in the old days they would of used metal work brake presses and such to cut i imagine and so the metal work guys i have spoken to that i have shown these to said.
i found that with the cost of labour nowadays laser cutting isnt any more exspensive and in fact most metal work places didnt want to bother with doing them and wanted them laser cut if thy were to do the folds (unless you were to cut and make them yourself, but they often have that home made look to them then).
also some sheaths i have, have curved shapes on the ends of the folds and making curves or shapes is no more exspensive if laser cutting, so that is a small avantage . the other sheaths are just neatly cut square ends to the fold over lips that hold the film in.
as you say its not rocket science to make them, but i was suprised how i had to twist their arm to get people to agree to make them--in the end they are doing it as a sort of a favour. they seem to prefer to make things that will bring in more money and bigger quanities of work. i was pushing my luck when i asked, if and how, they would go about making the actual plate holders. they freaked LOL, and said no way, look at all those folds and such and that 'we are only doing these to get you out of trouble' haha (i was only curious as i have heaps already)
the metal work guys reckon that in the old days they must of had machines specifically for these things, holders and the sheaths. as most modern machines in common use will only fold to a minimum of 4mm, whereas many of the old sheaths have a 3mm fold. in the end the guy will have to adjust his machine and then hold by hand to try and get the smaller fold, he says he thinks he can do it because of the very thin material, which is a special order by the way (for me anyway) because most commonly available stock is .5mm and the origianal sheaths are thinner than that
Dragging this old thread up from the dungeons, I am looking for 9x12 film sheaths now.
Are all the sheaths/inserts the same in principle? I see mention of differences between Recomar and European ones - it's the European ones I need.
Looking at a couple of Rhaco plate holders I have, I wonder if a simple sheet of aluminium could do as a base filler for the film to sit on.
In theory yes but the reality is the inserts have a lip which holds the film, they are very easy to use. I have a pattern for making them but I need to search where I saved it. Will find it Sunday if I get time and post it here.
Originally Posted by Ian Grant
It's just occured to me that a single sheet of ally with lips expoxied flat along each long side will hold the film central and I presume the film tucks under the top and bottom overhangs of the holder. The combined thickness of the sheet+lips would be the same as a glass plate.