How to change extruder gear speed (loading process)? - General discussion, announcements and releases

RE: How to change extruder gear speed (loading process)?

gkPrints — Sun, 16 Aug 2020 17:00:04 +0000

Yes, I'm talking about the MMU (in single mode).

Changing the actual purge line is clear to me and I've already done that, but right before that the extruder does back and forth actions that are too fast for the flex material. It's the final filament loading procedure, because in single mode it loads the filament to the extruder head before doing the heating (code line: Tx)

RE: How to change extruder gear speed (loading process)?

jsw — Thu, 13 Aug 2020 19:00:17 +0000

The one I posted is for the 'single mode', in which I feed the filament directly into the extruder. No, there's no loading into the MMU prior to the bed leveling and purge line.

The obvious difference at start-up is that those I sliced in MMU2S single mode do a full-width purge line and those I sliced in Mk3S mode (or with Cura) have the narrow purge line on the left side of the front of the plate.

RE: How to change extruder gear speed (loading process)?

bobstro — Thu, 13 Aug 2020 18:39:37 +0000

Does the MMU do some other filament movement at the start of a print? Or is it the actual prime line triggering the misfeeds?

RE: How to change extruder gear speed (loading process)?

jsw — Thu, 13 Aug 2020 18:34:49 +0000

Here's the gcode from the start of a print done in the 'single mode' with the MMU2S. This has the 'full size' prime line. This calls it the 'purge line' and some gcode for the non MMU Mk3S calls it the 'intro line'.

M203 X200 Y200 Z12 E120 ; sets maximum feedrates, mm/sec
M204 P1250 R1250 T1250 ; sets acceleration (P, T) and retract acceleration (R), mm/sec^2
M205 X8.00 Y8.00 Z0.40 E4.50 ; sets the jerk limits, mm/sec
M205 S0 T0 ; sets the minimum extruding and travel feed rate, mm/sec
M107
;; M862.3 P "MK3SMMU2S" ; printer model check
M862.1 P0.4 ; nozzle diameter check
;; M115 U3.9.0 ; tell printer latest fw version
G90 ; use absolute coordinates
M83 ; extruder relative mode
M104 S255 ; set extruder temp
M140 S100 ; set bed temp
Tx
M190 S100 ; wait for bed temp
M109 S255 ; wait for extruder temp
G28 W ; home all without mesh bed level
G80 ; mesh bed leveling

;go outside print area
G1 Y-3.0 F1000.0
G1 Z0.4 F1000.0
; select extruder
Tc
; purge line
G1 X55.0 F2000.0
G1 Z0.3 F1000.0
G92 E0.0
G1 X240.0 E25.0 F2200.0
M73 Q0 S280
M73 P0 R278
G1 Y-2.0 F1000.0
G1 X55.0 E25 F1400.0
G1 Z0.20 F1000.0
G1 X5.0 E4.0 F1000.0

RE: How to change extruder gear speed (loading process)?

bobstro — Thu, 13 Aug 2020 18:00:05 +0000

Are you using a MMU? If so, the startup gcode is different from what I understand. Somebody with a MMU will need to provide specifics.

How to change extruder gear speed (loading process)?

gkPrints — Thu, 13 Aug 2020 13:06:32 +0000

Is there a possibility to change the extruder speed right before doing the purge line?

I could only find the purging in the printer setting (custom g-code -> start g-code). But right before that, the extruder gears run forth and back with quite high speed - at least too high for my flexible filament. It gets tangled around the gears at that speed.

Thanks in advance!