The solution for jerky movement for Fusion users?

[Doncis]

We fighting to jerky movement and not good surface finish on high speed 3d toolpath for years, and still have no solution.

[ger21]

The main limitation I've experience with UCCNC is that the speed of 3D toolpaths are somewhat jerky and speed constrained on my machine because the paths are linearised. For example, fretboard radiusing is capped at 100IPM

You should be able to get much more speed by adjusting your CV settings. I have a friend that's been making necks and fretboards with UCCNC for close to 10 years now, with no issues. After switching from Mach3, he was able to increase his speed 3x.

[Roby]

Hi all,

I'm happy to report that my modified UCCNC Post Library worked as expected, which is to say I can now achieve the performance I have been looking for in 3D toolpaths.

I'm sorry I pointed my finger at UCCNC earlier in this thread. The software is been excellent; my issue was the GCode produced by Fusion linearised circular moves that were not in the XY plane. My modified UCCNC Post Library overcomes this limitation.

The GCode produced by my library looks good to the eye and running a number of my regularly used toolpaths on my CNC I confirmed the new GCode works as expected.

The impact will mostly be seen on 3D toolpaths, in my case radiusing a guitar fretboards and carving the back of guitar necks, but even 2D toolpaths have smoother lead-ins and and lead-outs. And the GCode files for some operations are significantly smaller, if that matters to anyone (due to many linear moves being relaced by a since G2/G3).

At relatively low speeds the improved smoothness may be less noticeable, but as you crank up the speed the impact of using more G2/G3 moves is huge for the examples I ran.

For example, whereas I was limited to ~100 IPM when radiusing fretboards, I am now limited by the maximum travel speed of my Z axis (for me this is a 2.5x increase in speed, not to mention the smoother toolpaths).

I've made the modified post available on GitHub if people want to try it. Please note that if you choose to try it, you are doing it at your own risk.

https://github.com/pacmansydney/uccnc-fusion-post

I hope this helps the community. I intend to try to push these changes upstream once I've tested them a little more.

Regards,
Roby