Multimaterial limitations?  

Re: Multimaterial limitations?

The minimum layer height is 0.15mm and variable height isn't really available. From what I've heard (and this may not be true), but abrasive filaments cannot be used. You need a smooth heat break and running something that is abrasive apparently ruins it. To my knowledge, Prusa has given no confirmation on that though.

I didn't know about any trade-offs during the pre-order. Maybe they just hadn't been found yet. Filament providers also seem to be an issue. MakerGeeks is giving me hell with the MMU. Hatchbox seems to work fine.

Re: Multimaterial limitations?

The minimum layer height is 0.15mm

Same as the single filament printer

variable height isn't really available.

Yes it is. Did you not see my thread about variable height printing?

As for abrasives vs heat break; that's a bit of a myth. As with the single filament printer. it's the PTFE which will suffer and that is replaceable.

Peter

Re: Multimaterial limitations?

There are a couple of limitations from my experience:

- cannot print flexibles as well (or at all depending on how flexible)
- needs more table/cupboard/whatever space
- As of today, the documentation and un-official support is severely lacking, compared to the standard MK2
- The software is still under heavy development, and it can be tricky to find out how exactly everything is supposed to be used together.
- I have not managed to get the same perfect print quality i had before the upgrade. I'm almost certain its possible, but certainly harder to get right. (might be just me ..)

On the plus side:
- It's cool as **** 🙂
- software and documentation will improve once the summer vacations are over

I guess it comes down to:

Do you need multi material capability? if yes, then buy it, it works, its just not as "smooth" of an experience as the normal mk2

If not, I would consider waiting a month or 2 until you have better documentation and software.

Re: Multimaterial limitations?

its just not as "smooth" of an experience as the normal mk2

Having been using the MM upgrade for around 8 months, I can honestly say that for me it is exactly the same as the single filament print, but betting in the result.

I now expect the prints to complete without issue; a while back is was just a hope. It may be me getting used to it, it may simply be that the parts have now "run in", but whatever it is, the only issues I now have are choosing the right extruder and slicer settings.

Peter

Re: Multimaterial limitations?

its just not as "smooth" of an experience as the normal mk2

Having been using the MM upgrade for around 8 months, I can honestly say that for me it is exactly the same as the single filament print, but betting in the result.

I now expect the prints to complete without issue; a while back is was just a hope. It may be me getting used to it, it may simply be that the parts have now "run in", but whatever it is, the only issues I now have are choosing the right extruder and slicer settings.

Peter

Oh, I don't want to imply I have more failed prints. Once I managed to find out which slicer version needs or deosnt need the post processing, and which settings are right for which mode, it prints as reliably as before. (with a bit of stringing and a rougher surface on some parts)

Its just that getting here was a different experience from the pure MK2.

As I said, i think its mainly a matter of documentation and transition between old slicer and new slic3r.

Re: Multimaterial limitations?

Its just that getting here was a different experience from the pure MK2.

Agree with that! Basically it's a new printer which takes longer to get used to than the single-filament version.

You really do have to get to know the printer and the filament you use and be more precise with slicing and slicer settings.

Peter

Re: Multimaterial limitations?

Here's another limitation for the multimaterial printer:

Doesn't work out of the box with 0.25 diameter nozzle. The Multimaterial Slic3r errors out with a message "The wipe tower is currently supported only for the 0.4mm nozzle diameter".

This is a big problem for me. Am trying to figure out what to do to get this to work. Looks like the source code enforces the 0.4mm nozzle restriction.

Re: Multimaterial limitations?

Just received my MMU kit, but due to other commitments I will have to postpone the upgrade a bit.

At time of ordering, I was not aware of the layer height restriction (150um). @Peter, why do you say that single filament is restricted to 150um as well? It's possible to go much lower (e.g. 50um). Seems I'm missing something here...

0.4 nozzle restriction is also new for me. Any details on why smaller and/or bigger could be an issue?

Haven't had the time to look at the new slicer, but are the limitations hard coded or are other settings just unsupported?

Rgds,
Arnaud

Re: Multimaterial limitations?

For clarification, the first layer minimum height is 150 microns; all other layers with the MMU are 70 microns (due to the fewer E-Steps), but I tend to set the minimum layer height to 75 microns, which produces a good enough finish.

The tower is currently only programmed to work with a 0.4mm nozzle. This may change in the future - it's certainly something I a looking to change within my post-processor. Larger nozzles may work, but are untested (or are not officially tested). As the tower extrudes at up to 0.5mm line width, smaller nozzles may not be able to cope.

Peter