I found that I hadn't set anything in the microstepping options on the X3 so I pulled the drivers off and set those for 1/16 (
see SD8825 Drivers Datasheet). Then I found
this nifty calculator over at Prusa's website. I looked at the
data sheet that ATI provided on the steppers, BOM to find the MXL belts and found the details on
the pulleys.
I decided that to make this calculation I needed to enter the following info into the
"Steps per millimeter - belt driven systems" calculator.
Note: Repetier now has this calculator built into their software in the Tools menu. It comes out with similar, but perhaps more precise numbers. (78.8177 on the belts.)
Motor Step Angle:
1.8degreeDriver microstepping:
1/16Belt Presets:
MXLPulley Tooth Count:
20Results: 78.82 steps/mm (X & Y Axis)I went into Repetier host, hit Alt + E to open up the firmware settings and put that in for the X and Y. Suddenly, things started to move as expected over distances that are much closer to accurate. The distances aren't bang on, in fact they are actually off by a lot, but that's an improvement. I measured the X-axis with a 100mm move and it went 39mm. Clearly some work needs to be done.
Over the two short period that I had this up and running, the drivers became extremely hot; the Y driver was almost to the point of burning to the touch the first time and the next it was was the Z driver (which still doesn't move). I'm letting them cool down right now. My first instinct after cutting the power was to turn the pots down a little bit. The drivers are sometimes making lots of whiny noise in certain positions, but they were doing that before.
While I was playing with Prusa's calculators, I also tried out the "Optimal layer height for your Z axis" calculator. I found out the following using the M8 lead screw preset giving me 1.25mm/revolution. I'm not sure what this chart does for me at this point, but I'm plopping it here for later reference.
- Code: Select all
Layer Height Steps
1.0mm 160
0.5mm 80
0.3mm 48
0.15mm 24
0.1mm 16
Oh, and the "Steps per millimeter - leadscrew driven systems" calculator from the same place is relevant to the Z so here's the result of that calculation using nothing not already mentioned in this post.
Results: 2560 steps/mm (Z Axis)Dragging this over from the SeeMeCNC EZStruder post so I have things gathered:
bdring wrote:I measured the steps per millimeter of the SeeMeCNC EzStuder at about 95.9 stes/mm
DEFAULT_AXIS_STEPS_PER_UNIT in Marlin
EXT0_STEPS_PER_MM in Repetier
NOTE: These aren't well tested and tuned values, just some calculations that will hopefully get me in the ballpark.