Sheet metal design 1

[tmox]

I'm sure there must be a formula for calculating the cut angle for each side of a box with a tapered bottom. Eg.- In the top view the angle between the two pieces is 30deg, in the front view the angle is 45 degrees on same joint. Q. How do i calculate actual cut angles without actually developing all the pieces.

This is not so bad when you are creating a square box, but, it becomes a little more confusing when the box becomes "L" shaped, the bent sides become longer and shorter, but, the angles remain the same.

Can someone point me in the right direction please. Potentially I would like to incorporate the formula in an Inventor drawing so that length, width, and height variables can be changed easily.

Thanx T

 

[Mandrake22]

Won't Inventor automatically develop the flat pattern from your model?

 

[tmox]

this item can only be made from separate panels and welded together.
Without a formula, the entire inventor model will need to be re-checked and modified for even the simplest change each time.

I am looking for a formula for compound angles on different planes. Again, say the joint in the x-y plane is at 45 degrees, but in the x-z plane the angle is 30 degees (or what if i had to use 27.5 degrees or 14.7) what is the resulting flat layout dimensions for those pieces.

once the formula is installed, no more thinking is required..............and we all know how many problems thinking has started.

 

[stuff]

We have many trigonometry problems like this with our projects. I worked this out:

A - desired face angle (acute angle)
B - side taper angle (your 45deg)
C - corner angle in plan view (your 30deg)

then

A = atan(1/sinB*tanC)

for your example A = 67.792deg (I hope!)

Hope it helps

Matt

 

[Deriv]

Can you give more information to may it clearer what shape the box is ?
Dimensions or coordinates of the corner points, or better still, attach a sketch here.

 

[stubby]

Solid works has a sheet metal priogram inside 2003. All you have to do is draw the box complete and it will unfold it for you.

 

[mloew]

tmox,

You may wish to investigate the free bend allowance utility software KCYB. The download site is:

http://www.cybelec.ch/infotips/kcyb1.exe.

My fabrication shop has recommended this utility to validate the "k" factors utilized in our Pro/E sheetmetal components.


Best regards,

Matthew Ian Loew

Please see FAQ731-376 for tips on how to make the best use of Eng-Tips Fora.

 

[616]

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