Comments on: Turn any motor into a servo with RepRaps new board

By: lonnie

lonnie — Sun, 06 Mar 2011 06:16:00 +0000

will this work to make a 12v windsheild motor as a steering servo on a 1/4 scale r/c car ? thanks

By: strider_mt2k

strider_mt2k — Thu, 17 Jul 2008 17:23:24 +0000

Consider for a moment that your new powerful servo could also be used to run the steering of one of those powerwheels vehicles as well!

Person weight translates wonderfully into payload weight on stuff like this.
I've got my eye on a scooter like an older or disabled person would use right now for that very reason.

My initial experiments with building my own wheeled rov included using a powerful gear motor for the steering of a two-seater barbie jeep. (painted primer grey of course) pink wasn't gonna cut it.

Mine wasn't as refined as to use any feedback, I just built everything up to withstand jamming all the way towards one side or the other and kinda just winged it with the RC control to steer it, but it worked.

Oddly what made me give up on it as a platform wasn't the steering, but the lack of traction with those stupid plastic wheels, even when modified.

I wanted my rov to go into the woods and such, which a differentially steered vehicle is much better suited for anyway.

For on the street, or on grass a powerwheels vehicle would probably be ideal, and as stated would be a VERY inexpensive proposition.

By: miked

miked — Thu, 17 Jul 2008 16:49:01 +0000

>Now, the motors in a powerwheels

If you keep your eyes open when driving around you will probably see a dead one on curb. a quick craigs search shows a complete working one for $25

By: Eric

Eric — Thu, 17 Jul 2008 12:23:16 +0000

Oooh. gear motor servo. Me likey very much. You win.

By: strider_mt2k

strider_mt2k — Thu, 17 Jul 2008 07:56:00 +0000

wolf has the right idea.

turn a _gear_motor_ into a servo.

awesome

By: Wolf

Wolf — Thu, 17 Jul 2008 01:33:53 +0000

Wheel chair motor servo’s anyone?

By: Eric

Eric — Thu, 17 Jul 2008 00:57:46 +0000

An actual servo versus a simple DC motor with a rotary encoder attached are two VERY different things.
Don’t get me wrong, I think this is a neat and very useful device, and for many things we would use this for either one may work interchangeably to some degree. To say they are the same thing however, or that they can DO the same tasks is overstating things by more than a little bit.
BTW, for cheap powerful DC motors, including treadmill motors, try http://www.surpluscenter.com, they always have some great random crap.

By: anthony

anthony — Thu, 17 Jul 2008 00:32:55 +0000

steve: Yeah. 8+ hp motors are bloody expensive, but ever see how much an 8hp servo would cost? Are they even avilable?
If you hooked the right AC controller board up, you should be able to use this to control AC motors (probably not worth it…)

By: ritsuki

ritsuki — Thu, 17 Jul 2008 00:04:25 +0000

now if only all my motors werent ac…

By: CalcProgrammer1

CalcProgrammer1 — Wed, 16 Jul 2008 20:23:34 +0000

Treadmills have powerful DC motors. You can get used ones at yard sales for cheap (haven’t bought any but my parents have sold 2 old ones that the motors were starting to go bad on, though still worked, maybe would need new bearings or oil or something).

By: Jasper

Jasper — Wed, 16 Jul 2008 20:11:04 +0000

I foresee many cordless drill servos.

By: ridefst

ridefst — Wed, 16 Jul 2008 20:05:29 +0000

This is new?
I thought that using a separate encoder and motor was common practice my now?
This is a good price break compared to commercial encoders, but I thought the general concept had been in use for quite a while.
At any rate, open source + cheap kit still makes for a good post :)

By: steve

steve — Wed, 16 Jul 2008 19:25:43 +0000

I hate to be a naysayer but big DC motors are not cheap. especially ones in the 8hp range (a few hundred bucks at least.) an automotive starter motor would be cheap but they are easy to burn out if you run them for to long. also the Tesla roadster uses a 3 phase ac motor why do you think it’s named after Tesla? he hated DC motors (and Edison.) Tesla invented the AC induction motor which is still the most efficient form of electric motor. these things aside I think this is still awesome. it makes small to mid sized servos much more affordable. I might just buy one of these.

By: Alexander

Alexander — Wed, 16 Jul 2008 18:45:37 +0000

Twisted: Yeah, but it’s not designed for continuous use.

Now, the motors in a powerwheels… Yeah. Those are some beefy motors. And rated for continuous use. :P

By: Andrew Pollack

Andrew Pollack — Wed, 16 Jul 2008 18:00:57 +0000

Cool. Now, where’s that phone number for the Tesla parts line…..I’ll bet they’ve got some good ‘lectric motors around…