held back in some way? My boyfriend is a mechanic (although he hasn't been able to take it in yet) and he doesn't think it's the transmission, but he's not all that familiar with manual transmission cars. It's got about 160,000 miles on it. Any thoughts?

Question by kokocooper   |  last reply