sheet metal flatten
large radius
opening length
How is it calculated?
drawing is this true is this false
sheet metal flatten
large radius
opening length
How is it calculated?
drawing is this true is this false
Hi Arif, This is calculated using a bend tolerance. This is dependant on material, sheet thickness, and also the machine. For rads larger than the thickness of the sheet, try a k-factor of 0.5.
It is unlikely your lay-flat is currently giving you a correct length.
I'm thinking (like Bjorn) that your flat pattern length would be incorrect for the material you are using. According to my calculations, if you are using a k-factor, then it is .272 which is indeed unlikely. I wold change that to something like .44 to .5. The k-factor is a percentage of the material thickness. As you can see from my screenshot yours is ~.272 or 1.36/5..
For jobs like this I would use the drawing itself printed 1:1 to check the bending. The flanges are easy of course and bumping the 100mm radius would give you a lot of room to play with, though bump bending is an art unto itself. I might have rolled this part myself on a 3-point roller then added the flanges in the press brake.
Having done 100's of these in the past I would use a K-Factor of .5 though I agree that it is likely that .44 would apply on the 5mm radius bends. That is easy to do in SW. Back in the day when I was rolling crash test dummy ribs out of 1/8" x 3/4" rolled edge steel alloy I would have used AutoCAD and just offset a line to 50% of the material thickness and converted that line to a polyline and just measured it. That was my flat.
For jobs like this I would use the drawing itself printed 1:1 to check the bending. The flanges are easy of course and bumping the 100mm radius would give you a lot of room to play with, though bump bending is an art unto itself. I might have rolled this part myself on a 3-point roller then added the flanges in the press brake.
Having done 100's of these in the past I would use a K-Factor of .5 though I agree that it is likely that .44 would apply on the 5mm radius bends. That is easy to do in SW. Back in the day when I was rolling crash test dummy ribs out of 1/8" x 3/4" rolled edge steel alloy I would have used AutoCAD and just offset a line to 50% of the material thickness and converted that line to a polyline and just measured it. That was my flat.