PETG build up around nozzle  

RE: PETG build up around nozzle

This does not look like just PETG sticking to the nozzle, melted filament on top of heat block and around nozzle is a sign of leaking. Usually if there's a gap between nozzle and a heatbreak. Tightening it while hot helps, but I'd disassemble and clean it up first, or you may get remaining of that black filament deposited into another prints over time.  Here's a guide on how to disassemble and re-assemble: https://help.prusa3d.com/en/guide/how-to-replace-a-heaterblock-heatbreak-mini_122769/  

As for PETG sticking onto nozzle when printing ... well, it does that. PETG likes to stick everywhere, preferably to print surface or layer below, but if it does not have that, it will stick to nozzle too  Putting silicone sock helps protect heater block, but some blobs will still stick to nozzle and get deposited all around print. It's just ... PETG.

RE: PETG build up around nozzle

Posted by: @tbn319

I'm having an issue where melted filament is building up between where the heater block and nozzle meet.  There is also some filament build up on top of the heater block.  I've contacted support and have physically moved the heater block up higher into the fan portion of the hot end.  This issue seems to happen more with PETG but has also happened with PLA.  I'm guessing this may be causing some of the jagged exteriors on my PETG prints.  

Any ideas?

 

 

 

 

Pretty sure the nozzle does not seal at the heatbreak and therefore molten filament escapes above the nozzle.

RE: PETG build up around nozzle

You need to take things apart and then reassemble, but this time read the E3D-V6 assembly instructions. Some of the steps are not intuitive and if you miss one you get exactly what you got.

RE: PETG build up around nozzle

Thanks for the replies, I'm waiting for some thermal paste before reassembly.  I am not having any luck getting the hot end thermistor out of the heatblock.  I have the grub screw removed. and I've tried heating up the block and then pushing it out with a allen key but it's not moving.    Any other tips?

RE: PETG build up around nozzle

If the thing is welded in place (corrosion or plastic melt are two possibilities) - heat can help. If you have it apart, a heat gun is a good idea. I wouldn't be afraid to tap it out with a VW wrench and nail set. If that fails, a new heater block is about $20 on Amazon. And you can use this opportunity to move up to the nickel plated copper version for an extra $5 and think of it as an upgrade you wanted. I'd also buy the E3D-V6 standard heat break, their titanium version - titanium is a good upgrade. 

https://www.amazon.com/Genuine-E3D-Plated-Copper-V6-BLOCK-CARTRIDGE-COPPER/dp/B07CYZ1ZBW

https://www.amazon.com/Genuine-E3D-Break-1-75mm-V6-175-BREAK/dp/B077Y2MHW8

https://e3d-online.com/products/v6-titanium-heat-break

RE: PETG build up around nozzle

Dang - this is a MINI - I keep missing that detail.  Ignore most of what I wrote.

RE: PETG build up around nozzle

@tim-m30

I think that your recommendations are ok if someone has modified the Mini like I did. In this case I can recommend the nickel plated copper block with titanium or maybe a bimetal heatbreak. The E3D V6 hotend workes great with the MK3 and does the same with the Mini. The small offset of about 2mm in the Y-axis is no problem for me. I replaced the heating block screws with Torx versions. All components were sprayed with copper paste.

However, the nozzlefan airflow is still expandable.

RE: PETG build up around nozzle

Reasssembled and still seeing the issues of the leaking above and below the heat block.  Prints fine though.  I'd guess my seal is still bad?  I don't have a torque wrench to torque the nozzle to 2.5 Nm (ordering one) so when I tightened the nozzle in Step 25 ( https://help.prusa3d.com/en/guide/how-to-replace-a-heaterblock-heatbreak-mini_122769/#122778), I just tightened a bit more, maybe 1/8-1/4 turn more, the gap is still there.  

I can try to tighten it more, but am open to other suggestions.  Can I installed the heatbreak into the block all the way (no threads showing) and then tighten the nozzle as far as I can?  I'm guessing that'll leave a big gap between the nozzle and block but it's the only way I can think of guaranteeing the seal is tight.  Other thoughts?

RE: PETG build up around nozzle

Ended up replacing the heater block with glued in thermistor and heatbreak.  Followed all of the reassembly instructions and tightened the nozzle more than "finger pressure tight", not too hard but tightened more than I have in the past.  Have run about 10 hours of prints with no issues!  Thanks for all of the help

RE: PETG build up around nozzle

@tbn319

Tighten the nozzle when the hot end is stable at 285c. If you only tighten when cool, it will come loose and leak.

RE: PETG build up around nozzle

Yes, the hot end was heated to 280c before tightening.