DRV8825 Board missing steps and heating

Hi all,

I built a CNC from openbuilds.com (it called the “OX”). I have been having problems with it. It would miss steps and the drivers would heat up after 10-15min even after using heat sink and a cooling fan.

Here’s my setup:

X-axis motor: 1 Nema 23 (2.8A per phase)
Y-axis motor: 2 Nema 23 (2.8A per phase) attached to a single Y-axis
Z-axis motor: 1 Nema 23 (1.68A per phase)
12V, 30A power supply
Controller Board: openbuilds.com/builds/laser- … nsion.515/

After a lot of reading, I suspected it could be the Vref volts but I have checked it multiple times (with motors disconnected and the drivers in full step mode). The Vref for Nema23s have been adjusted to 1.4V and for Z-axis it has been adjusted to 0.84V. After adjustment, I put the board to do 32 microsteps and check the Vref again and it remains the same. The motors run smoothly without making any noise but after 10min or so it will miss the steps (either X-axis or Y-axis but not Z-axis) and the driver boards will get really hot even after heatsink and cooling.

Could this be happening because I have attached 2 nema23s on a single Y-axis? (I have seen people do this online but they don’t seem to have any problems) - Am I doing anything wrong here?

It is very frustrating that this thing is ruining my projects. Please help!!

P.S: I am very new to all this so please be as detailed as possible in your answers/suggestions

Thanks!

The DRV8825 is not an appropriate stepper motor driver for most of your motors. Our DRV8825 carrier is only rated for a maximum of 2.2A, and all of your motors except the 1.68A per phase one exceed that rating. You should use a stepper motor driver that can supply the necessary amount of current for your stepper motors. I do not have a recommendation for where you might find more powerful stepper motor drivers.

- Grant

The smaller Geckodrives, such as the G250X and G251X would be suitable for those motors and are reasonably priced: geckodrive.com/geckodrive-st … rives.html

Thanks for the feedback guys… I think I may have to change the controller board altogether because the G250x or G251x won’t be compatible with my Borad (max 12V) as they require min. 15V.
My second option would be to change the nema 23’s that I have and go for lower amp ratings…

Thanks again!

We have some NEMA 23 motors with lower current ratings. However, I do not know if they would have sufficient torque for your application. If you use select the “23” option in the “(any NEMA size)” drop down menu at the top of our stepper motor category page and click the go button, you can see our selection of NEMA 23 stepper motors to see if one of them would work for your application.

- Grant