I have done it. Getting the right fabric is 90% of the battle. Mine was for a 6x9 and I used regular printer paper, not even construction paper, and it seemed to do fine.
I have done it. Getting the right fabric is 90% of the battle. Mine was for a 6x9 and I used regular printer paper, not even construction paper, and it seemed to do fine.
Science is what we understand well enough to explain to a computer. Art is everything else we do.
--A=B by Petkovšek et. al.
I made another bellows... this one turned out rather better as I used a wooden frame to build it on. Although the bellows are square, the frame isn't - it needs two sides the size of the outside of the mounting frame, and two sides the size of the inside, so the folds work. In this case, I had a large frame at 160x160mm and a small frame at 130x130mm. The thickness of the frame borders - 15mm - defines the depth of the pleat. So in this case, the frame was 160x130mm at the wide end, tapering to 130x100 at the narrow end (all external dimensions).
Sanded smooth to avoid any snags, and baking paper fixed for added slipperiness.
The fit of the bellows outer is less critical; it just needs to be big enough to cover the frame though too much overhang might be an issue. The outer seam will be on the bottom of the finished bellows, and uses a nice wide diagonal to distribute the thicker result.
And then this is glued to the other side; I used more of the baking paper to ensure that the glue went only where it was needed. I'm not sure that spray adhesive is the best option.
Neil
Apologies for these photos, taken in the dark, of a light-absorbing material, with the camera flash... oh well!
The inner skin is cut with a seam opposite the outer skin and temporarily taped in place:
It's then unwound but left attached while the bones are glued, first to cover the seam in the outer (so the bottom of the bellows).
The inner is then refitted and glued to the bones just fitted. It is then released from its temporary place to allow the bones on the two sides to be glued, and finally the top bones.
Everything is rolled nice and flat, then allowed to set. The excess material is trimmed and the complete bellows slides off the frame.
Then, as in the earlier attempt, it's turned right side in, the pleats folded, and it's weighted overnight to set the pleats. The final thickness is only 25mm so I'm rather pleased with that. I still need to find some stiffer bones, though; thicker paper or a thin plastic perhaps. It's also important to ensure that the bones on the four sides line up with each other, or the creases won't align. That needs a little marking on the build.
Neil
Neil,
What is the purpose of building it right side out instead of just starting with the inside fabric first, then the bones, then the outer shell? That way it wouldn't have to be turned right side out after you slide it off the frame. I must be missing something...
Good question... I think it gives better control of where the glue is going. The outside is always protected from sticky fingers, I suppose. I got the idea from a link on the web somewhere which did it that way, and I don't think I reason was given, and to be honest I didn't ask!
The outer shell though is the most robust in terms of sticking things to it.
Maybe I'll do the next one the other way in!
Neil
25mm is a good result. The Profabric material is a great find.
Neoprene is used for wetsuits and inflatable boats and they seem to have specialised glues for it.
Thanks for sharing, I will definitely have a go at this.
That 25mm does not include the frame thickness, so that would be needed too.
Neil
I am thinking about using FR4/G10 sheets for frames.
http://www.presspahn.com have it in black. Not really a traditional material for cameras but neither is neoprene
Thanks again....
I've thought of FR4 but unless it's quite thick it's not usually light-tight. Don't know about black, though; that might help. 5mm ply should do, unless you absolutely need the precision machining you could do with FR4.
Of course, if you want to make leather bellows, Tandy is your man: http://www.tandyleather.eu/en/produc...inished-splits or http://www.tandyleather.eu/en/produc...finished-split or http://www.tandyleather.eu/en/produc...lors-2-to-4-oz ... risky for size, though.
Neil
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