topic Re: C-axis not taking shortest path, rotating wrong direction. Mazak mill turn in Fusion Manufacture Forum

C-axis not taking shortest path, rotating wrong direction. Mazak mill turn

larsNR7Y2 — Tue, 01 Nov 2022 12:10:15 GMT

Hello,

Running a few Mazak Quick Turn lathes with milling capabilities, this specific machine has a Fusion640t control.

Trying to do a simple engraving on the outer diameter of a part but having problems with the C-axis not choosing the shortest path.

As you can see in the image attached, the machine just finished the row above going to C-161.738 and the next order of operations is to go to C-161.588, a difference in 0.15 degrees, yet as you can see on the buffer window the next move the machine will do is C-359.789, so spinning the wrong way around the part.

It does this on every C-axis row in the program, spinning back and forth instead of taking the shortest path.

Anyone seen this before?

We're using the standard Autodesk post processor which can be found here: https://cam.autodesk.com/posts/post.php?name=mazak%20quick%20turn%20250-msy

Here is some of the code: https://p.ip.fi/7DGe

Re: C-axis not taking shortest path, rotating wrong direction. Mazak mill turn

DarthBane55 — Tue, 01 Nov 2022 12:41:13 GMT

It has nothing to do with Fusion, usually it's a parameter in the machine, that dictates if it will do the shortest way or move according to the sign in front (for example -160. would move CCW but +160 would move CW, or vice-versa).

Re: C-axis not taking shortest path, rotating wrong direction. Mazak mill turn

larsNR7Y2 — Tue, 01 Nov 2022 15:01:06 GMT

You were absolutely right, and I do appologize.

I had to change A18 from 0 to 1 for it to use "Shortest path" approach, thank you.

Re: C-axis not taking shortest path, rotating wrong direction. Mazak mill turn

DarthBane55 — Tue, 01 Nov 2022 15:18:34 GMT

huh... no apologies needed, you asked a legit question, and you found your answer, that's what the forum is for, all good! 😀