Bending

[Michael Molloy]

Does anyone know of programs or at least formulas that I can use for
bending of thick sheet metals. Thin stuff (below 6mm) is the inside of the
bend, but for thicker stuff I'm unsure. Any help will be greatly
appreciated.

[rsc...@ix.netcom.com]

On 17 Sep 1998 08:37:21 GMT, "Michael Molloy"
<Michael...@btinternet.com> wrote:

There are a number of sheet metal bending programs available. The only
one I have "used" is ProFold:
(http://www2.appliedproduction.com/appliedproduction/)

ProFold will take a 3d drawing and unfold it and using standard K
factors, compensate for bendlines. It will also take 2d drawings and
fold them.

I say "used" with ProFold; I do not actually use it in my work. I've
gotten by for a long time with just some simple lisp routines which
will calculate bendline compensations. Here is one which you might try
which will calculate bendline compensations for 90 degree bends. It
could easily be modified for other angles. It uses a "standard" K
factor of .447, but is user changeable if your dies do not conform to
this.

;;; by Robert S. Carroll
;;;determines the bendline compensation for 90 degree bends for
;;;sheetmetal using the standard 0.447 "k" factor. Program may be
;;;altered by changing the "k" factor as required.
(defun C:BLA (/ BLT BLR BLK BL1 BL2 BL3) ;Determines bendline
compensation.
(prompt "\nDetermines inside bendline compensation for 90 degree
bends.")
(initget 1)
(setq BLT (getreal "\nThickness of material: "))
(setq BLR (getreal "\nInside bend radius: ")
BLK (getreal "\n\"K\" factor for material <0.447>: "))
(if
(= BLR nil)
(setq BLR BLT))
(if
(= BLK nil)
(setq BLK 0.447))
(setq BL1 (/ (* (+ BLR (* BLT BLK)) PI) 4)
BLA (- BL1 BLR))
(princ "\nBendline compensation is: ")
(prin1 BLA)
(princ)
);End BendLineAllowance.lsp

Robert S. Carroll
rsc...@ix.netcom.com

[Thomas J. Rambach]

This should help you out... I am assuming you are looking for bend radius
calculations?
All the AutoCAD addons and gizmos in the world won't help you out if you
don't know the
bottom line on how what your drawing actually works... so here's the
formulas.

L= Length in inches, straight stock required before bending.
T= Thickness in inches
R= Inside Radius of Bend in inches

For soft brass or copper: L=(0.55 X T) + (1.57 X R)

Half Hard Copper, Brass, soft steel, and aluminum: L= (0.64 X T) + (1.57 X
R)

Bronze, Hard Copper, Cold Rolled Steel, and Spring Steel: L= (0.71 X T) +
(1.57 X R)

Of course you'll have to convert the inches to mm for your application.

-Thomas J. Rambach

RAM-DC Rambach Advanced Media Design Company
http://www.rambach.com
Email us at: In...@rambach.com

Michael Molloy wrote in message
<01bde216$a367f920$2f30...@ibm2.blackburn.ac.uk>...