Ideamaker and Extrusion Factors

bitskrieg

Re: Extrusion factor in DWC overrides slicer flow rate %

I am able to sporadically reproduce what OP in the above thread was talking about - a Duet 2 Wifi and RRF 3.4 will occasionally (I can't tell what conditions must exist for it to happen) override the extrusion factor in the gcode file used by Ideamaker. By default, Ideamaker uses a M221 command to set the extrusion factor at the beginning of the gcode file rather than adjust the individual G1 E values (although, this can be changed in settings).

When the gcode file works as designed, I can observe that the extrusion factor is at 90 (or whatever is called for) in DWC. Other times, the extrusion factor will stay at 100 and it would appear that the M221 command is ignored; in these cases, over-extrusion is visible.

The same gcode file will yield different results depending on...something. I'm not exactly sure what.

Sample gcode with M221 command at beginning:
default-box_FI_POSG2_ASA+GF_nd0-3.0mm_nd1-2.5mm_lh-2.0000mm.gcode

Note that this is a pellet extruder and E-steps are set at the factory (and I'm not entirely sure how I'd go about doing that calibration anyway to be honest). Flow rate calibration is the only way to control the relative amount of polymer being extruded on a move.

Any ideas as to why this happens?

Phaedrux

M221 T0 S80.00
M140 S100.00
M104 T0 S230.00
M109 T0 S230.00
T0
M190 S100.00
G21 ; use mm
G90 ; set absolute positioning
M82 ; set absolute extrusion
M106 S0 ; turn off fans
M561 ; clear any bed transform
G28 ; home all axes
G32 ;  check bed tilt
G29 S1 ; load mesh map
G92 E0 ; Reset material counter to 0
T0 ; Select Tool 0
M116 S5 ; wait for hotend and bed to reach temperature to 5 degrees
M117 "Printing..."
M107
;end of Start GCode

Perhaps the problem is the T0 that they seem to be adding to the command. That's not part of the documented behaviour of the command.

https://docs.duet3d.com/User_manual/Reference/Gcodes#m221-set-extrude-factor-override-percentage

Parameters
Snnn Extrude factor override percentage (0..100 or higher), default 100%
Dnnn Extruder drive number (RepRapFirmware only), default 0
Examples

M221 S70
M221 S95 D1
Sets extrude factor override percentage. In the case of RepRapFirmware, sets the extrusion factor percentage for the specified extruder drive only.

bitskrieg

@phaedrux

I think you might be right - Ideamaker is targeted at Marlin, and M221 T0 is the correct syntax for Marlin gcode. I will play with it a little and then open a bug with them if that is what it turns out to be.

Good catch!

Phaedrux

Well you can manually edit the gcode file to remove the T0 and see if it makes any difference. It looked like ideamaker was set to reprap syntax, so that would be a bug on their side for including the T0. Not sure if it would matter though, dc42 thought the T0 would be ignored, so may be a red herring.

bitskrieg

@Phaedrux

After playing with it a bit, I've been able to reproduce the problem using both Marlin and RRF M221 syntax, so I don't think that's it.

Any other ideas about what this might be?

Phaedrux

Could the difference be whether or not a tool is selected before the print job is started or not?

The first T0 command comes after the M221 in the gcode file. Perhaps the cases where it's not sticking are the times where the tool is deselected when the job starts.