[TheForge] Precision Forging

[Demon Buddha]

Bob Rackers wrote:
> 
> I'm curious to hear how everyone calculates the amount of material (i.e.
> length) required when the piece will have at least one bend.
> 
> I figure there are four types of bends, and each requires a different
> calculation.
> 
> Assuming a 90 degree bend, you could have
>  A. Radius inside the bend / Radius outside the bend

	~ (2*Pi*R)/4 where R == the radius at the neutral axis, i.e.,
	at the center of the stock.  The actual value will be smaller
	as the ratio of R to the stock size approaches unity.

>  B. Radius inside the bend / Square corner outside the bend

	This would depend on the radius.  As it grows, the amount of
	material increases, and therefore  you will have to either do
	some serious upsetting, or significant drawing.

	In general, the volume will be approximately .215 R x the 
	thickness of the stock.  E.g., if you have a corner in 1"
	square stock with a 1" R inner fillet, the amount of material
	you will need will be .215 x 1 x 1 == .215 in^3.


>  C. Square corner outside the bend / Radius inside the bend

	Same as B, no?

>  D. Square corner inside / Square corner outside

	Something like 1.5 times the stock thickness across which the
	corner is being made.  That is, if you are supsetting a 1/4 x
	1/2 strap across the 1/4" dimension (i.e. the "easy" way), you
	should add 1/8" to the length.  This one's from rusty memory,
	so the 1.5 figure may be incorrect.  Anyone?

>  E. Long radius (many times the thickness of the material, e.g. a 10" radius
> made from 1/2" rod)

	Same as 'A'.
--
	-Andy V.

	It only takes one pork chop to put a kosher butcher out of business.