My next evolutionary step with overlaps and sheet metal

Thanks to Matt, I am now able to create an overlapping pipe using Spirals
and Lofted Bends. The next step is to be able to create a hole on the
flatten piece of material and have it roll up when its folded. Is this
possible? Is this the best way to approach make a Pipe with an overlap.

I have include a link to where you could see the pipe that i am working on.

ftp://24.42.130.192:21

Thanks again for all your help.

 

Mike,

I have uploaded an example to your ftp on how to make a hole in unfolded
state.
The example file (spiral-2.sldprt) is based on your spiral part .

Regards
Bengt Dahlborg

 

Mike, my friend,

You might recall from the first thread this sample model:

http://www.sheetmetaldesign.com/Cad-SolidWorks/Example11-Overlap-Round.zip

This (which I think you have already - grin) shows how to do this and
also how to add extrusions in the flat.

(I'm smiling really hard . . . really . . . really . . . really . . .
hard)

Regards,

SMA

 

The main problem I'm having with the Spiral/Lofted Bends method is
that I can't seem to get the Spiral as tight as I would like. For
instance, on a 24.25" cylinder and a 1" overlap, I should end up with
77.145 for my sheet metal flat, but using this method I end up with
78.17. Any ideas on tightening this?

Thanks,

John

 

Hi John,

Does the flattened length respond to adjustments to the k-factor in
the sheet metal definition?

This might be the first thing to try.

Otherwise I'm stumped too . . .

Presumably this is not a problem with the pitch of the spiral and your
"final state" geometry is being created to your liking . . .

Regards-

SMA

 

Hi John,

Well, actually the Spiral isn't as tight as I'd like it. Even tough it
looks like there is plenty of room without ending up with
self-intersecting geometry, Solidworks still won't let me tighten the
Pitch enough on this Spiral to reduce the sheet metal length to a
reasonable level.

If you don't mind, try lofting a 24.25" spiral out of .125 thick
material and you'll see that there is a substantial gap left where the
overlap occurs. If I could tighten the spiral enough that the gap was
near zero, this would go a long way to reducing my extra 1" of
material.

 

Hi there John.

I gave this one a few tries with the "pure" spiral and found myself
getting my nose bloddied too. Luckily I lack the comittment to try
when all hope has run our (smile).

I came up with an alternative that is well behaved and develops
properly. It is based on your sample numbers:

http://www.sheetmetaldesign.com/Cad-SolidWorks/Example13-5_ArcSpiralWithOverlap.zip

It includes a "how to". It does a reasonably good job of approximating
a "pure" spiral but without the hassle of the lofted bends that are
not too Lofty, by the way.

I hope this helps. I gave up in the pure spiral with zero gap, with
disgust I might add. Hehe.

Regards,

SMA