Cross Break in Sheet Metal

[RJake]

Does anyone have any ideas on how to make a cross break in a sheetmetal part? I'm trying to make a simple crossbroken pan with flanges, but SW will not allow me to bend over bends, so to speak.
Thanks.

 

[SBaugh]

SW will not allow a bend to exist inside another bend.

Since I'm not a SM guru. Could you explain or post a link to what a Cross break in SM is?

Thanks,

Scott Baugh, CSWP
3DVision Technologies

http://www.scottjbaugh.com

Merry Christmas
faq731-376
faq559-716 - SW Fora Users

 

[RJake]

The part I'm trying to make is relatively simple. Imagine a recangular piece of SM with the length ~5' and the width ~1.5'. In order to create a debris pan, I need to break this diagonally (2x) by about 5deg. What you end up with is essentially a concave piece of SM. Each of the breaks has to give a little, but it is manufacturable. Once I have the piece cross broken, I'll bend each of the long sides back to the original plane, so it can be mounted.
Thanks again.

 

[MadMango]

As far as I know, SW cannot do this.

A cross break is a shallow bend, corner-to-corner on a square or rectangular sheet metal panel. It's used as a stiffener. They are common items for duct work and enclosure panels.

[green]"But what... is it good for?"[/green]
Engineer at the Advanced Computing Systems Division of IBM, 1968, commenting on the microchip.
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[kp5054]

Hi Guys,
I had done this in the past, I used a "sketched bend" drawn corner to corner set the angle to maybe 10 dgrees. Then readjust your existing side bends to 80 degrees.
The actual application I did was a 3 sided pan that had 2 sketched bends that initiated in the corners and went to the middle of the side with out a flange. Dont start the line in the exxact corner, back off maybe .10 each direction, and dont end exactley midpint, back those off from each other as well.

Hope this helps,
Ken

 

[ShaggyPE]

Scott,
A cross break is simply a diagonal bend (very slight bend) from two corners of a part. They are typically used on relatively large flat ares to keep the panel from bowing easily. Most common are doors. You may see an "X" on the front of a sheet metal door or panel, from corner to corner. This was done by two cross breaks.

I have represented a cross break by sketching diagonal construction lines on the face of the part. You could also use a split line to break up the face, this will show up as a phantom line is the drawing as well. To my knowledge, there is no way to actually bend the part to represent this.

 

[ShaggyPE]

Correction: It appears some other posters have been able to create this geometry. They sent in their reply as I was sending in mine.

 

[RJake]

After messing with it for a while, I think I'm gonna just have to indicate it on the drawing with the final dimensions. Thanks for all the help.

Rob

 

[Drhinehart]

It can be done, as some of the others I have done this in the past to create drain pans which sound like what you are doing. I will see if I can recreate this, I am thinking it was not done as a sheet metal part... You might try creating it as a part and convert it to a sheet metal part.

Hope this helps.

 

[CorBlimeyLimey]

Drhinehart ... Even if you could create this part as a solid & then convert it to Sheet Metal, you would not be able to flatten it. The crossed bends would involve material stretching which (as far as I know) SW (and other comparable solid modellers) cannot handle. However if you have found a way, please, please post back here ... this would be a very useful feature.

Also, the example given by kp5054 is not a crossed bend, just two bends meeting at a point, which does not involve material stretch, and could therfore be flattened.



& all the best.

 

[aamoroso]

We usually do these as a pallete feature just like a louver. There is no stretching compensation by the flatten command and we suppress the break in the flat but it gives visual representation for drawing purposes.

 

[112275]

Can you make half the part with 2 bends almost meeting in the middle, then mirroring it.?