Hello, I have had my 'kinda' mill setup for about two months and have not really used it as its currently a positioning table with a drillpress on a crude bench but im starting work on my full Z axis and want to get it setup as an accurate positioning table and manual quill so I can start building parts.
I had the table pretty well setup by guessing but I had odd settings in my motor tuning tab, I have a new PC for the mill and the numbers are completely different on it.
On my old PC (Phenom Quad Core w/ 6G Ram):
Settings Screen > Time in Int: 3.0-3.9
Motor Tuning:
X Axis: Steps Per: 105, Velocity: 65, Acceleration: 20
Y Axis: Steps Per: 105, Velocity: 45, Acceleration: 10
On the new PC (Athalon XP w/ 1G Ram)
Settings Screen > Time in Int: 5.0-5.7
Motor Tuning:
X Axis: Steps Per: 2542.383, Velocity: 35, Acceleration: 8
Y Axis: Steps Per: 2543.324, Velocity: 20, Acceleration: 5
The positioning table is driven by parallel bipolar 2.5A 48V nema23 80oz-in motors on some sized differential roller screw. I have no idea how to measure this screw as its appears to be on a 1/4"-32TPI bronze screw and the roller screw has 5 rollers. Table movement is 6" x 4"
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The problem I am having is on the old PC with Steps Per Rev at 105 I had repeatability to around 0.001" through all my travels (tested it with g-code that went min>max>min x 50 on both axis while I had a caliper on the table)
On the new PC I did the Axis Calibration on the settings screen with the caliper clamped to the table and I get 2500 steps per rev and when I do a calibrate > y axis > move 4.000 the table moved 4.0005 but when I goto the MDI and put in G0 Y-4.0000 the table will move greater than 4". I go back to calibrate and did a calibrate > y axis > move -4.000 the table moved perfectly still.
This only happens is the Y axis and only on this new computer. I also notice that I had to drastically reduce my velocity and acceleration or it would stall. I think I need to figure out my roller screw ratio to get a real steps/rev count.
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Well enough talking for me, anyone care to try and explain my problem away?