follow focus gear for lens without knurls?

[strangelove]

not sure if this is better here or in the cine/dslr movies forum

I just picked up a beat-to-hell Olympus 50/3.5 macro that is missing the knurls on the focus ring (how did I miss that?) with the bare metal underneath exposed... but since it has good glass and it was cheap, I'm going to de-click it and adapt it for my OM movie kit - the problem is, the follow focus gears I normally put on my lenses will just slip around, so I'm thinking it might be better to permanently attach a gear to the lens, but I've never done anything like that... any suggestions?

[philslizzy]

If the lens is going to be converted for video use them why not sand the focus ring to provide a 'key' and glue the gear with epoxy resin. Unless the gear is made of nylon or polyethylene it will work.

edit: lightly sand the inside of the gear too to provide a key for that.

[strangelove]

[David]

Use Pliobond. It's a rubber cement with zero (or near as makes no difference) VOCs. It's what repair guys use to adhere leatherette to camera bodies. The stuff takes upwards of 24 hours to set sometimes, though.

One thing you could do is get a screw-on follow-focus gear. I have some that came with a used lens. They slide on and off very easily. To prevent slippage, a rubber band sandwiched between the gear and lens when you tighten the screw could provide excellent friction.

[strangelove]

[philslizzy]

Use epoxy resin. Use for all things 'permanent' and needing solid fixing. Like I say if the gear is made of nylon or polyethylene it wont stick. In this instance I would use the 'contact adhesive type' there is still a chance it may move. But it is tackier than dry epoxy and will still grip.

Screwing on a gear sounds good but dont over tighten it or you may deform the focus ring. even 0.01mm can have an effect.

[David]

The ones I have look like this:

http://www.cavision.com/followfocus/gearring.htm

Here's a link to another forum's post that has some details (I read the entry with the images in it and I'd never heard of this forum, so hopefully it's a legit site.)



http://photography-on-the.net/forum/showthread.php?t=725135&page=2

[strangelove]

thanks for the advice - I'll try it out this weekend and let you know how it goes

[luisalegria]

Easiest thing would be to put a new grip cover on the focus ring. Lots of materials will do.
Leather, vinyl, even adhesive backed foam.
Some of the guys here have even used material cut from old ladies handbags, crocodile skin even.