MK3S+ heatbrake hole diameter
Hi,
I had my first problem and I think I solved it already (there was a piece of filament stuck in PTFE tube which jammed the whole thing)
But, before I was about to reassemble the extruder, I just wanted to make sure that filament had free path through the hot end.
To my surprise it didn't. and here is why:
There seems to be a thinner hole in the middle of heatbrake - at most 1mm in diameter, probably less...
I thought that heatbrake should be at least filament diameter through all length.
when I try to push filament from each side, I am only able to push it to the middle part:
Is this normal?
I would already try to clear it, but it seems to me such a perfect circle that it couldn't be from filament stuck to the sides or is it?
Thank you and best regards,
Pawks
Difficult to tell
It looks small, but ti cook be normal. It hard to tell with the photo. Try using a neddle or paperclip and probe the hole. if it is hard like metal, it is normal.
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Chuck H
3D Printer Review Blog
A quick 30 second google search will turn up the official e3d heatbreak design used in the V6 hot end https://wiki.e3d-online.com/images/0/09/V6-175-BREAK.pdf
now the heatbreak used in the mk3 is slightly modified due to a request from Prusa for mmu purposes with a narrower section so I’d say that your heatbreak is normal from your description.
A simple test
The only test that matters is whether filament will feed smoothly through the heatbreak. Try sticking some filament through there. If it feeds cleanly, the narrower hole is almost guaranteed to be 2mm.
The big step at the top is where the PTFE tubing fits. That is normal. Prusa heatbreaks have a 2.2-2.0mm step below that, but it's hard to view without very good lighting and magnification. An E3D heatbreak does not have that step, just the 2mm tube.
In any case, if you're getting resistance in the heatbreak that won't clear up (e.g., shove a rod in there to clear it while heated) then just replace it. There's no sense risking future problems with a part that is failing. I have had a few bad heatbreaks, though mostly knock-off clones. I will never try a cheap bi-metal heatbreak again. I can recommend the E3D Titanium heatbreak.
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The only test that matters is whether filament will feed smoothly through the heatbreak. Try sticking some filament through there. If it feeds cleanly, the narrower hole is almost guaranteed to be 2mm.
The big step at the top is where the PTFE tubing fits. That is normal. Prusa heatbreaks have a 2.2-2.0mm step below that, but it's hard to view without very good lighting and magnification. An E3D heatbreak does not have that step, just the 2mm tube.
In any case, if you're getting resistance in the heatbreak that won't clear up (e.g., shove a rod in there to clear it while heated) then just replace it. There's no sense risking future problems with a part that is failing. I have had a few bad heatbreaks, though mostly knock-off clones. I will never try a cheap bi-metal heatbreak again. I can recommend the E3D Titanium heatbreak.
--------------------
Chuck H
3D Printer Review Blog