Core One MMU3 Prototypes - General discussion, announcements and releases

RE:

Chris Hill — Thu, 10 Jul 2025 20:04:39 +0000

My 1m MMU cable from Blurolls arrived today, so naturally I had to drop everything and try it out.

First step - replace the original cable and test it on the MK4S that the MMU is originally fitted to. Works fine.

Next step - take the plunge and try it out on the CORE One. The cable is plenty long enough now to reach the side-mounted MMU (using @dancan13f's mounting rail), and power and control work just fine. Unfortunately, my original plan to feed the output of the MMU into the side filament sensor isn't going to work, because the total path from the MMU, via the filament sensor, and through the original bowden tube, is about 1.4m, and the maximum bowden length that can be set in the firmware is 1m. Whatever length is set in the firmware is the distance that is loaded 'at speed', and then the loading speed drops while it waits for the filament sensor to trigger, but my impression is that it will only do this up to a total length of 1m. So when I set 1m, hoping that the last 40cm or so would be loaded more slowly, that didn't work - it loaded 1m at speed and then immediately gave up and unloaded back to the finda.

No matter - I had already printed @dancan13f's top-mounted pass-through and had had a new acrylic top panel made, so I just fitted a replacement bowden through that pass-through. After adjusting the bowden length in the firmware it now quick-loads to within a couple of cm of the filament sensor and then slows down for the last little bit. The bowden goes through the original bowden bend on top of the Nextruder, and the MMU seems to have no trouble at all pushing the filament round that bend. I guess I now need to print the extruder_PTFE_holder to secure the original bowden tube out of the way.

I haven't printed anything yet, but I've loaded and unloaded the filament numerous times while adjusting the bowden length, and it's worked perfectly. And it's nice to finally see a filamentalist rewinder doing its thing! Flawless so far.

So far the rewinders are all connected up with lengths of PTFE tube that I already had, but I plan to cut some to more bespoke (shorter) lengths once I'm happy with the setup. I've swapped the order - the nearest rewinder goes to input no.1, which is the furthest away on the MMU, because no.1 is the easiest to load and I didn't want to get used to using no.5 most of the time!

So far I'm pleased with the setup. The MMU is much more accessible on the side than it would be at the back in my setup, and I'm quietly confident that this setup is going to work well.

RE: Core One MMU3 Prototypes

Hari Hurtig — Thu, 26 Jun 2025 08:10:31 +0000

> Can I do the same on Core One?

Yes, that worked fine here, just turn off the MMU in the menu and change the PTFE tube.

> Also, do I have to go through all the calibration business when the MMU3 has already worked with MK4S?

I didn't. Worked just fine.

RE: Core One MMU3 Prototypes

NielsE — Mon, 23 Jun 2025 18:59:21 +0000

The manual on upgrading the MMU3 form MK4S to Core One confuses me a bit. It is not always clear when it guides you installing your MMU3 that functioned on your old MK4S or if you are installing a new MMU3.On my old MK4S (now converted to Core One) printer I swapped between using MMU3 for multi-colour printing and single-colour printing using a seperate single spool by just changing the the PTFE on the nextruder. It worked great and without problems. Can I do the same on Core One? (I am installing ther MMU3 Light Version, just attaching it to the back of the top frame).Also, do I have to go through all the calibration business when the MMU3 has already worked with MK4S? Of couse, I have to flash the latest MMU3 firmware.

RE: Core One MMU3 Prototypes

FoxRun3D — Thu, 19 Jun 2025 12:39:46 +0000

Posted by: @mercur12
Did you see this one? Exactly my intention ! Vary good work ! Thanks to @jvitri.
https://www.printables.com/model/1321861-mmu3-lateral-droit-pour-prusa-core-one

Looks very nice. Alas, not really an option in a farm environment with multiple printers next to each other.

At this point I'm most likely to go with https://www.printables.com/model/1283543-prusa-core-one-mmu3-install-and-mmu3-setup —if I ever find the time...

RE: Core One MMU3 Prototypes

GBMaryland — Thu, 19 Jun 2025 12:30:41 +0000

Posted by: @iftibashir
Anyone purchased? https://www.prusa3d.com/product/original-prusa-mmu3-enclosed-for-core-one-full-kit/
Or we waiting for the 'next-gen' solution, whenever that may be....?

Yup... I did. Waiting for it to arrive. Though, to be honest, I've also printed the full community version with the Ultramarine Blue (Prussian Blue) accents instead of the Netherlands orange, er, I mean Prusa Orange. ;) Gotta keep some things German...

RE: Core One MMU3 Prototypes

Mercur12 — Thu, 19 Jun 2025 08:06:21 +0000

Did you see this one? Exactly my intention ! Vary good work ! Thanks to @jvitri.

https://www.printables.com/model/1321861-mmu3-lateral-droit-pour-prusa-core-one

RE: Core One MMU3 Prototypes

David R. Campbell — Mon, 09 Jun 2025 13:11:54 +0000

Ordered

Posted by: @mercur12
Thanks for the link. I just ordered..

RE: Core One MMU3 Prototypes

Mercur12 — Mon, 09 Jun 2025 09:38:41 +0000

Thanks for the link. I just ordered..

RE: Core One MMU3 Prototypes

Chris Hill — Mon, 09 Jun 2025 08:52:15 +0000

Blurolls sent me a link for the 1m version, in case anyone else is interested.

https://www.blurolls3d.com/products/blurolls-prusa-mmu3-extended-1-meter-cable-for-prusa-core-one-mk39-mk4s-3d-printer-multi-filament-printing?VariantsId=11076

RE: Core One MMU3 Prototypes

Chris Hill — Sun, 08 Jun 2025 13:29:36 +0000

Posted by: @mercur12
From this, I conclude that extending the cable by a few centimeters does not affect data transmission from /to MMU.

Good work 👍

Posted by: @mercur12
To be on the safe side, I prefer a length of 1.20 m. Can you tell me the source at Blurolls/Ali where I can order this?

I simply messaged the seller of this item.