Hardened nozzles for Biqu B1

[Anthony Jackson]

Hi this is a tip for people struggling to find hardened nozzles for the Biqu B1, as I did.  I needed to start running PETG-CF and could not find readily find UM2 format nozzles.  UM2 nozzles are ~16mm long but the more normal MK8 are only 12.5mm, leaving them 4mm short. Also any UM2 hard nozzles I found tend to be for 3mm filament  After research I found hardened volcano nozzles readily availabe, inexpensive and the same thread (M6x1) as the UM2.  I do have a small machine available to me, I realize this may not work for everyone.  I bought 3 of the volcano .4 mm nozzles.  They arrived and as expected had a treaded stem far too long.  I annealed one of them (heated it red hot with a propane torch) and let it cool.  That allowed it to be lathe machinable.  i reduced the overall length to 16.3 mm by machining off the excess thread.  I held the head of nozzle clamped in 2 M6x1 nuts in the lath chuch trimming .25mm per pass to prevent bending.  When the nozzle was turned down to 16.3mm from the 21mm length I used a 2mm drill just to touch up the machined end and the removed the nozzle from the lathe and nuts.  Reheated it to red hot and then quenched in oil to reharden the nozzle.  Verified hardness with a file,  Tempering not needed.  That still left a threaded section on the volcano that was longer than the UMS thread stem that has about 5mm  I made a brass nutt tapped N6x1 and faced it to about 1/4 too short for the difference.   Screwed the brass nut down fully on the new nozzle and screwed the nozzle into the heat block.  Pre-heated it, snugged the nozzle (not outer nut) wit m7 socket.  Let it heat a few minutes then tightened the outer brass 1/4 turn to lock the nuzzle and act as a heat block.  It has performed brilliantly on my PETG-CF and has generally increased print quality with less drooling.  I think the outer lock nut helps seal the nozzle from stem leakage.  I realize this was long and not to a particular question but it has been an important development for me using my B1.  And it is a frequent issue that is asked.

[The Bob]

Now what you should do is email me above so I can pay you for a couple of said machined nozzles. 

This little Biqu B1 has become my goto for quick prints.   Just amazed you can't find upsized nozzles for it.   I had ok luck using .6 hand drill from inside out.  But still.  

Bob

Edited March 9 by The Bob