Are there still issues with arcs?

Are there still issues with arcs? I ran a relatively simple job several times and got the same 2 areas where the arcs were noticeably off. All other arcs in the job turned out fine. I checked the forums and it appears there still may be issues in this area. The Chilipeppr 3D viewer even tracks off the lines in these two areas when the job is running. When I run with no arcs, everything turns out fine. Is the problem in Chilipeppr or TinyG (or me)? I just got the TinyG and I believe I am running the latest firmware.

I used to have problems with arcs but the issues were resolved. What FW version are you on? 440.20 is the latest I believe.

Arc problems are definitely not ChiliPeppr. Keep in mind, ChiliPeppr does not change or interpret your Gcode (unless you’re using the dynamic feed rate override in the TinyG workspace, which has nothing to do with arcs). Only the CNC controller does that. If there are in fact arc issues, its how your controller is interpreting it.

What software are you using to generate gcode? I added a setting to mine (HSMWorks aka Fusion 360) to not output arcs and have not had any problems since.

tinyG FW 440.20 is the most recent release, there are likely still corner case arcs that may induce Gcode interpretation errors. Eliminating arcs usually works, but may run a biit slower (larger files, more moves to interpret).
It would be helpful if you uploaded your complete Gcode file to a cloud drive and posted a link here for analysis by the devs. These files (or found problematic sequences) often become part of the test suite

I am running TinyG FW 440.20. I put several pix and gcode in a shared folder and hopefully shared it correctly. I also checked some of my TinyG settings to ensure they were correct based on others that had similar issues - they appear to be OK. Using no arcs takes care of the problem but I hope that if it is a TinyG problem, it is fully resolved soon.

The red drawn circles indicate the problem arcs. There may be others but these two were very noticeable. In the gcode, they are at line 528 and 81 (when loaded into Chilipeppr).

@Alden_Hart any thoughts here? Could there still be arc issues?

@Phil_Aldrich Your shared folder of information works well.
Can you add a $$ parameter dump?
Also, if you have a chance, try generating a Gcode file in mm mode rather than inch to see if that runs any better. Does Vectric offer a line numbering option? If so, use it.

That is an interesting Gcode file - numerous curvey lines but relatively few actual arc commands, Vectric chose on its own to use short straight segments.

Carl - I put a parameter dump file in the shared folder. I’m not sure which post processor will gen line numbers but I can try to find one (or put them in myself). I know more now about arc commands than I ever wanted but that’s a good thing. I also noticed that Vectric does not use arcs as much as it looks like they could. I will try mm’s and see if anything different happens.

@Jimmy_Hardman VCarve Pro from Vectric

I don’t have any experience with Vectric, but this looks like a jumping off point for modifying the post processor to use no arcs.

If it’s any help for searching purposes, line 81 of the inch gcode contains “G02 X2.6699 Y1.3033 I0.0346 J-0.0949” and line 528 contains “G02 X0.0076 Y3.4317 I0.1010 J0.0000”. I did try it in mm and it worked perfectly. I put a pix of the same area done in mm (around line 81) below the original one done in inches. Looks like the problem may have been fixed for metric but not english measurements?

@Jimmy_Hardman Thanks James - I am able to select a different post processor and gen no arcs. This is how I figured out that arcs (running in inches) appeared to be at the root of the problem. I just tried running in mm and had a perfect run with arcs. I have no problem using mm or no arcs but all of my previous work is done in inches. Hopefully this is an easy fix.

@Phil_Aldrich Thanks for confirming that mm works, it will help the devs figure out the failure mechanism

Phil, I just got back into the US and saw you post. Can you let me know what firmware build you are running and is there a way you can make the Gcode file available? (The one in inches) – Thanks

Alden - below is the info you requested. I put a copy of the gcode in a shared folder with some other info as well:

[fb] firmware build 440.20
[fv] firmware version 0.97
[hp] hardware platform 1.00
[hv] hardware version 8.00

Hope this helps