4th axis values greater than 360deg? <answered>

[jake2465]

I was attempting to run a test part today and I noticed that my A axis DRO can only have values from 0-360 deg. The first A values given in the post were negative A values. I watched my 4th axis just rotate several turns before I decided to cancel the job. I looked in chapter 14 of the M400 manual, but I did not find anything resembling how I could get the control to accept A values like 735 deg or -311 deg, etc. Is changing this something that is done in the parameters?

[cnckeith]

please post a report.zip file so we can see the settings of the cnc configuration.

DRO for a rotary axis can be limited to 360 or allowed accumulate. bit wise CNC12 Parameters 91-94 are used to control the various properties of the axes. if your A axis is on Axis #4 then Parameter 94 is used to define the properties for that axis. Setting it to a value of 3 would make it a rotary axis with dro that wraps around.. setting it to a value of 1 would make it a rotary axis that shows rotations and degrees on the dro.

from the manual.

[jake2465]

Attached is the report.

[cncsnw]

The first A values given in the post were negative A values. I watched my 4th axis just rotate several turns before I decided to cancel the job.

What A position was shown on the current-position DRO?
What A position was called for in the CNC program?
What did the distance-to-go DRO say while it was moving several turns?

The confusion is probably over the difference between what you see on the DRO -- particularly with P94 = 3 -- and what position the axis is really at.

The Centroid control software does not automatically cancel extra turns, regardless of what value you set in P94. If you leave the A axis sitting at +730 degrees from part zero, then the DRO will read either "2R 10.000" (with P94 = 1) or just "10.000" (with P94 = 3). But if you then give it a command to go to A-10.0, it is going to move -740 degrees.

See http://www.cncsnw.com/4thHowTo.htm, particularly the section headed "Unwinding the rotary axis".

[jake2465]

The confusion is probably over the difference between what you see on the DRO -- particularly with P94 = 3 -- and what position the axis is really at.

Yes, that was it. I think I will go in there and change that parameter to a "1" so I can have some indication of how many rotations have accumulated.

Thanks for the help! I am new at this stuff!