Designing With Stepper Motors

Question

Hi Everyone,

I was wondering your thoughts on using an EZB-V4 to drive a stepper motor such as the one attached.

Stepper Motor link https://www.adafruit.com/datasheets/12vstepper.jpg

Uploaded data for driver.....

Using 24V battery with a 12V regulator.

Dave

thetechguru · Answer

Link is bad (it may only work when navigated from the product page at Adafruit, getting a "forbidden" error when linking directly). Anyway, if you search the forum for Stepper Motor, you will find that most have found it not to be worth the effort. Apparently, there are no driver boards that are as simple to interface with as H-bridges. Several have tried, and I don't think anyone has had enough success to make it worth it, particularly when there are plenty of good DC motors and h-bridges, including ones that can read position encoders (Sabertooth with kangaroo or Roboclaw are two examples). Alan

david.lawrence1234 · Answer

Try these....  A4988StepperMotorDriver.pdf Are you telling me that the EZB would have a difficult time driving this stepper motor driver board? Dave

Dunning-Kruger · Answer

Dave... you need to find a stepper motor controller board that will work with the ezb... To my knowledge no one has had much luck finding such a motor controller... If you find one that is compatible, please let us know...

david.lawrence1234 · Answer

My last post has a link to a stepper motor controller board. Please review that and tell me if it would work with the EZB. Dave

Jeremie · Answer

I don't mean to step on your toes @Alan but it isn't that difficult to drive a stepper motor. They can be driven simply with 4 digital ports connected to a Dual H-bridge such as a L298. You just have to generate the sequence in which the stepper coils are activated with the ez-b. I believe a driver such as the A4988 delivers that sequence automatically. In an age of a million 3D printers, stepper motor control has been dialed in quite nicely, and all the driving information has been open sourced since the RepRap if I'm not mistaken.

Dunning-Kruger · Answer

@Jeremie... Thanks for that.... I will retract what I said earlier.... It may be easy or easier to do this now, but to my knowledge no one on the forum with maybe the exception of Jeremie and DJ has a clue on how to work with a stepper... Maybe there is possibly others lurking out there that also can help you David, I am not sure....

Jeremie · Answer

I was looking at the A4988 and it seems pretty straight forward. It's a very popular driver in the 3D printing community. Here's the signals you would need to send to the driver from the ez-b: STEP: This needs to be a 0V to 3.3V signal. Each rising edge of this signal will cause one step (or microstep) to be taken. DIR (Direction): This needs to be a 0V to 3.3V signal. The level of this signal (high/low) is sampled on each rising edge of STEP to determine which direction to take the step (or microstep). Most of the other pins, such as reset, enable, MS1, etc need to be pulled high or low accordingly, but don't require a signal from the ez-b, only the two are needed.

jstarne1 · Answer

Hello everyone , late to the game to chime in. The latest Texas instruments drv8825 is excellent at driving stepper motors. If you use an actual stepper controller vs a h bridge then the board just counts the pulses , verify what mode it is in and does the work. This board for example has multipliers so that the motor can make several steps for one pulse. That is good for when you need a quick yet precise movement. I have several of these and look forward to making a ezb v4 , "shield" that just plugs into the top of the board and the rest of the pins just pass through. Make it easy peasy!

david.lawrence1234 · Answer

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

jstarne1 · Answer

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.

Dunning-Kruger · Answer

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....

leversofpower · Answer

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

david.lawrence1234 · Answer

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

thetechguru · Answer

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

bookmaker32 · Answer

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.

bookmaker32 · Answer

Here is a video of the steppers working

DJ Sures · Answer

bookmaker! Junior is really cool - thanks for sharing that video! You should create a Project Showcase Page for him!

bookmaker32 · Answer

Thanks DJ. I have been putting it off until I have him a little more complete. Edit: Two days later. Junior seems really depressed now because no one seems to like him except DJ.