Thank you Jeremie,

I agree with what you say. According to the A4988, it should work with the 3.3V PWM logic provided by the EZB. I will have to write some scripts to actually move the stepper motor. But the hardware is pretty straight forward. I will be providing power to the stepper through an external 24V battery [with a 12V reg].

I shouldn't be needing very high accuracy in steps so I do not think I will need the microsteps. Nice to have though just in case needed later.

My requirement is for a dual direction, high torque, slow speed application. Stepper motors are designed for that.

Dave

The biggest difference is that steppers are rated with a amperage limitation so that the magnets do not get hot. Many h bridges do not have a built in mechanism for regulating current so when you overvoltage a stepper for more torque ( normal practice) it draws more than the rates amps and demagnitizes the internal magnet structure. These controller chips have a build in , adjustable amperage regulator for longevity of a stepper and are ideal for 3d printers and reprap to keep them cooler.

David when you drop down your 24V battery to 12V with a regulator, make sure it is putting out adequate amps to drive your steppers or you'll have the same power problem you did with your servos in your other thread....

See this thread: https://synthiam.com/Community/Questions/2742

OK this is great. Yes Richard I do plan to use a regulator with enough current capacity to drive my stepper motor. Probably something with a 3amp limit.

Jstarne1......I do like the TI stepper controller. A bit more expensive but the driver IC looks better. I may also add the heat sink as you have done.

Thanks again!

Dave

Always happy to hear that I am incorrect about a limitation of EZ-B. In fact, I now realize that I already knew there was a good solution but had forgotten about it. I had bookmarked this thread https://synthiam.com/Community/Questions/6183&page=2

Check out specifically post #18.

Alan

In reference to the thread bookmarked by @thetechguru , @jstarne1 was correct. The Spark Fun controller is junk. I used his suggested controller and they work great. They are a little more trouble to hook up but make all the difference in the world. They are rock solid.

Here is a video of the steppers working