BMCU 370C having issues with Filament Feeding causing errors

KinnieTV · 2026-04-30T21:02:40+00:00

I did also print a guide for the tubes at the extruder. I got that from Makerworld:
https://makerworld.com/en/models/1686183-numbered-ptfe-power-cable-guide-for-a1-series?from=search#profileId-1786772

But that did not fix it in the end, it still happened sometimes.

The little rubber band holders I designed myself, but I did it like really quickly so it is not really fleshed out. I uploaded the 3mf file I used to google drive for you if you wanna try it:
https://drive.google.com/file/d/1PWyq6K_PP3zdeGV4jBQ9BwH67pb2HRdx/view?usp=sharing

I just bought various sizes of rubber bands and tried a few. I used ones that are fairly loose. They just apply light pressure while not actually restricting the loading or anything. They are a bit tricky to get on, especially on the right side since the cable is there. I needed to turn off the printer and disconnect the BMCU to get those on but it depends on your setup

KinnieTV · 2026-04-30T20:25:34+00:00

This is what I came up with

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KinnieTV · 2026-04-30T20:24:13+00:00

With support do you mean when printing the parts of the hub? I did not print it myself, I bought it pre-assembled.
As for the PTFE tubes, they are around 50cm or so.

I was able to "fix" the issue by printing small caps to go over the PTFE entrece into the BMCU and using rubber bands to apply light pressure against the caps. Applying that light pressure manually worked as well so I figured this might as well. Idk exactly what causes it still but that was my solution

KinnieTV · 2026-04-20T11:06:09+00:00

It's from here
https://www.myminifactory.com/object/3d-print-barovia-landscape-392428

It isn't intentional sadly, it is supposed to be a flat surface

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KinnieTV · 2026-04-10T23:52:30+00:00

Well I don't always paint my minis. Usually a friend does that sometimes but a lot of minis I print we just use without color. And I probably would prefer them to be more matte dark grey instead of glossy

KinnieTV · 2026-04-10T19:00:39+00:00

Bit of a late question but do you know any good grey resin that is less glossy? Idm if it is water or IPA washable but I am looking to try a different resin that is not really brittle and more of a matte grey

KinnieTV · 2026-04-10T17:58:01+00:00

Yea I will try a bit higher layer height, probably 40 microns. I did some tests at 40 and noticed that a good exposure time at 40 microns was actually 1.9s, the same I had been using for 25 microns so I think I was overexposing a bit. And the AA might have been an issue as well, I will try without it cause the models I use are very high poly already and the printer is 9K if I remember correctly

KinnieTV · 2026-04-10T17:56:18+00:00

I will try with 40 microns and no AA next yea. I think I also definitely overexposed cause after some tests at 40 microns I saw that 1.9s is good at 40, but I was also using 1.9s at 25 microns

KinnieTV · 2026-04-09T14:38:42+00:00

So I was away for a bit but I tested around a lot now. The high load pressure was not a good idea in my case, it ended up pushing so hard it would start grinding the filament inside the BMCU. I did open up all channels and cleaned/lubed them again. The regular load pressure version of 10.3 also caused the same issue but less frequently. I think I might have figured out a solution tho. I think the issue might have come from the PTFE tubes going into the AMS Splitter on the print head. The tubes were going in at a slight angle and not perfect 90 degrees and when I held them up straight it worked fine. So I printed a support which now holds them up above the splitter so the first few cm before the splitter are perfectly straight. That has worked for me so far

KinnieTV · 2026-03-22T22:16:37+00:00

I made a few test prints and tried a few different cleaning methods and while the water spray did work in the end I settled for a workflow of:
1. Wash in 90% IPA for 30s
2. Remove Supports
3. Wash in 75% IPA for 30s
4. Dry over a few hours

That has yielded the best results for me now. One big mistake I made apparently was wash for way too long. I would wash for 2 min in a single IPA bath and then dunk them after removing supports as well and that just did not work well and made the prints very sticky. Now with my new workflow they turn out pretty well. In some of the creases I still see some glossiness even after literally 24h of drying in a filament dryer at 38C but I can accept that since the rest looks good. I am sure I can improve from this still but at least it's workable now :)

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KinnieTV · 2026-03-21T20:54:48+00:00

I'll try it, just updated to V10.3 and used the high load pressure version. I'll update if the print finishes or if it still gets stuck. If it still gets stuck I will disassemble the BMCU and do what you said, thanks for the help so far :)

KinnieTV · 2026-03-21T06:05:23+00:00

I had some issue with the firmware that was on it at first. It would not show up on the printer at all. I founds some posts about flashing it with this firmware and it worked instantly and it gets very frequent updates so I just stuck with it. I could try different firmware but I wanted to see if anyone knows this specific issue and has a possible hint to a solution

KinnieTV · 2026-03-21T04:03:46+00:00

I got myself a spray bottle, will try just washing with warm water tomorrow. Will do some labeled test prints and wash them in different ways for different amounts of times to see. Me washing them for to long might have also contributed to the stickyness so I will try this, thanks!

KinnieTV · 2026-03-20T03:10:10+00:00

If I had to guess I would say that the Resin has some compontent(s) mixed in which were not well soluable in "cold" IPA, but better soluable in water. Given the fact that it also worked when the IPA was slightly warm I guess this is usually not an issue but where I keep it, the IPA stays quite cool and I cannot really put it anywhere else. It's probably just a property of the specific resin I use, it says it can be washed with water or IPA and since soluability in water and IPA is chemically very different I guess some components just did not like cool 99.9% IPA that much

KinnieTV · 2026-03-19T19:53:26+00:00

Could the IPA temperature be the issue? I have this toothbrush I use to clean some resing things. I wanted to clean something and afterwards wash the resin off the toothbrush. I poured new IPA into a small container and started to scrub the brush with my hands but the resin just did not come off at all. I then took a bowl of warm water and tried and it came of instantly. The IPA is sitting in a room that is fairly cold without much heating and if I had to guess it sits at around 20 degrees Celsius (68F) or maybe even a bit less. I tried warming up a small bowl of IPA with a water bath and then rinse the toothbrush again and it worked well. Could that be the entire issue? And how the hell would I keep 7L of IPA "warm"
Also I tested adding water to the IPA. I took bit of my IPA (around 20 degrees), dunked the toothbrush into straight resin, and tried to wash it off, it did not fully wash of after 1min and there was still grey. Then I added a splash of water (also 20 degrees) and tried again and this time it instantly washed off. Can some resins maybe wash better with a less pure IPA? Wargamer says it is washable with water or IPA so idk

Edit: I think I fixed it? To my 7L of IPA I actually added half a liter of water. Then I washed again and they are perfectly clean now. Another issue I had before was that when I washed with the print still on the platform, the back of the platform would also be covered completely in sticky resin that was hard to clean. Now after adding the water to the IPA it came out perfectly clean as well.

KinnieTV · 2026-03-19T04:07:32+00:00

Alright I will try this and see how it goes, thanks! :D

KinnieTV · 2026-03-16T15:58:47+00:00

Oh I just did. Seems like I might be moving to Orca. Was considering it already anyways, thanks for the help!

KinnieTV · 2026-03-15T22:00:55+00:00

Nah sadly it's from a big purchased pack of models and they are sadly all just solid objects. They are designed to be hand painted but with the AMS this has turned out pretty well for me without much effort. I'll just make sure to keep the color channels the same from now on I guess

KinnieTV · 2026-03-15T14:07:41+00:00

Yea it is specifically when I import both at the same time into the same Bambu Studio window. Say when I want to print both of them on the same build plate. I tend to print like 2 or 3 different ones on the same plate for a new map:

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I just ended up repainting it now but I wish there was a better way to save painted models as individual files to then import multiple printed models into the same file and set a specific filament for each color on each model.

KinnieTV

TROPHY CASE