Ai Dreams Forum

Robotics => Home Made Robots => Topic started by: ranch vermin on June 05, 2018, 08:44:13 pm

Title: absolutely nothing motor controller
Post by: ranch vermin on June 05, 2018, 08:44:13 pm
(https://scontent-syd2-1.xx.fbcdn.net/v/t1.0-9/34669858_667087356972658_8352558806181347328_o.jpg?_nc_cat=0&_nc_eui2=AeFEIg9seydyo86oUugH63q9OtSgP41ATDvlXXIiIMsa_XPoBM2UxvtqYdL8P3aFrOjG27jCFcE8mqRMs-gekY-1-1S1BoSMGfEXOSdg5DxgxA&oh=3f4dffb5740a0db41824de14cbade5f8&oe=5B8267CC)

Ive got this hooked up to a linear drive,  its not quite working yet, but im closest ive been for a while,   i think my theory is right, i just cant get it to work because it just takes so long to get things running for real, so much goes wrong and wires are so confusing to me still.

This circuit can be upgraded with transistors (guns :-)) in a h-bridge type setup to get less waste away from the motors - but still retain the absolute positioning.
It should be very accurate, just the circuit sans the machine,   i bet this circuit upgraded could step nanometres, electrically controlled.
Title: Re: absolutely nothing motor controller
Post by: Art on June 05, 2018, 10:34:05 pm
Hmm...I think I asked you not to talk about me that way...
"Lacks power but simple", really?!  :2funny:
Title: Re: absolutely nothing motor controller
Post by: ranch vermin on June 06, 2018, 08:44:23 am
No way Art, your special to me.  =)
Title: Re: absolutely nothing motor controller
Post by: Korrelan on June 06, 2018, 12:58:08 pm
Hi Ranch

Have you burnt the two potentiometers out yet lol.

 :)
Title: Re: absolutely nothing motor controller
Post by: 8pla.net on June 09, 2018, 01:35:06 am
Simple is good.
Title: Re: absolutely nothing motor controller
Post by: ranch vermin on June 09, 2018, 08:01:33 am
Hi Ranch

Have you burnt the two potentiometers out yet lol.

 :)

Nah thats old news, I did that ages ago :)   I killed em on the first day I got them  ($24 down the drain.)   your right of course.  got to be careful,  all my transistors are blown too. hehe

I actually use toaster wire for it and my own brushes,  but the problem is its not resistive enough.
Im pretty sure it works,  the easiest setup (which is even simpler than this)  is power left motor left pot, power right motor right pot, and my pully string has a tug of war,  its just my big problem is i have to get the amount of ohms on the pot to dissipate all the watts, or it just loses it as constant bias against itself.  (it took me 4 weeks to work something so simple out,  i think its the cigarettes.)

One thing id like to say about "pully wire systems" is they work pretty good pretty much first time,  just get some proper superglue (bostik is good, in australia.  if u superglued your hand to the table with it, you have to chop a block out of the table to get your hand off.)   you can superglue some fishing line, which is pretty tough, and then it just winds easy after that, i find they dont even have to be neat as long as your battery is strong enough to get through the viscocity. they were the least problem of the linear drive setup as long as you brace them properly, and they act as a anti-clockwise, clockwise to always clockwise converter,  because it doesnt matter which way you wind, they always pull.

But the good news is, I actually got something to work!!!
https://www.youtube.com/watch?v=Vt4avBzSgTg&feature=youtu.be



8PLA,  the other alternative is the H-BRIDGE (potentially resistors diodes and transistors all over the place and takes ages to put together).  and all the methods that power motor involve getting some loss of your energy, and the most complex systems deliver 100%,  but its hard to get it perfect. 

Thanks :).   dont worry ill get there in the end.  As I see it currently,  a robot is a bit like a fuse box to a house, one receptacle per motor in the body.    So concatenating the design is possible, and thats what I want to do,  because of fuse boxes can get more and more complicated the more tricks they put into them,  but its actually not mandatory, if u want to keep things simple, as long as you know what your doing.
Title: Re: absolutely nothing motor controller
Post by: ranch vermin on June 09, 2018, 09:28:54 am
heres the expected full concatenated circuit,  its very simple.

(https://scontent-syd2-1.xx.fbcdn.net/v/t1.0-9/34779981_669100353438025_4926864531222691840_n.jpg?_nc_cat=0&oh=d0ca45f6a9b794410e5935e4167e8a9a&oe=5BAC2317)
EDIT - X no Ive done it wrong...  woops....

(https://scontent-syd2-1.xx.fbcdn.net/v/t1.0-9/34872817_669106553437405_6906137494471835648_n.jpg?_nc_cat=0&oh=f5a1cc1f65ce874f1cda09eb94b21319&oe=5B772C74)
Title: Re: absolutely nothing motor controller
Post by: Art on June 09, 2018, 02:00:40 pm
Looks as if this setup will be good for lighting one of your cigarettes.

OH yes...Do get a bottle of Nail Polish Remover (acetone) and keep it nearby for those "Superglue accidents". ;) O0 ;)
Title: Re: absolutely nothing motor controller
Post by: ranch vermin on June 09, 2018, 03:28:16 pm
yes they do glow when the watts is up,   i need to get something better thats more resistive.
If i just want 16 positions, I can just chain up that many resistors,  but i was exploring getting a fluent value, for attempting to get micromovements.
Title: Re: absolutely nothing motor controller
Post by: Korrelan on June 09, 2018, 04:43:39 pm
No... No... And thrice no... Lol.

Acetone is extremely flammable. Don't put it near that circuit, perhaps a fire extinguisher too lol.

I do admire your 'inginuety' and hate to be the bearer of bad news, but that circuit ain't ever going to work Ranch.

 :)
Title: Re: absolutely nothing motor controller
Post by: ranch vermin on June 09, 2018, 05:04:37 pm
no hurt feelings. :)   im just on my little learnin' journey, the same as everyone here on earth.
oh well at least my little motor oscillator hack worked.

Korrellan - what do ur circuits look like?  I know that you get your hands grubby in the hardware,   you should post an electromechanical thread.   
Id love to see your take, i promise ill be respectful.  :)
Title: Re: absolutely nothing motor controller
Post by: Korrelan on June 09, 2018, 06:21:57 pm
Your post 666...

https://www.youtube.com/watch?v=7-iRf9AWoyE

I will reply in a mo...

 :)
Title: Re: absolutely nothing motor controller
Post by: Art on June 09, 2018, 06:31:59 pm
The acetone was for removing stuck fingers from whatever they might be or have been Super Glued to...Not for use in or near a live electrical circuit. Likewise, no smoking should also be the rule when near Acetone or other flammable substances. I should not have to say that.
I thought that would be implied, then again, McDonalds has a label on the side of their coffee cups, "Caution Contents is Hot!"
This is due to an Accidental Spillage of a cup of Hot coffee in a lady's lap while driving her car. Like people need to be told that freshly served coffee is likely to be Hot! Oh well. Ya live and ya learn...at least some do. O0



Title: Re: absolutely nothing motor controller
Post by: ranch vermin on June 09, 2018, 09:24:41 pm
how longs a mo im still waiting!
Title: Re: absolutely nothing motor controller
Post by: Korrelan on June 09, 2018, 11:12:30 pm
@ Art

I wrote that in a hurry on my phone… I hate typing on my phone.  I understood your acetone reference; I was just making sure Ranch knew it was highly flammable lol.

I acquired some new storage boxes today… this sticker made me smile.

(https://i.imgur.com/O30jwOX.jpg)

@ Ranch.

Soz for the delay… things keep interrupting me lol.

In my past I have done quite a bit of electronics design… yeah quite a bit… lol. 

I used to build my own control gear, but these days there is just no need.

If its pneumatics, hydraulics, DC motor, servo, stepper, ADC, DAC, timers, etc there are loads of pre-designed boards available.  You just plug them up and write the control code.

https://www.phidgets.com/?tier=0&catid=0&pcid=1

I’ve used Phidgets for loads of projects. 

 :)

Ed: If you require a simple method to control a DC motors speed try using a triac. 

https://www.electronics-tutorials.ws/power/triac.html

Though this won't give you proportional feedback.  About the simplest proportional circuit uses a NPN/ PNP transistor gate arrangement.  A simple LM741 OpAmp drives the gate. (not my design).

(https://i.imgur.com/NUfCnVm.jpg)

 :)
Title: Re: absolutely nothing motor controller
Post by: ranch vermin on June 10, 2018, 11:29:42 am
I think I can sorta see how it works.  (im hopeless at it tho.)
thats cool use of a ground, being able to go to and from it, from the + and -,  is that why its called a triac?   because it uses +, - and ground?

Does this triac spin,  or does it actually rest a motor at a position?  I cant tell.

Doesnt look over complicated,  I probably prefer this to a H-bridge.
Title: Re: absolutely nothing motor controller
Post by: Korrelan on June 10, 2018, 12:07:09 pm
You can think of a triac as a kind of high power bi-directional transistor or an analogue relay. It will handle large loads and is designed for accurate current regulation. 

The second diagram does use a split power supply to enable the geared DC motor to reverse, and the LM741 is acting as the voltage comparator.

https://www.adafruit.com/product/2591

Its worth investing in a decent breadboard/ prototyping board if your really going to build your own circuits… makes life much easier.

https://en.wikipedia.org/wiki/Breadboard

If you are not using pre-built USB control boards, you are still going to need some method to get the control voltages/ codes/ instructions out of your computer.

I’ve used simple LDR’s before, you place a strip of LDR’s across the bottom of your monitor and by simply altering the brightness of the pixels under the LDR you can control motors, relays, etc. It also obviously provides optical isolation of your project. Simple LDR circuit…

(https://i.imgur.com/KwA0uNF.jpg)

The Light Detecting Resistor (LDR) just changes resistance depending on the level of light falling upon it, this alters the + at the base of the NPN transistor, which is balanced (biased) by the pot to negative.  The load/ LED can be swapped for a relay etc.

These are very handy bits of kit... 16 outputs and 16 inputs...

(https://i.imgur.com/NTexV7E.jpg)

https://www.robotshop.com/uk/phidgets-1012-sensor-interface.html?gclid=EAIaIQobChMIlJvNuYPJ2wIVSr7ACh3MTAU7EAQYASABEgL1OfD_BwE

 :)
Title: Re: absolutely nothing motor controller
Post by: ranch vermin on June 10, 2018, 12:20:31 pm
As I see it,  apart from the battery/power source, a robot is a framework/skeleton + powered joints + motor drivers + brain/computer.

So we were talking about motor drivers here.

How have you handled the powered structure that contains the circuit.

What im planning on doing,  is making 4 dc motor cross junctions (for x and y freedom), then connecting them with double sided half rings (which hurt my angular freedom a bit.) then connecting these together with pipes.

(https://scontent-syd2-1.xx.fbcdn.net/v/t1.0-9/35055614_669745170040210_6267412970645487616_n.jpg?_nc_cat=0&oh=5e417f53ecf3246d9dfb89c1fc7b1e00&oe=5BAB3C1D)

All I have is solder to connect things together, and im stuck where to find these half rings I need, which slide over each other.

But I want to solve the whole robot with one kind of connection, im too lazy otherwise.

Title: Re: absolutely nothing motor controller
Post by: Art on June 10, 2018, 03:52:53 pm
Kind of looks as if you're describing a "Universal universal joint".
Imagine if we had articulated cars like some construction equipment.

Are you thinking of these joints for wheeled, tracked or legged robotic applications?

@ Korrelan - I wasn't pointing at your comment, just on basically how society has adjusted and dumbed down warning labels and other notices in general out of fear of lawsuits or other threats. Common sense has left the building, better yet the planet!
Coffee is hot - Why?
Ice is cold - Who would have thought?
Flammable liquids are flammable - Imagine that!
Electric circuits can shock or electrocute you! - Hmm...really?
Slippery when wet - Ya think?
Small pieces and plastic bags can become choking hazards if left near an infant and irresponsible parents or guardians!
Come on people!

Just venting a tad...been a rough week.
Title: Re: absolutely nothing motor controller
Post by: ranch vermin on June 10, 2018, 05:04:18 pm
dont put your baby in the tupperware.

on my body work->  (and the universal joint)
Its for an X-walker, of course.  and its for every joint of it, yes,  UUJ.  I guess its why they call them universal because they can be used by themselves for a robo. it turns out mine is going to be pretty big, i wonder if the motors can lift it?  or i need longer and thicker ones.

https://www.youtube.com/watch?v=VfZLozYET-4&feature=youtu.be

Title: Re: absolutely nothing motor controller
Post by: Art on June 11, 2018, 12:20:57 am
If that guy in the video was you then I really liked the design. I did leave a comment as well.

Don't forget about PVC, Aluminium in both round and/or square tubes. Lastly you might run across some carbon fiber tube sections.
You can also use channels with back to back or front to front with two sections of flat bar along each length.

The Plastic / PVC might serve as a good prototype because it's easily obtainable, cheap and the sections can be easily cut and connected/glued.

Some more wood for the fires in your mind. Do I smell smoke? Hehe... O0

Keep working it!
Title: Re: absolutely nothing motor controller
Post by: 8pla.net on June 11, 2018, 12:31:01 am
Seems more understandable drawn by hand.

Title: Re: absolutely nothing motor controller
Post by: ranch vermin on June 11, 2018, 12:41:36 am
Thanks alot Art,    now im getting nervous. :)

Yes, i saw a few PVC robots on U-tube,   devious idea.
Ill settle on something,  just need a bit of time.

8PLA->
For the simplicity of doing it that way,  kinda -> "sans motor controllers"
I have to sacrifice power to get it,  im not getting the full delivery of the battery,  thats why using a well crafted transistor circuit makes it more efficient to the power source,
so I have to start from a hotter beginning.
Im just off to the shop to get a better range of resistance to finally nail it...  and ill post the vid here,  maybe later on today.  I just have to make it to the electronics store and im getting a pack of high watt resistors better suited to the job and order 20 more dc motors,  cause ive ruined alot of them and i had too many delays, even just to get to here.

I think its going to be pretty sharp and fast,  even tho its actually a log action how the motor changes its position,  just depends on how much power i give it.

(on the computer communicating with it. - like that card Korrellan showed.)
I have a "pre brain" drawn up ready to go in too, cause the computer wont be in it at first, that remembers a programmed posture.
After that ill be finished stuffing around and ill go for the whole kaboodle again.  but, i bet there is going to be heaps more problems.
Title: Re: absolutely nothing motor controller
Post by: ranch vermin on June 13, 2018, 02:24:51 pm
https://www.youtube.com/watch?v=_UIYXB5e1jY&feature=youtu.be
Title: Re: absolutely nothing motor controller
Post by: LOCKSUIT on June 13, 2018, 03:20:45 pm
WHAT, IS, THAT THING!?

Lol omg that is so cool.

What is the thing levitating doing? And is this the hard drive thing or your main robot project?...
Title: Re: absolutely nothing motor controller
Post by: ranch vermin on June 13, 2018, 03:28:51 pm
;D

little baby steps im slowly getting there.

It looks way too overcomplicated compared to what its doing,  theres wires all over the place on it,  but all it is mostly, is a "multitap resistor" so i can get the varying resistance i need - to send the tab left and right.

I think for certain now,  theres not going to be a single transistor in my circuits,  as long as i have my capacitors, resistors and my devious RC oscillator to go with them,   i wont need a transistor ever again.   just to put a bit of personality into my circuits.  8)
Title: Re: absolutely nothing motor controller
Post by: LOCKSUIT on June 13, 2018, 03:33:53 pm
Not sure just a guess but what about a hydrolic pump motor that slowly pushed a rod out left/right/left/right very small amounts in change? 3 of them woul also allow 3D position in anywhere of a 3D box.
Title: Re: absolutely nothing motor controller
Post by: ranch vermin on June 13, 2018, 03:50:06 pm
yep.   thats basicly what this thing is,   its 1 dimension of a 3d printer.   You can do it hydrolicly too yes,  maybe hydrolics has some advantages.

So im off to the shop again tomorrow with my resistor adjustment,  then ill scoop all the resistors off the board and replace and rewire them all and hopefully this thing will finally work.
Title: Re: absolutely nothing motor controller
Post by: Art on June 13, 2018, 05:43:08 pm
Hydraulics like steam are extremely powerful but the downside to both is that they generate a LOT of Pressure and Heat. After all, hydraulic pistons rely on pumps to push a liquid through a cylinder be it hoses, tubes or valves. That pump requires a motor which needs to be on whenever the pump is actuated (in most cases - thinking pressurized reservoir). So the Motor and Pump both generate heat which needs to be properly dissipated or vented. Not saying that small hydraulic pumps can't work in robotics they just might not prove to be very practical. Steam, on the other hand, would likely win you a big prize at the nearest Robotic Steampunk Convention!! LOL!

Some experimenters have also tried using pneumatics which is like a small air pump pushing a volume of air through valves, tubes, and cylinders.  I'm just not a big fan of that Whoosh-pop sshhhh...noise every time something like an arm or leg moves. Then again that's just me.

There's always outdoor SOLAR robots that work well on sunny days! OK Kidding here a bit!

There are many robotics sources for parts, controllers, batteries, etc. all over the net.

Lots to choose from.
Best of luck in your endeavors O0
Title: Re: absolutely nothing motor controller
Post by: LOCKSUIT on June 13, 2018, 06:05:21 pm
So it's a Turing tape?
Title: Re: absolutely nothing motor controller
Post by: ranch vermin on June 13, 2018, 06:45:41 pm
Hydraulics like steam are extremely powerful but the downside to both is that they generate a LOT of Pressure and Heat.

Heats usually a bad thing,  but pressure is what you want.   its "pressure" that pushes your widgets and things around.

Locksuit, it could be anything, its just a moving arm.
Title: Re: absolutely nothing motor controller
Post by: LOCKSUIT on June 13, 2018, 11:58:00 pm
Not sure tho still....

Is this a NEW hard drive invention....

or

a robot AI?
Title: Re: absolutely nothing motor controller
Post by: ranch vermin on June 14, 2018, 10:57:52 am
Not sure tho still....

Is this a NEW hard drive invention....

or

a robot AI?

Just do it for every axis of your robot,  and its the motor controller.    u can use it for anything, because robots take many forms,  a car is a robot, any machine is, if you want to look at that way.

Its its body,  not its brain,  But I have the most awesome idea for a brain!    but people wont even believe me, because everyone thinks we are on such clever stuff already ill keep it to myself. ;)
Title: Re: absolutely nothing motor controller
Post by: Art on June 14, 2018, 12:38:20 pm
Constructing a robot framework is really the "Easy" part...
After all, without a Brain, it's just a glorified Paperweight!  ;)


Title: Re: absolutely nothing motor controller
Post by: ranch vermin on June 14, 2018, 02:02:45 pm
Constructing a robot framework is really the "Easy" part...
After all, without a Brain, it's just a glorified Paperweight!  ;)

and let them all fail like the bible.   with great self appreciation of how s**t they are.

Who cares how many sensors the body has, if it cant even do the simplest thing.
Title: Re: absolutely nothing motor controller
Post by: Art on June 15, 2018, 01:16:09 pm
Sources for one's hobby/endeavor are always nice to have so I've taken the liberty to do a bit of searching in an effort to provide a few additional ones.

While this listing might be a mixed bag of tricks, there's sure to be something for everyone interesting in learning or experimenting with robots/robotics.

https://www.robotshop.com/ (https://www.robotshop.com/)

https://www.robotshop.com/en/robot-parts.html (https://www.robotshop.com/en/robot-parts.html)

https://www.amazon.com/Robot-Parts/b?ie=UTF8&node=8498889011 (https://www.amazon.com/Robot-Parts/b?ie=UTF8&node=8498889011)

https://www.superdroidrobots.com/shop/ (https://www.superdroidrobots.com/shop/)

https://hobbyking.com/en_us/3d-printing-diy/robotics-diy-kits/parts.html (https://hobbyking.com/en_us/3d-printing-diy/robotics-diy-kits/parts.html)

http://www.robotmarketplace.com/ (http://www.robotmarketplace.com/)

https://www.pololu.com/ (https://www.pololu.com/)

https://www.active-robots.com/ (https://www.active-robots.com/)

http://www.trossenrobotics.com/ (http://www.trossenrobotics.com/)

https://www.jameco.com/Jameco/robot/robotstore.html (https://www.jameco.com/Jameco/robot/robotstore.html)

https://www.vexrobotics.com/vexedr/products/accessories (https://www.vexrobotics.com/vexedr/products/accessories)

http://www.zagrosrobotics.com/shop/ (http://www.zagrosrobotics.com/shop/)

* Type in these last two then Search for 'Robotic Parts'
https://www.ebay.com/ (https://www.ebay.com/)

https://www.amazon.com/ (https://www.amazon.com/)
Title: Re: absolutely nothing motor controller
Post by: ranch vermin on June 15, 2018, 01:46:05 pm
I had a look,  and the motor connectors look interesting to me,    but someone just brought some tin snips around and now im going to make the brackets myself. :)
Title: Re: absolutely nothing motor controller
Post by: ranch vermin on June 15, 2018, 08:49:36 pm
Got a more solid prototype of the jointy done.

https://www.youtube.com/watch?v=hPF0qh0AeY4&feature=youtu.be

Title: Re: absolutely nothing motor controller
Post by: Art on June 15, 2018, 09:57:37 pm
Nice improvement over the paper one!

A true Universal joint as in a motor vehicle drive shaft would or should provide 180º of rotation. Affixing drive motors to the 4-way joint, however, might prove to be problematic I would think.  Then again it's your design!  O0
Title: Re: absolutely nothing motor controller
Post by: ranch vermin on June 15, 2018, 10:11:38 pm
Thanks art. :)

its shy off 180, its about 145?   because of the back bracing - but i need that because it would be easier to break it without it.  But i might regret that later,  im not sure about it.

This isnt the final one,  but its my first taste of using the nasty metal, i had a bit of a sick high after i got it done   :D

i cut myself a little bit but my friend had some sand paper luckily so i got rid of most of the burrs before i bent it into shape.

The new one is going to be much smaller radius and still keep the 145*.   if u notice there is a large radius outer ring, and a small lobe on the back, and it actually can be alot smaller than it is,  so im going to start again even better.


The next one, (version 3) is going to be mounted by a self tapping screw into the front of the motors, and that will be ALOT stronger than the crappy soldier job on it now

Also should have pipes bolted to it,   but im still not sure what to do with the cross fitting,  its still just a blob of solder.

Title: Re: absolutely nothing motor controller
Post by: LOCKSUIT on June 16, 2018, 02:39:05 am
So it has 2 motors (2 axises of rotation)?

How much did it cost to make that?

Because online I'm always seeing/hearing that arms with only like what 6 motors are over 15,000-80,000 dollars which annoys me because my logic tells me the Dollar Store has 1 dollar motors which makes NO sense whatsoever!! Lol.
Title: Re: absolutely nothing motor controller
Post by: ranch vermin on June 16, 2018, 01:02:22 pm
So it has 2 motors (2 axises of rotation)?

How much did it cost to make that?

Because online I'm always seeing/hearing that arms with only like what 6 motors are over 15,000-80,000 dollars which annoys me because my logic tells me the Dollar Store has 1 dollar motors which makes NO sense whatsoever!! Lol.

Its cheap (my one)  its $5 a hobby motor, they have "low torque" on the description for them.  Ill have to see how they go,  i havent actually wired it up yet - except that broken linear drive,  but on that they seem to be too powerful! :)   not sure, until i finish it for real!

I dont think i could stand on it, and ride off into the sunset, but im pretty sure itll be able to lift itself easily.

But those $80,000 arms your talking about are finished products,  so the price does go up for a full finished unit.  Its because its ready to go manufacture (if u know how to use them.) straight out of the box,  so the price would be higher.
Title: Re: absolutely nothing motor controller
Post by: LOCKSUIT on June 16, 2018, 02:00:49 pm
So if I want an arm with 6 motors (3 rotation, 3 location), how much could it cost if I have a freelancer make it? 1 8th the price?
Title: Re: absolutely nothing motor controller
Post by: ranch vermin on June 16, 2018, 02:11:11 pm
So if I want an arm with 6 motors (3 rotation, 3 location), how much could it cost if I have a freelancer make it? 1 8th the price?

Dont like your chances,  when I was on game programming forums people that tried to get people to code games for them didnt have much luck.  ;)

Your best bet is to get a 3d printed kit,  and go order a print done for you.
They dont print robots out in one hit yet,  you have to post assemble all the parts.


https://3dprint.com/106725/wednesday-roundup-ten-3d-printable-things-awesome-beginner-3d-printable-robotics-projects/   

theres a page,   they are a bit beginnery,  but it would be a good place to start your search.
Title: Re: absolutely nothing motor controller
Post by: 8pla.net on June 17, 2018, 11:47:29 am
Ranch said, "For the simplicity of doing it that way"
That way being the Engineering Design Process.

Good success is my prediction.  Thank you for sharing.

Just adding, the material (other than hand-drawn)
posted to this thread is quite interesting as well.

Title: Re: absolutely nothing motor controller
Post by: ranch vermin on August 19, 2018, 11:49:42 am
still... havent got it!!  im getting close tho.   so i have to add something more -  the side which is the target, has to be moving with the resistance, and the side which stands for the current position - should be going away from the resistance.

still no luck  - im getting close tho.