Re: 4th axis and fusion 360 problem
The gcode is telling it to run really slowly. That's about a sixtieth of the speed in the previous line. It appears to be happening when there is a much larger movement in A than in previous lines. Suggests something happening at the CAM toolpath generation stage, which I why I wondered about the feed settings. At this point, it doesn't look like a Mach3 or machine issue.
Re: 4th axis and fusion 360 problem
i think you're on the right track I changed the gcode line where it slows down f346 to F646 and i moves faster. I just need to work out why now. But I'm a lot happier than I was this time this morning. Slowly getting to the bottom of it