RE: I found serious design error in MMU2 electronics hardware
I purchased a new sealed board from someone. Factory sealed and running great for two weeks and Im having power issues on this board Also.
This is Completely ridiculous…
I wanted to See how long I can go with a new board and this happens again.
RE: I found serious design error in MMU2 electronics hardware
Where does the negative side of the DC output (light blue wire) connect / terminate?
RE: I found serious design error in MMU2 electronics hardware
Does anyone know if the 3.x MMU firmware fixed this issue? Seems like a hardware issue but want to double check.
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I read all the comments so far in this thread, I must say that it was a very informative and fun to read, and I wanted to share my own story...
I built my own MMU2S (except the board, which I understand can also be replaced with an SKR board if you update the pins in the firmware...), all the other parts are sourced from Amazon, and I'm running my MMU2S on my Ender 3 Pro, after all the modifications I had to do both mechanical and Marlin firmware my MMU2s working very nicely. The only problem left was the all blinking leds issue that I had from time to time, and thanks to this thread I solved it by injecting 5.5V (not 5.2V btw) to get 5V at the output of D1.
I also accidentally put 8.5V (mixed the VCC-in pin with the 5V pin on the Arduino Mega) as the input and the MMU2s run around 1 hour without getting burned. so you can be a little bit relaxed when adjusting the buck converter 😊.
If anyone is interested to run the MMU2S on an Ender 3 Pro with an SKR Mini E3 v3 board and Sprite Extruder Pro, I can post the details of my hardware and firmware modifications.
Thanks again for all the contributors 🙏
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5 hours into a 13 hours print with 500+ tool change, and it is going without an error 👍
Apparently, this voltage injection is improving not only the flashing LEDs issue, but also the idler behaviour as it supplies more power to the TMC 2130 drivers.
RE: I found serious design error in MMU2 electronics hardware
The print finished in 17 hours with only 1 unload and 3 load errors and it was all related to the filaments and how I feed them to the MMU2S, I'm super happy with the current state of my setup.
RE: I found serious design error in MMU2 electronics hardware
I just ripped off all my MMU hardware and am now super happy with the result. Side note: Couple MMU units for sale if anyone wants to rehab them, I'm done trying to get these things to work without major surgery.
RE: I found serious design error in MMU2 electronics hardware
If the price is right (I’m Broke) I’ll gladly rehabilitate it and make it functional
RE: I found serious design error in MMU2 electronics hardware
yeah I excised the MMU2S when I upgraded my two MK3S'es to MK4's. And now I also have the 5 extruder XL lol. I can't believe I spent as much time as I did trying to serenade the MMU to work haha. Eventually the MMU and I came to an understanding. However after watching the XL do tool changes, I'd never go back to the MMU.
RE: I found serious design error in MMU2 electronics hardware
I think I fixed almost all flaws with the MMU and now I’m printing with barely any issues except when I’m using my 4 year old filament and it might have an issues here and there. I’ve invest so much time remixing and fixing all the issues. But I can say that now I have a reliable MMU
RE: I found serious design error in MMU2 electronics hardware
Yeah I mostly got to the point, especially after the new firmware, it totally changed/improved the behavior. But I had ordered two MK3S - MK4 upgrade kits and so I decided to ditch the MMU on the one printer I had it on. it's ok if you stick within the limitations. Not being able to print tpu with it was a big downside. Also there was some soluble support filament(aquasys 120) I could NEVER get it to work with due to the requirement to shape the tips perfectly on unload. I spent easily a few hundred hours messing with that thing. PLA + PLA, PETG + PETG, PLA + BVOH, and *sometimes* PETG + BVOH worked. Never tried any other combinations that required filament switches. Multiple extruders really is the way to go though.
I think I fixed almost all flaws with the MMU and now I’m printing with barely any issues except when I’m using my 4 year old filament and it might have an issues here and there. I’ve invest so much time remixing and fixing all the issues. But I can say that now I have a reliable MMU
RE: I found serious design error in MMU2 electronics hardware
after 2 years plus I was finally able to complete a 48 hour print. After 15 hours my Generic White PLA crapped out with a string and a chunk. at 36 hours actual load failure. I have fussed with the buffer (length of runs probably related to voltage) to end up with the RMU Buffer. Re-printed the MMU parts with the best of the community, Did the Ikea Lack Table enclosure to minimize the runs, the latest firmware upgrade (which actually helped) then adding a buck converter and injecting 5.2V to the MMU. I can't even guess how many time I tried this print. Finally I would call this a win. Thank you guys for making this posssible.
RE: I found serious design error in MMU2 electronics hardware
[einbetten] [/einbetten]
18:56 Leistungssteigerung
RE: I found serious design error in MMU2 electronics hardware
There is a strange issue, eventhough I feed 6-6.5V to the MMU I keep getting the 5 flashing lights... But my setup is kind of hacky... I've a Creality Ender 3 Pro + SKR 3 EZ board, I use the MMU board, the FINDA sensor and the MMU cables from Prusa, but everything else is sourced from Amazon... So my Nema 17 42-40 motors may not be adaquete... But the problem increased when I used the printed parts from the MMU3... I'll try compiling my own 1.0.6 firmware and disable the flashing lights, as the 3.x firmware is not compatible with Marlin yet... or bite the bullet and make Marlin MMU3 compatible...
RE: I found serious design error in MMU2 electronics hardware
Thank you for the video.
About to put my MMU2 together but will be printing the MMU3 parts first. Very useful to see.
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To anyone having MMU2S board and "almost 5V " issue. Just replace D1 with Schottky one, plus add 100uF capacitor after it. That's all you need to get stable board.
Then you can reflash printer and MMu2S board to MMU3 versions and that's all you need to get full MMU3. The whole $100 HW upgrade from MMU2S to MMU3 seems done to mask the fact that MMU3 is only a major/ultimate bugfix over MMU2S (voltage + access from printer's menu), not a new version.
RE: I found serious design error in MMU2 electronics hardware
Did anyone measure the output of the new PD board? I'm not sure that I'm willing to spend £23 (AliExpress) for a board that possibly costs no more than £2 to make and keep my buck converter, but I at least want to match the output of the PD board.
RE: I found serious design error in MMU2 electronics hardware
It's not just power it fixes communication errors. I'd go for the pd board if I was you.
Did anyone measure the output of the new PD board? I'm not sure that I'm willing to spend £23 (AliExpress) for a board that possibly costs no more than £2 to make and keep my buck converter, but I at least want to match the output of the PD board.
Please help me out by downloading a model it's free and easy but really helps me out https://www.printables.com/@Hello_474427/models
RE: I found serious design error in MMU2 electronics hardware
What communication errors? I don't have any communication errors...
RE: I found serious design error in MMU2 electronics hardware
From what I have seen, it is only power supply related. With a bit of work, convert a buck converter to do the same thing. I have not looked at the mod but it is on my "to do" list as I am now in the process of building my MMU kit I purchased last year, and printing the MMU3 parts. I have a spare buck converter and may put that to use.
A decent picture may show the final circuit and how it connects to the second connector. A Monday project I guess.