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Bypassing MMU2s?
 
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Bypassing MMU2s?  

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markus.i2
 markus.i2
(@markus-i2)
Trusted Member
Bypassing MMU2s?

I've read a couple of other messages in a similar vein, namely single material printing with the MMU2s installed.

In the current manual (and software version), as far as I understand it, I still have to (should) feed my material through the MMU for any single material print. Since I'm slowly coming to learn (i.e. my MMU is currently out of comission while I'm waiting for the delivery of a long micro USB cable) that the MMU is a fickle beast (which impression might change over time), I'd like to have a way of bypassing the MMU completely. Feeding the filament directly to the extruder is no issue mechanically - we've been doing this all the time. The different behaviour of the filament sensor I can live with. So which options do I have?

  • The brute force approach would be to unplug it - or, maybe a little bit gentler on the connectors, add a switch in the power line to the MMU so I can simply switch off its power supply. Any comments (from Prusa?) on this approach?

    • The other two options would require a change in the firmware, and I'm not firm enough in this to submit a pull request to the depot, so I'll simply list them here:

  • Add an option in the filament selection menu that comes up when you are printing in single filament mode that simply states "direct feed" and disables feeding through the MMU

  • Or, finally, automatically use that "direct feed" option if the printer detects that it's handling a legacy (i.e. not created with any of the MMU options) gcode

    • Posted : 16/04/2019 7:23 pm
    toaf
     toaf
    (@toaf)
    Noble Member
    Re: Bypassing MMU2s?

    block the finda with short filament that wont get into the gear

    I have a Prusa,therefore I research.

    Posted : 16/04/2019 7:56 pm
    TNDave
     TNDave
    (@tndave)
    Active Member
    RE: Bypassing MMU2s?

    I use my MK3/MMU2 single filament without the MMU2, found that putting a small switch in the brown wire from the MMU2 works.  With the switch off, power on (or reset) the MK3 and it comes up non MMU, menu is MK3 only.  

    Posted : 31/05/2019 1:34 am
    Jan Bassett and markus.i2 liked
    Jan Bassett
     Jan Bassett
    (@jan-bassett)
    New Member
    RE: Bypassing MMU2s?

    @david-s87

    A nice fix that I've just implemented.  I've printed a new top cover with an extension to mount a switch so it's neat & tidy.

    Posted : 02/06/2020 2:32 pm
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