RE: MMU3 printable parts R4 (F1)
Well - kinda.
No, really. Towards the end, it says quite plainly:
Blade-holder, Pulley-body, Selector - all three parts must be R4
RE:
Jeremiah, you're absolutely right. I will definitely be testing the two different parts when my kit gets here today, and I'll report it to Prusa support if there's any binding. I guess there could be a reason the hole spacing is different between the two parts, but I can't imagine why.
I've decided to use R3 for the selector and blade-holder and R4 for everything else. Hopefully that works. Printing the parts using PC-CF.
The first post literally says that the selector, blade-holder AND pulley-body all need to be of the same revision...
Well - kinda.
The description of the R4 blade-holder says that they changed the tilt of the blades and the screw is closer to provide more grip. The selector is ditto, but they also changed the openings for the smooth rods. That particular change should only affect the width of the openings, but they changed the position too. That causes binding with PC-CF from what I can tell.
If the R3 selector slides better, then I don't really see that the incompatibility listed should affect anything.
The R4 pulley description focuses purely on the smooth rods as well. If the rods slide smoothly for me, then I don't really see any other incompatibilities listed.
I really don't want to disassemble the pulley-body again, and I can't use the R4 selector with the R4 pulley-body. I'll take the risk I think.
RE: MMU3 printable parts R4 (F1)
Well - kinda.
No, really. Towards the end, it says quite plainly:
Blade-holder, Pulley-body, Selector - all three parts must be R4
I guess I'll report my findings if it doesn't work out. 🤷♂️
RE:
I printed all the parts and converted my org. MK4 to the MK4 for MMU3 (my MMu3 was working before with some modifications).
For those who do not have the very smal magnet for the filament sensor I modified the "idler_nut" so that the old magnet can be used.
RE: MMU3 printable parts R4 (F1)
Well - kinda.
No, really. Towards the end, it says quite plainly:
Blade-holder, Pulley-body, Selector - all three parts must be R4
I guess I'll report my findings if it doesn't work out. 🤷♂️
Looks like there is a good chance I'll be reprinting those bits with PETG. Cutting is occasionally having problems. I also suspect my print of the pulley body just didn't turn out right to begin with.
RE: MMU3 printable parts R4 (F1)
Any updatets on MK3S+ MMU3 to MK4/MK3.9 MMU3?
RE: MMU3 printable parts R4 (F1)
Any updatets on MK3S+ MMU3 to MK4/MK3.9 MMU3?
The kits are in the store https://www.prusa3d.com/en/product/original-prusa-mk3s-mmu3-upgrade-kit-to-mk4-mk3-9-2/
RE: MMU3 printable parts R4 (F1)
Update: I reprinted the main body using the R4 parts in PETG. Went together better, and so far filament swapping has been flawless. It's not totally loose on the rails, but there's no real binding. Hasn't needed to cut the filament yet, but from the way things went together, I suspect that will work as designed.
Looks like if you want the MMU3 in another material, the tolerances are tight enough that you'll need to test and modify the design. I don't want to rebuild my MMU3 multiple times, so it'll stay as PETG.
RE: MMU3 printable parts R4 (F1)
I just reprinted the Idler Body (R4) part from the STL that is on Printables and realized, that it differs from the part, that is included in the pre-sliced R4 plate gcodes.
Here are pictures of the differennt parts. Bith parts say "R4" on the back.
Now : which one should I use?
Idler-body (R4)
There is no functional improvement, there is no need to reprint this part
RE: MMU3 printable parts R4 (F1)
Hi there,
what’s it exactly with the upgraded spool holder wheels, I don’t get it.
It states in the article that the upgraded ones are included in the upgrade to the MMU3, but I don’t have any in my box. 🤔
Cheers,
Martin
RE: MMU3 printable parts R4 (F1)
So, as I researched further, I found it even more contradictory.
The article states, that...
However, if you're upgrading your existing MK3S+ MMU3 setup to MK4/MK3.9, we recommend changing the wheels (wheels are part of the upgrade package).
... but neither are wheels included in the MMU2S to MMU3 upgrade, nor is there any listing of the new spool holders on the shop site. I have the VAC version from the MMU2 upgrade. As it states, the old setup will cause issues with the MK4 MMU3 setup in the long run, so why are no new spool holders or wheels included in the upgrade? How can it be a trustworthy upgrade if crucial parts are missing? Even if the new holders are just for looks and a better circular organization of the spools, I would like to have them. They are part of the full set, so upgrading is not guaranteed to provide the full experience. 🤨🤨
Hi there,
what’s it exactly with the upgraded spool holder wheels, I don’t get it.
It states in the article that the upgraded ones are included in the upgrade to the MMU3, but I don’t have any in my box. 🤔Cheers,
Martin
RE: MMU3 printable parts R4 (F1)
I just reprinted the Idler Body (R4) part from the STL that is on Printables and realized, that it differs from the part, that is included in the pre-sliced R4 plate gcodes.
Here are pictures of the differennt parts. Bith parts say "R4" on the back.
Now : which one should I use?
Idler-body (R4)
There is no functional improvement, there is no need to reprint this part
Sigh, I've been back and forth in my head wondering if there are differences between the pre-sliced and the ones that are uploaded, as I didn't use the pre-sliced. Rather unfortunate they are different, and would have spared me a lot of reprints had I known.
A lot of people report success with the pre-sliced. I'd go with that.
RE: MMU3 printable parts R4 (F1)
I got the MK3S > MK4 MMU3 upgrade kit and it came with a set of new spool holders + wheels so if that wasn't included in your package I'd reach out to support.
RE: MMU3 printable parts R4 (F1)
That item is the idler, and not the idler body. This is the idler body: 
RE:
I have the VAC version from the MMU2 upgrade. As it states, the old setup will cause issues with the MK4 MMU3 setup in the long run, so why are no new spool holders or wheels included in the upgrade?
You've misread a bit. The vacuum-formed (VAC) version works fine with MK4, it's just the injection molded version that needs new wheels to avoid issues.
Since all MMU2S came with the vacuum-formed version (the injection molded version was introduced with MMU3), new spool holders are not included with the MMU2S upgrades. They're only included in the upgrade package for moving an MMU3 from MK3S+ to MK4.
RE: MMU3 printable parts R4 (F1)
Thanks for clarification. 🤗
As I’m not a native speaker nor spend my entire day studying the ins and outs of every product variation, I was confused by what Prusa has or hasn’t included in the upgrade. Still, I find those differences between upgrades towards a “full version” funny smelling. That’s why I opted for a full MK4 kit and not the upgrades. You never know what's missing! 😁
I have the VAC version from the MMU2 upgrade. As it states, the old setup will cause issues with the MK4 MMU3 setup in the long run, so why are no new spool holders or wheels included in the upgrade?
You've misread a bit. The vacuum-formed (VAC) version works fine with MK4, it's just the injection molded version that needs new wheels to avoid issues.
Since all MMU2S came with the vacuum-formed version (the injection molded version was introduced with MMU3), new spool holders are not included with the MMU2S upgrades. They're only included in the upgrade package for moving an MMU3 from MK3S+ to MK4.
RE: MMU3 printable parts R4 (F1)
Thanks for clarification. 🤗
As I’m not a native speaker nor spend my entire day studying the ins and outs of every product variation, I was confused by what Prusa has or hasn’t included in the upgrade. Still, I find those differences between upgrades towards a “full version” funny smelling. That’s why I opted for a full MK4 kit and not the upgrades. You never know what's missing! 😁I have the VAC version from the MMU2 upgrade. As it states, the old setup will cause issues with the MK4 MMU3 setup in the long run, so why are no new spool holders or wheels included in the upgrade?
You've misread a bit. The vacuum-formed (VAC) version works fine with MK4, it's just the injection molded version that needs new wheels to avoid issues.
Since all MMU2S came with the vacuum-formed version (the injection molded version was introduced with MMU3), new spool holders are not included with the MMU2S upgrades. They're only included in the upgrade package for moving an MMU3 from MK3S+ to MK4.
You are not the only one to read it that way. I haven't got my kit, but also have the vacuum formed spool holders and read it as there would be the injection molded ones in the upgrade kit.
RE: MMU3 printable parts R4 (F1)
I just reprinted the Idler Body (R4) part from the STL that is on Printables and realized, that it differs from the part, that is included in the pre-sliced R4 plate gcodes.
Here are pictures of the differennt parts. Bith parts say "R4" on the back.
Now : which one should I use?
...
I just checked the STL and gcode on Printables, both uploaded in April (weeks before your post), and both have that notch in the same place (the lower one, with bearings installed, in your image). Something looks a bit weird to the left of the notch in the upper part in your image, are you sure you didn't get a layer shift coincidentally affecting only the notch?
RE: MMU3 printable parts R4 (F1)
I've been looking at the R3 and R4 segmenter files, and maybe I'm just dumb, but I don't see the difference. I can see the version marking is updated for the R4 version, and it looks like the R4 has a slightly less aggressive chamfer on the top and bottom outer edges, but those aren't functional changes. What's changed that makes the R4 compatible with the new segments that the R3 doesn't have?
RE: MMU3 printable parts R4 (F1)
Why don't you publish the step files, like you did for MK4?
thanks a lot