What is the best way to ensure the correct gap between nozzle and the heatblock?
Hi, I know we need to leave a gap of about 0.5mm in between the nozzle and the heatblock. What is the best way to ensure that the gap is just good enough and not to big but not to small.
That gap of about 0,5mm isn't (can't be) "good enough". It serves only one purpose: to guarantee there will be no gap between nozzle and heatbreak after you finally tighten the nozzle.
[Mini+] [MK3S+BEAR]
E3D Installation instructions
E3D recommends tightening the nozzle flush to the heat block, then backing off 1/4 to 1/2 turn.
Source: E3D-v6 Assembly - E3D-Online
missing bit of information
and after that 1/4 to 1/2 turn you need to screw in the heatbreak from above until it hits the nozzle. This will limit the upward movement of the nozzle when tightening and ensure there is really good contact between nozzle and heatbreak.
Well actually not only good contact but a good seal otherwise:
It took me a while to get my head around this whole thing. It is not really about the "gap" at all. It is about the ability to screw the nozzle upwards to generated that seal. If there is still a bit of thread visible after proper tightening you can be sure that it was the contact between nozzle and heatbreak that limited the upward movement and not the contact between the outside of the nozzle and the heater block.
I still don't understand why most of the "how to change a nozzle" tutorials omit this tiny bit of helpful explanation.
Cheers
Hansjoerg
RE: Concur
I agree with this, as the 1/4 to 1/2 gap is put into place before hand tightening the sink/heatbreak on the nozzle. Further, the nozzle needs to be set by tightening it at working temps.
Agreed 100%
[...] It took me a while to get my head around this whole thing. It is not really about the "gap" at all. It is about the ability to screw the nozzle upwards to generated that seal. If there is still a bit of thread visible after proper tightening you can be sure that it was the contact between nozzle and heatbreak that limited the upward movement and not the contact between the outside of the nozzle and the heater block.
Agreed 100%. There's too much focus on "leaving a gap" when, if everything is properly assembled and tightened, there should be now way there isn't a gap.
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RE: What is the best way to ensure the correct gap between nozzle and the heatblock?
AS @bobstro said, if the hotend is properly assembled, there's no way there ISN'T a gap when you (hot) tighten the nozzle. If you have to leave a gap manually, that means the heatbreak is not screwed in deep enough: (click on picture of full view)
Formerly known on this forum as @fuchsr -- until all hell broke loose with the forum software...
It is possible that there is some filament inside(if not all parts are new), wen you screw in the heatbrake, wen it is cold you can hit the hard(cold) filament, wen you heat up , there could be more room to screw in.
If you do not screw the heatbrake far enough, after screwing on the nozzle(heated), it is possible that you can screw in the nozzle to far, and leave a gab between the 2.
If i do this again with old used hardware I will try to do this heating up with the nozzle hanging in the air, and not with a complete build, and finding out I can turn the nozzle to far in.