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Sean Farren
10-May-2005, 12:13
I am currently restoring a Korona 8x20, and find myself a little short to have a new bellows made by Turner Bellows. So I have decided to attempt to build a replacement bellows, but have found most of the information on the net very general, and a little simplistic for what I need to accomplish.

The 8x20 bellows was made in two pieces. Does anyone know if this was by design, or necessity. There have been some thoughts that wide enough material may have been cost prohibitive, while others have pointed out that the garment industry as a whole was much more accomplished that what we have today.

After some trial an error, I have made the first complete template of the bellows. Unfortunately not only is the 8x20 bellows tapered, it also drops. That is, the bottom of the bellows is flat, while the top slopes. Before cutting the template, I am wondering about the pros and cons of making it as one piece (one inside sheet, one outside sheet) or cutting it in half horizontally? This brings up another question of design or practicality: The inside seams (2) and the outside seams (2) are not in the same place. A design trick to avoid bulks on the overlap? Or happenstance?

Another question, and there may be some Greek formula for this that I am unaware of: How to determine how many folds a bellows should have? It appears that on the 8x20 I have, there are 23 peaks. The rise/fall sections vary from 1/2" to 3/4", getting longer as you get closer to the lens board.

We are also in the process of modeling the camera to make a metal version (most likely aluminum), so we will need to make another set of bellows assuming that we are successful with the first. We have been experimenting with fabrics and adhesives. So far interfusing and sanding disc cement hold out the most promise.

I came across some Deardorff notes on the net about bellows construction, but they are a little cryptic. I fear they contain just enough information so that the master wouldn't forget. However they are elvin to a origami newbie such as myself.

Several people have suggested recovering the existing bellows. Unfortunately the bellows got wet in some Louisiana attic and became quite deformed. While this would work, it would be as ugly as all.

Any input, guidance discouragement (as long as it is well placed) would be appreciated.

Regards,

Sean

sanking
10-May-2005, 13:04
There was a good article on making bellows in View Camera magazine some years ago. Somebody might be able to point you to the issue. When the article came out I had already made several large bellows but still learned a lot from it.

Sean Farren
10-May-2005, 15:05
Sandy,

In folding a ULF bellows, where would you recommend starting the folding process? Narrow end? Wide end? Middle? Doesn't really matter?

I have made alot of medium format bellows, but this is a beast. Luckily I found some really big construction paper to make the veins out of.

Thanks,

Sean

sanking
10-May-2005, 17:24
I always started to folk at the small end.

However, when yoou do this with bellows for ULF cameras you really need help from a frieind, if you don't already have three or four hands.

Paul Fitzgerald
10-May-2005, 21:38
Hi there,

A few thoughts,

You already have a bellows so use it for the pattern. An 8X20 has a large growth difference between the top panel and side panel. Don't re-invent the wheel.

Make it out of paper, then split it down one corner and open it up. A rather large, odd shape, probably why they made it from 2 panels.

Off-set seams for bulk and for light-leaks.

Try auto interior headliner adhesive, sand disc glue stays tacky for months. Vinyl top adhesive sets too hard and dries out.

Take your time.

Good luck with it.

Dave Savidge
10-May-2005, 23:25
Whatever the size of the bellows, I have found that making a solid shell of the full extended unit on which to glue together the inner, outer and stiffeners makes for a very much more accurate assembly than doing it in the flat. It is also easier to get the overlaps well positioned.

I use 1/2 inch MDF to make the shell. I know that 8x20 is pretty large, but, MDF is very cheap and easy to work with in this way.

Best of luck.

Sean Farren
11-May-2005, 06:02
Paul/Dave,

Thank you very much for the information.

Headliner adhesive seems like a good venue to pursue, as yes the sanding disc cement is very tacky.

Interestingly enough, I recently saw a glass negative of the bellows making process at the Eastman Factory c1900 and while they were making small bellows, they had an item similar to a shoe insert that a cobbler might use to glue up the bellows. A small investment in some MDF is definitely in order, especially since I need to make more than one. We are almost done modeling an 8x20 Aluminum replica uses S&S holders and will need a bellows for that as well. Unfortunately I cannot afford the $4000 - $6000 that some of the much more competent camera makers demand.

Sandy,

Many hands will be available. I mentioned my idea to a friend (mechanical engineer) and he was as excited about the project as I am. You mentioned in a previous post from the 90's that you used contact cement on your 20x24 bellows. How has that withstood time? Would you still recommend it?

Thanks again to all the contributors. Fortunately, I am not smart enough to be afraid.

Regards,

Curt
15-May-2005, 00:47
Sean, I made a 4x5x16" tapered bellows in 1980 and used contact cement that I brushed on. I made it from one piece of craft paper with cloth liner inside and outside. I use it today with no leaks and it still looks as good as the day I made it. Still flexable too, I started with a fan shape and just folded and folded until it was a bellows.
Good luck, Curt