substitute for gear rings?

[Seanothon]

I need to get a gear set for my Oly 9-18mm and they are all around $100 or more. Seems a bit excessive for a couple small pieces of plastic / rubber. I was looking at my other gears and thinking that they look a lot like a timing belt for your car. When I get some free time I'm going to head to the auto shop and see if they have a belt with teeth and size might match. I was also thinking I would just try a gear for a follow focus, which can be had for around $10. Anyone tried a cheaper alternative for gear ring?

 

[mjh]

Not sure what housing you have but a Zoom Gear for the Oly housing is $44. Making a Focus gear would be more complicated as most just rely on the Autofocus of the lens and camera.
Ports, Extensions & Gears :: Mirrorless :: Lens Gears :: Olympus 9-18/14-42II Zoom Gear -

 

[MrMagica]

Funny, I just butched my 9-18mm zoom gear to try and make it fit on a 12-50mm. I then went round a DIY shop to find some pipe that was the right diameter to extend the zoom ring to suit the 12-50mm.

The only way I could work out to totally make something from scratch was a 3D printer, and some people have. However no cheap access to a local 3d printer for me.