J-Head Leaking

Hi everyone.

After having my J-Head jam, I cleaned it up and it worked well again.
Now after printing for about two hours I noticed some dark liquid dripping on the printbed. I though it was oil from the bearings, but when I removed it from the hotend it hardened up. Took the J-Head apart while still hot and it looks like this.

[flic.kr]

I guess the PTFE liner was not tight enough, but not sure. I did follow the instructions to assembel the J-Head after the clog. I screw the brass into the PEEK while its hot as it makes it so much easier, and I screw it all the way to the bottom.

How tight should the setscrew that holds the PTFE be, and how to clean up this mess..?

Jonas

Just had the same thing happen to me a few weeks ago. I'm not sure about how tight the setscrew needs to be - email reifsnyderb@hotmail.com to get an idea.

I just tightened mine down until I could see about 1/8" of thread. Worked ever since.

Cleanup (for me at least) involved tweezers, acetone and a frosty beverage. Took some time, but eventually cleaned up nicely.
Good luck!

---

- akhlut

Just remember - Iterate, Iterate, Iterate!

[myhomelessmind.blogspot.com]

Thanks Akhlut!

I have a spare J-Head that I bought for my brother. I compared the initial depth of the screw before I assembled it after the first clog. But this was obviously not enough.

Does acetone dissolve PLA?

Jonas

Edited 1 time(s). Last edit at 06/04/2012 01:40PM by jonasl.

I think you have to adjust the screw by feel rather than position. It needs to exert some pressure on the PTFE but not too much the cause it to deform inwards. Whether it will stay tight over time I don't know as all my experience with PTFE tells me it creeps until there is no tension on it.

No acetone does not dissolve PLA but it does have a strange effect on it: [hydraraptor.blogspot.co.uk]

---

[www.hydraraptor.blogspot.com]

Thanks nophead

I will try that!
Hope its just because I didnt manage to clean it enough the first time.
Is it safe to dump the PEEK in acetone as well? Or is that a bad idea?

Jonas

Acetone is fine on PEEK and PTFE. I used it to clean a J-head that I broke a drill in the nozzle of and I reassembled it and it is still going strong a after a few weeks.

---

[www.hydraraptor.blogspot.com]

I cracked the PEEK when I pulled my seized J-head apart cold. Never do that again. Believe it or not I re-assembled it and it prints fine, even with the broken PEEK.

Can't say enough about J-heads.

---

- akhlut

Just remember - Iterate, Iterate, Iterate!

[myhomelessmind.blogspot.com]