My friend Mike made me a custom 120 Index Gear for my Omni-e. Jersey Instruments does not make a 120 Index Gear and told me that the gear pitch was too small to manufacture.
This index gear is machined from aluminum and has engraved markings. The original index gears that came with my Omni-e have painted-on numbers and markings – these wear off through use. More critically, the paint can be dissolved and wiped from the gear if you happen to get a solvent like Refractol on it by accident – I can confirm this with my 80 Index from Jersey Instruments.
The 120 Index Gear that Mike made works like a charm. The center hole was a bit tight so I had to sand it out – I’ve informed Mike of that problem and he is loosening off the tolerances of his machining to account for the vaguarities of the parts on the Omni-e. The index pin does not seat completely into the groove but this is not an issue – it sits deep enough to hold the quill in the appropriate setting without fear of it jumping out or being knocked loose.
Unfortunately Mike is no longer manufacturing these parts and his old domain has been taken over by some Chinese company.