Loxia's Hot End
- 1 Borosilicate Glass Nozzle (No easy sourcing at the time of writing)
- Outside diameter should be about 6mm and inside diameter be between 3.3-4 mm for 3mm filament.
- 8 ohms of Nichrome Wire - Gauge 30.
- Easily found at most hobby shops in the USA. Woodland Scenics ST1436 Foam Cutter Replacement Wire was a good choice and can take a lot of abuse. Also if you had 24 gauge Nichrome fishing line (No coatings!) that would be managable.
- Kapton Tape: I used the 1/4th of inch wide roll which was nice for winding around the nichrome.
A good guide on assembling the glass nozzle is found at http://reprap.org/wiki/Glass_Nozzles though the variation of my hot end comes from the fact that the extruder cannot and should not be mounted as it is shown on this page! Doing so will cause a weakness to the exposed edge which can cause the nozzle to crack during filament feed.
Cut a wood block to the precise dimensions of your glass nozzle's outside diameter and two holes to mount onto your extruder. The result should be that the glass nozzle is not supported by a typical groove mount; and should pressures or a failure occur for any reason the glass nozzle will free itself from the extruder cold end; this has only occurred once before under extreme stress of abusive testing.
It should be noted that this design can jam under poor operator conditions! If you reverse filament too far up the length of the nozzle and outside of the heat zone so that it cannot melt; it is possible to create a block that will have enough friction to prevent further extrusion of low torque motors; it is very rare though and usually involves extruder movements deemed 'dangerous' by Marlin. With proper use it should never jam; and even if it does somehow jam; the filament cleanly comes out with a slight tug.