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UMO+ Heater Block leaking - Existing fixes not working

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My question is if anyone can try and walk me through all the possible causes of my leak. I noticed that after I built the printer there was a pool of the silver metallic PLA appearing on top of the heater block, after finally dissambling the print head and cleaning it I can confirm that the leak is coming up from within the block itself. When I reassembled the print head and hotend I made sure all pieces are as tight as possible without tools.


I have been printing with the stock Cura settings for this except for changing infill and layer height. As a troubleshooting step I reduced the print speed from 60mm/s to 30mm/s and printed a 10mmx10mmx10mm cube but still had the pool of PLA grow. The only other issue I could find on the forums that is like mine also had a printer using the metallic silver PLA which I think could be the cause of the issue.

Edited by Guest

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I don't like the way it is explained in the manual, it is a source of trouble...

This is what I recommend:

  1. Screw the nozzle in the heater bloc, but NOT flush against the heater bloc -- leave approx. a 1mm gap
  2. Screw the brass pipe until it reaches the nozzle -- do not apply excessive force as it is fragile
  3. Now tight the nozzle against the brass pipe with a wrench. You don't have to over-tighten it, 0.5 Nm should be enough. At the end there still should be a gap between the nozzle and the block, if you are tightening against the bloc you will have leaks!
  4. Optional, but recommended: repeat the last operation when the hot-end is at temperature (don't burn yourself!)

Your bloc will never leak again after that ;)

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So I made the mistake of not tightening the nozzle more while it was hot but the leaking has all but stopped and I just tightend the nozzle furthur while hot and that appears to have been the problem


Need to do one more clean up on the hotend do to some burned PLA but the leak is fixed

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