The drive gears in my X1 mill (axminster mini mill) finally broke. I say finally because they are said to break very often and Mine has not broken in the 3 years iI have had it.
Living in the channel Islands it is just a bit more difficult to get bits than what it was in the UK
So I decided to mod the mill and and make all the bits - then I know it is easy to get replacements again.
For the belt I decided to use a NItrile Seal ( BIG O RING ) 5.33 MM diameter and 13 inch sirc.

THis is the Large ( driven) pulley roughed out ready for the mandrel

Then I made a Expanding Mandrel 20mm from 25mm MS

And final shape of the Pulley with the O ring to see if the fit is positive and if it grips - The grip is for the v sides and no contact in the bottom of the grove.
The pulley is shaped for a standard 6mm 40 deg v belt This engages the round belt just fine.

Then the same for the Driver / Small pulley
Next is the mounting plate and the pulley tensioner
These are still on the drawing board as the mill is out of action to make them????
More later
Gerhard