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Remove G20 and G21 commands from start gcode
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I'm not exactly sure when G20 and G21 were removed from the Marlin firmware but they work in and are unknown in and

I can't comment on the removal of the commands but if they were removed on purpose, they should also be removed from the Start Gcode.

In CuraLE 3.2.32 the TAZ 6 Single Extruder start gcode still has a G21 in it. I have not (yet) checked all of my other extruder start gcodes.

UPDATE: FW does not support these commands, remove from all start gcodes.

Event Timeline

Orias assigned this task to karrad.
Orias added a subscriber: Orias.

See report in the forums at:

I was looking at the serial.log (optionally) produced by OctoPrint and found this:

2018-12-17 07:29:29,636 - Send: N4 G21*30
2018-12-17 07:29:29,642 - Recv: echo:Unknown command: "G21"
2018-12-17 07:29:29,644 - Recv: ok N4 P 15 B4

While the printer is idle, I can send a G21 and it indeed comes back as an unknown command. This seems strange to me.

TAZ 6, Marlin provided with CuraLE 3.2.32.

Edit: Ignore the

Mentioned Here P15 Cura2 build failure on system2

karrad reassigned this task from karrad to marcio.Jan 8 2019, 2:56 PM
karrad triaged this task as Normal priority.
karrad added subscribers: marcio, karrad.

@marcio Not quite sure what is going on here, but looking at the marlin page these commands look to be active.

marcio added a comment.Jan 9 2019, 8:14 AM

@karrad: These commands are only supported if the FW is compiled with INCH_MODE_SUPPORT, which our current firmware does not have. Remove G20 and G21 from the start GCODE as our FW will do millimeters exclusively.

marcio closed this task as Wontfix.Jan 9 2019, 8:14 AM

Unless there is a task to remove G20 and G21 from the start GCODE, this task should not be closed until that work is completed.

karrad claimed this task.Jan 9 2019, 8:38 AM
karrad reopened this task as Open.
karrad moved this task from Backlog to Release 3.6.xx on the Cura LulzBot Edition board.
karrad removed a project: Marlin.
karrad renamed this task from G20 and G21 are unknown commands but are still in the start gcode to Remove G20 and G21 commands from start gcode.
karrad updated the task description. (Show Details)
karrad changed the edit policy from "All Users" to "Cura LulzBot Edition (Project)".

I did not see any G20 commands, but all G21 commands removed from start gcode in 3.6.3 and newer. Closing this one down, thanks for the report @b-morgan

karrad closed this task as Resolved.Jan 10 2019, 12:36 PM