Filament issues
So, guys, after basically trying every spool of filament I have around I'm now in the following situation:
I have 8 spools I cannot use with the MMU (Ingeo 830). I systematically iterated through retract length, retract speed and temperature, made sure that my filament path is good and my gear tension is optimal. I confirmed material diameters for several meters of each spool. Material is expensive here. I store my material in dryboxes and use it up within a year, but still I opened a fresh spool to make sure it's not somehow storage damage or moisture.
Then I bit the bullet and ordered some Fillamentum (which I knew works well) and Prusa PLA (which is cheap and worked well) at PR. Fillamentum is almost impossible to get here, and the tax handling charges are killing me, so I made a big order. And guess what, the very first Prusa PLA spool I opened up refuses to print. The material thickness meanders between 1.71 and 1.80 within only 20 cm.
4 colors means 4 spools. If even the "official" Prusa filament doesn't work reliably, and you also consider a manufacturer mix (because of color selections, local availability etc.), how can I ever trust my printer again? What happens if Fillamentum or <fill in your favorite brand here> change their mix or pigment, build a new factory, or whatever? These are small companies and it happens all the time. It ultimately means you can never ever again order more than one spool at a time, which in my country means it is twice the cost due to postage. A spool randomly might not work, and the seller will probably refuse to take back an opened spool (which I would understand).
In principle you need a second printer to use up the filament which is incompatible with the MMU. In my understanding the people who never had issues were just lucky and probably using the same filament brand all the time which happens to work. Personally I had every single problem ever reported on this forum, and the filament issues thrown on top of that. I'd never have believed the filament could be an issue because I have used the stuff for more than a year on several printers without a single problem. I don't have any issues if using only Fillamentum, but as I said I'd much rather use something I can easily get locally.
For now, the most reasonable approach is certainly asking PR for a replacement spool which I'm sure they'll send me. There are other indications this is just a bad batch (discolorations and the color doesn't at all look like it should). But the base problem remains and I'm really not sure what to do. My MMU might end up on ebay.
Re: Filament issues
I'm kinda in the same state of mind as you. I don't really know what to do with my MMU. None of my spools of filament works reliably. Some of them fail each time, like you said Natureworks Ingeo based filament or PVA soluble support. I got filament stuck in every part of the extruder head, skipping/clicking, incomplete loading of filament, ... Most of my print are just failure, and that starts to make a lot of wasted filament and time.
I really wanted this to work, but I think I'll just revert it back to a single filament printer.
Re: Filament issues
Hi,
After two months since upgrade MK2 to MMU, I think similar than you.
I've tried everything mentioned on this blog (specially the advices by Peter on the Blockage topic, and including the installation of a brand new hotend kindly replaced by Prusa).
But, anyway, since upgrade to MMU i've printed only one or two multimaterial models (¿good luck?). All the other tries to print MM were a failure.
I've printed successfully in single mode but only after adjust the temperature for the precise spool of filament used. And this after loosing the original quality I used to have with the original MK2.
I printed the temp tower for the different filaments i've around (ten spools of prusa, ingeo, bq, etc...) and determined that one prints well in the range of 180-215ºC (i.e. bq) since other only between 210-215ºC (i.e. ingeo).
I concluded this:
1. Bowden printers are very much difficult to fine tune than direct drive printers (I've the Prusa MK2 and the Anicubic Kossel, and know well the difference). And much more if you try to print with four different filaments.
2. Mixing different filaments (with different fuse temp) complicate very much printing with multimaterial. Just because the different "ideal" temperatures.
3. Blockages can be by a lot causes: temperature not "ideal", not unloading after finished print job, bad seated PTFE, gears on extruder motor not aligned, extruder screew-spring not adjusted, etc. etc. etc... a lot of causes. I haven't any blockage with the original MK2, never.
4. With MMU (bowden) it almost impossible to print with flexible material.
5. I've lost the 0,05mm layer height after upgrading to MMU
Also I suspect that after upgrading to last firmware some things go better (first layer height) but other things go worse (nozzle temperature control).
So I am only one step away from mount again the extruder motor near to the hotend and use the printer like the original MK2.
I'm thinking about a mix system (mentioned in other topics of this forum) where four motors "collaborate" with the 5th motor. I will study the alternatives and try to do something about the next Hollidays.