Mentioning a 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 (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 torque setting.
Hope that helps someone.
Steve.
Thank you for the tip and good work on getting things back in order
It is difficult to define how much to tighten the parts, since someone that does pipe fitting for a living will naturally have more raw force than someone like me with a desk job. They will both have different perceptions of how much is enough, and they will apply their force differently. One person will break the parts easily, while another may not tighten them enough. Teflon will not always be the solution.
Luckily, most people succeed in assembling the nozzle. But, in case of trouble, they can always contact customer care support.velleman.be/ to get new parts, because things like this happen and the most important thing to us is for people to get their printer working.