Hi guys, sorry Kammo i ment to hit reply today but its been a busy day for me as its my little girls 3rd birthday today so i'v been busy putting things like trampolines together all day and maintaining order on the bouncy castle, mind you i never was one to share :D

coming back to the business end of things...

Jeff is right, steel on steel like that is not a good idea, go with delrin and you cant go wrong.

I do sell them for £4 each ready to go:



Each drive nut kit consists of the following parts:

M4 X 50mm Zinc Plated Pozi Pan Head Screws x 2
M4 Stainless Steel Nylon Insert Lock Nuts x 2
M4 Zinc Plated Flat Washer x 4
Delrin Drive Nut x 1 - 20mm X 40mm X 16mm

The mounting holes are 20mm from centers, countersunk 5mm. The threaded hole is 8mm on center, from the bottom.

This drive nut as been designed for use with standard UN (Unified Thread) M8 Threaded Rod.
If you want to grab some delrin from ebay £3-4 and make your own i would say "why not" its true it is easy if you'v got all the tools and so on.

You will need an M8x1.25 TAP also the pilot boring drill bit needs to be 6.8mm OD not 6.5mm. You can use over and under size bores but you will more then likely run into problems later on. Ending up with you needing to remake them, as you will find the thread will strip from the nut or it will be lose and so on. Other then that you shouldnt have any problems making them yourself.

Only other thing for me to add is I consider my drive nut on a machine to be properly the most important thing on the machine, think about what it does and how important it is for it to be reliable.