Wheels for drill-gearboxes?

[Runsler]

Soo... reviving this thread...

I am completely lost on imperial measurements.
So on the usual drill gearboxes, as well as on ranglebox neptunes and a few others we have a 3/8 unf thread on the outside.
And a reverse M5 on the inside?
Anybody can tell me why use two systems of measurement?

The video from Ellis that was mentioned at the start of this thread is sadly gone (or really good at hiding).
I did watch the one posted by Jamie on the hex hub adapters.

Anyway... so to put the wheels on it's like this:

1.get 3/8 UNF Nuts.
2.drill holes in the wheels just a bit smaller than the diameter of the nuts from flat side to flat side.
3.Hammer the nuts in or heat them up and melt them in (both seem to work).
4.put a big washer on the shaft.
5.screw the wheel on the shaft.
6.Put another washer onto the M% reverse screw.
7.Screw that one into the inner thread.

Did i get that right? Or is that outdated anyway by now?