Having problems with MMU - Please Help
Hi everybody,
I have an MK2S with the MMU and unfortunately I'm having the following issues:
I am constantly getting blockages in the PTFE tube under the multiplexer. When the printer switches the filament during the print, the filament has a "blob" that is too thick to go back up the PTFE tube.
Another issue is that often the filament just doesn't get extruded. It's loaded fine but nothing comes out during the print. If I am using two extruders, the one will come out fine but as soon as it switches to the other one, nothing comes out.
These problems are using multiple brands of PLA.
How can I fix this? 🙁
Thanks in advance.
Re: Having problems with MMU - Please Help
The blob, in my experience, is usually because there is some room between your nozzle and the heatbreak. The plastic gets a chance to expand in that space, will still fit through the heatbreak, but is blocked by the rest of the path (teflon or the metal pipes in the multiplexer).
Is it a problem that you had before you upgraded as well?
XL (5T) / MK4 / MK3S+-MMU3 / MK3S / MK2.5S-MMU2S / Mini / SL1S
Re: Having problems with MMU - Please Help
The blob, in my experience, is usually because there is some room between your nozzle and the heatbreak. The plastic gets a chance to expand in that space, will still fit through the heatbreak, but is blocked by the rest of the path (teflon or the metal pipes in the multiplexer).
Is it a problem that you had before you upgraded as well?
No, have only had the problem since installing the MMU. 😥
Re: Having problems with MMU - Please Help
I'm afraid you'll have to figure out where exactly it has the room to expand while hot and resolve that.
The MM kit ships with a new hotend, so that might still be the cause if you used it, best to make sure it isn't.
In case you don't know what I'm referring to, perhaps you can look at this or if you prefer text instructions
XL (5T) / MK4 / MK3S+-MMU3 / MK3S / MK2.5S-MMU2S / Mini / SL1S
Re: Having problems with MMU - Please Help
I was getting those larger blobs with my MMU until I lowered the temperature by about 10 degrees.
Any advices given are offered in good faith. It is your responsibility to ensure that by following my advice you do not suffer or cause injury, damage or loss. If you solve your problem, please post the solution…
Re: Having problems with MMU - Please Help
it's worth checking your PTFE liner shape,
it should have a small chamfer on the outside at the bottom, and a taper on the inside at the top,
try reducing the retraction distance all printers are different... mine is better at 2.5 mm
consider reducing the print temperature, this reduces stringing
good luck
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
Re: Having problems with MMU - Please Help
@steve.g
@aaron.s5
@joan.t
Thanks everyone. 😀
Everything suggested above and any more suggestions given after this post I'll definitely try out and give a go this coming week.
I'll also give an update with regards to what and if anything solves my on-going issues.