RE: Cable MMU3 to MK4
I modifid my MMU3 to Mk3 cable by taking the plugs off one end and then crimping molex pins onto it and into the 2x6 socket. The pins are very small and even with a pretty good crimping tool it took a long time and a lot of messed up pins. The proper Molex tool is around £350 so it is worth persevering with cheaper tools!
The PTFE tube uses the same quick release adaptor as the Mk3+ which just screws into the Nextruder without needing to make a modified chimney
My MMU3 is now hooked up and giving some functionality. I can change filaments and load to nozzle etc. The printer will accept a gcode from the normal slicer without any MMU3 code needed as it stores the type of filament in each tool and you can have any type loaded in any slot. When you go to print it will select a tool (MMU position) with the correct type and load it. If you have different colours of the same material you can change the default position for that material.
That's as far as you can go just now. It will load but not purge the filament. To actually print with it you have to do a load to nozzle then disable the MMU and then load again which will then purge the filament and you can start the print.
RE: Cable MMU3 to MK4
Great info, thanks.
RE: Cable MMU3 to MK4
Anyone know if the 24V are coming from the xbuddy or the pd board? I don't have the pd board so just curious if the 24V is not directly connected to the MMU anymore? I guess not since the MMU can be turned on/off via the printer now, right?
RE: Cable MMU3 to MK4
Beginning of this thread (Page 1) there is a link to the xBuddy pin outs for the MMU connector. Yes it does have two +24 VDC pins.
RE: Cable MMU3 to MK4
Is there a reasonable cheap supply for the molex connector? I only find suppiers with very high shipping cost (no matter US or EU) and also find no supply for the pins.
RE: Cable MMU3 to MK4
In the UK try Radio Spares, Mouser or Farnell. They all have a minimum delivery charge and its not worth buying singles. I bought 10 plugs and 100 pins for delivery to store and the cost was around £9. I used most of the plugs and nearly all the pins - they are not easy to crimp without the correct tools.
uk.rs-online.com/web/p/wire-housings-plugs/1790609
uk.rs-online.com/web/p/crimp-contacts/7206078
The plugs are called 12 way 2 row, not 2x6 as you would ex[ect.
RE: Cable MMU3 to MK4
Hey Mykal. I've rewired my MMU3 cable to match your corrected diagram. I'm ready to plug it in. Just wondering, before I make the leap, if you have any additional suggestions or revisions. Thanks very much for your work on this.
Tim
RE: Cable MMU3 to MK4
I ordered the connectors and pins from Digi-Key located in US. Shipping was more than value of the goods. So what. Crimping was difficult - but with a couple of try and error and quite a couple of pins I managed to make the harness. Hooked up the MMU3 to the MK4 and it worked! I loaded and unloaded filaments to the nozzle (no purge). Next I try to modify PrusaSlicer Settings to print really in multicolor. I hope it will be possible with all the custom G-code settings.
So far happy with the actual status.
RE: Cable MMU3 to MK4
Hi Tim, you should be good to go, seems we have a few others chiming in with successful cabling and connectivity between MMU3 and Mk4.
br -mp
Hey Mykal. I've rewired my MMU3 cable to match your corrected diagram. I'm ready to plug it in. Just wondering, before I make the leap, if you have any additional suggestions or revisions. Thanks very much for your work on this.
Tim
RE: Cable MMU3 to MK4
After loosing and then finding the Molex connector and consuming 20 Molex pins I'm up and running. Thanks again.
RE: Cable MMU3 to MK4
I was able to create a MK4-MMU3 profile. Loading and changing of Filament is working. But nothing is extruded.
I tried a gcode created with the MK3-MMU3 profile. It started as expected. Sometimes the first layer is printed correctly. The Filament is changed as expected and the second filament is loaded - but nothing is extruded.
I think the filament is not pushed in the extruder enough after the sensor has detected the filament. So the gear is not catching the filament.
Any idea how to get the filament pushed in? Or is this parameter hard coded in the firmware?
RE: Cable MMU3 to MK4
I would compare the two extruders, what's the distance from MMU3 to the extruder filament gears, then in the MK3 generated gcode, what is the feed distance programed when you slice for MK3 + MMU3, your findings say that the MK4 distance is longer, maybe a shorter PTFE tube could be used to compensate for the delta?
Does the MK4 generate a feed error when filament 2 fails to reach feed gears?
-michael
RE: Cable MMU3 to MK4
Thanks to your help I was able to build the MMU3 cable for my MK4. I can load and unload filaments from the MK4 menu. What printer profile are you using to print from PrusaSlicer? BTW filament 5 failed to load. I opened up the MMU3 and found that the bearing/wheel in the idler for filament 5 had dropped out. I found the wheel but not the shaft. Luckily I had the old idler from the MMU2s and used parts from that.
RE: Cable MMU3 to MK4
Actually I'm using the same tube and I think the length of the tube will not make any difference. The MMU is feeding the filament up to the point when the filamentsensor of the extruder is triggering. Then the extruder has to take over. At the MK3 the filament sensor is triggered by the extruder gear itself. So if the sensor is on, the filament is in the extruder gear. At the MK4 there is a bit of distance. So the MMU has to feed a couple of mm more to give the extruder gear a chance to grip the filament. If there is no way to force this by gcode there might be no chance to make it happen with the actual firmware (MMU and MK4).
RE: Cable MMU3 to MK4
MK 4 with MMU3 - I'm having the same issue, loading but no extrusion. I think the filament is being captured by the extruder gears. If I try and pull the filament out of the extruder after it is loaded it won't come. I'm guessing the code that starts the extruder after loading on the MK4 is different or missing from the MK3s. Unfortunately I understand Greek better than gcode, and I don't understand Greek.
RE: Cable MMU3 to MK4
There is a gcode for "extra load distance":
M708 A0x0b X10
With this code in the start gcode section I was able to load the filament. Now I'm fighting with the tool change during the print.
RE: Cable MMU3 to MK4
I just printed in two colors on my MK4 with an MMU3. I used the MK3s+ with MMU printer profile. When I sent the file to the printer via Prusa Connect, the display said the gcode isn't fully compatible and the printer model doesn't match. I was offered the option to run the printer in MK3 mode, I did. Next on the tools mapping page the two filaments I picked in prusaslicer (2 and 3) were displayed with question marks beside them. I selected print. The next screen said, detected mismatching filament types. I selected print anyway. After the usual delays the printer printed the item in the attached photo. I'm going to try three next.
RE: Cable MMU3 to MK4
Excellent, nice work . . . give us your firmware versions, slicer version, and anything special about your mk4 to mmu3 setup. I'll give it a try later today.
ty -michael
RE: Cable MMU3 to MK4
MK4 firmware 5.1.3, Prusaslicer 2.7.1, MMU3 3.0.1
I was able to print a simple piece in 3 colors last night. I used the MK3S+ MMU3 printer profile. In the printer start gcode, 3rd paragraph I removed the line above {endif} G92 E0. Just printed the attached three color piece.
RE:
The trick with MMU3 /MK3 and MMU3/MKč as well is when the printer is executing the so called "Trial load" : filament reached the head filament senzor, MMU is disengaged.
The gear is pushing the filament for a certain length and then retracts the filament back. If after this process the extruder FS does not recognize the filament, it means the gears were not able to push through the nextruder tube. And at least MK3/MMU tries to repeat this process.
If the FS still recognizes the filament, then the grears continue to push the filament till extrusion. the 5.1.2 FW does not reach the phase, when the printer asks "is filament loaded correectly?" like the MK3/MMU2s is asking. It jumps back to the menu.