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Simple position servo drive for your encoder motors


#1

Hi,

How cool would it be to have a simple closed loop servo drive for your encoder gear motors. I can’t imagine how many more applications can be accomplished with this type of product. I currently am using many of your encoder gear motors for projects, however I have to jump through hoops to purchase a driver that was designed many years ago but works flawlessly, but hard to get. This would be a great addition to your product line. Here is a link to what I am currently using. Try finding something that even comes close on the world wide web. You should be making this…
imsrv.com/deskcnc/servospecs.pdf

People could be using closed loop servo instead of steppers for so many projects and simply use the same step and direction source they are currently using, but have a close loop system instead. Jeez, how hard could this be for an outfit as talented as you. Your jk drives come close, but not quite the same thing.

You can do it Pololu, and I will bank on a HUGE success for this product. Just reading your forum, and others, so many people would benefit from something cost effective like this!!!

Like Nike says, Just Do It. You might be surprised.

Thanks

Jim

P.S. Here is a video of your encoder gear motors being used in a vending machine project using position servo drives.

youtu.be/EZ1hDXe-epU

And another showing simple position control again using your encoder gear motors.

youtu.be/cmpqfwz93vE


#2

Hi, Jim.

Thanks for the suggestion (and enthusiasm!). Making a version of our jrk motor controllers that supports quadrature encoder feedback has been on our to-do list for a while, and I think it must be pretty close to the top by now (although I probably felt that way three years ago, too). We definitely take your encouragement to heart, enough to feel newly saddened that we haven’t made it yet.

- Ben


#3

Hi Ben,

Don’t be sad (or saddened), be glad. A little pic, a little pid and you’re there man. You guys are so close to having a complete solution by including position control. I have used your jrk boards for several projects and they work great. This would be the missing link for sOOOO many projects that I read about on this forum and many others. You would be on the forefront if you had this product. I wish I had the half the knowledge you guys have and a bigger wallet, I would do this myself. But you don’t have any excuses. Everything you sell, works so well but when this one thing is missing from a stellar product line, it might be time to pull the cord. I can’t wait to see a separate thread to this forum from people that dig cnc, robots, etc. that would wreak of “holy crap, it’s about time… I can’t believe how easy it was to make this and that… Thank God, Pololu finally brought this to market… etc. etc. etc.” Please take this into major consideration. NOBODY has this, and it is in demand when people realize you sell it. The next best thing ANYWHERE on the web is the gecko 320x, which runs 20 amps at 80 volts. Way overkill for your encoder motors.

Thanks for reading……


#4

I heartily second that suggestion. Way overtime for such a product - in fact I’ve been working on and off on a program to emulate the LM628/629 motor control chips, which were an industry standard for some time. But with that approach, you need two separate micro + driver boards for each motor.