"Downgraded" from MMU2S - Which firmware to use now for firmware updates?  

RE: "Downgraded" from MMU2S - Which firmware to use now for firmware updates?

I've had the MMU2S for almost two years, and for almost two years my printer has been a paperweight.  I got one print out today, after a lot of help (mostly to get me motivated to care about it).  I got one single-filament print out.  I was ecstatic.  I tried to do a second print, and all that I get is "MMU requires attention".  I have manually been able to get filament to extrude, but at one point it was jammed in the orange PTFE tube.  How can I get the MMU out of the picture? I have to give up on it, which makes me very sad. But I want a real, functional 3D printer, and will settle (unhappily) for single-filament, but I don't know how to do the downgrade.  I have a dozen projects that have been waiting for a usable printer, and I'm tired of waiting.  Please tell me how to get the MMU out of my life.

RE: "Downgraded" from MMU2S - Which firmware to use now for firmware updates?

@joseph-n5

Hey, it is actually VERY simple.

1. Disconnect the power and data cable from the board, that runs from the MMU2S unit.

2. Remove the unit from the bar that goes across the top.

... thats it!

Start printing as though it was a non-MMU2S unit now.  I'll be flashing the MK3S firmware back to it, rather than the MK3S\MMU2S firmware that is has loaded now, but I have a print going right now after doing those two steps.  I was in the same situation as you, basically had given up, and once I figured out how simple it was... I spent the 15 min it took to get it all going again.

RE: "Downgraded" from MMU2S - Which firmware to use now for firmware updates?

You should be able to use the MK3S as a plain printer without the MMU2S.  I keep mine disconnected most of the time.  No downgrading needed.

RE: "Downgraded" from MMU2S - Which firmware to use now for firmware updates?

@joseph-n5

As has already been confirmed several times - simply remove the MMU2 with all cables and you are done. You don't need to update the firmware either.
I think you should first deal with the MK3S for a while and later, if you feel like it, try again with the MMU2/S.

Good luck!

RE: "Downgraded" from MMU2S - Which firmware to use now for firmware updates?

I disconnected mine back in the spring - yes MK3s is the way to go; the MMU is now a semi cannabalised set of spares/project parts...

BUT

I am now doing far more multicolour printing than I ever did with the MMU.

The MMU turns out not to be much use for multimaterial - I envisaged being able to print in one a PETG chassis with FLEX suspension, PLA gearing and soluble PVA supports ... no way.  It was just about possible to print multiple colours of the same material if you tended it carefully. 

Take a look at this thread:

https://forum.prusa3d.com/forum/prusaslicer/manual-multicolor/

Using this method I can print all the muliticolour (no not multimaterial) that I ever need for enginering parts and with less fuss.

Cheerio,

RE: "Downgraded" from MMU2S - Which firmware to use now for firmware updates?

I just posted this in response to a similar topic elsewhere in the forum ( https://forum.prusa3d.com/forum/original-prusa-i3-mmu2s-mmu2-how-do-i-print-this-printing-help/how-to-delete-mmu-from-mk3s/#post-299104):

Having had similar frustrations with the MMU2, which in terms of reliability is the polar opposite to the Mk3S, I just went through the process of reverting back to the original Mk3S. All in all it took me less than an hour.

I thought others might be interested in my notes from the process. In addition to a description of each step I also give a pointer to the respective steps in the MMU2 and the MK3S assembly guides that provide relevant photos and additional detail. To keep it concise, I use "MMU-UP" as a shortcut for https://help.prusa3d.com/en/guide/3b-mk3s-mk2-5s-extruder-upgrade_41560 and "MK3S" as a shortcut for https://help.prusa3d.com/en/guide/5-e-axis-assembly_28536 . You want both pages up on your screen as you go through the process.

There's no need to reflash the firmware. Make sure you use the original Mk3S profiles in PrusaSlicer, not the MMU2 ones.

Electronics

1. Open Einsy enclosure and remove the MMU2 signal cable and the power cable. LEAVE IR-sensor cable in place. Close Einsy enclosure.
   ( https://help.prusa3d.com/en/guide/6-electronics-and-mmu2s-unit-assembly_44728#45808 )
2. Remove the MMU2 from the printer frame and set it aside (for good...).
3. Remove the signal and power cables from the cable sleeve.

Disassembly

1. Loosen four M3x10 screws on X-carriage-back (MMU-UP Step 15)
2. Remove M3x40 screw with spring that provides tension to extruder-idler-mmu2. Remove M3x40 screw that holds extruder-idler-mmu2.(MMU-UP Step 14)
3. Carefully remove extruder-idler-mmu2 without dropping the pulley inside. (MMU-UP Step 13)
4. With 2.5mm Allen wrench, push shaft though and remove the pulley. Make sure bearings stay in pulley. (MMU-UP Step 14)
5. Remove hotend fan by removing three M3x14 and one M3x20 screws. (MMU-UP Step 10)
6. Loosen two M3x10 and two M3x40 screws on X-carriage. (MMU-UP Step 9)
7. Remove M3x40 that holds IR assembly in place. Remove M3x18 and remove IR sensor assembly from extruder body. (MMU-UP Step 8)
8. Remove M3x10 and separate the two parts of the chimney. (MMU-UP Step 7)
9. Remove M2x8 screw and separate lid and IR sensor. (MMU-UP Step 6)
10. Remove sensor cable from IR sensor and put IR sensor aside for now (will re-use it later). (MMU-UP Step 5)
11. Remove orange adapter (adapter-printer-mmu2). (MMU-UP Step 2)

Re-Assembly

1. Insert steel ball into original adapter-printer. Place adapter with steel ball into extruder body. (MK3S Step 7)
2. Insert pulley into original Mk3S idler and slide shaft through idler and pulley. (MK3S Step 29)
3. Insert extruder-idler into extruder and secure with a M3x40 screw. Don't tighten it firmly, idler must rorate freely. (MK3S Step 31).
4. Use M2x8 to secure IR sensor on top of extruder body and plug sensor cable in. (MK3S Step 21)
5. Secure sensor assembly to extruder with M3x40 screw. (MK3S Step 22)
6. Use M3x10 to attach original FS cover to extruder. (MK3S Step 34)
7. Tighten two M3x10 screws in the X-assembly. Make sure no cables are pinched. (MK3S Step 21)
8. Re-attach the hotend fan (and re-secure shroud) with M3x14 and M3x20 screws. Make sure fan cable is properly routed and not pinched.(MK3S Steps 24 - 26)
9. Re-tighten the four M3x10 screws on the X-carriage-back. (MK3S Step 61)
10. Re-tension the M3x40 screw with spring to the idler. (MK3S Step 32)