Quote Originally Posted by progomez View Post
I thought of buying some delrin block from ebay. I have some delrin 10x2 round nuts but they are a pain to mount unlike the block ones you supplied.

How straight forward is it to make a tap using a length of trapezoidal screw ?
put a 4" length of trap rod in a drill chuck or lathe. Spin it up and apply a file to the last inch to taper it to the thread depth. Lock the chuck or hold rod in vice) and grind 3 'slots' at 120deg for 3" using a thin cutting disc (or file it if you feel up to it). lastly file the untapered end to a square.

Good enough for delrin. For a tigher finish lightly file the overall thread by about 0.05 - 0.1mm

I did it and it works... for nylon or acetal a few times... but wont do brass without hardening...