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Thread: 4x10 metal?

  1. #21

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    About home made cameras! Have you seen this?

    http://www.mamutphoto.com/forum/index.php?topic=279.0

    It's a European site. There is some handy people here and there building a lot's of cameras! I love it!!!!!

  2. #22

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    (Bruce Watson) Why not aluminum? 6061-T6 would work fine - strong and light, and anodized it would be basically impervious to the weather. While stainless (any of the hundreds of metals in the stainless family) tends to have better strength, it also tends to be more of a pain to machine and weld.

    I don't know any welder that would think that it is more difficult to weld stainless steel than to weld aluminum. Stainless welds like regular steel with stick, MIG, or TIG. In fact, you can weld stainless with E70 if you don't have 308 rod or wire available. The only problem is the weld will rust. You can weld stainless to regular steel with 309L. The ONLY problem with stainless is that some alloys require back purging of the weld with argon during welding for the best weldment strength.

    Aluminum requires higher amperage for the same thickness of metal because of the heat transfer characteristics, the metal has to be brushed, cleaned, and AC TIG welded for best results.

    Also, aluminum has the nasty characteristic that, when welded, the weldment is at the base metal strength and not at the treated strength. In the case of a T-6 treatment, the weld area is about T-2 after welding and will slowly age back to about a T-4 level. The weldment is never as strong as the surrounding metal. The only way to guarantee the welded area will be as strong as the base metal is to make the weld from both sides; or to heat treat the entire piece after welding.

    Stainless has NONE of those problems. You just setup and weld it.

    As for machining, stainless is no more difficult to machine if you use cobalt tooling. Aluminum has the nasty habit of "pushing" (compressing) if the tool feed rate is a bit too high or the tool is dull. This means the cut will slowly change dimension as the metal decompresses after it has been machined. In my experience, this can be as much a .001 - .002 inch.

    While you can hog more metal faster with aluminum using high speed steel tooling, the cleanup cuts required for the final dimensioning make it nearly as time consuming to work as stainless steel.

  3. #23

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    And, I'd still choose aluminum if I was building a camera. It's much lighter, cheaper, plenty durable and corrosion resistant when anodized. Of all the metal cameras I own and have owned in the past, none are/were made from stanless steal and not one has had a single welded joint.

    I believe Walker is the only current LF camera maker that uses stainless steel for anything larger than fasteners - and even he doesn't use it for the camera body. If you look at the metal-bodied large format cameras currently available from Linhof, Canham, ARCA-SWISS, Wista, Toyo, etc., they are all made out of aluminum. It is a perfectly suitable material for camera building.

    Kerry

  4. #24

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    Quote Originally Posted by steve
    I don't know any welder that would think that it is more difficult to weld stainless steel than to weld aluminum.
    Welding? I was thinking more along the lines of a punch press and a CNC milling machine. Hadn't considered welding. I've destroyed a fair amount of aluminum with a heliarc rig - I never could seem to get the hang of it. ;-)

    I didn't consider stainless largely because of the weight issue, and the idea that aluminum is plenty strong enough for the application.

    But don't let my poorly preconceived notions stop you. Thinking out of the box is a good thing. Using stainless is an interesting idea. I'd love to see it if you decide to build one, and I'd certainly consider it if you decide to sell them.

  5. #25

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    Quote Originally Posted by kthalmann
    And, I'd still choose aluminum if I was building a camera. It's much lighter, cheaper, plenty durable and corrosion resistant when anodized. Of all the metal cameras I own and have owned in the past, none are/were made from stanless steal and not one has had a single welded joint.

    I believe Walker is the only current LF camera maker that uses stainless steel for anything larger than fasteners - and even he doesn't use it for the camera body. If you look at the metal-bodied large format cameras currently available from Linhof, Canham, ARCA-SWISS, Wista, Toyo, etc., they are all made out of aluminum. It is a perfectly suitable material for camera building.

    Kerry

    I never said stainless would be a better choice for making a camera - you're projecting whatever you want into my response. My comments do not address making a camera from the materials only the base working characteristics of each material. The statements made in the original post about stainless versus aluminum weren't accurate, especially the comment on welding - and that's what I was addressing.

    If you had the money to make whatever camera you wanted, a rough casting from a magnesium alloy would be the best choice for weight versus strength. It's also not difficult to machine (actually easier than aluminum), you just have be careful with the cutting rates and chips so you don't start a fire.

    When weight and strength are balanced against cost, aluminum would be a very good choice for building a view camera. The 6000 series being relatively inexpensive; and some of the 7000 series being stronger but more expensive.

  6. #26
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    I have gas welding equipment and have welded stainless steel with it. You have to be a very good welder to weld stainless and aluminum. I was thinking of more of mechanical attachments and had not been designing any "welded" joints. I could if I had to but I don't see the need. With the new plots with airline terror and no carry on luggage in effect, to lesser and greater enforcement, I think a simple camera made of some strong materials that can go in the check in luggage hold is the key. For oversea flights a camera that can withstand some abuse is right for the time. It can't cost a lot of money, who wants an expensive camera taken apart by someone who doesn't know what it is?

    Film and lenses are another thread.

  7. #27

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    Quote Originally Posted by steve
    The ONLY problem with stainless is that some alloys require back purging of the weld with argon during welding for the best weldment strength.
    Steve

    I think that's a common myth amoungst welders, have you ever pressure tested purged and unpurged stainless pipe and compared the two? I've done it and there's no difference, the purge's main use is to keep the inside weld clean which is especially useful where a pig has to be pushed down a line to clean it out.

    Clayton

  8. #28

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    Quote Originally Posted by steve
    I never said stainless would be a better choice for making a camera - you're projecting whatever you want into my response.
    I'm not projecting anything, just stating my opinion on what material I'd choose if the goal was a lightweight 4x10 camera. The original poster specifically stated: "I'd like it to be metal and designed for light weight." IMHO that rules out stainless steel. If I was to design such a camera, no welding would be required. So, the relative ease of welding of stainless vs. aluminum would be irrelevant.

    I'm not attacking your post, or even responding directly to it. I was just sharing my opinion based on the original poster's requirements (which happen to be very similar to my own).

    Kerry

  9. #29

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    Quote Originally Posted by Curt
    I have gas welding equipment and have welded stainless steel with it. You have to be a very good welder to weld stainless and aluminum.
    You're absolutely correct. I don't gas weld anything. I only use the gas setup for brazing, silver soldering, or preheating before welding. Stainless is quite easy to weld with MIG and TIG equipment. The MIG is no more difficult than welding regular steel. You just need a little more amperage because of the uneven heat transfer of stainless.

    TIG is ...well...TIG. It takes a certain touch with the torch and feed rate with the rod. A pulsed TIG makes it easier as you can time the rod feed with the pulse.

    Aluminum can be MIG welded but I've never had the correct setup to do that (push/pull gun). I TIG weld aluminum. Once you learn how the metal puddle looks when it is correctly wetted and get the rod feed at the right rate so the arc doesn't drift because the aluminum is too clean, you can make a usable weld.

  10. #30

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    Quote Originally Posted by claytume
    Steve

    I think that's a common myth amoungst welders, have you ever pressure tested purged and unpurged stainless pipe and compared the two? I've done it and there's no difference, the purge's main use is to keep the inside weld clean which is especially useful where a pig has to be pushed down a line to clean it out.

    Clayton
    Most of the stainless I weld needs to be clean on both sides so back purging helps keep the back of the weld cleaner making final finishing easier. It also seems to make the weld on the back side smoother as you don't get carbon dioxide in the air combining with the heated metal.

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