Creating Flat Pattern

[Tablor]

Using NX6.0 with 'NX Sheet Metal' available but not 'Forming/Flattening' I've not been able to figure out an easy way to create a flat pattern for the attached file. None of the 'NX Sheet Metal' tools allow me to select this unparameterized body generated from a .step. I also tried the wrap/unwrap using edge curves in modeling but I think that's no good for this either. Thanks in advance.

John

 

[Alderfek]

Well we dont have NX6 anymore, so I used the fabric flat patterning in the composites tool. Only thing you might have to do is scale up the part by 25.4 as we seem to have that issue in converting to dxf.

Hope it works,
Kirk

Kirk Alderfer
Designer
Meggitt Polymers & Composites
Rockmart, Georgia

"Imagination continually frustrates tradition, that is its function." -John Pfeiffer

 

[wiengines]

I was able to make it work by going to:

Start->All Applications->Sheet Metal->Forming/Flattening

Chris T.
Project Design Analyst
Kohler Co. Engine Division
Using NX6

 

[Toost]

Note that the part supplied contains self intersecting surfaces,
Which is one reason why it "doesn't want to cooperate".
Analysis - Examine Geometry.
Use the Export - Heal Geometry to fix it.

I think that since the flanges are curved ( the bendlines non linear.), and also B-surfaces ( instead of planes/ cylinders etc) the flat pattern / flat solid of the Sheet Metal application will not even try unfolding since the flanges needs to be deformed.
You need the Forming/Flattening for this.

Btw, what system did that part come from ?
- Since the flanges are degree 5x3 B-surfaces.

 

[Tablor]

Alderfeck - I'll have to check out the fabric flat patterning in the composites tool. Not sure I have access to it at the moment though - I didn't find anything like that in NX6. I wonder if it does something different than the sheet metal tool specific to composite parts?

wiengines - That's what I was wondering. I may need to get that added to our license. Thanks.

Toost - I don't know much about the source of the model. I'm just doing some work for the tool maker. I hadn't noticed the self intersecting surfaces so I'll have to look out for modeling errors by the original designer. Unfortunately, I'm not good enough with NX to troubleshoot model errors when something doesn't work the way I expect it to. I'm not familiar with Export-Heal Geometry so I'll go mess with that. I generally just figure I screwed something up when things don't go as expected! Anyhow, thanks for seconding wiengines suggestion that the Forming/Flattening would do the trick, I'll certainly see what it takes to add that.

Much appreciated gentlemen. One last question - is this 'body' the equivalent to an unparameterized sheet body as opposed to an unparameterized solid body? I don't know that I had seen that before. From Toost's comment, I'm guessing that if I had the original solid body I would still need to use Forming/Flattening application due to the complex contours? The model I have isn't specifically causing the issue? As always, thanks in advance.

John

 

[ewh]

Yes, as noted composite parts often contain free form geometry, and the sheet metal packaged wont always give you accurate results (when it gives any at all) with complex surfaces.
On a related note...
Alderfek,
How is the composites package overall? When we looked into getting it eight years ago we were told that we could purchase it but UG wasn't going to put any further effort into development, so we went with FiberSim.

"Good to know you got shoes to wear when you find the floor." - [small]Robert Hunter[/small]

 

[ewh]

Also, while I haven't used it, from what I understand Metaform in the Advanced Sheet Metal package might work, depending on the part complexity.

"Good to know you got shoes to wear when you find the floor." - [small]Robert Hunter[/small]

 

[Toost]

Tablor, Yes that body is as you say, an unparameterized sheet body.
( the only difference to normal people is that a solid body contains a volume and that the surface normals point out from the volume.)
You would still need the forming Flattening no matter sheet Body / solid Body.

The specific model contains self intersecting surfaces, which makes it more troublesome than it could have been. The heal Part option will save a copy of the part, with the model repaired. ( It removes the parameters from parametric bodies, but in this case there are no parameters.)

Tomas