In short, if I enter a value for 'counts per unit', I can get it move 1 inch accurately
but not for longer distances (9") and V.S.
Initial X motor settings:
counts per unit: 25850.3034 <- generated using Mach StepsPerUnitCalculator to calculate steps per 1 inch distance
velocity (units/minute): 200
acceleration (units/(sec^2)): 24.18
for 1 inch distance. result is 1" +/- .001" - repeatable
for 9 inch distance, result is ~9.25" <- ** BAD ** - repeatable
changed counts per unit to: 25108.1258 <- generated using Mach StepsPerUnitCalculator to calculate steps per 9 inch distance
for 9 inch distance, result is 9" to 9 & 1/64" - repeatable
for 1 inch distance. result is 0.96" <- ** BAD ** - repeatable
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This is only a problem for X axis.
Y motor settings:
counts per unit: 25121.7720 <- generated using Mach StepsPerUnitCalculator to calculate steps per 1 inch distance
velocity (units/minute): 200
acceleration (units/(sec^2)): 24.18
For distance in y axis, result is accurate for 1" (+/- .001") inch and 4" (w/in 1/64") inches - is repeatable.
Z motor settings:
counts per unit: 25075.2508 <- generated using Mach StepsPerUnitCalculator to calculate steps per 1 inch distance
velocity (units/minute): 200
acceleration (units/(sec^2)): 25
For distance in z axis, result is accurate for 1" (+/- .001") inch and 6" (w/in 1/64") inches - is repeatable.
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Based on videos:
- Mach support: Mach4's Steps Per Unit Calculator Wizard -
https://www.youtube.com/watch?v=d-xCWDR0Uvg- Mach4 Motor Calibration - Counts Per Unit -
https://www.youtube.com/watch?v=jzYG5VOztFY----------------------------------------------------------------
Used a dial indicator for 1" distance and pointer pointing at a ruler for longer measurements.
Used simple commands like:
G20
G91
G00 X1
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The setup:
- software: Mach 4.
- A LittleMachineShop.com HiTorque Mini Mill 3990
https://littlemachineshop.com/products/product_view.php?ProductID=3990&category=1387807683- Thomson C7 ball screws. .625" X .2" pitch.
https://www.heavymetalcnc.com/x2/- motors:
https://www.automationtechnologiesinc.com/products-page/stepper-nema23-3-axis-kits/cnc-stepper-motor-3-axis-kit-3/- pokeys57cnc board
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Tried:
- initially all the motors were set to 16 micro steps. Figured some steps were being ?skipped?. Changed to 4 micro steps for X motor controller.
X settings:
counts per unit: 52221.3064 <- generated using Mach StepsPerUnitCalculator to calculate steps per 1 inch distance
velocity (units/minute): 200
acceleration (units/(sec^2)): 24
for 1 inch distance. is 1" +/- .005" - repeatable
for 9 inch distance, is ~9.3125" (20/64") - repeatable (worse than 16 micro steps)
- Changed to 32 micro steps for X. Got similar results as 4 micro steps.
- changed velocity for x motor to 100 and acceleration to 5 - made no difference.
- Played with 'rapid rate' at different percentages like ~30% - made no difference.
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Any ideas, suggestions?