Minimal rolling back from MK3S-MMU2S to MK3S  

  RSS
othman.a2
(@othman-a2)
Active Member

Hello,

I upgraded my MK3S to MMU2S a few months ago and it's been a headache. I'd like to restore the printer to MK3S in the least time/effort possible since I'm a bit pressed on time. Any advice?

Thanks,

Othman

Best Answer by kevin.h35:

After weeks of frustration and months of not using my printer, I decided to go back to what works.

Steps I took to disable/remove MMU temporarily:

1. Uplug power and data connectors on MMU board. These are the 2 connectors on the right.

2. Disconnected PTFE tube from extruder at the blue collar. I put in a short PTFE tube I had laying around.

3. Removed MMU assembly from the top frame and set it behind the printer. The wiring is still connected. Re-installed the original spool holder to the top of the frame.

That is all. Printer says it is a MK3S and operates as it should.

This also allowed me to verify the MMU2 was the source of my problems as the MK3S still works flawlessly.

The MMU is still wired in and easy to reconnect if I want more pain and frustration later.

Posted : 03/02/2020 8:10 pm
apromain
(@apromain)
Trusted Member

It doesn't take long at all to roll it right back, I've done so once or twice, as I rarely use the MMU2S, and prefer to use it stock when doing lots of bulk runs (but that's another story).

You just need to swap out the 'chimney' on the extruder, leave the sensor as it is (don't bother to readjust the length of the cable, just ensure it won't catch on anything), swap the door over, and undo a couple of bolts to refit the piece with the ball bearing in.  Undo the control box, remove the FINDA sensor cable, and the power cables (the power cables are probably the fiddliest part).  All in, around 40 mins or so at a conservative pace.

Posted : 03/02/2020 8:59 pm
alamatth
(@alamatth)
Active Member

@apromain

I’ve considered rolling back as well.  I’ve thought the process over several times, and I don’t really see a need to remove the chimney, and put the ball bearing back in.  Seems to me leaving the sensor in the chimney without the ball bearing would work just as well.  

Posted : 03/02/2020 10:14 pm
kevfquinn
(@kevfquinn)
Active Member

I've taken a lazy approach to this a few times when I can't be bothered to change the filament loaded in the buffer and MMU2S, but just want to run a single-colour print.

I have a short piece of bowden tube to hand; disconnect the MMU2S bowden tube from the hot end (just press down on the pneumatic fitting and pull the tube out), stick the short piece in instead, and disconnect the data cable from the MMU2S itself (with the printer off, of course). Takes a couple of minutes, if that. I'm tempted to fit an in-line switch on the data cable to make that last part instant...

Takes a little encouragement to get the filament to autoload (need to push it into the hob gears) but I've not had any difficulty doing that once I twigged that's what it takes to get the hot end filament sensor to trip. Slice with the normal MK3S printer profile of course, as the MMU2S is then not being used at all.

Also I don't know if over time this will wear the pneumatic fitting, but that's hardly an expensive component to replace 😀 

Posted : 07/02/2020 10:53 pm
keri.h
(@keri-h)
Eminent Member

I kept the chimney in place, unscrewed the QSM-M5 connector from the extruder, turned off the filament sensors, and then loaded manually.  Pre-heating and then moving the extruder axis until it loaded.  

It wasn't perfect but it worked for me!

...
Posted : 16/02/2020 1:51 pm
SecondCityPrinter
(@secondcityprinter)
New Member

After spending a few months trying to print unsuccessfully, I happened upon your post and immediately printed my first object in months.

Apparently you can just unplug the mmu2s, disconnect the PTFE tube and be back to printing perfectly.  Who knew?

Thanks for this post, you're a godsend!  This should be stickied.

Posted : 19/02/2020 4:09 am
kevin.h35
(@kevin-h35)
New Member

After weeks of frustration and months of not using my printer, I decided to go back to what works.

Steps I took to disable/remove MMU temporarily:

1. Uplug power and data connectors on MMU board. These are the 2 connectors on the right.

2. Disconnected PTFE tube from extruder at the blue collar. I put in a short PTFE tube I had laying around.

3. Removed MMU assembly from the top frame and set it behind the printer. The wiring is still connected. Re-installed the original spool holder to the top of the frame.

That is all. Printer says it is a MK3S and operates as it should.

This also allowed me to verify the MMU2 was the source of my problems as the MK3S still works flawlessly.

The MMU is still wired in and easy to reconnect if I want more pain and frustration later.

Posted : 22/06/2020 2:07 am
othman.a2
(@othman-a2)
Active Member

Thanks, Kevin! This has worked. It only took 5 minutes to do.

Posted : 04/07/2020 5:30 pm
SecondCityPrinter
(@secondcityprinter)
New Member

Just want to point out that you don't actually have to disconnect power to the MMU2S, you can just unplug the data connectors.

Obviously there are pros and cons, but if you want to do less work to change back and forth, power disconnection is not necessary.

Posted : 04/07/2020 9:12 pm
james.m36
(@james-m36)
New Member

I tried this, but I'm having trouble with the filament sensor in the chimney. When I got the MMU2S, it came with the MK3 -> MK3S upgrade as well, so I don't have the lever/magnets that are in the current instructions. Does anyone have a complete list of parts I need to order & print to get back to a "standard" MK3S ?

Posted : 09/08/2020 9:38 pm
joan.t
(@joantabb)
Veteran Member Moderator

https://www.ebay.co.uk/itm/3D-Printer-Filament-Break-Detection-Module-Sensor-for-MK2-5MK3-MK3S-Prusa-i3/333233218601?hash=item4d963f6429:g:ZZQAAOSwwYFdA2qQ

Plus, extruder top, filament sensor, Bondtech door , and  filament sensor ball adapter

regards Joan

I try to make safe suggestions,You should understand the context and ensure you are happy that they are safe before attempting to apply my suggestions, what you do, is YOUR responsibility. Location Halifax UK...
Posted : 09/08/2020 9:52 pm
james.m36 liked
joan.t
(@joantabb)
Veteran Member Moderator

you end up with a spare cable and spare sensor...  with the above parts

 

I try to make safe suggestions,You should understand the context and ensure you are happy that they are safe before attempting to apply my suggestions, what you do, is YOUR responsibility. Location Halifax UK...
Posted : 09/08/2020 9:53 pm
Share:

Please Login or Register