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-   -   Build your own 35mm Follow Focus Gear (https://www.dvinfo.net/forum/alternative-imaging-methods/65272-build-your-own-35mm-follow-focus-gear.html)

Shane Valdez April 17th, 2006 06:22 AM

Build your own 35mm Follow Focus Gear
 
Quick and painless way to build a 35mm Follow focus gear.

Step #1
go to your local hobby shop and buy a 70mm Helicoptor gear.

Step #2

Clip to fit.

Step #3

Place it on your 35mm lens!

Shane Valdez April 17th, 2006 06:25 AM

Also, i'm using the Chrosziel 202-16 Focus Gear Drive - Canon 16x Manual Lens.

Ben Winter April 17th, 2006 09:50 AM

The gear is available online for purchase here:
http://www2.towerhobbies.com/cgi-bin...&I=LXLBN7&P=FR

I just ordered three. I will post if this is cine-pitch gearing. If it is, I plan on keeping mine. If they aren't, I'll probably sell them.

Andy Gordon April 17th, 2006 05:20 PM

Where's a good place to buy the gear drive and what is the cost? I searched for Chrosziel 202-16, seems to be 64 euros, is that item number all you need? The full unit was over $1000.

David Delaney April 17th, 2006 09:49 PM

That's the main problem - once you get the gear to go on the lens, you need the gear to turn the lens. Like a chicken in the egg I suppose. Dan was selling one, IndiFocus has one, they just aren't cheap.

Shane Valdez April 20th, 2006 12:50 AM

Sorry the link was removed, here is the new link:

http://www.dvinfo.net/gallery/browse...3&userid=13126

Jim Lafferty April 20th, 2006 08:51 AM

No, the IndiFocus is cheap, at $299. Dan's follow focus is an entirely different product, and almost twice as much, IIRC.

Bill Porter April 20th, 2006 12:17 PM

Quote:

Originally Posted by Ben Winter
The gear is available online for purchase here:
http://www2.towerhobbies.com/cgi-bin...&I=LXLBN7&P=FR

I just ordered three. I will post if this is cine-pitch gearing. If it is, I plan on keeping mine. If they aren't, I'll probably sell them.

I don't know what your reasons are for wanting cine-pitch (e.g., maybe you already have a FF with gears that are cine-pitch), but pitch is irrelevant if one uses the same tooth profile on all gears. It won't matter whether your gears are helicopter, cine-pitch, or otherwise. (assuming there's no lash!)

Also, you can simply find out what the pitch is without buying any gears. For that gear for example, you could call or email Helimax.

Forrest Schultz April 20th, 2006 02:50 PM

Im not sure if anybody ever thought of this.. but remember when everyone was trying to find good metal 90 degree gear box. you know, one shaft is 90 degree to the other and they both turn inside a gear box. very important peice for follow focus unit. well the problem was they are made, but they are always really expenisive for a metal one and not plastic.

well...how many people use a drill press in here? then youve probally used a chuck key alot also. and did you know that that key is a 90 degree gear also? and what happens if you take 2 chuck keys, and fit them in a little box holder? you get a 90 degree gear box. and it will cost you about 3 bucks
http://www.lowes.com/lowes/lkn?actio...95302-70-U1533

i thouhght of this a week ago as i was working with my drill press. How easy is this!??

eh, eh? do i get a kiss?

Bill Porter April 20th, 2006 03:00 PM

Wow, I wish I'd been following the threads about that because I could have helped give something back to the forums. I know a lot more about mechanical stuff than I do cameras.

Those sorts of gears are called miter gears.

http://www.mcmaster.com/catalog/112/...e/6529kp1l.gif

They are available in plastic (molded nylon usually) for about $2-3 a piece in a variety of shaft diameters, tooth counts, diameters, and so on.

Check out mcmaster.com. You could build everything from a follow focus to a space shuttle from that place. Super inexpensively, too. McMaster Carr is heaven on earth.

Have fun!

Forrest Schultz April 20th, 2006 03:05 PM

thanx Bill that will help people find alot of gear parts.

The problem with the miter gears on their site is that the nylon ones are cheap. but their steel ones are over 20 and going up. that price sucks, and is not as nearly as cheap as the lowes replacement chuck keys. nylon could be fine, but isnt as durable as steel.

I also have a question. its something that i cant seem figure out.

from what i see on most follow focus's is the handle/wheel, (the wheel with the whiteboard attached) that is linked by a shaft which goes into a 90 degree gear box. The shaft that comes out of the box is attached to a smaller sized toothed gear (usually plastic) which interlocks to the SLR lens plastic toothed gear which is about as big as the diametter of the lens. and then you turn your wheel as it simultaniously turns the 35mm lens. since the slr lens gear(helicopter gear in this case) is large compared the the smaller gear that is on the 90 degree box shaft. How is the gear ratio still 1:1. wouldnt you need 2 gears the same size to get a 1:1 ratio.

or is there another gear involved somewhere that i missed. (note, i know that on professional FF's they have an adjustable extension peice that is pulley driven, that way you can swivel your gear back and forth for differnt size lenses. But i assume that pulley driven extender is 1:1 in itself. so i left it out of my question. to keep things simple)

Bill Porter April 20th, 2006 03:18 PM

Nylon isn't as durable as steel, nor does it need to be in this application. You won't ever wear out a Nylon gear in a follow focus since Nylon is a hell of a lot stronger than you even need. In a follow focus it will go through a very low number of rotations in its lifetime, at very low pressure, and very low speed.

Nylon is cheaper, lighter, and easier to work with (in case you want to drill a set screw hole, etc) than steel, and these are things you do want in this application.

Forrest Schultz April 20th, 2006 03:24 PM

You are right Bill, that makes alot of sense since steel is a pain to drill or dremel and work with for that matter. thanks

Bill Porter April 20th, 2006 03:26 PM

Happy to help!

This place rocks

Alex Raskin May 2nd, 2006 09:58 PM

How's this for a remote-controlled follow focus:

http://www.cameraturret.com/focus.htm


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