MMU2 on sale $299  

Re: MMU2 on sale $299

Guys, what about purge block? does it remains same as in MMU1?
Rumor says some percentage of purge block would be used as infill? is that confirmed by Prusa?

Also, would it be possible to combine different materials such as flexible + abs or something like this?

Re: MMU2 on sale $299

Guys, what about purge block? does it remains same as in MMU1?
Rumor says some percentage of purge block would be used as infill? is that confirmed by Prusa?

Also, would it be possible to combine different materials such as flexible + abs or something like this?

Completely unknown, In my opinion there is no software for MMUV2 Yet.... nothing. it's a prototype. They haven't showed it actually functioning yet but given they added more people to the slicer team, i think this is for MMUv2 and will most likely try to purge inside the model.... but just a guess.

Re: MMU2 on sale $299

My understanding regarding the purge block used in infills is that it will be software related (Prusa edition of slic3r) and therefore compatible with both version of MMU.

Infills made from the purge block would be really nice as it may speed up the print and be more economical for the filament as the time and filament both used for the purge will be part of the regular printing operation. I suspect it may however require that at least the infill surface of the object is at least equal or higher of those of the current purge tower.

Re: MMU2 on sale $299

So we know nothing about how it works right?

It has to push the filament back up to the block for every filament change doesnt it? sooo wont that just mess up every near full spool of filament?
i am using a reverse bowden drybox setup and if i unload filament without disconnecting the bowden it just unwinds the spools and the filament jumps over the sides of the spool. That makes it realy a hit or miss situation wheter or not i can feed correctly after that.

Wont that just take quite some extra time at each filament change?

There is some sort of knife in the changer block. is that cutting at every filament change?

I am exited for a direct drive MMU. but at this point it seems cracy to anounce and put up for preorder without any proof of concept..

And to be honest with all the problems the MK3 still has it feels like those Problems are beeing ignored since now a part of the prusa teams is obviously working on the mmu instead of making the MK3 as reliable and perfect as the MK2s is

Oh and advertising a second filament sensor is not a good thing in my book 😀 They have not adressed the huge problems with false triggerings with translucent or white or some greens or glossy black and and and and
so a second one just screams more problems with the filaments i personaly use if its the same sensor and system.

Re: MMU2 on sale $299

I don't think it will mess up the spool. I have MMU1.0 . The retraction is lower than what is expected with MMU 2.0 but even after a full unloading with MMU1.0 which is probably the closest of what MMU 2.0 will do, the PTFE tubes and the spool holders, as stupidly simple as they seem never lead to some entanglement so far.

I however think that the load/unload process during the filament change will take longer than with MMU 1.0 which is not really appealing considering multimaterial printing takes way longer because of the purge operation. However if they manage to combine infills and purge, multimaterial printing will probably become closer to single mode printing in terms of time even if it always be longer due to the filament change process.

The cutter from what I've seen is just a cutting tool in case something is jammed. It doesn't seem to be part of the regular operation of the MMU.

Re: MMU2 on sale $299

Unfortunatly using infill and purge probably doesn't work well for soluble support...

- Martin

Re: MMU2 on sale $299

nor will infill from purge material work, properly when the new filament is transparent translucent or light coloured, following a dark colour.

the old colour will show through

regards Joan

Re: MMU2 on sale $299

So we know nothing about how it works right?

It has to push the filament back up to the block for every filament change doesnt it? sooo wont that just mess up every near full spool of filament?

Hi Oliver,
if you have your feed tube split, so that one end is anchored to the MMU and the other is anchored to the spool cabinet / holder, when the filament is retracted, the middle split in the tubes will part and leave the spare filament in midair, rather than pushing it into the spool holder / cabinet. this will prevent it from pushing the filament over the edge of the reel

regards Joan

Re: MMU2 on sale $299

Hi Joan,

Interesting! Have not thought of that.
I started the hole Drybox reverse Bowden thing with trying to avoid moisture as much as possible.
So splitting it might be a solution for PLA but i am not sure if i want to do that with PC or Nylon.
But interesting idea none the less. I will keep that in Mind if i ever buy the MMU 2.0 (and if thats actually a problem)
Thanks !

Re: MMU2 on sale $299

I am excited for this product!

Re: MMU2 on sale $299

The way how the recent E3d toolchanger purges filaments looks good.

Basically it just dumps the last bit of filament into a dumping area outside the print bed, then move the nozzle to rub it against a brass brush to clean it before extruding next type of filament.

The advantage is that there is no need to build up a purge block.

The disadvantage is that the nozzle is needed to be able to move outside the print bed, don't know if it is possible with the current MK3 config.

People have already pointed out the limitations of using purge material as infill. I think E3d is moving towards the correct direction. Prusa should take a look at it.

Re: MMU2 on sale $299

Agreed, in the long term separate toolheads are the way to go. But: You need enough space in your geometry, and a lot of work still needs to be done on the slicer side. And each toolhead is an additional investment (at least one motor, gear and a complete hotend).
The Prusa approach has the potential to work now, at a < 1000 € budget (which I would still call hobbyist). Maybe if the E3D platform becomes a de-facto standard we will see these systems around 2000€ in a few years.
The chances are not bad, their implementation of corexy with linear rails is certainly the way to go. There are a lot of great builds out there using the same principle, e.g.
This guy has a magnetic head changer in place, the print speed and quality is amazing.

Re: MMU2 on sale $299

Separate extruders have been around for some times now. I think about the BCN3D sigma for example. Not to have to swap filament reduce the print time but for some reason (e.g. http://3dprintingcenter.net/2016/06/13/sigma-from-bcn3d-3d-printer-review/ ) there's also a purge tower on that printer because it seems that without that, there are more defects on the print. I suspect it's because the temperature is probably lowered when an extruder is at rest while waiting its turn for the print.

So yes, infills with purge tower would be nice but sure limited if the filament is transparent, soluble, flexible... well, maybe simply mixing too different filament will results in a mess. But the option to have a purge tower or to use infill or both would be nice in slic3r.

Re: MMU2 on sale $299

Agreed, in the long term separate toolheads are the way to go. But: You need enough space in your geometry, and a lot of work still needs to be done on the slicer side. And each toolhead is an additional investment (at least one motor, gear and a complete hotend).
The Prusa approach has the potential to work now, at a < 1000 € budget (which I would still call hobbyist). Maybe if the E3D platform becomes a de-facto standard we will see these systems around 2000€ in a few years.
The chances are not bad, their implementation of corexy with linear rails is certainly the way to go. There are a lot of great builds out there using the same principle, e.g.
This guy has a magnetic head changer in place, the print speed and quality is amazing.

You don't "need" linear rails. depends on the application... look at print quality between solid v-wheels (even mini) and hwin rails. there is none. you could build the D-bot and put the tool changer on it, they will be selling the changer servo locking mechanicsm and kinematic couplers separate and it's 100% open source.

Far as price goes, depends who makes it. Brands like ultimaker would sell that thing for like 10k....

Re: MMU2 on sale $299

Well I guess whether you go for linear rails or not depends on a lot of factors, they are certainly not without problems. And expensive. My own boring corexy runs on sensible smooth rods/bearings/belts and I'm quite happy with it (but only 220x200).

If I had more time and money, I'd go for the E3D approach (maybe not the Z axis, but time will tell). Using a massive base plate for stiffness and simplicity is very appealing. It's easy to close off and keep the electronics out of the heat. Probably another reason why they went for rails is the assembly time, getting this thing smooth and square will be easy if production tolerances for the plate are good. After all, the target market is probably (very) ambitious hobby use & small business, so not too much fiddling. The only thing I don't like is their belt standoffs, they seem a bit flimsy. They could have given credit to similar existing designs though.

I never had a Sigma to play with, but I don't see why it would need a tower. You can brush off filament and dump any excess in a bucket. The artifacts mentioned in that article are not shown...could be any number of other reasons. It's kinda hard to believe Sigma would overlook this kind of quality issue. I'll test one if ye goode olde Ultimaker ever dies 😆

Re: MMU2 on sale $299

No video of it working, first new version had issues, prusa production delays. Learned my lesson with the MK3 it better to wait a year and let the beta testers that have cash to burn work out the bugs