H-bot issue - steppers move 70mm for commanded 100mm
I just built an H-bot printer, I have azteeg x3 pro board (2560) with SD8825 drivers set to 1/16th (I've tried 1/8th with same results)
I printed my first test piece and the diameter was about 13mm instead of 20mm
I used the belt calculator here - I have 1.8degree steppers, 2mm belt, 20 tooth drivewheel and 1/16th stepping
http://prusaprinters.org/calculator/
That gives me 80 steps per mm so I double that for H-bot/core-xy and put in 160 for X and Y into the EEPROM but the head moves about 70mm when I tell it to move 100mm
I have also set STEPPER_HIGH_DELAY to 1 after having uneven motor movements
I am on v0.91 (rev 8?) and used the configuration tool. I have tried 1/8th stepping and 80 steps per mm and it still only moves 70% and I've tried 1/8th stepping with 160 steps per mm and it moves about 140mm when told 100mm. X and Y are the same.
Starting to get very frustrated, I've double checked all my hardware specs, belt size, tooth count... etc. Any other ideas?
I printed my first test piece and the diameter was about 13mm instead of 20mm
I used the belt calculator here - I have 1.8degree steppers, 2mm belt, 20 tooth drivewheel and 1/16th stepping
http://prusaprinters.org/calculator/
That gives me 80 steps per mm so I double that for H-bot/core-xy and put in 160 for X and Y into the EEPROM but the head moves about 70mm when I tell it to move 100mm
I have also set STEPPER_HIGH_DELAY to 1 after having uneven motor movements
I am on v0.91 (rev 8?) and used the configuration tool. I have tried 1/8th stepping and 80 steps per mm and it still only moves 70% and I've tried 1/8th stepping with 160 steps per mm and it moves about 140mm when told 100mm. X and Y are the same.
Starting to get very frustrated, I've double checked all my hardware specs, belt size, tooth count... etc. Any other ideas?
Comments
I've checked and re-checked my parts - I have 2mm belt, 1.8degree steppers, 20 tooth pulley...
Are there any other reasons that would cause this? Or do I just have to manually change the steps per mm by a factor about 1.4? That seems way too big a factor, I should be able to get much closer distances from these calculations. Everything is moving smoothly, belts are tight, nothing is skipping or jumping so I'm out of ideas.
Perhaps I need to increase my STEPPER_HIGH_DELAY to 2? Could that have any affect? Changing it to 1 fixed my uneven motors issues and currently the head moves perfectly straight, maybe both the stepper drivers are only catching 70% of the steps now? I have SD8825 drivers