Unexpected Table Rotation on M31 Command - Hurco (Autodesk Fusion Library)

[laromosrl]

Hello,

I’ve correctly configured my Hurco machine, and the issue occurs when using the post-processor from the Fusion 360 library.

I believe it’s related to the graphical simulation within Fusion. In fact, when the program reaches the line containing the M31 command (as shown in the video), the table starts rotating around the C axis until the B axis head reaches position 0.

Can anyone understand what might be causing this abnormal behavior?
Is there a way to fix it or adapt the post-processor to handle it correctly?

Thanks in advance for your support.

https://go.screenpal.com/watch/cT1IiYnXrp7

[AchimN]

Hello @laromosrl ,

Thanks for your feedback!
I'm guessing that what you see is a limitation of the simulation.
When you run the program on the machine, you probably won't see that behavior.
In the NC code, the last positions of the BC axes are B-45.017 C-42000.453, and the next position is B0 C0. Therefore, the simulation shows the movement as continuous movement while unwinding the C-axis.
From what I know, that does not actually happen on the machine because of the M31 command, which resets the rotary encoder to a position within the range of -180° to +180°.

You can try changing your machine definition to set the range of the C-axis from "unlimited" to "cyclic," as shown in the screenshot below.
This will result in an NC program that keeps the C-axis values within 0 to 360 degrees, and the simulation will show the correct behavior as well.

You must test the program to ensure that your machine accepts the G-code with the C-axis coordinates being limited to 0-360deg and if it behaves correctly with this output.

[laromosrl]

Hi,

thank you for your support and kind response.

The manufacturer's instructions specify using unlimited range and always with the M31 command. Since I have never encountered any issues with these settings, I would prefer not to modify anything on the machine side regarding this matter.

I was wondering if there is a way to make Fusion’s simulation recognize the M31 command, in order to make the simulation more accurate and closer to reality.

Thank you.

[laromosrl]

Hi, is there anyone who can give me some advice on how — and if it's possible — to make the Fusion machine simulation read the M31?