# perfo

## Achievements

100+ Comments Earned a bronze medal
• perfo commented on Kipkay's instructable How to Make Vortex Cannons

You want a little bit of tension left in the bungy when the ball if fully forward.

I know this is an old Instructable, but I’ve only just foundit so wanted to say I liked it and thanks for posting. I have a question though(if you still read your comments). The speaker will be designed to self-centralisewith no signal on it. If you put a square wave on it then this will only displacethe cone one direction and for half of its travel. It would need a bias on itmoving the cone fully back and the Square wave, then sending it completely forwards. How did you over come this in this project?or did you only use half the travel? Thanks again.

No. The key element of a stable vortex isthe velocity and quantity of air as it goes through the hole. This is set byhow much air you move with the diaphragm divided by time (so move as much as possiblein a short as time as possible). If you make the body too big or too longthere will be so much compression of the air inside the body, you will belosing a lot of the velocity. Similarly if the hole is too big thevelocity will drop to a point where it won't make a vortex and just puff outthe hole or too small and you’ll not end up with enough volume of air to make thevortex and end up with a jet..You can pretty much scale everything up or downwithin limits, but it would have to be everything not just one component. Thegood thing is the tolerances are pretty big. If you make one completely…

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No. The key element of a stable vortex isthe velocity and quantity of air as it goes through the hole. This is set byhow much air you move with the diaphragm divided by time (so move as much as possiblein a short as time as possible). If you make the body too big or too longthere will be so much compression of the air inside the body, you will belosing a lot of the velocity. Similarly if the hole is too big thevelocity will drop to a point where it won't make a vortex and just puff outthe hole or too small and you’ll not end up with enough volume of air to make thevortex and end up with a jet..You can pretty much scale everything up or downwithin limits, but it would have to be everything not just one component. Thegood thing is the tolerances are pretty big. If you make one completely guessingthe sizes it will probably work.

• perfo commented on lingib's instructable CNC Graphics Tablet V2

Some good improvements. It seems to work well.. thanks for the instructable..

• I believe the onMessage routine is no longer included in fauxmoESP. I'm not sure but maybe earlier version had it. @MJROVI , I liked this instructable and it's predecessor and it has helped me understand how to do simple switching on of ESP8266 outputs. What I can't figure out is how to do an input to the ESP8266 and get Alexa to announce it.

• perfo commented on shahdivyank's instructable Wizard Chess

Yep reed switches would do and I know there area few how tos on the net suggesting how to set it up. I'd prefer optical (butthat has big problems on a practical level) or the RFID's. The trap door istricky but if you had a chute on your gantry that opened the door and ensuredthe piece fell through the chute then as long as you have enough clearancebetween the tallest piece and the lowest bit of your mechanism it should work.Plus you could make this section in to a draw so that at the end of the gameyou open the draw to retrieve the dead pieces... Smoke would have to be a wateratomiser I guess or maybe a converted E cigarette as I believe you can getdifferent colour smoke etc... It is a project I thought of many moons ago buthaven't had time to get started. So if you do develop this please…

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Yep reed switches would do and I know there area few how tos on the net suggesting how to set it up. I'd prefer optical (butthat has big problems on a practical level) or the RFID's. The trap door istricky but if you had a chute on your gantry that opened the door and ensuredthe piece fell through the chute then as long as you have enough clearancebetween the tallest piece and the lowest bit of your mechanism it should work.Plus you could make this section in to a draw so that at the end of the gameyou open the draw to retrieve the dead pieces... Smoke would have to be a wateratomiser I guess or maybe a converted E cigarette as I believe you can getdifferent colour smoke etc... It is a project I thought of many moons ago buthaven't had time to get started. So if you do develop this please keep theinstructables coming so we can see the progress...

• perfo commented on shahdivyank's instructable Wizard Chess

nice project..RFIDs in the chess pieces and a reader on yourgantry would enable you to know where each piece is and thus reset if thingsget knocked or allow the computer to play against you. Plus obstacle avoidance,though i like your idea of ensuring enough space so pieces can move withoutcollision. I know it's not practical to do but a trap door to disappear thedead pieces with a puff of smoke would be cool.

• A bit of a journey but it was interesting and great results.Another detailed clear instructable Lingib keep them up.

• Great instructable and well written , thanks for takign the time to do such a detailed presentation. What about building multiple of these and getting them to talk to each other all printing a smlla bit of a bigger plan. That way you could possibly smash some world records on domino toppling... as others have suggested a clean up bot could also be a huge advanatge :-)

• perfo commented on lingib's instructable 4-Wire Horizontal Plotter

Great plotter and great instructable. Well documented.

• Hey nice project.We don't need to know why you had so many purses , that's private information :-)May I make a suggestion ? If you are going to mount this on a sleigh particularly if the text is to be on the back then you could consider a short throw projector and put a frosted perspex panel i the back or on the sides of the sleigh.. It would give you massive flexibility. Projector are cheap enough now and coming down all the time. The only downside would be vibration. A laser or LED projector would be best but hmm that may rake up the costs.. anyway however you do it I guess you have a year to get that sleigh wired up and give us some pics... mind you a old plasma screen is proabbly just as cehap mouting in a waterproff box..

and to find a better display made from purses you could not...

• perfo commented on shinkdifferent's instructable Plywood Reindeer

Yes 😃

• perfo made the instructable Plywood Reindeer

Got round to making the reindeer and sleigh. Excellent instructable and design Shinkdifferent...thanks.

• perfo commented on lingib's instructable Servo Deadband Correction

Excellent instructable. The last servo plotter was usable for sketching but this dead band compensation has made it about as good as you are possibly going to get using this simple and quick (cheap) build process. Thanks for the time to do the instructables and then updating them as you do...

• perfo commented on lingib's instructable CoreXY CNC Plotter

Like all your instructables LingIb this one is great, well detailed and well written. thankyou for taking the time to do these instructables and give the rest of us interesting reading and ideas. I have been messy with CNC stuff for a few years but the simplicity and accuracy of the CoreXY set up is quite remarkable

• perfo followed lingib
• perfo commented on lingib's instructable Omni Wheel CNC Plotter V2

The big problem here would be the wheel may drop in to the cut you've just made and may either get stuck or simply throw it off and thus loose its' zero.

• perfo commented on lingib's instructable CNC Drawing Arm

One big complaint here. You need more video's of it doing things. I could watch these things do stuff for hours... One short video is just not enough.. :-)Another great instructable Lingib, very detailed and nicely explained. Thanks...

• perfo commented on lingib's instructable Servo Plotter
• perfo commented on lingib's instructable Servo Plotter

You could probably compensate a bit by using a PID type controller. So for big changes you'd accelerate the movement then slow it down to hit target. You may even be able to tune out the dead band but I'm guessing you will always have things needing a very small movement (ie drawing an arc) and PID wouldn't help at all. Something I don't know , or should I say one of the many things I don't know :-) is if the circuitry of the servo can handle a min change or PWM of say 6 us then it this linear for a 45 degree servo or 90 or 180 etc. If the resolution and error remains constant then gearing a 180 degree servo down to 45 would 0.25 your error . But if the difference in the servo motion is simply internal gearing then I guess it wouldn't help at all. The other thing that may help a bit whic…

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You could probably compensate a bit by using a PID type controller. So for big changes you'd accelerate the movement then slow it down to hit target. You may even be able to tune out the dead band but I'm guessing you will always have things needing a very small movement (ie drawing an arc) and PID wouldn't help at all. Something I don't know , or should I say one of the many things I don't know :-) is if the circuitry of the servo can handle a min change or PWM of say 6 us then it this linear for a 45 degree servo or 90 or 180 etc. If the resolution and error remains constant then gearing a 180 degree servo down to 45 would 0.25 your error . But if the difference in the servo motion is simply internal gearing then I guess it wouldn't help at all. The other thing that may help a bit which I think you are eluding to with your last comment and that is produce a compensation curve and use it to add or deduct from the calculated position to bring it back to roughly where it should be . So for example if you want to move one step in the X direction then you are tied to the resolution and not much you can do about it but you maybe able to compensate by taking one steep off every 50 or whatever if the movement is in the same direction is should be fairly constant error. .

• perfo commented on lingib's instructable Servo Plotter

0.1 degree looks like that may be workable. So maybe that is setting your max X and Y Area. Interested to see what you actually get with the dead band. Though I'm not quite sure about the dead band figure. Does this mean a change of 5us or less on the pwm and the servo may not move? In which case you'd have 480/5 = 96 or 9.6 degrees resolution ? Surely that can't be right ?

• perfo commented on lingib's instructable Servo Plotter

They look chunky servos. What sort of resolution are you reliably getting ?0.1 degree ?

Commiserations on the thumb.. probably the worst digit to injure when you want to fiddle with things..

Good stuff, I'll look forwards to seeing the upgrade.

I think (and I'm certainly no expert) The resolution is basically set by the angle of rotation divided by the timings of whatever is kicking out the PWM up to the point where the dead space between pulses gets too short. So a typical servo may need 1ms pulse for 0 degrees , 1.5ms for 90 degrees and 2ms for 180degrees. So a PWM resolution of 0.5ms gives you a servo resolution of 90 degrees and thus a 0.05ms pulse gives you 9 and 0.005ms (5 us) gives 0.9 degrees. But as stated the servo itself can only go down to a certain length of pulse before it can't read it properly and gets swamped. What I haven't a clue is , how far can you push these servos ? Maybe put a laser on one and aim it across a large room move it the smallest distance you can and work out the angle.. I haven't got any at …

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I think (and I'm certainly no expert) The resolution is basically set by the angle of rotation divided by the timings of whatever is kicking out the PWM up to the point where the dead space between pulses gets too short. So a typical servo may need 1ms pulse for 0 degrees , 1.5ms for 90 degrees and 2ms for 180degrees. So a PWM resolution of 0.5ms gives you a servo resolution of 90 degrees and thus a 0.05ms pulse gives you 9 and 0.005ms (5 us) gives 0.9 degrees. But as stated the servo itself can only go down to a certain length of pulse before it can't read it properly and gets swamped. What I haven't a clue is , how far can you push these servos ? Maybe put a laser on one and aim it across a large room move it the smallest distance you can and work out the angle.. I haven't got any at present or I'd be doing that myself now I've sparked my own interest.. This will then let you know how big you can go with your plotter and still get the resolution you want.

• perfo commented on lingib's instructable Servo Plotter

Great project and a very detailed indestructible. Top marks fella.Would you have a video of how the finished version works ? The only comment I could have made was the wobble in your test piece which proved your maths and set up was correct but also some more mechanical stiffness was needed. I see from the pic you've beefed up the motion linkagage arms. Did this cure the porblem ?

• perfo commented on shinkdifferent's instructable Plywood Reindeer

Another type of glue I've just remembered is mounting glue https://www.amazon.co.uk/SprayMount-YP208060506-Adhesive-Spray-Transparent/dp/B000J68HBO/ref=asc_df_B000J68HBO/?tag=googshopuk-21&linkCode=df0&hvadid=262024380476&hvpos=1o1&hvnetw=g&hvrand=7814422438779741391&hvpone=&hvptwo=&hvqmt=&hvdev=c&hvdvcmdl=&hvlocint=&hvlocphy=20343&hvtargid=pla-436109169041&psc=1 The above is an amazon link to it. Basically you can get glue that would hold your pattern to the ply nice and firmly but the patter can be pealed off afterwards. I've got some so I'll give it a bash when my ply turns up..

• perfo commented on shinkdifferent's instructable Plywood Reindeer

Thanks, I'll get it printed and order some Ply.....

• perfo commented on shinkdifferent's instructable Plywood Reindeer

I would really like to have a dxf file as well, please.I have access to an A0 plotter and I have CAD software. I haven't got photoshop and can't get the PDF thing to print properly and at the right size. If I had a DXF then it would be simplicity to print it. I can assure you I have no intention of doing anything other than building one for myself.. Thanks you

Great project. May I make a suggestion? Instead of transferring the pattern on to the wood, simple stick the paper to the wood with water soluble glue. Cut the shapes out then using water and a stiff brush wash off the paper. If you are going to paint it anyway then maybe you don't even need to remove the paper ?

• No , I haven't made one yet but get close to having a go when the weathers nice.. My latest plan is to dig a hole, fill it with sand. Put a plastic sheet over it and shape the bottom. slurp my concrete in then another plastic layer on top suspended from some sort of frame and filled with water to displace some of the concrete and give me the dish shape I want.. I haven't a clue if it would work or not...Other way would be to rig up a rotating plate that woudl rotate for 24 hours and be slightely conical..

• Ok, good idea. I haven't one real close but I'll keep my eyes open next time I go past one...Thanks

• I thought the PiCam would only go down to about 1 micron wavelenght. How are you getting it to register heat ?

I should have said in my last post. Thanks for the very interesting ible. I had a great hope you had managed to get the PiCam sensor to go to 5-micron or something and thus opening up a whole new playground for Pi fiddlers. Making a wearable FLIR type device is one of my planned projects to do one day but not being a company or the holder of copious paper beer tokens I didn't think I'd be able to do it anytime soon. Could you divulge the details for the thermal imaging set up you have above please?Also I'm still a little confused how you get the focusing right for the micro display module. As the distance from the pupil to the screen is only something like 5 cm why isn't it out of focus? Thanks again...

• Nice instructable. I think you rose to the challenge. If you are interested, I have another challenge for you.I think you'd be able to get rid of the vacuum motor and build a centrifugal fan possibly out of CD cases and boxes..

Nice instructable. I think you rose to the challenge. If you are interested, I have another challenge for you.I think you'd be able to get rid of the vacuum motor and build a centrifugal fan possibly out of CD cases and boxes..

You can build em out of ply so CD cases shoudl be do able. Make them backward facign centirfugal and they will handle particles no prob..

• Thanks for this ible. I've just spent a few hours trying to get fauxmo working on my RPI without much success. So I wiped the card and started again with your ible and 30 seconds later it was working. I'm not quite sure what the difference is between your build and the others I tried (except your's works) so thanks for making it so clear. I've adapted your code to control a few gpio's and it's workign great.

• Hello, This ible was just what I was lookign for. A little typo if (I may) when you clone the git you get the file gpio-control.py not gpio_control.py so that may help some folks that get the file not found error.Also I'm hoping someone can point out what I've done wrong as I get two errors file "gpio-control.py" , line 9, in <module> import fauxmoand file "/home/pi/echo-pi/fauxmo.py",line 31 , in ,module.import requestsimporterror: no module named requests.Thanks

• Ok , thanks for your comments... Though even a huge exercise ball may not be big enough.... :-)

• perfo commented on nhampto9's instructable How to Disassemble a Pallet

I don't do this very often. But when I have I have spent time trying to pry the heads out enough to get a jimmy on them. broken pallets and a fair bit of effort was the normal result. This way seems so much easier and better and simple especially as I have a chunky Bosh reciprocating saw and didn't think of using it... Thanks for the tip..

I don't do this very often. But when I have I have spent time trying to pry the heads out enough to get a jimmy on them. broken pallets and a fair bit of effort was the normal result. This way seems so much easier and better and simple especially as I have a chunky Bosh reciprocating saw and didn't think of using it... Thanks for the tip..

• informative post thanks. You love what you do which is always a good thing. I wondered if you'd have any ideas on a project I'm hoping to do. I want to build a fountain with maybe a 2meter bowl at the bottom then maybe a 1m bowl and 0.5m one on top with a stand between them. I can buy these sorts of cascade fountains if I had oodles of cash.. but as I haven't I'm thinking of how I could make one. The mould for those kind of sizes don't come readily to my mind..

informative post thanks. You love what you do which is always a good thing. I wondered if you'd have any ideas on a project I'm hoping to do. I want to build a fountain with maybe a 2meter bowl at the bottom then maybe a 1m bowl and 0.5m one on top with a stand between them. I can buy these sorts of cascade fountains if I had oodles of cash.. but as I haven't I'm thinking of how I could make one. The mould for those kind of sizes don't come readily to my mind..

• Nice I'ble thanks. I've been thinking of building one of these for a while.@ Mom33 please write an I'ble on how to mould the players at home..I'd be keen to find out how to do it an maybe combine the two....

• Maybe abit like Dobbie from Harry Potter?

Maybe abit like Dobbie from Harry Potter?

Though Dobbie Harry did have a song "I can see Clearly" ....

• As long as the float ,floats it will work in any density of liquid...

As long as the float ,floats it will work in any density of liquid...

If the float floats then it will work with that liquid. So potentially you could have a number of floats' n rods and adjust the effective density of the various floats by adding a grain of sand or two so that it sinks one specific density and floats in another. It wouldn't be a linear scale of density but could be used as a yes/No for a couple.

• Good project, Have you had it installed for long?The reason I ask is whenever I've used buzzers (particularly with sensors) it isn't long before they drove me nuts and got decommissioned. However, as your aim is to stop you leaving the room and locking yourself out then maybe a servo actuated door bolt would be more useful? You'd have to do it in a manner that could be easily overridden in case of fire or hardware failure but a simple spring-loaded deadbolt would prevent you leaving without swiping. A downside is you'd also have to swipe to let someone in but I guess that's preferable to getting buzzed as you move near the door.

• perfo commented on TheSuperSewcio.'s instructable Drawing Plotter

Nice Build..Maybe a metal table and a magnet on the pen holder to make sure it retains a bit of force against the page ? I guess spring loaded could also work . Better still a return spring and an electro magnet you'd be able to pen up/down very quickly with a reliable repeatable force on the pen...

• I haven't tired it yet but yes it is very much possible. It is just about getting the right power and type of transducer. For example if your tank is insulted (acoustically speaking) from the surroundings you can bash it with any object and it will ring with a certain frequency . The frequency will change depending on how full it is. So this should be equally possible with a controllable exciter but ultrasonic or not I'm not sure...

• Do you only need this to get in and out of your car ?If so it seems to me that you maybe able to rig up a charger using the weight of the car. So that every time the car drives over a board. Using a few pulleys etc it lifts a weight that then slowly falls charging the batteries. Maybe a big air bag under a flap and the air bag pushes a piston up a pipe that then falls.. Anyway the idea is use the huge weight of the car every time you drive in and out...

• Nope, as long as the rotation speed remain somewhere near constant then it doesn't matter is there is a slight delay. In fact by altering the delay you can make the image move around the globe.. triggering earlier to make it rotate clockwise and later for anti clock (or visa versa) .. the important thing about the sync is that it is consistent which I believe the reed will be.. Of course optical pickups etc etc can all be used but a lot of folk use commutators and the reed isn't going to be worse that that and in my opinion is quite a bit better.. a pick up on the equator obviosuly gives you more resolution..

Reed switch does a good job for a sync pulse.

Great I hope you will post the results

Nice project. I like POV stuff. I had a thought. If you mounted all your electronics inside the rotating ring and put a magnet or two near the axis (on the stationary part) and a coil to pick up the field as it went past you could make a self contained self powered (minus the main motor) display.. Spin it up and it would start generating the power needed to drive the leds.. another way would be to use a pedal bike type dynamo as your top axis / bearing of the disk ..

• Nice, thanks for the instructable.Out of interest an old Desktop PC power supply (ATX or other) can be had for near nothing or about £10 brand new in the UK these can provide a fair bit of current.If you get hold of a cheap ammeter (moving coil type will do) and put it in series with your supply. Whenever you find the right spot for the croc clip to cut whatever then mark it on the ammeter so you can get repeatability and fast set ups.. I need an instructable on how I can get my workshop to look as organised and clean as yours :-)