DIY Servo motor controller

posted Nov 1st 2007 2:11pm by Will O'Brien
filed under: robots hacks

[Jim Fong] sent in this demo of his version of the UHU servo motor controller. [Uli Huber] has actually shipped over 2500 controllers for the servo. He doesn’t charge much for the chips, and only asks for something like a token beer in return for his work. I used [Jim]s boards in my mini mill controller, so I know he does good work. This servo controller really is a big deal. It can handle high power, and servo motors are *the* way to build a fast milling/robotics setup.

If you’re into Cons, you might be interested that the first round of Shmoocon tickets went up for sale today - looks like they’re already out, so keep your eyes open if you want to go. It’s a decent con that takes place in DC. I know that I’m planning to be there.

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Comments [11]

Reader Comments

That’s pretty stylin’.

Posted at 5:13 pm on Nov 1st, 2007 by Johnny B. Goode

am i trippen balls or is that cnc mill a sign from god i wan just about to order some expensive as shit parts to build my own thx so much for saving my ass peace out

Posted at 6:17 pm on Nov 1st, 2007 by Alex McCown

By servo here do they mean stepper?

Posted at 7:57 pm on Nov 1st, 2007 by kcbanner

[3] no. A stepper motor is an open-loop system, which means there is no position feedback. You can lose track of position if you push it too hard. A servo system is CLOSED loop: there is an encoder that keeps track of rotational position. Steppers are simpler and cheaper. Servo motors are less cheap, but can really fly.

Posted at 8:15 pm on Nov 1st, 2007 by MacMarty

Very nice… I have been looking to start playing around with servos. kcbanner… servos and steppers are two different beasts. A servo is basically a DC motor. A stepper is a motor that takes incremental steps.

Now… lets see it play music!
http://images.myonlinesite.com/cnc/use/20070830/videos.html

Posted at 8:41 pm on Nov 1st, 2007 by Adam Ziegler

That was very cool. If I might make a small suggestion, it would probably be useful to attach the suction right to the cnc mill.

-Crystal

Posted at 9:25 pm on Nov 1st, 2007 by crystal amaia

I have seen mentioned a few closed loop stepper systems (encoder added)

Posted at 11:00 pm on Nov 1st, 2007 by Adam Ziegler

I couldn’t find exactly how many motors one board can control … is it one or two?

Posted at 9:23 am on Nov 2nd, 2007 by Nate

Don’t servo’s use stepper motors along with encoders?

Posted at 9:38 am on Nov 2nd, 2007 by jimdandy

Crystal (post#7)–

I just finished the cnc conversion over the weekend and haven’t had a chance to add a vacuum attachment to it yet.

I have another cnc mill that uses a locline vacuum attachment http://www.embeddedtronics.com/micromill.html.
I might use the same concept for the gantry mill.

Nate (post#8)–

Each servo driver board is for one motor. You would have to build three of them for a 3 axis cnc mill.

Jim

Posted at 9:39 am on Nov 2nd, 2007 by Jim Fong

Servo motors do not use steppers with encoders.

Servo’s use standard DC motors (or brushless) with an encoder on the back. Or a pot that tells the motor how much it has left to turn.

Posted at 4:31 pm on Nov 2nd, 2007 by Alexander