Calculating length of a wire product

Take a U-shaped wire, bent from 10 mm O.D. stainless steel. You model it as a swept extrusion or a pipe (solid) and when finished, you calculate the required length to cut from your stock material, either by doing the geometry math yourself or by creating an evalute feature. Either way you end up with the same answer, 3 straight lengths and 2 quarter circles.

If you model the same part but now as a square (10x10 mm) section and then declare it as a sheetmetal part you can get the required length by using a flat pattern feature. When a sheet metal part is bent, it stretches and therefore, which ProE recognizes, the total length required is less than the "geometrical answer" above. Its obvious that in reality, the wire stretches when bent just like a strip of sheeet metal and that therefore the second smaller answer is correct.

Now, does anybody know a way of getting a "flat pattern" answer without having to redo the part in square form. This redo can get complicated if there are more bends to the wire that are not all in the same plane.

Bertil

Reply to
Bertil Rogmark
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If you model the same part but now as a square (10x10 mm) section and then declare it as a sheetmetal part you can get the required length by using a flat pattern feature. When a sheet metal part is bent, it stretches and therefore, which ProE recognizes, the total length required is less than the "geometrical answer" above. Its obvious that in reality, the wire stretches when bent just like a strip of sheeet metal and that therefore the second smaller answer is correct.

Now, does anybody know a way of getting a "flat pattern" answer without having to redo the part in square form. This redo can get complicated if there are more bends to the wire that are not all in the same plane.

Bertil

I would say that you use the K factor as do the sheetmetal guys, for example

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While Pro/e does it automatically based on bend tables and K factors built into material properties, there's no reason you can't do the same with hand calcs. You just have to find out what the K factor is for the particular metal that you are bending. This may also be of some help:
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As this makes clear, bend tables adjust for other factors, such as stock thickness and bend radius. Most are discovered and verified in practice.

David Janes

Reply to
Janes

Thank you for your help David, I have done a lot of work with sheet metal bending, long before computer software gave us a solution straight from the modeled part. I was hoping to be able to use the sheet metal functionality on wire products but I guess I have to go back to do the calculating myself. By the way, do you know a ProE forum where lunatics like this guy Joe788 are not allowed to go on like he is doing here?

If you model the same part but now as a square (10x10 mm) section and then declare it as a sheetmetal part you can get the required length by using a flat pattern feature. When a sheet metal part is bent, it stretches and therefore, which ProE recognizes, the total length required is less than the "geometrical answer" above. Its obvious that in reality, the wire stretches when bent just like a strip of sheeet metal and that therefore the second smaller answer is correct.

Now, does anybody know a way of getting a "flat pattern" answer without having to redo the part in square form. This redo can get complicated if there are more bends to the wire that are not all in the same plane.

Bertil

I would say that you use the K factor as do the sheetmetal guys, for example

formatting link
While Pro/e does it automatically based on bend tables and K factors built into material properties, there's no reason you can't do the same with hand calcs. You just have to find out what the K factor is for the particular metal that you are bending. This may also be of some help:
formatting link
As this makes clear, bend tables adjust for other factors, such as stock thickness and bend radius. Most are discovered and verified in practice.

David Janes

Reply to
Bertil Rogmark

I just killfiled him. No more stupidity.

Dave

Bertil Rogmark wrote:

Reply to
David Geesaman

How does one "killfile" a poster (I assume this results in you not being forwarded anything by them any more?) ? I am poking around the google group site here and not seeing a switch that looks like that...

So tired of sifting through all this yelling John Banquer chaff to get the good bits of advice out

Thx

Magnus

Reply to
Lehnsherr

Killfile is a generic term meaning use whatever filter your newsreader has to delete the garbage posts. JB is very easy because he posts under the same user name (newsreader softwares still aren't sharp enough to filter based on the stupidity of the content)

I'm using Mozilla Thunderbird and it's pretty easy to set up a Filter to delete particular messages. I poked around google groups and found no such features. However, I did flag all of JB's threads as spam, so if others do the same maybe we can collectively vote the threads into oblivion or something. :)

David

Reply to
David Geesaman

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