MMU2S Pre-purchase Question  

RE: MMU2S Pre-purchase Question

Works just fine for me, the majority of my prints are still one colour. There are three approaches you can take:

1. Slice parts in MMU single mode. It'll ask you for a filament at the start of the print and unload it at the end.

2. (what I do) load a filament to nozzle, and slice parts for non-MMU printing (e.g. standard Mk3S). At the end of the print it stays loaded for the next job and I can run off more parts in the same colour.

3. Remove the extruder PTFE and direct-feed the extruder. (I do this if I need a colour/material not in my 5-spool drybox) You need to trip the FINDA  with a filament scrap as there's a firmware bug that causes the printer to reboot if IR=1 and FINDA=0. Note you lose filament runout sensing here as the MMU setup uses the FINDA for runout instead of the IR.

RE: MMU2S Pre-purchase Question

If the filament you want to use is already loaded, you can slice it in MMU mode and select the extruder you want to use.  If only one filament is selected no purge tower will be created and it will start printing without having to select the extruder.

RE: MMU2S Pre-purchase Question

Posted by: @charles-h13

I am looking at the MMU2 vs Palate.  How well does the MMU2 print single colors?  I want to print multiple colors but I do nto want to give up the ability to just print one.  

I've had the MMU2s for a month now.  Multicolor stuff was sometimes been finicky.  Now I can print 50 hours in multicolor PLA with just 0 or 1 interventions.  I'm still working on my PETG settings; right now I can do 20 hours of multicolor PETG with 6 or 7 interventions (only certain PETG filaments require interventions, so I think I'm close to getting this down).

But single mode has never posed a reliability problem.  The MMU2S is only involved in loading the filament at the beginning and after that has no effect.  I usually print in MMU2-single mode, where you slice the model, and then on the printer (or in octoprint, with the right plugin), you get asked which of the 5 filaments you want to use, and then it loads that one and does the print in that color.

I would say the following:

the filament buffer included with the MMU2S makes it annoying to change which 5 filaments are in the MMU2S.  If you mostly just have 5 at a time, this might not bug you.  There are various ways to eliminate the buffer (it's job is just to prevent filament from tangling when it is retracted back to the spool by the MMU2S, or, perhaps more simply, to improve the buffer to make it easier to load.  Like with this:

https://www.thingiverse.com/thing:3545935

Also, I would highly recommend this mod for the MMU2S which improves how the PTFE tubes from the buffer connect to the MMU2S:

https://www.thingiverse.com/thing:3233579

As vintagepc says, the "load to nozzle" feature means you can do single-color prints with gcode that was sliced for an MK3S instead of an MK3S+MMU2S.  The MMU2S puts the filament into position, and then from there, the printer follows the gcode intended for a single-filament printer.

RE: MMU2S Pre-purchase Question

Posted by: @vintagepc

Works just fine for me, the majority of my prints are still one colour. There are three approaches you can take:

1. Slice parts in MMU single mode. It'll ask you for a filament at the start of the print and unload it at the end.

2. (what I do) load a filament to nozzle, and slice parts for non-MMU printing (e.g. standard Mk3S). At the end of the print it stays loaded for the next job and I can run off more parts in the same colour.

3. Remove the extruder PTFE and direct-feed the extruder. (I do this if I need a colour/material not in my 5-spool drybox) You need to trip the FINDA  with a filament scrap as there's a firmware bug that causes the printer to reboot if IR=1 and FINDA=0. Note you lose filament runout sensing here as the MMU setup uses the FINDA for runout instead of the IR.

@charles-h13, this is the best answer. It covers every way you would use it with the MMU.

Let me add to this:

If the filament is in my dry box and I want to just use one of them, I just slice it in MMU single mode (option 1 above). This will still use the idler and selector motor to pull it through to the extruder. In most cases, this is as reliable as the MK3S, but I still have some issues from time to time as you still have to make sure your MMU2S is set up correctly.

If it's not, I use a filament spool on one of the provided Prusa spool trays, put it on top of my Lack enclosure, slice it as I normally would a MK3S, and direct feed the extruder (option 3 above). In addition to this though, I also completely bypass the MMU2S by disconnecting the power cable from the unit. If you have the underslung panel mod ( https://www.thingiverse.com/thing:3211711) , this makes it stupid easy. Next time you power on your printer, it will think it's a normal MK3S and it will completely bypass any MMU2S component (no need to worry about the FINDA, selector motor, or anything).

The palette is probably more reliable for multi color prints because of the stupid buffer the MMU2S comes with to deal with retracted filament (compared to internal buffer of the palette). You have to remember, if filament is left in the buffer for days, it will become brittle because of the tension on it and end up breaking, which means you'd have to feed it in again from the spool, which is a chore.

For single prints though and the occasional multi color print (which is basically my use case), MMU2S is fine. Just expect to have a lot of trial and error setting up and finishing a multi color print. Also keep in mind it's significantly cheaper than a palette. Once it's dialed in, I think it's the way to go because of the community here + PrusaSlic3r which is especially designed for it.

RE: MMU2S Pre-purchase Question

Yes, I ditched the buffer in short order. My setup has auto-rewinders inside the drybox so at worst only the very end of the filament gets brittle. Cut off a foot or so and you're back in business if it's sat too long.

RE: MMU2S Pre-purchase Question

Posted by: @vintagepc

Yes, I ditched the buffer in short order. My setup has auto-rewinders inside the drybox so at worst only the very end of the filament gets brittle. Cut off a foot or so and you're back in business if it's sat too long.

Not to hijack this thread, but do you have a list of everything you used for a 5 filament drybox with autorewinders? That would be ideal. I wasn't able to find a good solution for this as it seems most autorewinders assume you are placing them standalone on a bottom or top shelf. Or the only drybox style ones I've seen are single filament ones made out of rubbermaid containers.

And yes, the buffer is awful. That alone takes so much effort to get properly mounted / fed / etc.

RE: MMU2S Pre-purchase Question

The palette is probably more reliable for multi color prints because of the stupid buffer the MMU2S comes with to deal with retracted filament (compared to internal buffer of the palette). You have to remember, if filament is left in the buffer for days, it will become brittle because of the tension on it and end up breaking, which means you'd have to feed it in again from the spool, which is a chore.

I'm not sure about this.  It depends on what you mean by reliability.  When the palette has a problem I think it usually means your print is ruined.  Whereas when the MMU2S has a problem it means it needs your attention.  One thing the MMU2S is really great about is holding a print (even for 12+hours) while it waits for your attention (with the print head near the wipe tower, not the object), and then continuing it without any sign that anything was amiss.  I have yet to lose a print due to an MMU2S failure.

RE: MMU2S Pre-purchase Question

That is a lot help - thanks all.

RE: MMU2S Pre-purchase Question

Posted by: @wpegden

The palette is probably more reliable for multi color prints because of the stupid buffer the MMU2S comes with to deal with retracted filament (compared to internal buffer of the palette). You have to remember, if filament is left in the buffer for days, it will become brittle because of the tension on it and end up breaking, which means you'd have to feed it in again from the spool, which is a chore.

I'm not sure about this.  It depends on what you mean by reliability.  When the palette has a problem I think it usually means your print is ruined.  Whereas when the MMU2S has a problem it means it needs your attention.  One thing the MMU2S is really great about is holding a print (even for 12+hours) while it waits for your attention (with the print head near the wipe tower, not the object), and then continuing it without any sign that anything was amiss.  I have yet to lose a print due to an MMU2S failure.

Good point, you can technically have a bunch of failures on a MMU2S setup and recover it manually for the most part. I guess I meant more that a MMU2S set up would fail more than a Palette, where strings and loads/unloads are rarely an issue with their internal splicing mechanism. But that also has it's issues.

Overall I just prefer the MMU2S. Once you understand how it works, it gives you the most flexibility. $300 upgrade for it is a no brainer, although I do wish some of the components were better thought out.

The Palette is more like an iPhone (even with cost) with a set it and forget it mentality whereas a MMU2S is like an Android where it gives the user the options to do what he/she wants. They both get the job done.

RE: MMU2S Pre-purchase Question

First let me say that once I got things sorted with my MMU, I have been happy with it and had few problems.

The last few weeks I've been trying to help a coworker get a MMU working. This is a guy who has built multiple MK3s (he built up so many spares for his first over time that he was able to assemble 2 more!), has done a full Bear upgrade on one, and swapped to a Bondtech + Mosquito on one, so he is far from clueless about how these things work. He has had all the usual issues, plus others I haven't run into or read about. I'm sure if I was there to help him in person we could knock it out quickly, but being multiple states apart prevents that.

Contrary to his MMU experience so far he installed a Palette on one of the other MK3 printers and was printing in under a day. So far he hasn't had any failures or miscolorings. It also allows you to use their painting program (which he says works pretty well) to colorize single object models.

So based on second hand experience I would say that if you just want a simple and quick payoff, the Palette is the better choice. If you are up for a challenge and have the patience to work through it, however, I think the MMU has features that make it a better tool for some situations (true multi-material, better error recovery, better integration with other printer features, etc..). We also know that when Prusa makes changes to the MMU that we will be able to get an upgrade kit rather than having to buy a whole new unit, so not only is the MMU cheaper in the short term it will likely be cheaper in the long run too.

RE: MMU2S Pre-purchase Question

@gnat

Agree with you.

The only thing is. Having x Prusa printers build or having y 3d printers rebuild doesn't mean much. With all the great guides available, it's like assembling LEGO parts. If you stuck somewhere, ask in the forum or FB and you will get immediate response. You don't need to be an engineer or have special skills/education to do that.

With MMU it get's complicated because there are no guides which explains you how everything works in detail. You can have mechanically everything set correct by the guide and still have issues. Without deeper understanding it's hard to find the right screw to tension/loose or change the right parameters in the slicers. The good thing, everything is open source and available. You should be able to dive as deep as you want.

If I compare the first MMU2 version (which I've received) to the one which is available right now (upgraded mine as-well), I can tell it got a lot better. Failed prints because of skipped layers are no longer an issue. The amount of interventions required hardly depends on the material and settings used.  

RE: MMU2S Pre-purchase Question

Posted by: @nikolai-r

@gnat

Agree with you.

The only thing is. Having x Prusa printers build or having y 3d printers rebuild doesn't mean much. With all the great guides available, it's like assembling LEGO parts. If you stuck somewhere, ask in the forum or FB and you will get immediate response. You don't need to be an engineer or have special skills/education to do that.

I agree. I was paraphrasing his experience into more concise items that are recognizable rather than double the size of my post for little use 😉 

The point is that he is quite used to fiddling with the hardware and debugging issues as he has been an early adopter for many changes and mods.

RE: MMU2S Pre-purchase Question

Also, forgot to mention, any cloud based software (e.g. Canvas) is a no go for me. Cloud software needs to die. Prusa encourages improvements to their open source design. It's so open that you can build your own MMU2S if you choose to do so, or your very customized Slic3r.

So that made my choice pretty easy.

RE: MMU2S Pre-purchase Question

Posted by: @nimaim

Also, forgot to mention, any cloud based software (e.g. Canvas) is a no go for me. Cloud software needs to die. Prusa encourages improvements to their open source design. It's so open that you can build your own MMU2S if you choose to do so, or your very customized Slic3r.

So that made my choice pretty easy.

^^ That should definitely be considered. If the service goes away, you're left with an expensive brick unless someone steps in to fill the void with a replacement service. The only people SaaS benefits is the provider since it's basically free money. It's definitely happened a few times already with high profile companies/products, often after an acquisition and the new owner doesn't want to continue to support the product.

RE: MMU2S Pre-purchase Question

Posted by: @vintagepc

Posted by: @nimaim

Also, forgot to mention, any cloud based software (e.g. Canvas) is a no go for me. Cloud software needs to die. Prusa encourages improvements to their open source design. It's so open that you can build your own MMU2S if you choose to do so, or your very customized Slic3r.

So that made my choice pretty easy.

^^ That should definitely be considered. If the service goes away, you're left with an expensive brick unless someone steps in to fill the void with a replacement service. The only people SaaS benefits is the provider since it's basically free money. It's definitely happened a few times already with high profile companies/products, often after an acquisition and the new owner doesn't want to continue to support the product.

All of the above applies to the non-open source hardware too.   With proprietary hardware you are at the mercy of the manufacturer to provide replacement parts.   If they go out of business,  you maybe out of luck.

RE: MMU2S Pre-purchase Question

Posted by: @bruce-p4

Posted by: @vintagepc

Posted by: @nimaim

Also, forgot to mention, any cloud based software (e.g. Canvas) is a no go for me. Cloud software needs to die. Prusa encourages improvements to their open source design. It's so open that you can build your own MMU2S if you choose to do so, or your very customized Slic3r.

So that made my choice pretty easy.

^^ That should definitely be considered. If the service goes away, you're left with an expensive brick unless someone steps in to fill the void with a replacement service. The only people SaaS benefits is the provider since it's basically free money. It's definitely happened a few times already with high profile companies/products, often after an acquisition and the new owner doesn't want to continue to support the product.

All of the above applies to the non-open source hardware too.   With proprietary hardware you are at the mercy of the manufacturer to provide replacement parts.   If they go out of business,  you maybe out of luck.

 

Sure, but at least with physical hardware the hardware continues to function after the manufacturer goes away (barring IoT garbage which is the worst of both cases). So it still has a useful service life until it does fail. Not when the manufacturer has decided you've had enough use out of it.

RE: MMU2S Pre-purchase Question

All good points.  Thanks.  

RE: MMU2S Pre-purchase Question

Posted by: @vintagepc

Sure, but at least with physical hardware the hardware continues to function after the manufacturer goes away (barring IoT garbage which is the worst of both cases). So it still has a useful service life until it does fail. Not when the manufacturer has decided you've had enough use out of it.

Unless the hardware relies on single source consumable parts that the manufacturer decides not to make or sell anymore.

An example is the TAZ 6 wiper pads that are currently very limited availability.  

RE: MMU2S Pre-purchase Question

Posted by: @charles-h13

All good points.  Thanks.  

The bottom line is that both the MMU2s and the Pallet have their own issues.   I have spent equal amount of time troubleshooting both of them.

Right now they are both working well.    They both could just stop working tomorrow.