Jamming in the steel tubes  

Re: Jamming in the steel tubes

For everybody who is still having problems.

I meanwhile can print - not perfect - but without jamming.

Steps which helped me

- don't use bad filament (my oldest pla filament spools were stiff and bumpy in the end of the spool and probably not best quality)
(use now innofil3d and the original prusa silver i got with the kit working fine)
- lower temps
(print now with 210 und 205 like suggested)
- put the spools on a nearly friction free holder (that was very important)
- reduced the tension on the feeder als much as possible so the filament keeps in shape
- ah forgot one - i tried every of the 4 feeder with a single color print to see it work good

and last not least

- learned to slice on my own - something you have to do anyway
good thing here is - i had a problem with sticking on the bed with the original Marvin file - maybe bed temp problem - don't know
and solved it with a brim - i used slicr 1.37.2

Here are my first two object.

So for everyone keep trying - it works!

Re: Jamming in the steel tubes

Troubleshooting the multi material upgrade has become a full time job. I want it to work so badly! Trying to read through 40 complaints of jammed filament trying to figure out what's wrong with my printer. 6 failed gear prints later. A different problem every time. I usually use this printer for work.... But can't take any work because I don't trust my printer now. This is more than a hobby for me. Wasting so much filament and time, the printer is almost not worth it at this point.

Here's what I've tried:
- Tried to cool filament to keep from warping. The enclosure I built to keep drafts out... is now making the filament too soft. Because of the heat build up. So I can't use an enclosure anymore (major problem) The printer now takes up so much space because the filament has to be behind it, instead of on top.
- Tried to release the tension on the filament.
- Using only PLA multi material. The silver PLA that came with the printer is having the most problems. I took that out.
- Using the G.code that came in the objects folder.
- Had to move the print away from the center (The prints were stopping from too much cooling on the heat bed center)

Please printing gods!!! I need suggestions!
The latest problem is that the silver prusa PLA got jammed and started spewing out the side of the stepper motor. It was printing a part of the gear model where it was only using the silver pla. It got jammed about halfway through the print.

Re: Jamming in the steel tubes

filament above printer

ptfe feed tube between filament and printer, has a split in it to prevent the back feeding of filament from causing filament to spill off e side of nearly full rolls

Re: Jamming in the steel tubes

I was wondering what people would think about a poll thread? Like "if you have problems with your MMU leave a note here". No details, just to get a general idea how big the problem actually is...

Re: Jamming in the steel tubes

Hi Nils, all that would achieve would be an indication of the numbers currently having difficulty, whilst ignoring anyone who is not having difficulty, and it would perpetuate issues after people become familiar with the technology, when problems are likely to go away!.

regards Joan

Re: Jamming in the steel tubes

I was wondering what people would think about a poll thread? Like "if you have problems with your MMU leave a note here". No details, just to get a general idea how big the problem actually is...

If my printer worked as it should I wouldn't be here. So a poll for that reason may may lead to a slightly one sided poll. Maybe we should start a poll to get more support here from Prusa in general?

Re: Jamming in the steel tubes

I think that would be useless as well, don't think there's anyone who wouldn't like more support (and not only from Prusa )

Re: Jamming in the steel tubes

I had jamming in the steel tubes also. 2 of the steel tubes would not line up correctly. I had to drill the holes in the plastic so the tube lined up correctly then have not had any jamming problems. Also use 205 temp for PLA so that the end does is not a little bigger.

Re: Jamming in the steel tubes

I have never gotten MMU to work. Same problem. Clogging while retracting. No print with multiple materials will finish. PTFE tube in the extruder and lower part of Y-splitter seems to clog. I am printing ABS.

Is there a solution? What about comments from Prusa?

I stopped using this printer two months ago. Now i found this thread.

EDIT:
I might have found the issue. When printing with ABS filament, some of filament probably will flow back into hot-end's PTFE tube and solidifies there, so the filament will get stuck there. So when trying to pull out, either some residue will be left into tube or it just don't move.

I had a bit of new PTFE tubing with 2.0mm inner diameter. So after i replaced hot-end's tube, i had more success. I will get 1.9mm tubing and try with that.

Re: Jamming in the steel tubes

I have never gotten MMU to work. Same problem. Clogging while retracting. No print with multiple materials will finish. PTFE tube in the extruder and lower part of Y-splitter seems to clog. I am printing ABS.

Is there a solution? What about comments from Prusa?

Your filament tension screws are way too tight. Deforming the filament that much will cause problems.

Peter

Re: Jamming in the steel tubes

I think I did post something about changing to stock chinese heatbreak and solved my issues of jamming, but that is only for ABS.

Now I wanted to venture into PLA world because I might need to print large objects where ABS would be surely to have warping/peeling off but my problem with PLA is that it is jamming.

My initial use of PLA last week (somewhere in the last year I did used PLA once or twice) didn't have jamming issues on the first print. second print it starts to show evidence of jamming by having the extruder clicking/losing steps. That second print I slowly cranked up the nozzle temp and in the end until about 225'c. Of course during the print at this temp, the extruder did loses some steps but for about 3-5 clicking noise only then it is gone.

Earlier I wanted to print with PLA for another parts, but this parts I enabled supports. After first layer of 215'c, I cranked up to 230'c because of the previous print that were successful. Then the filament jamming starts to kick in. It is stuck in the cooling steel tube due to the end of the filament are larger than the cooling tube. Then I tried on 200'c after the first layer, same thing happening but the end blob were shorter compared to that 230'c.

By observation the length of the blob of the 230'c is about 3-4mm, while at 200'c is about 2mm. I was thinking that the possibilities of filament jams if supports were enabled are quite high.

I am actually looking for solution to this filament jamming issues with PLA 🙁

Re: Jamming in the steel tubes

Try Seth's redesigned multiplexer as detailed here: https://shop.prusa3d.com/forum/original-prusa-i3-mk2-multi-material-f26/monoplexer-and-multiplexer-redesigns-no-metal-part-t12801.html

As mentioned, I couldn't finish a single print with the original steeltube multiplexer because of random jamming in the steel tubes. I spent countless frustrating hours reading and doing EVERYTHING mentioned in this forum without success.

Then, after replacing the original multiplexer with the one designed by Seth, there have been NO MORE FAILURES (using PLA and PVA, at least two dozen prints now) and I'm, finally, VERY happy with the MM!

Re: Jamming in the steel tubes

Try Seth's redesigned multiplexer as detailed here: https://shop.prusa3d.com/forum/original-prusa-i3-mk2-multi-material-f26/monoplexer-and-multiplexer-redesigns-no-metal-part-t12801.html

As mentioned, I couldn't finish a single print with the original steeltube multiplexer because of random jamming in the steel tubes. I spent countless frustrating hours reading and doing EVERYTHING mentioned in this forum without success.

Then, after replacing the original multiplexer with the one designed by Seth, there have been NO MORE FAILURES (using PLA and PVA, at least two dozen prints now) and I'm, finally, VERY happy with the MM!

Yeah, I will give the seth's design a go. I did a design as well of the multiplexer jig but I wasn't good enough, it sometimes jam in there on my custom machine. I will be sure to try the new design out

Re: Jamming in the steel tubes

I did give seth's redesigned multiplexer a go, it was ok, but the PLA still formed as a blob and ended up jamming in the heatbreak entrance. Upon unloading, the filament didn't get jammed in the steel cooling tube n the original MMU. I am still stuck with ABS =\