InterchangeableNozzleMk2

To make the Mk 2 Extruder nozzle interchangeable, just drill the 3mm central hole right through the brass M6 bolt normally used for the body of the nozzle.

• The detatchable nozzle concept. This one has been reduced in diameter with solder around a piece of nichrome wire, which is then removed to leave the vital hole.
  

Take a threaded section of M6 brass - a bolt offcut or somesuch at least 20mm long for ease of handling - and drill a 3mm hole into it about 5mm without wrecking the thread. Tidy the face up if needed. You will also need a brass M6 nut of a minimum 5mm thick; if the nut is much thicker, you'll need a deeper 3mm hole in the threaded section.

Drill your nozzle's hole into the bottom of this hole, going in maybe a millimetre. As the drill bit does not emerge from the other side of the rod yet, it should be less prone to breaking fine drill bits off - I hate it when that happens.

Now, probe the depth of the 3mm hole. Add on a millimetre, and mark that as the edge of where you'll cut the threaded rod, and take it off with a hacksaw or grinder. Wrap the short piece you cut off with tape to protect the thread, leaving the ends exposed. If you can't find the fine hole's exit and it doesn't go through, start filing. When you've found it, use your file to shape the end so that the little exit hole is at the highest point on it.

Finally, screw the nozzle into that M6 nut about 1/3 the way down it, and solder it there without flooding the remaining thread. Use a big soldering iron, or preheat the assembly with a torch, then touch up with a small soldering iron.

When cool, check the nozzle is clear, scrub off excess flux and screw it onto the end of your Mk 2 extruder. There must be no debris of any kind left over in the nozzle, or the thing will clog.

I liked this method because I am a lazy beggar and found with a little practice I could make one quite passably without having to set up the lathe. -- Main.VikOlliver - 07 Jan 2006