First decent print from MMU 2
Thought I would post something positive as I have just had my first multicolour print turn out with no defects.
Like alot of other people I had MMU V1 and gave up then got MMU V2 and still had problems with jams when doing multicolour but after alot of messing about I'm really happy I've managed to actually get something to work.
After days of tuning hardware and settings in slic3r I'm ready to try something with more tool changes.
To everyone having problems don't get frustrated and really take the time to get the setup perfect for the material your using. It's worth it in the end.
Re: First decent print from MMU 2
Can you elaborate on which calibration/hardware tweaks/slic3r settings you ended up changing to get this awesome print?
Which ones seem to help the most?
Re: First decent print from MMU 2
just so you know, I have been having very good luck with all default settings,
everyone seems to have different issues.
it is nice when you first start getting prints out. I swear to god. start low layers.. then just up 50mm or so. baby steps. filament loads abit different as you get higher. well as I get higher anyhow
I have a Prusa,therefore I research.
Re: First decent print from MMU 2
I'm sure everyone's setup will be slightly different depending on how the machines setup and the environment it's working in.
I have hardened nozzle fitted. The filament spools are about 1 meter back from the machine about level with the base feeding from the bottom and I'm not using the guide things just the PTFE tubes hanging in mid air.
I made sure to check everything in the 101 guide on YouTube, everything seemed fine bar a couple small tweaks to the top barrel on the MMU to align the bearings better with the knurled rollers and the tension screws in almost flush on the extruder idler and just past flush on the MMU.
Loading would be clean but unloading would cause a bit of grinding. I reduced the unloading speed in slic3r and the grinding stopped.
Next was trying to tweak the temp and ramming settings to get the best looking tip possible on a tool change. This is really the most important thing in my opinion. A wrong setting produced a hair on which won't cause a jam straight away but they build up and eventually one with cause a jam or cause the finda ball to get stuck. A wrong setting the other way would produce a bulge on the end of the filament which would cause too much friction when loading and unloading and would eventually cause a jam. You want to find a fine balance to get a clean tip on the end of the filament with no bulge or hair.
This has to be setup and fine tuned for each filament you have, I'm not far off the default settings but small changes are enough to go from constant jams to getting clean tips on every change.
As an example I'm using 3D filaprint PLA, for most of them I've found 205 first layer temp dropped to 200 with loading speeds at 19 initial going up to 22, unloading speed of 80 going down to 10 coolling moves 2 and ramming settings increased to 4 seconds. For the silk PLA they do I use exact same settings except unloading speed is slightly higher at 90. The traffic black PLA they do comes in a vacuum pack instead of a box and I haven't been able to get that setup yet, I'll have another go at setting up the black but may end up just changing to a different brand, it's perfect on single colour prints but just won't give a nice tip shape on any of the settings I've tried so far so not suitable for more than a few tool changes before causing a jam.
It's great if the default settings work but if your having problems just a slight tweak of a few settings might make the difference.
Re: First decent print from MMU 2
Yikes. That tip calibration sounds like a time-eating nightmare.
If this has to be done for each filament, that's quite a bit of calibration.
I think it would be nice if the firmware had some kind of... filament tip calibration mode, that would be nice. Similar to the live-Z calibration test.
Something where it would go through all the steps you mentioned, and let you tweak each variable, then form a tip for you.
You could then manually input and save those settings in Slic3r, for later use.
Re: First decent print from MMU 2
I used this https://www.thingiverse.com/thing:3112541 and printed at 200% scale on Z so that it does a change on every filament on the first layer temp and one at the normal printing temp. Kept doing these with small tweaks to settings in slic3r until all the tips looked good. It is alot of time just to set things up but should pay back in more successful prints in the long run.
It would be handy if there was a setting that allowed you to run one temp for printing and change the the temp slightly for doing a filament change, even if this causes a short pause while changing temp it would be worth it I think for better finish on the print. I assume this could be done manually editing some g-code so might give it a go on something simple when I get some spare time.