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Author Topic: After using the “Steps Per Unit” in “Axis Calibration” my CNC wont run properly  (Read 32859 times)

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Offline Hood

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Hey I'm ready to cut but want to drill a hole through my work table.

When you use the Wizards in Mach 3 such as circle cut and hole drill, do you position the Z axis bit down and just kiss the surface to be cut then press the Zero axis button and then Press Start??

Thanks ???
Yes thats exactly what you do :) The top of the workpiece is set as zero and all cuts are negative numbers.
Thank you Thank you Thank you.  Two Gold Stars for You!

I looked it up in the Mach 3 mill manual and it talked about running the Wizards but not this very important point.
Mr. Chips
Retired 3M'r
Here are the test procedure and results from measuring the X and Y axis. As you can see all the results from moving 1” came out to be 0.996” on all three tests that were ran on each axis. I am using ½” 10 TPI 1 start Acme rod. All three axis were cut from one piece of rod. This is not a high precision piece of iron.
After setup I did not have to touch the indicator, it came back to zero every time.

I will try and attach the spreadsheet with test details.

What do you think of the test results?
What would be my next step?



I would be suspicious of the accuracy of whatever indicator you're measuring.  Either that, or your screws are not reall exactly 10TPI.  Do the measurements again, using a different indicator.  If you get the same result, then you're screws are off, and the solution is to simply re-calculate steps/inch based on 10 turns = 0.996 inches.  If you get a different result, (hopefully 1.000"), then you know you have at least one lousy indicator.

Ray L.
Ray L.