If your german is up for it, here is an article in the german wikipedia: http://de.wikipedia.org/wiki/Biegeverkürzung
Aha. I'm sorry, no experience from me. But I'd think it depends on the machinery you have acces to, and the preparation. I mean, a fancy spancy industrial bender will have much tighter tolerances than a block of wood and a hammer. And scoring always helps. Isn't there a little piece you can practice and measure on?
It's been a long time (13 years) since I was working as a fabricator. but I recall something along the lines of adding the thickness of the material for each bend, or subtracting the thickness of the material for each bend, depending on if the overall dimensions are internal or external. This was with sheet metal bent using a break press, and 8 out of 10 times I would have to make things twice as I'd get it wrong, best thing I would suggest is to have a go with a bit of scrap and see how you get on. With regards to your example there's a deep rumbling from within my brain that is saying 201mm by 201mm
That seems counter-intuitive. As I too, don't want to go ploughing trough formula's, care to explain why it is like that? Also, do you measure on the inside of the bend, or the outside?
Great question I’ve always added the two lengths to the thickness which has stood me well in the past so basically you would be looking at 200 + 200 + 1.5 = 401.5mm but for a more accurate measurement the guys doing the bending are the ones to talk to as different bending presses work with different tolerances. EDIT - just found this Bend Allowance
