The hole in the centre is 2.1mm

First thing set up the dividing head using a DTI

Using a 7 leaf Module .7 cutter you can calculate the overall diameter this work out to 6.1mm
First set the centre

Once done I cut it down to 8mm and facing it on a lathe next drill the centre out to 2.1mm this would allow me to slide it over the arbor

Hand turn the arbor to size

I fitted the pinion to the arbor using loctite 638 and the collet which I would screw the wheel onto

Finally screw the wheel to the collet of the centre wheel

How it interacts with the barrel I’ve made

Just needs to be crossed out next

First thing was to remove the old one by turning of the rivet on a lathe and then punching it out

Using it as a reference it was time to turn the new one, I did this using an old Bergeon lathe and a 5x lupe the end pivot was .11m

Then start on the other end at this point it is so fragile and very very small

Next polish the pivots using a set of turns

Fit the roller and then after poising it, this gets the balance weight even and test it in the movement

It worked first time but what a pain in the neck lol