Mark, are you still working on this? Do we have a plan for a motor controller yet? I think the motor controller is the first thing we need to get nailed down. From what I understand it will consist of a microcontroller and some power electronics. The microcontroller will need to implement a motor control program which can receive commands from a PC, I'm assuming. I'm also assuming it will be based off G code.

Is anyone else working on the controller currently?

here are some links to some stuff..
http://reprap.org/wiki/Stepper_Motor_Driver_2_3
http://reprap.org/wiki/StepperMotor

unfortunately services performed for non profits are not tax deductible

I wasn't saying for tax deduction, the OSE isn't without funding, so they should be able to reimburse me for the purchase of assets for the exclusive use of the OSE.

That raises the question... As a donor I would like to see the financial records of the OSE to see exactly where the 2000+ dollars a month us true fans pour into the organization. They can't expect the volunteers to absorb all of the expenses for all of the work being done. I do think there needs to be a process whereby project expenses need to be approved and not just throw money at all the projects without accountability. But if I am doing work as a member of a project for the OSE I should get a budget to work with.

@ Jason - Yes exactly, there is no way Marcin can handle all this by himself. Time to delegate.

The Dawg

This is Marcin speaking for himself to some of these issues: http://openfarmtech.org/weblog/2011/04/explosion-after-the-online-ted-talk/

I have traded emails on the subject of servos vs. stepper motors with Marcin in the (distant past), and I think that even though there are existing (& Open Source) projects that are mature enough to be adaptable for or directly usable for this, there wasn't enough volunteer time (on my part?) to lead that charge.

Open Source Servo project would be good for the electronics, and can be scaled up with some effort by one familiar with electronics at http://www.openservo.org/ - this is focused on small hobby servos for mainly RC-controlled devices, but the electronics can be re-purposed for any motor that you can obtain a suitable controller for.  No matter the size!

Also, the Open Source Motor Controller project has a mature enough product that it can probably be directly used with DC motors, as is.  They are most active in their Yahoo Group at http://groups.yahoo.com/group/osmc/ but there is also a website located at http://www.robotpower.com/osmc_info/ that has more information on the project too.

I still don't have the time to pull this out, but when I get to a point where I'd be making any CNC machines, this is the route that I expect to take, for better accuracy than what is possible with stepper motors.

Perhaps someone else here will be better able to capitalize on this information now, rather than later, as I feel that eventually, all of the serious CNC work on the GVCS50 will have to be moved to servos to be market competitive.

@Allen15
The servo motor controller project, like many OSE projects, started strong and kinda fade.  My part in it got shifted over to the Steam Engine project, which also may be stalling or seriously changing at this point.  I think an open source servo motor (AC or DC) would be very useful on several other projects.  The robot comes to mind, since it seems to be nearing the end of it's design/spec phase.

If the project appeals to you, jump in and start pushing it.

- Mark

LOL, I sympathize with you.  I also have my own business, but it is a consultancy rather than retail.  Perhaps the trick is to find a product with a very high margin that allows you to have a comfortable work schedule that leaves time for other activities.

- Mark