Two extruders with different steps/mm
I thought about a way to have a (non-mixing) multi-material extruder on my big delta printer. Now I wonder if RRF (v3.1.1) supports it the way I would like to build it.
My idea is to have multiple filament spools (lets say 3 for now), each with a extruder pushing the filament through bowden-tubes. Those bowden tubes join together just above the flying extruder of my printer. The flying extruder is a BMG-dual drive extruder.
So when printing, with filament from spool A, two extruders have to move. The one at spool A and the flying extruder. But they have to move at different speeds, hence both have different length per step.
Is there any way to implement this with RRF on a Duet2 (and Duex5)?
Yes I think so, if I understand what you're saying correctly, you can setup the extruders with their different steps per mm and then define the tools with the appropriate motors with a 1:1 mixing ratio.
So let's say the spool extruders are ABC and the geared extruder is G. Your tools would have AG BG CG motors assigned.
The 1:1 mixing ratio means both motors will advance the same amount of filament based on their individual steps per mm.
The idea to implement this non-mixing extruder with a mixing extruder confguration is quite genius. Thank you. So you are suggesting something like this?
; define motors and direction ; (motors 0...2 for delta axis) M569 P3 S0 ; geared flying extruder M569 P4 S0 ; extruder A M569 P5 S0 ; extruder B M569 P6 S0 ; extruder C M584 X0 Y1 Z2 E3:4:5:6 ; map motors to axis M350 X16 Y16 Z16 E16:16:16:16 I1 ; configure microstepping ; [config for motor current, speed, acceleration and jerk go here] M92 X80.00 Y80.00 Z80.00 E415.00:120:120:120 ; configure steps per mm ; define tools M563 P0 S"ExtruderA" D0:1 H0 F0 ; A M563 P1 S"ExtruderB" D0:2 H0 F0 ; B M563 P2 S"ExtruderC" D0:3 H0 F0 ; C ; definine "mixing" M567 P0 E1:1:0:0 ; Tool 0: drive extruder 0 and 1 M567 P1 E1:0:1:0 ; Tool 1: drive extruder 0 and 2 M567 P2 E1:0:0:1 ; Tool 2: drive extruder 0 and 3 ; turn on "mixing" M568 P0 S1 ; for extruder A M568 P1 S1 ; for extruder B M568 P2 S1 ; for extruder C
deckingman last edited by
@justus2342 You wouldn't be the first to do something like this, so hold back on calling yourself a genius
You need to define 3 different tools so this won't work
M563 P0 S"ExtruderA" D0:1 H0 F0 ; A M563 P0 S"ExtruderB" D0:2 H0 F0 ; B M563 P0 S"ExtruderC" D0:3 H0 F0 ; C
In the above, you have only defined one tool - the same one 3 times. You haven't posted the rest of your config.g so I can't tell, but normally heater 0 is the bed heater and heater 1 is the hot end heater.
Try this instead
M563 P0 S"ExtruderA" D0:1 H1 ; A M563 P1 S"ExtruderB" D0:2 H1 ; B M563 P2 S"ExtruderC" D0:3 H1 ; C
The mixing ratios you have look OK and will work if you define the tools correctly.
Unless you are using a very old firmware (older than 1.19), you don't need the three M568 commands. From the wiki (quote) "If a G1 command for the tool provides just one E value, then the mix ratio defined by M567 will always be used."
Thank you for confirming that this way is the right idea for configuration. I will try to implement it this way.
Two remarks on your comment:
- I do not call myself a genius. I called the answer from @Phaedrux genius.
- Tool numbering was a c&p mistake, I already fixed it 8 minutes prior your post.
Definitely hold back on calling me a genius too!