I have a Prusa MK3 with the MMU2, and I definitely plan on upgrading at some point to the MK4 and MMU3. Since I don't have any direct experience with any multi-material options other than the MK3 with MMU2, the only thing I will say is to ensure that whatever you buy is an open source printer. I cannot tell you how much of a difference that makes when there are so many incredibly smart makers in the community that can take full advantage of that to provide solutions for basically any problem. My first printer was closed source, and I had a document that was several pages long that broke down everything that you needed to do (and not do) to get that machine working well and upgrade it yourself within the confines of what was possible. Prusa support is top notch, as is their quality. I can't recommend the brand enough, even if I don't have experience with the latest multi-material options.
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My current printer is a MK3S+, and I love that Prusa is still pushing firmware updates for it. However, my personal experience with the machine has been pretty lackluster with multiple parts breaking and sub-par print quality. In fact, something else just broke yesterday (I have yet to diagnose exactly what) which is making me more eager to upgrade. I do wonder if I just got unlucky considering their reputation, but I can't say I'm rushing back to then with enthusiasm.
I do agree with your general point about open source. For that reason, the Prusa, Voron, and Ratrig are the most intriguing options. However, if one of the other two are likely to provide a better experience, I think it's silly to not even consider them.
I'm definitely surprised to hear that you've had so many problems with your Prusa. Mine has been smooth sailing pretty much since day one.
That’s wild, I’ve put dozens, maybe even hundreds, of days print time onto my MK3S+, never followed any maintenance regimen. The only issue I’ve ever had was with the MMU2S, and it was a printed part so I just printed another and it’s been going for days print time again. Voron is a sweet beast, if you go that way, buy a kit. Self sourcing was an expensive endeavor and frustrating at times.
Did you build your MK3S+ or buy a prebuilt?
Admittedly, I bought it used. However, it had very little use and was a prebuilt model. I'd be surprised if that has much to do with the issues I've had since I didn't have any issues the first month or so.
The issues I've had have been all over the place from fans breaking, to having to reflash the RasPi I put in it, to it digging the nozzle into the build plate and ruining it. At one point, the print lifted off the build plate and clumped up to the point I had to replace most of the hotend, although that could happen on any printer I guess.
I think I'm leaning towards a Voron kit. Self-sourcing sounds awful.
Note that I don't own a multi-filament setup so I can't speak from personal experience, but this is after I'd done extensive research into it and determined it wasn't worth it for my personal use case.
What kind of parts will you be printing in multi-material? The kind of prints you are doing will greatly determine the best approach. Some smaller prints with many filament changes will result in purge blocks with more mass than the part itself.. ie more than double normal filament usage.
IMO the tool changers are the way to go and I think we will be seeing more of them in higher end machines. I personally wouldn't use multiple materials for the sake of colors, but different tool heads offers the ability to print with different materials at different temperatures, as well as different nozzle sizes or different setups altogether. For example you can have a 0.6 volcano nozzle for the bulk of your print, a standard 0.2 nozzle with the same filament for fine details, and a 0.4 nozzle with a water soluble filament for supports.
This is just speculation, but I'm betting that we'll see tool changers with more than just extruders on deck - imagine if you could add a Dremel head for post-print sanding, or a drill bit to clear out holes.
I have an MK4+MMU that I bought partially with the intent of building PLA-supported PETG and TPU parts. I haven't dug in too far yet but in the few prints I've done the PLA has severely degraded interlayer adhesion. Presumably this can be addressed by purging (much) more on changes from PLA, but if I had known this before I bought, I would have seriously considered a multi-head printer.
My understanding is that PLA and PETG will not adhere together, so I guess if there's any residual PLA when printing the PETG it will cause it to not adhere fully. Makes sense and is a perfect example of where a tool changer would be incredibly useful.
I'm assuming you're using PLA to support the PETG parts because of their inability to adhere to each other? Don't know if you've seen it, but if you have relatively large, flat overhangs that need support, you can color in the top layer of the supports with a permanent marker. This will cause the same inability to adhere and you can snap the part off easy. Not really practical for multiple areas of support or if you need something like tree supports, but if you've got angular parts or similar could save a lot of time
I'm curious to hear if you find a solution to this as you play with it more. I think some people are able to make it work with some setups, so I'm curious if something makes the Prusa different. If there isn't a way to make it work, I think this has to be crossed off my list of options.
I like to do a large variety of prints. Small, big, batch, even using separate filament for support. So yes, I expect to use lots of purged filament, but I don't think that is really avoidable.
I agree that tool changers are probably the endgame. However, given that the Prusa XL is the only one on the market, and no other brand has even announced anything, I think its going to be at least two years before an affordable high-quality tool changer hits the market. I think these are my options in the mean time.
I do know about the DAKSH, but given that it's an early community project, don't think that will be ready any sooner.
How quickly do you need to get a setup going? The way I like to approach these kinds of things (printers, computers, etc) is to get a good platform that will support what you want to do in the future even if it can't do it now. If you're thinking about a DAKSH setup on a voron, I would build the voron now with the DAKSH in mind and build that add-on when it's more available.
What I would be trying to avoid is getting something like the ERCF and then getting buyer's (builder's?) remorse if significant progress on the DAKSH is made shortly after. Yes, the ERCF let's you print multi-filament NOW, and you could theoretically use it with a voron and then upgrade it to a DAKSH system later, but if you invest in that approach, you likely won't want to rebuild your setup for a multi-tool setup.
All of this is assuming that you care about the other benefits of multi-tool, which of course you may or may not. If all that's important is multiple filaments with relatively similar properties, just get whatever is in your price range and you feel comfortable toying with. If multi-tool interests you at all and you don't need something right away, I'd build something with that in mind and feel out the progress before making a final decision.
My personal experience with a couple MMU2 on a mk3 at college is it's garbage. You have to sit there and babysit it as it will error frequently and the filament changer seems to need endless readjustment lest it jam with a filament sprig for the 55th time today. Maybe they are better if you customize them more and don't beat on them like college freshmen do, but... I like the idea but the ones i've used are not that fun.
Be careful of what other kind of filament changers you buy though. If you want to do multi material changes involving TPU, systems like the MMU where it's a single feed tube switcher seems to be OK, but integrated feeders like the Bambu Labs ams style will eat tpu for breakfast because it doesn't follow guided paths very well. I think? the ERCF can feed tpu fine?
I know this post is quite a few days old already, but I still wanted to add a bit to the discussion.
The printers you list vary wildly. Both in terms of design goals ("what is the printer meant to do well") and assembly requirement (from "ready to print in 10 minutes" to "you build this for like a week until something moves"). A Qidi is basically ready to go, a Prusa will take some time to put together (how much depends on if you got it as a kit or fully assembled). A Voron 2.4 takes about a week to build just for the printer, not including ERCF and/or tool changer, let alone tuning of said ERCF/tool changer.
Also there's the Troodon, which is a Formbot prebuilt that is closer to a real Voron 2.4 than a Sovol SV08, just to add to your list. It has a stock stealthburner tool head compared to the proprietary thing that Sovol uses, for example.
I've recently built a Voron 2.4r2 (Formbot kit) and loved it, but it was like my 4th printer (and a previous printer was a self-sourced scratch build). So do you have experience with 3d printers, and building them or tinkering with them? I would probably not recommend building one otherwise, but it's not impossible either, just expect a relatively steep learning curve if you have no prior experience.
Do you want to mostly just print in colors but same filament ype, or do you want to mainly have multi-material capabilities? So do you need 5+, or would 2 colors with the option to expand work for you?
If the Voron is a real option for you, I'd highly recommend it. Just make sure you're going with a can-bus based build/kit (like Formbot). These days I wouldn't go with an ERCF due to the complexity of building it and then setting it up, as tuning is supposedly a bit of a process. Also you mentioned that the amount of waste during multi-color prints is a real factor for you, and that puts single-nozzle systems inherently at a disadvantage as you just have to purge the hotend on every change. So I would suggest a tool changing system, and I would either start with that (but just 2 tool heads), or add it as the first project. Specifically, I would suggest using the Tapchanger as a modern system. Frankly adding a tool head like that is much less effort than building an ERCF, but also just adds 1 filament each and not like 9 at once.
Thanks for replying! I like your suggestions.
One small addendum/correction: I meant Stealth changer (which is based on Tap changer), but got the names confused.
I can't speak to multi colour perse, however the creality K2 went on sale today for certain countries and they have a 50% off sale for a limited number of units, they sold out today's stock but will have it again tomorrow then they will drop to 40% then 30%. Might be good if your willing to be a beta tester essentially.
The Prusa units seems to waste less filament.
I didn't realize they have that big of a sale going on. However, I still don't want to spend that kind of money with Creality until it's been in many peoples hands for a while. I haven't heard the best things about them as a brand overall.