I don't understand metal bending.

[Aukai]

I am pretty much a functioning illiterate(kind of embarrassing) when it comes to math, it's pretty much the reason I'm the resident hack. Anyway I need to bend a 1/8" x 4" 316 SS flat plate that needs to have 2 90* bends, and have a + or - loose close tolerance of 10" between them. I'm not sure of where to mark the line to include the bend radius, so I get the 10" outside measurement, I have a mental block looking at the formulas, and K factors etc., can someone make sense of this for me? I am this using the Swag press brake.

 

[pdentrem]

Do you have small piece to do a test bend and measure the change in length?

 

[Aukai]

That's what I was going to try, and hope for the best, I had to fly this in, so I don't want to waste too much of it

 

[markba633csi]

The lazy man's way is to do tests on scrap first- you'll get a clearer idea of what happens during the bend
Mark the scrap piece with some parallel lines in the vicinity of the bend then analyse the result after bending

 

[Aukai]

I'll see if I can find other 1/8 scrap to use, thank you guys.

 

[f350ca]

I've tried using the formulas to calculate where to bend, trust me, a test piece is MUCH more accurate.

Greg

 

[extropic]

Not enough information (no bend radius specified, is the 10" inside or outside the part) in the OP to solve the problem.
Like everyone else said, test piece. Mark the test piece where you will make the bend. Also make a second mark a convenient known distance from the first mark (maybe 2"). Make the bend, then measure the test piece relative to second mark.
What was the distance between the marks?
What is the measured distance on the test piece?

 

[Aukai]

The 10" is the outside.... I'm going to check what I have for stock to practice on.

 

[mickri]

This is how I would do it. Mark 2 lines 5" apart. Bend line and center line. Make the bend on the bend line. Now measure from the center line to the outside of the bend. This distance should be greater than 5." For example let's say this measurement is 5.2." Subtract 5 from 5.2 leaving .2. Double the difference giving you .4. Now subtract .4 from 5 leaving a remainder of 4.6." Mark your next bend line 4.6" from the center line. Bending on this line should give you 10" to the outside of the bends.

 

[pdentrem]

Just need a piece of mild steel of the same thickness.