Build your own Lens gears

Inspired by this thread, I made my own zoom gear for my Tokina Fisheye lens today for a Sea & Sea Housing.

Cost me all of $2.00 and a couple of hours of my time.

Went to the local Bunnings (hardware store) and picked up a 75mm round down pipe. This fits very snugly around the zoom ring on the Tokina and doesn't need any extra padding on the inside. It also tapers slightly so you can push it in and will stay snug. Longest part of making this was cutting off the flange with a hacksaw.

To make up the required diameter to reach the zoom gear on the housing I used a combination of some flexible magnets and those rubber bands people wear around their wrists.

The rubber grips the housing's zoom gear quite well and at the telephoto end once you reach the limit it won't turn further unless you really crank it but it does slip on the wide end when you reach it. I might try and find a toothed belt that will fit around it or may use velcro or have a go at making a tooth rack from polymorph.

Nice post.

I've always wondered about trying to create a "gear coupling" with some of those strong magnets...one set on the inside of the sleeve, another tacked (hot melt glue?) to the lens zoom ring grip. So you get a friction fit between the sleeve and the lens...with magnets holding the two together. Seems like 3 of them 120-degs around would give enough contact strength, if you spaced them right to be in reasonably good contact (and of course matched polarity correctly...)

If there's not enough diameter space for the smaller rare-earth mags, maybe refridge mag strips cut to run all the way around might work in a pinch.

Probably a silly thought....

Nice post.

 

I've always wondered about trying to create a "gear coupling" with some of those strong magnets...one set on the inside of the sleeve, another tacked (hot melt glue?) to the lens zoom ring grip. So you get a friction fit between the sleeve and the lens...with magnets holding the two together. Seems like 3 of them 120-degs around would give enough contact strength, if you spaced them right to be in reasonably good contact (and of course matched polarity correctly...)

 

If there's not enough diameter space for the smaller rare-earth mags, maybe refridge mag strips cut to run all the way around might work in a pinch.

 

Probably a silly thought....

Not a silly thought at all. Except Inon beat you to it. Inon make/made magnet ring and ports for some of their housings. The idea was that you turned the ring on the port just like you would on land.

Not a silly thought at all. Except Inon beat you to it. Inon make/made magnet ring and ports for some of their housings. The idea was that you turned the ring on the port just like you would on land.

Interesting approach. Not really sure the shooting position is that congruent with using a zoom-ring topside though...

Great idea and definitely nice to have in the tool kit. If you are a bit more adventurous and have an old gear that is close to the desired size, I have cut the gear on a table saw to allow it to expand to the needed size and then simply slip over the lens.

These guys make a zip tie zoom gear: http://jag35.com/store.php/products/follow...ziptiegear.html

I have not tried them, but they seem like they would work.

These guys make a zip tie zoom gear: http://jag35.com/store.php/products/follow...ziptiegear.html

I have not tried them, but they seem like they would work.

That looks like it would work well, except unfortunately it's relatively expensive.

I received my Polymorph yesterday and have been experimenting with it. It is not as easy to work with as I hoped. My plan was to create a mould, out of Polymorph, from the zoom teeth from an existing Sea & Sea focus ring that I have. When soft the Polymorph is the consistency of thick honey rather than a liquid. This means that it is quite hard to get the Polymorph to fill the little gaps between the teeth of the zoom ring. This problem is further exacerbated when you try use the mould as the Polymorph won't easily fill the gaps in the mould that I just made. So in the end you come out with a very blunted zoom gear ring rather than one with nice sharp teeth.

In a similar thread, I showed how I used a vacuum cleaner belt as a gear; it's still works great.

Similar Wetpixel thread

Ben

Yeah, I've been on the lookout for a vacuum cleaner belt but haven't come across one yet.

Here is my latest effort, I found that some cable loom I have meshes almost perfectly with the zoom cog of the housing.

I cut a short strip of the cable loom and flattened it out. I attached it to my original metal ring with some polymorph and it works well. Doesn't skip any teeth and stops when you reach the limits of the zoom.