Geeetech

Hello,

I was a happy user of the I3 Pro B printer in the last few weeks since I own it, but something must've happened yesterday. I usually print with PLA, but yesterday I did ABS - which actually turned out great.

I wanted to print another piece, but then it happened... after about 20 seconds of printing, it stopped for about 10 seconds.. then it printed for 20 more, then stopped again, and this repeating, print a bit, stop.
I think it then got even worse, the extruder motor didn't move (but the X, Y, Z were fine).
I plugged the extruder motor into another driver (X) and then it moved.
I tried to replace the original factory driver module with another I had (DRV8825), and that didn't work either. I think something on the GT2560 "died' around the extruder 1 slot/port.

What helped is when I used the "extruder 2" slot with the module (DRV8825), that way, it started working. However, I still get the stopping error, and when I touch the extruder motor, it feels hot (probably 50-60 degrees), even after just a bit of work. There's also a bit of faint 'buzzing' sound from the motor when it's running.

Now I am thinking maybe the motor overheats, draws too much current and that shuts things down?
I even adjusted the voltage on the DRV8825 to 0.8volts (is that the good value?), I think that should be okay?

I think I will try to get a new motor for the extruder and try that. My theory that the ABS got stuck for some reason and overloaded my (maybe not configured) original circuit, and that killed things.

Any ideas welcome.

Just an update: things seem to now work with PLA, printing is working, also I have turned the potentiometer so that the DRV8825 voltage is 0.5V, which should mean 1A current limit. Maybe also the motor cooled down because it was turned off?

There is still a slight "buzzing like small bees in the motor" sound from the extruder motor. Maybe the motor got damaged earlier by too high current?

update2: i think maybe nothing is broke, I realized the motor won't turn if hotend is cold because of "cold extrusion protection".
Maybe the stepper is broke a bit because of driving it with too high current.. i will check later.

Never try to repair your printer late evening/night

Great sharing

One more update: printing runs all great and fine now!

* I did a Marlin Firmware update to version 1.1.9, it was pretty easy: just download it from Marlin website ( http://marlinfw.org/ ), make sure to copy the right "example configuration.h" named Geetech, make sure to go over it to check things (one of my driver boards is now DRV8825, so I changed that) and get a recent Arduino IDE (1.8.x), set device to Atmega 2560, compile, upload -- great! I don't know why Geeetech is not at least recommending that firmware in their firmware section?

* I did replace the extruder stepper motor.
** I think my problems originated by the extruder stepper motor "clicking" on extrusion many times, so that's why I increased the stepper driver voltage (and current), which caused the overheating problem later with ABS
** Maybe I killed the stepper motor, or maybe not, but anyway, I bought a new NEMA17 motor with 1.5 Amps max and 40 Ncm holding torque, replaced it in the extruder, also now using DRV8825 and all is great! No more "clicking" at all!