spring steel for camera back?

[Curtis Nelson]

I'm building an 8x10, and I'm a little stuck on what thickness spring steel to use for the spring back? Is 0.025 too thin? 1/16 too thick? I've never handled an 8x10, so I don't really have a feel for how more force is required to hold do the GG frame and film holder.
Any suggestions on where to find spring steel already cut into strips? I looked at an old hacksaw blade, but it didn't seem stiff enough for me.
Thanks

[Jac@stafford.net]

I took advise for the springs from our member Rafa who cut down hacksaw blades. Think of it - they are flexible, and do not lose their temper. The idea worked just fine for him. Maybe Rafa can show us what he did.
.

[mdarnton]

Someone the other day (Vinny, maybe) suggested feeler gauge stock from mcmaster.com . It's 1/2" wide in any thickness you want. Someone else can measure for you, since I'm not near my camera now. If you have a belt sander, you can taper those parallel strips down in nice ways into sculpted ends while leaving the middle fat for the screws.

[vinny]

.031 stainless feeler gauges that come in 12" lengths. One spring does it. No reason to do all that work for crappy hacksaw blades which are not rustproof. Pics on my website.

[LabRat]

I found the .031 X 3/4" X 12" S/S strips at a hobby store that specialized in RC model cars for about $1.29 each (K&S brand)... Worked well (easy to form/cut/drill)!!! Thanks, Vinny for that tip!!!!

Steve K

[Jim Fitzgerald]

Vinny, I got a roll! Future builds?

[Curtis Nelson]

.031 stainless feeler gauges that come in 12" lengths. One spring does it. No reason to do all that work for crappy hacksaw blades which are not rustproof. Pics on my website.

All I can find on Amazon is the 0.029 - is there much difference between that and the 0.031?

[vinny]

All I can find on Amazon is the 0.029 - is there much difference between that and the 0.031?

About .002:)
Mcmastercarr.com as mdarton said. 1/2" x 12.

[mdarnton]

You need to know about them, anyway. Best place in the universe for people who like to fix and build things.

[Pali K]

I went through this whole process with my build recently and after many failures I learned that I should have listened to vinny at the get go. I eventually got .034 feeler stock roll from mcmaster which I used on a 11x14 back and it works great. The rolls are 20 feet and should last a long time.

[Jeff T]

0.31 inch thick, 1/2 inch width, 12 inches long brass strips are readily available from the hardware stores. I prefer working with brass as it is easy to cut, bend, grind, sand, and drill. In addition, brass looks great new or tarnished. For my 14x17 camera back, I cut 2 strips from a sheet of brass originally made as a door kick panel.

[Duolab123]

Here's a off the wall idea. My dad and made an 8x10 back for an old 11 X14 back,probably 30 years ago. We looked for spring steel etc. He made the springs out of hickory wood strips. Worked perfectly. Just the right amount of tension. And it's really pretty. I sold the camera to a friend, she still has it, works perfect.
Best Mike

[Drew Bedo]

The TravelWide cameras come with a spring clip to grip the film holders. You might check with them on how they sourced that material.

[Curtis Nelson]

Here's a off the wall idea. My dad and made an 8x10 back for an old 11 X14 back,probably 30 years ago. We looked for spring steel etc. He made the springs out of hickory wood strips. Worked perfectly. Just the right amount of tension. And it's really pretty. I sold the camera to a friend, she still has it, works perfect.
Best Mike

This is one of the coolest ideas I've heard of! I might try it on my next build.

[Rafael Garcia]

Sorry for the long silence... have been away. All I did was file the teeth off two hacksaw blades. The build was a prototype, to solve problems, so I was not concerned too much with appearance. Here is a shot of the springs of my totally built 8x10 back.146022

[Rafael Garcia]

146023

a second view...

[Curtis Nelson]

146023

a second view...

Very nice! Question - what keeps your camera back attached to the box? I see some metal tabs on the bottom, but nothing on top.

[barnacle]

I have a concern about using hacksaw blades - my experience is that although they're very flexible and springy, they're also rather fragile and if bent too far they simply break - shattering and spraying shrapnel around the place. Has this been an issue?

Neil

[Rafael Garcia]

Very nice! Question - what keeps your camera back attached to the box? I see some metal tabs on the bottom, but nothing on top.
Spring pressure and the head of the four sliders! Works great and, so far, no spring breakage from the hacksaw blades!

[Rafael Garcia]

Very nice! Question - what keeps your camera back attached to the box? I see some metal tabs on the bottom, but nothing on top.

Curtis: I re-read your question and now I understand what you ask: not what keeps the GG frame on (the springs) but what secures the actual back to the camera. The experiment was to use "base" materials and build a prototype I could refine later. I used a lot of off-the-shelf hardware store parts. In this case, there is a vertical pin in the center of the top of the back, and a double-hung window sash lock engages it and provides the spring tension to hold it while it sits on the two tabs at the bottom. I'll try find a photo now, or I'll take a fresh one with the I-phone if that is acceptable here...

146067

The two "scars" on the back are filled holes: initially I had mounted the GG screen on studs: they hampered the movement and made film carrier insertion difficult, so I eliminated them. The GG screen stays in place fine with just the hacksaw blade spring pressure, as I said in an earlier post.

The same type lock secures my lens boards in place on the front standard...

146068 (photo before bellows were folded)

I folded two sets of bellows. The first was too heavy a material and the folds were not crisp, the second is better, but not pretty... I need to practice a bit more and try to trust thinner fabrics. But they work!

146069 146070

[Rafael Garcia]

146071

Taken with the camera above... in 8x10.

[Rafael Garcia]

I have a concern about using hacksaw blades - my experience is that although they're very flexible and springy, they're also rather fragile and if bent too far they simply break - shattering and spraying shrapnel around the place. Has this been an issue?

Neil

Neil: No, the blades give a lot, and have stayed strong for several years now (I finished the camera in December 2009). The amount of flex needed to insert and remove a filmholder is really not a lot; the film holders might bend them an additional 1/2" more? (I use plastic Lisco Regal 8x10 holders).

146073

Holder inserted - see the total bend on the hacksaw blade; not much!

[barnacle]

Thanks, Rafael.

The only springs I have to hand are some an engineering friend made for me from spring steel; I believe he softened them to work the material and then retempered them. I'm about to start a new 5x4 and it looks like hacksaw blades are a good thought, then.

Neil

[Curtis Nelson]

Rafael, that's a very ingenious solution to locking the back to the frame! Iw ill ave to give it some serious thought on my camera. Thanks for sharing those pictures. Looks great!

[Rafael Garcia]

Thanks! Hope it works well for you.

[Carsten Wolff]

bamboo works well, too.

[john.l.barford]

I use car windscreen wiper springs


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[Barry Wilkinson]

Sorry for reviving am old thread but I am considering using feeler gauge for my 5x12 camera back. I would like to know if you had to heat the gauge before forming?

.031 stainless feeler gauges that come in 12" lengths. One spring does it. No reason to do all that work for crappy hacksaw blades which are not rustproof. Pics on my website.

[Jim Jones]

Annealing, forming, and retempering feeler gauge material sounds risky unless one has plenty of experience. I'd rather grind down the teeth on an old quality hacksaw blade and use its mounting hole in one end to improvise a clamp that restricts movement of the ground glass frame parallel to the spring.

[LabRat]

Regular sheet stainless accepts folds, drills readily with a carbide drill, and small strip pieces are in stock in many hardware and hobby shops...

Steve K

[Colin Graham]

Sorry for reviving am old thread but I am considering using feeler gauge for my 5x12 camera back. I would like to know if you had to heat the gauge before forming?

Barry, I've used both the 0.025" and 0.031" of the 302/304 stainless steel feel gauge stock from McMaster, and both could be formed into loop ends and drilled easily without any heat treatment. I don't think this feeler gauge stock is true spring temper since it's relatively easy to work with, but the elasticity does seem to hold up fairly well. I used the 0.031" stock on a bail back which puts the springs under a lot of load.

http://colinflanarygraham.com/darkshop/public_html/darkshop/wp-content/uploads/2017/07/bailed.jpg

[pacviewcam]

A few years ago I had to make some leaf springs for a camera back. On the old cameramakers group there was quite a bit of discussion on this topic. And there, I learned that if you hammer on brass, it changes its composition and turns it into a spring.

I don't know why this occurs. I wonder if pounding on it heats it up just enough to change its molecular structure.

Anyway, I got a brass kick plate at the hardware store, cut some pieces to shape (sabre saw with a hacksaw blade did the trick), filed the edges, etc. Before I started pounding I did all the drilling and looping necessary. Then I just pounded it along its length (on a small anvil I have; a big old vise would do nicely for a pounding surface).

I was really surprised at how well it changed the brass from bendable to flexible. Works really well.

Hope this helps.

[gphoto]

I've used carbon fiber strips for my 8x10 back. I used 1/2mm and layered it up like an old truck spring, epoxied the strips together. Works great, easy to work with and doesn't rust.

[Barry Wilkinson]

Barry, I've used both the 0.025" and 0.031" of the 302/304 stainless steel feel gauge stock from McMaster, and both could be formed into loop ends and drilled easily without any heat treatment. I don't think this feeler gauge stock is true spring temper since it's relatively easy to work with, but the elasticity does seem to hold up fairly well. I used the 0.031" stock on a bail back which puts the springs under a lot of load.

http://colinflanarygraham.com/darkshop/public_html/darkshop/wp-content/uploads/2017/07/bailed.jpg
Thanks Colin and all others for your guidance, its seems there are a number of solutions to be investigated.

[radii]

I used phosphor bronze shim stock for my build

https://www.mcmaster.com/9014k315

[Michael Roberts]

A few years ago I had to make some leaf springs for a camera back. On the old cameramakers group there was quite a bit of discussion on this topic. And there, I learned that if you hammer on brass, it changes its composition and turns it into a spring.

I don't know why this occurs. I wonder if pounding on it heats it up just enough to change its molecular structure.

Anyway, I got a brass kick plate at the hardware store, cut some pieces to shape (sabre saw with a hacksaw blade did the trick), filed the edges, etc. Before I started pounding I did all the drilling and looping necessary. Then I just pounded it along its length (on a small anvil I have; a big old vise would do nicely for a pounding surface).

I was really surprised at how well it changed the brass from bendable to flexible. Works really well.

Hope this helps.

Okay, as of today, I can attest to the magical transformation (i.e., hardening effect) of hammering brass strips. I am fabricating an 8x10 reducing back for my 7x11 camera and thus needed a slim, 1/4", top and bottom above/below the ground glass frame. I bought a pair of K&S Precision Metals 1/4" x .064" brass strips to use for the GG springs. My first attempt was a bust--when removing an 8x10 film holder, the springs bent. I removed them, hammered them, then reinstalled. Abracadabra, the brass was transformed into a spring. If I hadn't seen it with my own eyes, I wouldn't have believed it.

https://www.bladeforums.com/threads/can-you-spring-temper-brass.159928/#post-1303170

Cheers,
Michael

[Drew Wiley]

I too would recommend certain bronze stocks. Gives you a bit of classic old camera look, yet with much greater corrosion resistance than brass, and a more reliable flex.

[reddesert]

Okay, as of today, I can attest to the magical transformation (i.e., hardening effect) of hammering brass strips. I am fabricating an 8x10 reducing back for my 7x11 camera and thus needed a slim, 1/4", top and bottom above/below the ground glass frame. I bought a pair of K&S Precision Metals 1/4" x .064" brass strips to use for the GG springs. My first attempt was a bust--when removing an 8x10 film holder, the springs bent. I removed them, hammered them, then reinstalled. Abracadabra, the brass was transformed into a spring. If I hadn't seen it with my own eyes, I wouldn't have believed it.

https://www.bladeforums.com/threads/can-you-spring-temper-brass.159928/#post-1303170


FWIW, this process is called cold working, or work hardening. https://en.wikipedia.org/wiki/Work_hardening The post on bladeforums has the right process but incorrect explanation. It doesn't have to do with density of the material, but rather its structure. Work hardening increases the number of defects (dislocations) in the crystalline structure of the material, so it resists plastic deformation - it doesn't take a set, but springs back. The disadvantage of work hardening is that it makes the material less ductile, more brittle - this is in a sense what happens when you bend a paper clip back and forth until it breaks at the bend. However, if your spring uses enough material, it probably won't break from a lifetime of camera use.

Heating the material very hot (as described in the bladeforums post) anneals it, relaxing the crystalline structure and making it more ductile and easier to shape.

[Michael Roberts]

Fantastic. Thanks for the explanation!

[jurgenestanislao]

Reviving this thread.

I picked up several referrals to mcmaster—so the feeler gauges work well and would last as spring backs?

Or are there other options at McMaster that would work as well or better?

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[eli]

Think about .5 in. Bandsaw blades in carbon steel, which, like hacksaw blades can be thinned with files or abrasives for better action.

[Tin Can]

Maybe I missed it on McMaster Carr and I know their catalog well

A lot depends on what type spring back you are making and what size...

Many excellent variations in the last 150 years

Give us more data and pictures

Thank you!

[Jim Jones]

Straight spring wire may be more practical and should be relatively inexpensive and available at your local hardware store. This back for 4x5 film was improvised from a scrap of plywood about the size of the view camera back, a scrap of flat board about the size of the film holder, and three scraps of 1x2 wood. The spring wire was 0.055" in diameter, somewhat stronger than I wanted, but usable. A table saw and electric drill were the only power tools used. If I ever make another back, I may widen the slot for the screws that enter the side of the moveable piece, and link those screw with the ones at the open end of the back to eliminate friction between those screws and their slots. A flat strip of stiff metal should suffice for that link.