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FIXED - DRV8825 Driver settings

Posted by IG88 
FIXED - DRV8825 Driver settings
October 31, 2015 09:28AM
Hello beautiful people,

I've just finished my homemade 3D printer, but I'm running in to something that might slightly affect my prints, my motors ain't moving.
So far i've tried moving all axes with my ''Intelligent LCD Smart Controller'' by going to the apropriate menu and turning the button.

At first, the DRV8825 heatsinks were getting very hot, and moving the selected axis made a high pitch squeeling noise (like old tube TV's) aswell as noticable white noise coming from the motor.
I heard some stepping as i moved the knob of my display, but no movement.
I've tried all axes with the same result, so it would be fair to assume it's not the drivers or motors that are faulty.

So i started troubleshooting, I found out Vref was too high (1.7 V) so I set it to about 0.7 volts. (about 1.4 A if my sources are correct!)
I made sure i wired my motor pairs correctly by measuring coil resistance and placing an LED between coil pairs and moving the motors (1A, 2A, 1B, 2B )
I'm assuming that when i short all 3 rows of jumpers below the stepper driver, it makes my DRV8825 operate at 1/32 microstepping.

I've set steps/mm on Marlin as follows:

#define DEFAULT_AXIS_STEPS_PER_UNIT {88.88, 88.88, 5120, 203.72} // X, Y, Z, E

I'm using direct belt drive so I calculated this by STEP/MM = (Motor steps per rev * microstep) / (belt pitch in mm * number of teeth)

What i'm going to try:
- Moving the axes with software from my PC instead of the display controller.
- Unclamping the belt so the pulley moves freely, maybe it's too tight and the motor has insufficient torque (unlikely though?)

Anyway guys, if you could point out some mistakes i might have made, or things that i've assumed wrongly I'd greatly appreciate your input!

Edited 2 time(s). Last edit at 10/31/2015 03:41PM by IG88.
Re: DRV8825 Driver settings
October 31, 2015 03:41PM

I tried to move the motors using Repetier-Host, same issue.
However when i pressed the homing buttons the selected axis would move slightly, so i figured it had something to do with the endstops.
I altered their function in Marlin, problem solved, it's alive!

Not sure how to delete threads, i'm trying to at the moment.
Re: FIXED - DRV8825 Driver settings
October 31, 2015 09:31PM
Just keep your post up. Someone may stumble along it one day and your post will help them fix the same problem!

Prusa i3 Rework - Ramps 1.4 - E3d Lite6 - Full Graphic LCD Controller
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