Buyer's Remorse?
Just kind of me venting I guess but also looking for assistance/confirmation on some things.
It seems like I have to babysit every print. Once a print gets going it seems to turn out great, just the initial time is a pain. After finishing prints the printer always seems to require a full extraction of all used filaments then cut the end off and re-insert next print. Even doing that I still seem to get lots of stuck filament in the metal tube section. Sometimes the initial purge lines just don't extrude correctly and the nozzle can get gummed up and deposit small pieces around the print bed.
Am I doing something wrong or is this just how the current multi material life is? Thinking of just rolling back to a single direct drive setup at this point 🙁
Re: Buyer's Remorse?
This has not been my experience AT ALL. I have printed dozens of items (well over 100) - many with prints over 56hours. The MMU has been VERY reliable for me. BUT ONLY AFTER DROPPING THE TEMPERATURE. I was having the blockages part way through a print, and blockages in the steel tubes, but those are now completely gone.
The full story. First did upgrade. Fussy as you have seen (was printing metallic Hatchbox PLA (bronze, copper, silver, gold and black)) Dropped the temperature from 215/210 to 210/205. Became very robust - and did dozens of four color prints with no issue. New projects required (again Hatchbox) red, yellow, white, blue. Fussy again. Clogs and ruined prints 12 hours in. Clogs in the steel tubes after each print. Dropped the temps to 205/200. Bullet proof since. It is on its fourth 48hour print in a row without unloading colors (large batch of the same things).
Read the threads here on clogs and things. If you find the issue that is causing yours (mine was temperature, but for others it was the chamfer on the PFTE tube, etc) and address it, you can find the MMU to be just as reliable as the MK2. Except you will get hooked on multi-color things, and will do far more of them than you expect.
At least that is my experience. Hope you find your issue, and you get to this point too.
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: Buyer's Remorse?
I felt the same, but am now into my 3rd multicolor print and starting to like my printer again. Will try a really long run over the weekend. For me it was probably the way the hotend was assembled. Taking it apart and putting it back together seemed to do it. Also I had to change to different filament, just couldn't find good printing parameters for the stuff I had. It would always block right below the PTFE.
One thing I'd like to mention: My printer sits in a room next to our bedroom, so I cannot run it overnight. On all three prints I paused it while we slept and restarted the print in the morning. No intervention necessary, no oozing. Absolutely flawless results.
Re: Buyer's Remorse?
Here are few suggestions based on what I've experienced.
- Check the ptfe tube in the hotend, replace if necessary, if it is expanded at the bottom due to clogging.
- Check your hotend fan, is the air flow the direction correct, does it have recommended air-flow if you have changed it.
I initially had problems with some of the filaments, they clogged and such. Now I don't have any problems except
one filament which I think can't be printed on MMU.
I've discovered that I've slightly damaged the PTFE tubing in the hotend. It was expanded a bit at the lower end while
pulling the filament out. I've changed the ptfe tubing and it made a dramatic difference. It was visibly larger at
the bottom and measured larger than the spare one. Now the unloaded filaments have pointy tips indicating a good separation.
So, I don't pull now, I push it down to extrude a bit and then pull when it is quite hot.
It seems like MMU requires tight tolerances for the filament characteristics.
For example, the protopast matte high tem pla, for some reason expands a bit, even though I've dried it +5 hours.
It just clogs mostly just above the nozzle at the bottom end of the ptfe tube or sometimes within the steel tubes.
It never happened with the direct drive and I printed many long prints and fine detailed prints as well.
I am guessing the larger diameters and the extra force of the direct extruder overcome the clogging.
Re: Buyer's Remorse?
I was having tons of trouble until dropping the default temps and properly calibrating the steps per mm and extrusion multiplier, the MK2 was much more tolerant of having too much flow. Now works great