I am using MKS Gen V 1.4 with DRV8825. Vref set to 0.750 V.

(Tech World) #1

I am using MKS Gen V 1.4 with DRV8825. Vref set to 0.750 V. Motors are getting more heat even after printing 2hrs. Also, when we touch the Drivers, it is also hot.

When printing with CoreXY -300mm machine, I am not getting satisfying results. Please find the attached image. It is having some issues in the perimeter. Printed with 200deg PLA.

And I bought some High temperature (300deg) thermistor from Aliexpress. Temperature is fluctuating between 3-4 degrees.

(Stephanie A) #2

The motors can handle a lot of heat, but the stepper drivers cannot. I typically run my motors at an uncomfortable temperature, that is it is uncomfortable to hold your finger on if for more than 5 seconds.

Stepper drivers run much better with a heatsink and a fan. If everything is too hot, turn down the current. If you’re missing steps or the carriage is easy to block when moving, turn it up.

Or you can set the current to 80% of the stepper motor rated value.

(Selvakumaran Ganesan) #3

@Stephanie_A I tried to lower the current. But still it was hot. Heat sink also present. As of now, the board is left open (without enclosure).

I changed the drivers to A4988 and now it is working fine.

Temperature is initially fluctuating 5-6 degrees. It takes 4-5 minutes to get stabilized. But at the time of printing, it is stabilizing between 1deg.

I have done PID tuning 4-5 times. And the manufacturer asked to select temperature sensor option ‘1’ in Marlin. (100k thermistor - best choice for EPCOS 100k (4.7k pullup)

(Mano Biletsky (Open MAKER)) #4

Maybe your bearings are not running as smoothly as they should? That could cause friction and thus, more power is needed to move the gantry.

On both my printers only the extruder stepper gets warm but not hotter than 43 degrees celcius. The rest stays at a comfortable room temperature.

(Eric Pavey) #5

@shauki : lol, that’s actually my design (although the top is cut off). They’re just really easy to make in 3D \ print, \ look neat, that’s why I do it :wink: