WED Treadwell Motor System

[Dunkles]

Hello everyone, i am currently working on building a WED Treadwell droid, i have the basic materials for it, but i have no idea what kind of electronics i should buy. when it comes to anything with wiring or motors or anything like that i'm clueless, so i was wondering if anyone has like a diagram of how to wire the base of a Treadwell, and what type of equipment i should use, i think i need like, 2 motors, batteries, a transmitter, controller, and mabye a gearbox? I'm building the bot 1:1 scale, so i will be using the plans from this site (thank you) but like i said, i have no clue where to start with electronics, i just need it to be able to turn, go forward and backwards. thank you everyone for your help.

-DUNKLES

[kresty]

I'm not sure if there are specifics for a Treadwell. I, personally, would hook up two "scooter" motors running @ 12 volts, one to each track. Presumably they would need to be geared down a little. Since I used chains on Artoo's feet, I might do that. How big at Treadwell's wheels? Similar gear ratio might be appropriate.

I'd use a cheap transmitter that can do V-tail, and hook it to a couple Pololu simple motor controllers. IIRC the motor controllers have a regulator, so you could use one (not both) to power the receiver (to bump it down from 12V). Or you could use a separate receiver.

We have a wiki page about R/C http://www.rebeldroids.net/wiki/index.php?title=R/C and R/C for tank drives http://www.rebeldroids.net/wiki/index.ph...=Turnigy9X

[savagecreature]

Thorne knows a lot about powering robot chassis's much like a treadwell. I'll ask her to post and see what she suggests

[kresty]

Thorne knows a lot about powering robot chassis's much like a treadwell. I'll ask her to post and see what she suggests

Well, there's a name I have not heard in a long time...

[Dunkles]

Thorne knows a lot about powering robot chassis's much like a treadwell. I'll ask her to post and see what she suggests

Thank you very much, i await her response.

[Dunkles]

I'm not sure if there are specifics for a Treadwell.  I, personally, would hook up two "scooter" motors running @ 12 volts, one to each track.  Presumably they would need to be geared down a little.  Since I used chains on Artoo's feet, I might do that.  How big at Treadwell's wheels?  Similar gear ratio might be appropriate.

I'd use a cheap transmitter that can do V-tail, and hook it to a couple Pololu simple motor controllers.  IIRC the motor controllers have a regulator, so you could use one (not both) to power the receiver (to bump it down from 12V).  Or you could use a separate receiver.

We have a wiki page about R/C http://www.rebeldroids.net/wiki/index.php?title=R/C and R/C for tank drives http://www.rebeldroids.net/wiki/index.ph...=Turnigy9X

thank you very much for this response! this is the most information about the treadwell i've ever gotten, but i still have a few questions. would i hook up 2 pololu controllers together, with them both connecting to a v tail transmitter, then have a receiver connected to 12v batteries and the two motors (which would probably be geared down with a 4/1 gearbox ) and have the batteries connected to the motors as well? i'm sorry for all the questions, i have no problem building things, i'm relatively good, but i am absolutely clueless with wiring and electronics, i thank you very much for your help again. thanks for all responses

-Dunkles

[kresty]

I'm not sure if there are specifics for a Treadwell.  I, personally, would hook up two "scooter" motors running @ 12 volts, one to each track.  Presumably they would need to be geared down a little.  Since I used chains on Artoo's feet, I might do that.  How big at Treadwell's wheels?  Similar gear ratio might be appropriate.

I'd use a cheap transmitter that can do V-tail, and hook it to a couple Pololu simple motor controllers.  IIRC the motor controllers have a regulator, so you could use one (not both) to power the receiver (to bump it down from 12V).  Or you could use a separate receiver.

We have a wiki page about R/C http://www.rebeldroids.net/wiki/index.php?title=R/C and R/C for tank drives http://www.rebeldroids.net/wiki/index.ph...=Turnigy9X

thank you very much for this response! this is the most information about the treadwell i've ever gotten, but i still have a few questions. would i hook up 2 pololu controllers together, with them both connecting to a v tail transmitter, then have a receiver connected to 12v batteries and the two motors (which would probably be geared down with a 4/1 gearbox ) and have the batteries connected to the motors as well? i'm sorry for all the questions, i have no problem building things, i'm relatively good, but i am absolutely clueless with wiring and electronics, i thank you very much for your help again. thanks for all responses

-Dunkles

A receiver for an R/C toy expects 5V or 6V, so you can't hook them up to a 12V battery directly.  R/C cars use a "BEC" (Battery Eliminator Circuit - which converts the motor's battery to 5 or 6 volts for the receiver.  (Way back when they use to have a separate receiver battery). 

Robots tend to have different motor controllers, so they'd need a voltage regulator to go from 12V to 5V - sometimes those can be built-in, sometimes they're separate components.  12V +/- wires goes in from the battery, and 5V +/- wires go out to the receiver - https://www.pololu.com/category/131/step...regulators has a big list, you'd want at least 12V in and 5V out.

Then, separately, 12V + and - go to the motor controllers (you'll need two controllers for two motors, or a dual controller that powers two motors), and then the two wires to the motor itself from the controller.  The motor controller probably needs to be able to handle 4+ amps.  https://www.pololu.com/category/94/polol...ontrollers the 18v7 would probably work (two of them)

[Lichtbringer]

As this is in fact more of a strange looking tank than really a robot, i would suggest to look for advice from the big RC tank builders (not sure about those that build and modify the Heng Long type).

They should have experience with the way to do the RC, and also with gears to slow it down (if needed).

[kresty]

Hmm, I didn't consider that since we use the 2nd stick for domes on astromechs, however you could do a dual-stick drive where each stick independently drives that related track.  (Doesn't really impact the wiring if you used the Pololu motor controllers, though you'd want to find an R/C controller that didn't return one stick to center).  The FrSky Q X7 has dual centering sticks (you can remove springs if you want airplane type sticks.)

One big difference between our builds and most R/C builds are that R/C kits are usually vacuformed or other lightweight parts.  We tend toward wood and heavier construction.  (In other words you might need bigger motors).  That said, we drive our mouse droid from a 12V R/C motor, and more normal R/C motors might be able to be used if the build is light enough.  (Our mouse droid is 20lbs and seems to do OK with that motor.  A lighter mouse droid is OK with the 9.6V motors.  Our Lego R2 is 60lbs+ and I wouldn't want to try him with anything less powerful than the 100W Scooter motors).

Also check out the robotics sites for tracked robots, which are reasonably popular.  Purpose built robotic stuff might be pricier than DIY mounts, and probably aren't the perfect size for a droid build - but they can probably give reasonable ideas about how other folks have done tracked vehicles.

[savagecreature]

These are nearly identical to the drive systems we use for the competition bots. Thorne has just been very busy with work and holiday stuff. I'll poke her again about posting tonight and see if we can get a response.