2.7-alpha1 skips leading zero on G2 J/I parameters for legacy marlin machines (Snapmaker A350)

[tyeth]

Description of the bug

Legacy Marlin Machine doesn't like instruction that is missing leading zero. Using official printer profile for Snapmaker A350 supplied by Prusa as part of PrusaSlicer 2.7.0-alpha1
e.g.
G2 X186.82 Y226.366 I.037 J-.212 E33.22049

Project file & How to reproduce

FrameAndVentPETG_A350.zip
Printer pauses at inner walls here in mid section of model (90 degree bend) which appears to use the G2 move for inner walls.

Checklist of files included above

• Project file
• Screenshot

Version of PrusaSlicer

2.7.0-alpha1

Operating system

win11 64

Printer model

Snapmaker A350

[neophyl]

This is a duplicate issue. Its been raised before. Please see #7505 or #6996

In particular this comment #6996 (comment)

[tyeth]

If a regex is needed to fix printer profiles that Prusa supply (yes for other manufacturers) to fix known faults, then include it in the profile.

It's a bug, Prusa just chooses Won't fix.
See #7505 (comment)

If users can submit patches for the profiles then let me know what key would achieve that regex, but to be honest it feels like bodge to make every user of an officially supplied printer profile add a regex manually to fix a known issue with that profile.

As far as marlin2 and klipper go, that's fine, they've got a modern spec and systems designed for powerful string processing, but devices using legacy marlin have a good chance of breaking with any quirks of convenience (like dropping leading zero).

[neophyl]

Profiles for non Prusa machines are submitted by users. There’s another repo for those but I don’t know what the process is for submitting to it. I’ve seen other issues here where one of the devs has pinged someone else when profile issues come up for other machines though.

[tyeth]

Thanks neophyl, I could and should have done this years ago. PR submitted after copying from my exported settings bundle.

[rtyr]

Using official printer profile for Snapmaker A350 supplied by Prusa as part of PrusaSlicer 2.7.0-alpha1

G2/G3 commands are emitted only with arc fitting enabled. It is not enabled in bundled profiles and it may be not good idea to enable it for printers with old Marlin (various bugs in arc implementation).

Do you have any issues without arc fitting enabled?

[tyeth]

I am trying to use arc fitting as it was recently added to the snapmaker firmware for lasering tool, but technically has been supported for a while in 3d printing. I am reluctant to turn that on in the live profile (arc generally for the reason you mention), but the regex is an "official" fix which resolves issues with certain firmware versions (it happened before with G1 years ago so it's a general improvement for snapmaker machines known to be potentially vulnerable to this issue).

…

On Wed, 8 Nov 2023, 23:18 rtyr, ***@***.***> wrote: Using official printer profile for Snapmaker A350 supplied by Prusa as part of PrusaSlicer 2.7.0-alpha1 G2/G3 commands are emitted only with arc fitting enabled. It is not enabled in bundled profiles and it may be not good idea to enable it for printers with old Marlin (various bugs in arc implementation). Do you have any issues without arc fitting enabled? — Reply to this email directly, view it on GitHub <#11620 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/ABTBZ4Y6UOYL45UNQMW564LYDQHMBAVCNFSM6AAAAAA7DKNBZKVHI2DSMVQWIX3LMV43OSLTON2WKQ3PNVWWK3TUHMYTQMBSHA4DCMZSGM> . You are receiving this because you authored the thread.Message ID: ***@***.***>

[rtyr]

PR was merged and distributed via configuration update 1.0.1.