If you have poor print definition, check your nozzle
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Maybe this can save somebody else a few hours of frustration ....
I have been printing with PETG on a particular printer and was having all kinds of print quality issues. The print was overall ok but the detail was terrible with lots of cleanup required. More cleanup than the usual PETG issues. Holes and voids were the biggest problems with the inside dimension being too small. Stringing seemed to be more than usual as well.
I tweaked all kinds of settings without success. In frustration, I finally took the filament spool off the printer and installed it on another printer and ran the same print - it came out beautiful.
I had eliminated the filament and most settings as being the culprit.
I decided to look at the nozzle in some detail thinking that maybe it had worn oversized or maybe there were other issues. When I unscrewed the nozzle, there was no initial 'break' as the nozzle started to turn which to me indicated that it wasn't totally tight. I cleaned out the nozzle (propane torch treatment) and re-installed. A new print resulted in the problem printer printing as clean as it did on the previous test printer!
The moral of the story - an imperceptible wiggling of the nozzle caused me a LOT of grief! While it is also possible that the nozzle had some sort of partial internal obstruction that was cleared out in the torch treatment, I believe that all my problems were related to the lack of proper tightening of the nozzle.
An important detail - I run a Dragon hot end on this printer. In the Dragon, the nozzle does not seat against the heat break like it does on most regular hot ends. A regular hot end also generally uses an aluminum heat block which expands when heated, this would cause all kinds of oozing of filament out the top and bottom of the heat block and the problem would be immediately obvious. A regular hot end must be hot-tightened because of that.
The Dragon uses a copper the block which does not expand anywhere close to an aluminum block and hot tightening is not required.
Anyway, I thought I would share the lesson I have learned over way too many hours! -
@jens55 said in If you have poor print definition, check your nozzle:
A regular hot end must be hot-tightened because of that.
I can copy your findings about leaking aluminum block.
I just want to point out, that I always get a "heater fault" error when I hot tighten the nozzle, because of the immediate temp drop caused by the metal-tools I'm using.
While at the printer, doing some "heart surgery" this error is pretty annoying, because I have to drop the tools, go to DWC PC, cancel the fault and start heating again.
So, hot tightening is a one chance game...firmware wishlist: allow temp drop while maintaining the hotend.
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@o_lampe you could use M570 to adjust the fault detection before hot tightening and then change back afterwards
https://docs.duet3d.com/en/User_manual/Reference/Gcodes#m570-configure-heater-fault-detection -
@jay_s_uk
That's cool ( or hot?), but it would be even better to do this automatically and have an easy way to switch it back to "normal". By drop down menu in DWC or a macro perhaps?
Wondering, if the parameters are part of the object model?
Anyway, thanks for pointing it out!
