I test out an idea I had a few months ago for doing 2,3,4 and 6 start threads by using a collet block to index the screw around.
There's a bit of runout - but this was meant to be a proof of concept rather than a perfect part. There won't even be a matching nut for this! I will be making a tap with this same method (smaller diameter), and I'll take a bit more care in setting that up.
