Multi color printing with Prusa's MMU V2 & Duet?

gavatron3000

the problem ive found when trying to home to endstop/pinda is if it doesnt reach the sensor it just carrys on with the rest of the macro, if there was a feature to home to endstop but if not reached by Xmm or Xseconds then pause or retry. but this may be leaning towards conditional gcode

ive got a home built MMU2 unit hooked upto the duex2 now, just testing at this stage

dc42

@gavatron3000 said in Multi color printing with Prusa's MMU V2 & Duet?:

the problem ive found when trying to home to endstop/pinda is if it doesnt reach the sensor it just carrys on with the rest of the macro, if there was a feature to home to endstop but if not reached by Xmm or Xseconds then pause or retry. but this may be leaning towards conditional gcode

If it doesn't reach the endstop, then I presume either the amount of movement specified in your G1 S1 command is too low, or you are using G1 S1 without selecting relative coordinates first, or your axis is getting stuck. The first two are easily fixed, the last is mechanical

gavatron3000

Yes exactly, the drama is with relation to the mmu2 is if there is a jam during loading the firmware isn't able to detect this until perhaps the filament sensor is reenabled just before printing with a new tool
This also applies when unloading too
I guess though it still picks up the error eventually, I'll try jigging the macro's differently by enabling the filament sensor at different points see what outcomes occur during tool changes

Just thinking out aloud here, don't mind me

gavatron3000

Hi all, id thought id report back to say running the mmu2 with the duet and duex is possible and working even with loading and unloading detection using the "finda" style setup. its all working as expected now i just need to dial my ramming settings to get good tips. if anyone has any questions let me know. but its a win

my next thing is to setup filament-change.g to unload filament through the front of the mmu

Ungreon

I'm assuming you got the full thing working without the prusa MMU v2 board? If so did you modify the MMU assembly at all or just assemble it without the board? Would you consider sharing the g code or slapping together a short tutorial on how to accomplish your solution?

gavatron3000

@ungreon said in Multi color printing with Prusa's MMU V2 & Duet?:

I'm assuming you got the full thing working without the prusa MMU v2 board? If so did you modify the MMU assembly at all or just assemble it without the board? Would you consider sharing the g code or slapping together a short tutorial on how to accomplish your solution?

So my mmu2 is just the original without the Prusa electronics. It's hooked up to the duet and a duex2. Longest part in getting it running was getting the endstop configuration on the fly and loading and unloading detection triggers running correctly with additional axes. I'm happy to share my macros, I'll write some things down and share when I get some free time.
Hardest part is shaping the tips so it's reliable,

gavatron3000

Here's the first document I wrote for the mmu2. Treat it as a beta at the moment as I'm sure as more people get more hours with it I think there would be improvements.

https://docs.google.com/document/d/13r_6BTYTO-xlD6cQeNwOx4qeCEYYGrxOcHc0mC-tT8Q/edit?usp=drivesdk

NicoLab28

I used the few scripts you had given me, and it's almost starting to work for my MMU.
But my questions are, do you use a cutter, and where?
Do you use ABS filament or just PLA or other.

For my part, I have big problems with the ABS, because it happens to make obstructions, or he puts me back pieces.
The only solution I found is to cut as close to the head as possible.

I saw that some used a cutter at the level of the selector, but it might congest too?

gavatron3000

I don't use the cutter, for me I didn't think it's necessary as the ramming before retraction forms the tip anyways. Abs just works but pla is more difficult. Make sure you use the correct I.D PTFE tube in the Hotend as well. 1.8mm to 1.85mm. capricorn tubing isnt narrow enough either, ive tried.

I almost forgot! I'm adding some modded STL and scad files soon so the filament change will function perfectly as the filament ejection will snag on T4 without a small mod to the selector and main body of the mmu2

NicoLab28

You are in live drive, I looked at your Tipsmoothing.g
10s break anyway, it's just for testing, or is it really necessary?

On my side, it is not too much a problem of diameter of ptfe, I ordered, but of hair, which does not see itself and accumulates until stuffing. I should test your method.

I put transparent tube, and it is obvious.
The worst thing is that it's not regular, it happens from time to time. 15-20 tool change without worries, and boom!
That's why, I put a cutter.

I have the impression, that reliability will be a very hard thing to obtain.

I think I'll test the standard version, what change do you think you'll make? Your files are coming soon?

gavatron3000

look at the link above the info is there, but the files ill add are only for filament changes that affect T4 so 90% of printing is unaffected. if you getting strings you need to tune your ramming settings correctly. this you need to do on your slicer to suit your machine

@nicolab28 said in Multi color printing with Prusa's MMU V2 & Duet?:

You are in live drive, I looked at your Tipsmoothing.g
10s break anyway, it's just for testing, or is it really necessary?

probably not its just a value that definitely works, i was finding that if i retracted too quickly through the extruder it was mashing my tips and causing jams

gavatron3000

adding a cutter to the macros wouldnt be hard youd just need to add a fast selector move across the mmu that chops the tip off if thats what you want but again it'll just build up under the selector anyway. better off just tuning the ramming right

fma

Quality of the tips also depends on the time the filament spents in the nozzle (without extruding). Especially with PLA. I have a simple settings which work great, unless the PLA is sitting in the nozzle for 2 or 3 minutes (in this case, I get oozing).

The solution is to pre-retract the filament at the end of a print.

Scachi

Where do you buy 1.8mmx3mm ptfe tubing from ?
I can't find a source for that. A german shop would be nice but shipping to Germany is good enough

gavatron3000

theres a link in the document above

Scachi

@gavatron3000 said in Multi color printing with Prusa's MMU V2 & Duet?:

theres a link in the document above

Thank you.

gavatron3000

@dc42 regarding triggers, are they meant to go off with immediate effect?

in my document above for loading the MMU2 they work and function as intended but it seems they are delayed until the tool change has completed. is this expected behaviour? id prefer being able to set it off immediately

dc42

The movement system is locked during a tool change, therefore if the trigger macro has any movement commands or other commands that affect motion, those commands will wait until the tool change is complete.

gavatron3000

The triggers in question are like this

M400
M291 "message and wait till ok is pressed"

Should I just remove the m400?

NicoLab28

@gavatron3000 said in Multi color printing with Prusa's MMU V2 & Duet?:

in my document above for loading the MMU2 they work and function as intended but it seems they are delayed until the tool change has completed. is this expected behaviour? id prefer being able to set it off immediately

You're saying that you have the same problem as me, (my post "M581 M582 M291, What am I doing wrong?") To know that the dialog comes at the end of the tool change.
Too late, because the script continued to execute, after the error, which should have been blocking.