Travel Distance Calibration

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cyprian21
Posts: 3
Joined: Fri Nov 29, 2019 6:09 am

Travel Distance Calibration

Post by cyprian21 » Sat Nov 30, 2019 5:47 am

Hi there,

Is there a way to calibrate an axis in Kmotion CNC similar to how it's done in Mach3?

In Mach3 you can select the axis and tell it how far you want it to travel. You then measure how far it traveled on your physical machine and enter in that value. Mach3 then decides how many counts/inch it needs to set the system to.

Theoretically (on my machine) at 2000 counts/revolution and a ball screw pitch of 0.196/inch I get 10,204 counts/inch.

My result: going in one direction my calipers indicate I'm off by 0.01".

Is there a way to properly fine tune this?

Thank you,
Cyprian

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TomKerekes
Posts: 665
Joined: Mon Dec 04, 2017 1:49 am

Re: Travel Distance Calibration

Post by TomKerekes » Sat Nov 30, 2019 8:54 am

Hi Cyprian,
My result: going in one direction my calipers indicate I'm off by 0.01".
After going how far? Is it linear? If you move 10 times as far are you off by 0.1”?
Regards,

Tom Kerekes
Dynomotion, Inc.

cyprian21
Posts: 3
Joined: Fri Nov 29, 2019 6:09 am

Re: Travel Distance Calibration

Post by cyprian21 » Thu Dec 12, 2019 5:51 pm

Hi Tom,

I travel over 6 inches. Here are the measurements at every inch:

1.000" kmotion CNC = 1.002" on machine
2.000" kmotion CNC = 2.004" on machine
3.000" kmotion CNC = 3.006" on machine
4.000" kmotion CNC = 4.008" on machine
5.000" kmotion CNC = 5.010" on machine
6.000" kmotion CNC = 6.012" on machine

It is linear yes. I do not have a way of measuring more than 6 inches. I'm using digital calipers.

Thank you,
Cyprian

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TomKerekes
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Joined: Mon Dec 04, 2017 1:49 am

Re: Travel Distance Calibration

Post by TomKerekes » Thu Dec 12, 2019 6:58 pm

Hi Cyprian,

In this case try:
10,204 x 6.0 / 6.012 = 10,183.6 counts/inch
Regards,

Tom Kerekes
Dynomotion, Inc.

cyprian21
Posts: 3
Joined: Fri Nov 29, 2019 6:09 am

Re: Travel Distance Calibration

Post by cyprian21 » Thu Dec 12, 2019 9:40 pm

Hummm after testing some more I have discovered that I do not get repeatable results moving still in only one direction.

For instance when I move in 1" increments over a total distance of 5" I get a different result that if I move the entire 5" in one continuous movement.

I have also discovered that when I send Gcode commands to move by 0.001" increments I do not hear my stepper advance.

I seems that I get the stepper motors to move consistently if I'm commanding moves of 0.004" increments or larger. Any commands below 0.004" I observe an inconsistency in the movement of the steppers, sometimes they move and sometimes they do not.

So aside from anything to do with ball-screw pitch and counts/inch, I believe that I have a different issue altogether at the moment.

Thoughts?

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TomKerekes
Posts: 665
Joined: Mon Dec 04, 2017 1:49 am

Re: Travel Distance Calibration

Post by TomKerekes » Fri Dec 13, 2019 1:25 am

Hi Cyprian,
For instance when I move in 1" increments over a total distance of 5" I get a different result that if I move the entire 5" in one continuous movement.
What results do you get? Are those different but repeatable?
I have also discovered that when I send Gcode commands to move by 0.001" increments I do not hear my stepper advance.
If you open KMotion.exe Axis Screen does the Destination change consistently by 10 or 11 steps each time you do this?

What kind of Stepper Drives do you have? It seems they are supposed to be 10X microstepping?
Regards,

Tom Kerekes
Dynomotion, Inc.

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