Worm gear for focusing - where oh where?
 

Anybody come across decent worms/mitre gears? I have tried in Canada and can't seem to find them anywhere!

Go to ---- http://www.mcmaster.com

Type "worm gears" into the search window!

One of the greatest places on Earth.

Mike

Another source is Stock Drive Products:
www.sdp-si.com

Good luck,

Arthur

Stock Drive Products was great, but I am still wishing for the miter box, alas I guess I will have to do without. Does anyone have the size needed in the miter gears to create a follow-focus system - there are several on the Stock Drive Products and they are cheap!

I bought my Bevelled Gearbox from Maplin.co.uk - enter "Bevelled Gearbox" in search panel.
It only cost about 19GBP including tax and posting - although your post might be a bit more...
see also: http://www.dvinfo.net/conf/showpost....9&postcount=75

Robin

Is it to build a follow focus?

If yes, I bought the parts of my follow focus on www.conrad.com , including a bevel gear. You can see some pictures and part numbers at http://www.pana3ccduser.com/showthread.php?t=7575

cheers

Jelle,

Do you have any breakdowns of the unit? I saw the pics on Panauser, but they don't show how the unit is attached to the rods and how it is all held in place.

What kind of Pitch and number of teeth would one need for a FF gear box? I have found some myself, but can't determine what would be the best fit. Any ideas?

A quick question: when searching gear boxes, am I looking for Low Torque or high torque?

David, I'm not sure if you want worm gears...I believe mitre gears with a 1:1 ratio would be more appropriate. I stand to be corrected on this, but I guess the question is this:

How many turns of an FF knob are normally associated with a 35mm lens focus ring? To my mind, one FF knob rotation should be at least one 35mm lens rotation?? Can anyone comment on a commercial version out there?

im looking for the best solution to make my own as well.. a DIY guide and parts list from someone who has made one of these would be awesome. I have a gear for my lenses now (from dan diancu) and would love to get a follow focus on the go.

what canadian parts source would be good?

I think the worm gear would be ok, but the part that attaches to the lens would have to be larger to accomodate the smaller turning ratio of the gear. I have a semi-working version at home, but the torque is too much for it.

If a worm gear is too slow (which is pretty likely) you can also try to find some other 'ready made' gears to use..
I've posted this before, but I still haven't tried it in the mean time:
A 90 deg. screwdriver gear. Or another 90 deg. accessories for things like Dremel precision tools or something.
Another idea I had is to use a flexible shaft. You could bend it in any direction you want. If you got a large flexible shaft for a drill, you can put the knob (you use to turn the lens) on a tripod for instance so the chance of shaking the camera when focusing is reduced. But you could also use a short flexible shaft and put the wheel next to the lens like a normal FF.

That's sound like a good idea, but the problem is the cost. I am trying to keep the cost down. It seems to me that the major challenge in all of this is the gear box. After some testing, I think I can make one pretty simply, but I need the bevel gears at a cheap enough price to make it worth it.
Having a dremel part is about $39.00+ tax. But the RedRock and the IndieFocus guys have found a suppliers, so it has to be out there somewhere. It is just a matter of finding it. My friend in Toronto said there is a place on Queen Street that supposedly sells loads of gears and equipment like that...