Extruder fell apart

[raualex]

Hi,

after a couple of weeks not using the printer I tried a fresh run.

During the print of the 1st layer I noticed that the hot-end (V3B) fell off. There was no noise nor head crash.

Now I'm investigating what's wrong and it seems that the v3b uses a groove mount which is not properly sitting anymore.

According to the groovemount page on makergear.com it seems it's not as it should be anymore:

IMG_1484 copy.JPG (79.75 KiB) Viewed 7963 times

I'm not able to adjust anything by using fingers only - so the groovemount is not loose itself. Before making any mistakes I'd appreciate some help on what to do.

PS: the counterpart seems to be deformed as well and I'm not able to connect both parts in their current state.

Thanks and regards,

Alex

[insta]

... how hot were you printing?

If it was under 245C, contact MakerGear and see if you can arrange for a replacement. They will probably ask you to ship that one back so they can investigate it for failures.

[jimc]

agreed. if its deformed then it got hot from printing too high a temp or your fan stopped working for some reason.

[raualex]

Sounds plausible...

I noticed the fan making more noise than earlier although it's still running. Not sure if it's still working at full speed but would explain that the cooling could have been insufficient for a while... this plus the typical vibrations of the printer could explain the result.

For getting this printer up and running again I'm now wondering how to fix the GrooveMount - I would guess that's it's not completely broken but become loose when the hot end is hot. According to http://cdn.shopify.com/s/files/1/0030/7 ... 1300743202 it should be rebuildable.

Right now I would assume that:

1) heat up hot end
2) pull out pins
3) properly (until top is plane again) reinsert inner top into tube
4) push in pins again
5) cool down hotend

might fix it.

Does that make sense ?

Alex

Update: of course I'm trying to reprint the counterpart then somehow for a complete fix...

[jimc]

Vibrations dont defirm the plastic at all. Deformed plastic is from only overheat. groovemounts are cheap. If its deformed then your not fixing it. Toss it and order a new one.

[raualex]

Sorry for the confusion:

The counterpart (a printed ABS part) is deformed (due to heat). It's the part where the GrooveMount is inserted.

The GrooveMount itself looks good except that the inner part is pulled out (check the pic in the first post). I guess it's possible to reinsert it properly, right ?

I mentioned the vibrations because I think they helped moving out the inner part (PTFE) of the GrooveMount from the PEEK tube when the GrooveMount was warm (differences in the expansion of those 2 materials).

[jimc]

Ohhh i see. I thought the mount was deformed. Yes the ptfe liner does come out. Usually just put it back in and put the pins back in to lock the two together. Inspect the holes though where the pins go to make sure they arent all jacked up. Put a piece of kapton around it to cover the pins and keep them from working out again.

[raualex]

It was impossible to push in the inner part of the Groovemount at all. The depth of the hole was 12.75mm while the inner part was of length 15mm. Everything looked good except the 3mm discrepancy. After a while I found the cause when I disassembled the GrooveMount:

2015-05-21 22.07.53.jpg (34.48 KiB) Viewed 7908 times

The black small disk is ABS I guess and was the result of a jammed extruder. Because it was actually "molded" it looks exactly like the surrounding PEEK material (no surface structures etc.).

Reassembled everything was good (except the pin holes being wider :S ):

Here the effect on the counterpart:

2015-05-21 22.12.56.jpg (99.06 KiB) Viewed 7908 times

Completely delaminated and deformed over time (did not notice)...

Here's my one time fix hoping I'm able to print the replacement part (don't try this at home.... lol).

2015-05-21 22.39.24.jpg (150.93 KiB) Viewed 7908 times

Regards, Alex