Threaded rod not turning?


#1

I’ve been trying to get my beta unit’s extrusion mechanism to work. I’ve hooked up to a Velleman k8200 and matched up extruder motor wiring. Repetier communicates with it just fine. I start with:

M302
M92 E1700
M500

Then I “extrude” 10mm of filament and I hear the motor moving in the Discov3ry, but no movement of the threaded rod. Before I take it apart, am I missing something super obvious? I removed all the packing tape and have the allen wrench inserted. Thoughts are welcome :slight_smile:


#2

OK, I took a break and looked at it again. Taking the cover off really helped. Turns out I had two things wrong. First, I had my “Speed” at 60mm/s and my ESteps too low. The drive gear was moving, but slower than a snail. I bumped the speed to 400mm/s and ESteps to 6000 and the drive gears visibly turn and the syringe definitely is moving. That said, these settings are probably stupidly incorrect. Time for some calibration? :smile:


#3

Hello @skjain2,

From my experience so far I am getting EEPROM Esteps similar (in order of magnitude) to you:

Felix 3.0 - Around 5000
Ultimaker 2 - Around 12000
RAMPS RepRap - Around 2-3000

For the speeds in manual control, I am typically using 100-500mm/s and longer lengths to help purge the tubing.

Please let me know how it is going, cheers!


#4

Thanks @skjain2 and @fink for the firmware advice, these settings seem to be working well with my RepRap.

However, the planetary gears aren’t driving the threaded rod. The stepper motor is running and the gears are turning, but the rod and syringe aren’t moving. When I remove the allen key and turn the rod manually it works just fine and the syringe starts to move. Any suggestions on what’s going wrong here would be much appreciated.


#5

@Stroje The threaded rod will not rotate, it will jut move up and down. If the large gear is turning, and the rod is not moving, it would mean a stripped nut. This is very unlikely.

My guess is that it is moving REALLY slowly. Perhaps try extruding a long length (or many small) and make a small mark on the rod to see if it moves. The setting of 2-3k for EEPROM may be to low, try increasing this until the motor stalls.

Typically, the large gear should move about 1 RPM (ish).