That's my experience. I've never supplied a flat pattern. I just show
exactly what I want the finished part to look like, and let them figure it
out. Maybe in a big operation, where the sheet metal is done in-house, the
flat pattern would be useful. Or, if the sheet metal shop was using
Inventor, they could make use of this portion of the tool.
"Albert Allen" wrote in message
> The guy at the particular shop that had questions about our bend
> says they like to get the finished piece drawing (no flat pattern) and
> developed their own solid and do the flat. Is this normal operating
> procedure for most sheet metal shops? If so it would be easier for me.
> "Mark A. Bystry" wrote in message
> > welcome to sheet metal. i used to use pro/e's sheet metal package when i
> > in the sheet metal field. i remember that they used some thing like
> > or some thing like that. it was loosely based on the K-FACTOR. this
> > setting didn't jive with our tried-and-true bend allowances out in the
> > we used v-dies for all our breaking. we pretty much learned how to fudge
> > models so the flat pattern would come our perfectly for our machines.
> > was just like SW and Inventor though. you were able to make a custom
> > allowance chart in xcel. we just never used that feature.
> > i'll tell you this though. bend factors are ALWAYS different for every
> > i still regard K-FACTOR as reference only. let the shop guys tell you
> > your bend allowances are. with that info and a little trial-and-error
> > get it right every time.
> > --
> > Mark A. Bystry
> > Engineer
> > Ziggity Systems, Inc.
> > firstname.lastname@example.org
Don't get me wrong on my comment about avoiding supplying flat patterns
like the plague.
Once in a blue moon, I've asked for sheet metal parts that aren't normal
and the fabricator throws in the towel and admits he can't figure it
out. In those rare cases 'Flat Pattern' makes me look like the genius I
wish I really was. Oh yah!
Autodesk, don't interpret this thread as an excuse to stop improving the
Sheet Metal application.
Albert you need to remember that there is also the difference between bottom
bending and air-bending and the different V-Dies. On some materials I have
14 different k-factors. At least you can have them all in one template and
can choose between them my sheet metal template has over 200 styles. That is
over 200 k-factors welcome to sheet metal
"Albert Allen" wrote in message
> I did a simple bent up part in Inventor sheet metal by starting with a
> plate,adding flanges and finally adding holes to each face. I then
> the flat pattern and used this flat pattern in an idw with ordinate
> dimensions for the holes from a set corner. I also used the flat to show
> bend centers and specified an inside radius for the bends. Ok simple Simon
> stuff but when I sent it out to one of our vendors to be punched and bent
> they called back and said the bend allowances and the flat pattern did not
> jive with the drawing....what?! Turns out that when their engineer (who
> SW) did a solid from my flat pattern and bent it on the lines I spec'd
> the same inside R that I used that things didn't work out. I have always
> used the default K factor in Inventor sheet metal and everything has
> turned out exactly as the model when it's built in the shop, so what gives
> here???? He did say that he uses K factors they load in from a spread
> into SW but there should not be more than a couple of thousands difference
> should there?