Extruder leaking between nozzle and cobber barrel…
Had tightend it, I thought, firmly. But cobber barrel broke when trying to tighten it further…
Do I have to use a washer or anything else to make this functioning???
I will now buy a wrench which can measure 3.5 newtonm.
Anybody who has any advise??
Then please fil free, I have bought a new set, which I do not want to break 
Thanks
I used a little bit of sealant to prevent the leakage.
My extruder was also leaking although I tightened it to specs.
Thanks, 2stimpy
what type of sealant did you use?? was is fluid or a washer!!
I used a two component heat resistant epoxy.
I applied only a few drops.
Fixed a leaking extruder.
Mentioning a 3.5nm torque setting in an instruction manual is ridiculous, who other than an engineer has any idea of what that means. Not being an engineer myself or knowing anyone who is, I (and probably many others) felt that under tightening to be less of a problem than stripping the thread, resulted in me not tightening the tip enough, resulting in a leaking extruder. The manual states this is not repairable.
The only reason I could see for that statement is the difficulty of undoing the thread/tip that is filled with solid plastic. By just removing the extruder from the K8200 and heating the brass tip, the plastic remelts and as a liquid permits it to be unscrewed/removed.
The main problem with any brass on brass thread is they tend to bind against each other due (no two threads are a perfect fit). On re-assembling I did the logical thing that anyone assembling brass fittings normally do (and I should have done), and put some Teflon tape on the male thread.
Provided you don’t put to much tape on, the two items screw together easily. Then as you tighten the tip, it reaches a point where it just stops and you can feel it is tight enough.
Though the Teflon tape may prevent heat transfer across the threaded area, there is still more than enough brass to brass contact with other surfaces to give correct heat transfer from the heater to the tip. My extruder now works as it should.
The inclusion in the assembly manual, of putting Teflon tape on the thread would have been more logical/practical (and worked) than confusing things with a 3.5nm torque setting.
Hope that helps someone.
Steve.
If you raise the extruder to 150mm.
Then remove the 2 screws holding it to the 8200.
Heat it to 190C (PLA) then gently grab it with a pair of pliers and remove the white Teflon tube.
Then with a 13mm wrench tighten it a little (just a little) while it is still hot.
Put the Teflon tube on let it cool then reinstall it.
Run another job and watch for leaks.
It took me 2 times but I got it and did not break it.
I agree with Steve on this one. Tape (or some type of sealer) is the way to go, and should be in the instructions.
I have a tension wrench, and tighten to the correct torque - tip leaked, tightened a it more - tip broke.
At $20 plus this is a ‘nice little earner’
The issue is heat expansion on the thread.
Tightening while hot is a ‘fluking it’ situation, just enough to stop leaks - without breaking it.