What is the differance in the MMU3 kits for the MK3 and the MK4?
So.. I placed an order for a MMU3 for my MK3S+ a few weeks ago, but now I am contemplating upgrading my MK3S+ to a MK4. What is going to be different in the 2 kits for the MMU3?
Thanks!
Rusty
RE: What is the differance in the MMU3 kits for the MK3 and the MK4?
I believe that’s unclear, because Prusa hasn’t started shipping the MMU3 for MK4 yet, and doesn’t expect to until October.
RE: What is the differance in the MMU3 kits for the MK3 and the MK4?
Support have previously told me that the connection cable for the MK4 will be different, given it has a different board to the Mk3S+.
There may also be some differences in how it connects to the extruder, given Mk4 uses Nextruder. These aspects remain unclear.
RE: What is the differance in the MMU3 kits for the MK3 and the MK4?
I expect that it will contain the same materials except:
- different cables for MK4
- may be a new IR sensor extruder top and some changed parts for the Nextruder of the MK4.
the MK3S+ required to dismount the whole X axes to put the cables of the IR sensor, and to assemble the new top IR sensor and the rocker sensor in the extruder
I never really understood the technical reasons why the needed that, since it already had a filament sensor to detect the automatic filament load. What I though was that if a slippery filament could not be loaded or the filament distance was wrong, the motor could not guess if the filament was inside the grind. Let see how they will detect this with the nextruder. I can imagine that the new sensor if any, will be connected to the daughter board avoiding to dismount the whole X axe, but however it will require certain extruder disassembly to fill the cables till the board. And from my experience after the MK4 assembly, there is not so much space remained.
In addition suspect that then also on the MK4 the automatic filament load should be disabled in the firmware.
RE: What is the differance in the MMU3 kits for the MK3 and the MK4?
The top of the nextruder has an M5 thread for a bowden tube to attach, so I think they've thought of connecting the MMU3 during the design. In fact, I am using that right now (without the MMU obviously) as it solves an issue I had with my filament path. I bet the delay is in the programming side of things, and how the MMU3 and Buddyboard talk to each other. Otherwise physically it should only be a cable that's different between versions.
RE: What is the differance in the MMU3 kits for the MK3 and the MK4?
That's not just for the MMU3. The Prusa Original Enclosure uses a bowden tube to feed the Nextruder, since there's not space inside the enclosure to have the filament mounted above the printer as is normally done when the printer is not in an enclosure.
The top of the nextruder has an M5 thread for a bowden tube to attach, so I think they've thought of connecting the MMU3 during the design. In fact, I am using that right now (without the MMU obviously) as it solves an issue I had with my filament path. I bet the delay is in the programming side of things, and how the MMU3 and Buddyboard talk to each other. Otherwise physically it should only be a cable that's different between versions.
RE: What is the differance in the MMU3 kits for the MK3 and the MK4?
in the Mk3, the filament sensor is before the bondtech gears, in the revised mk3 for MMU, the filament sensor is actioned when the filament actually arrives at the Bondtech gears, at which point the MMU3, hands over control of the filament to the printer and the MMU3 disengages it's pulley drive mechanism, thereafter the Printer handles the filament movement, until the unloading filament allows the bondtech gears to close together at which point the MMU3 again activates the filament pulley, and continues to draw the filament back into the MMU Pulley Body and prepares to feed the next filament.
the original Mk3s and Mk3S+ Infra Red filament sensor and filament sensor lever setup, could not show when the filament actually arrived at the Bondtech gears, making handover from MMU3 control, to printer control.
the Mk3 Laser filament sensor was not used with the MMU2 and is not able to be used with the MMU3
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RE: What is the differance in the MMU3 kits for the MK3 and the MK4?
In this PRUSA BLOG article https://blog.prusa3d.com/development-diary-update-on-mmu3-for-the-mk4_85043/ Mikolas explains the difficulties to have a reliable MMU3 on the MK4 due to how the Nextruder works.
A vital function will be done by the new PrusaSlicer, that will be responsible to create perfect filament tips as I made in my PrusaSlicer Dribbling or like Erick's Bjorgan Skinny Dip, but it will use a different technique.
We were both mentioned and thanked by PRUSA 😊 for the efforts and the time we worked try to solve this difficult task.
So the MK4-MMU3 kit will contain for sure Nextruder modified parts in order to allow a reliable load and unload and will use a new version of PrusaSlicer.
Regards