Alternate materials that work like wood

[jjstafford]

This past Winter was the second full of failures trying to build a rather unique camera using wood. Wood is just not strong enough when as thin as I need it.

I am hopeing that net-wisdom here can point me to alternative materials that can be worked using wood-working tools (and meanwhile saving my pennies to have the parts machined in aluminum.)

The application is entirely of flat materials, 1/8th and 1/4" thick, with no joints (corners). Help?

tia

 

[Dandy97]

PVC, Polycarbonate and Nylon. All much stronger than wood in simular thickness and all workable with woodworking tools.

 

[argus]

PVC, Polycarbonate and Nylon. All much stronger than wood in simular thickness and all workable with woodworking tools.

Those might be workable like wood, but they won't all be as rigid as wood.
Stability is a very important issue, rigidness is the key.

G

 

[rogueish]

Use your woodworking tools to make molds for epoxy or plastic resins?

 

[noseoil]

"Wood is just not strong enough when as thin as I need it."

Will you please list the properties necessary and engineering application which requires this material? Is the camera you are building a secret? Shear, axial load, tension, compression, bending? Spill the beans. tim

 

[Bob F.]

Have you thought of ply? Model makers shops sell it in various thicknesses. Or, you could laminate your own if you want something with an exotic wood finish... or laminate two sheets of wood with a kevlar, fiberglass or carbon fibre centre....

Bob.

 

[Donald Miller]

In aircraft pattern building there is a material that is called Phenolic. I am not sure of the exact and proper name for this material. It can be machined to very precise tolerances, is rigid and strong. You may want to check into that. This material would not be susceptible to dimensional instability in the way that wood could be possibly.

Additionally, carbon fiber would be a good material. This composite is finding it's way into many aircraft fuselage assemblies because it is strong and it is light.

 

[jjstafford]

"Wood is just not strong enough when as thin as I need it."

Will you please list the properties necessary and engineering application which requires this material? Is the camera you are building a secret? Shear, axial load, tension, compression, bending? Spill the beans. tim

First, please understand that I am not an engineer so I don't know what you are talking about; all I can give you is an idea.

4x5. The lens weighs around nine pounds. Picture an almost symetrical lens with 6" front lens, 5.25" rear lens with a Copal #2 in the middle - a deep waisted profile.

The lens would sit in a two-point cradle fastened (welded is fine) to a rail - round is good. Except for the back, there are no squared surfaces. Front and middle cradle points hold the very front of the lens (the only flat area up there) by a simple light pinch (not pressed), and the middle cradle is split with the top piece to pin the lens (gently) using sunken allens (like a scope mount). A third point is the tripod mount in front of the rear cradle. The bellows is anchored/swung from the very rear of the lens which, incidently, sits about 1" from the film. Bellows is about 2" deep (focus from very close to infinity is possible in that space).

Stainless would be nice, but aluminum will do.

I have tried plywood, and even laminated my own. Too weak for the thinness I want.

 

[noseoil]

Look into the materials used in aircraft cabinetry. Honeycomb should do the job, but it takes a bit of practice to work out the details of fastening and construction. tim

 

[Claire Senft]

All of these tips you received are fine but at least you are now in the position of building a nice cozy fire. Try that with your polycarbonate.

Good luck
Claire

 

[Murray@uptowngallery]

So what kind of beast lens is that?

Another thought I had was a machinist 'hogging out' a body from one piece of metal. I've seen that done (not for a camera, however). It seemed like a waste of a cube of aluminum but it was the only solution.

Murray

 

[jjstafford]

Phenolic resin will work for your application, as Donald suggested. Go to www.mcmaster.com and search under plastics for "garolite". [...]-Greg

Ah, good tip. I do appreciate it Greg. Don, you too. Thanks. Black 1/8 and 1/4" should work out very well. And it is light, too!

 

[jjstafford]

So what kind of beast lens is that?
Murray

The second proof-of-performance prototype is here: http://elearning.winona.edu/jjs/nl

(The first was a crude wooden platform - literally, a platform with an 110v shutter.)

However, the lens I'm working on now (#3) is is machined differently, using a Copal #2, and we are retaining the filter holder... and of course, getting rid of that Sinar body.

 

[Mongo]

The second proof-of-performance prototype is here: http://elearning.winona.edu/jjs/nl

That is a spectacular piece of glass! I want one...but then who wouldnt.

 

[barryjyoung]

Laminate hardwood veneer and rotate each layer 45 degrees or so making your own plywood in whatever shape you like. Or just use aluminum. You can work it with a portable drill and files. Just go slow and be careful. Or get a machinist to do it for ya.

 

[John_Brewer]

That is a spectacular piece of glass! I want one...but then who wouldnt.

What a monster. Where did you find that piece of glass or did you make it?

 

[jjstafford]

What a monster. Where did you find that piece of glass or did you make it?

Here is more: http://elearning.winona.edu/jjs/proto/

I got several of these lenses through a government sale. I kept four good ones, and turned the rest back to the market, giving one away and sacrificing another to a bad job of disassembly.

 

[Ole]

With a lens that big and heavy, wouldn't it be easier to make a camera back and mount it to the lens? A strong cradle for the lens, a lighter one for the back. Bag bellows between. Since the "camera" wouldn't be carrying the weight of the lens, it can be much lighter and simpler.

Just a thought...

 

[jjstafford]

With a lens that big and heavy, wouldn't it be easier to make a camera back and mount it to the lens? A strong cradle for the lens, a lighter one for the back. Bag bellows between. Since the "camera" wouldn't be carrying the weight of the lens, it can be much lighter and simpler.

Just a thought...

My drawings are abysmal, I know. (did you see them on the second page?) Let me try to clarify: the lens and frame is one piece attached to the tripod block. The back moves back and forth on the rail on the and is not stressed.

Here's a larger sketch. The bottom shows a shadow where the tripod screw goes into the block. http://elearning.winona.edu/jjs/proto/NW13.jpg

The tripod block is at the balance point and can be moved a bit left anyway.

A bag bellows is a good idea. Thanks!

Dunno. Is that more clear or am I still missing something?

 

[Ole]

That's what I thought I saw - a camera back attached to a lens. Which leaves me wondering where you need strength for the wooden (or not) parts? The back will only be carrying it's own weight, not the lens...

 

[barryjyoung]

Confused here.

OK, we have the Ferrari priced lens and now we want to skimp on the body? Why does the body material have to be workable with hand tools? Why not have a machinist (me for example) make you what you need? This seems an awful lot like a Holga on a Ries tripod. Am I missing something here?

Barry