Surface projection

[tristram]

I am trying to take a surface and get a flat template that I can use to cut the material. Any suggestions? I am at a loss.....SW has to be able to do this, right...

 

[Rocko]

It depends on how complex.

 

[rocheey]

AFAIK, You can only get a flat pattern from a 3d model.
Turn your surfaces into solids, and you will be able to get a flat pattern.

There is no way to account for bend radii, and stock thickness on a surface, since the surface *has* no thickness

 

[TheTick]

Perhaps model the part as a sheet metal part?

 

[tristram]

The surface is complex and sheet metal or thicken surface won't work. I need to knit all surfaces together and do a shell to get a solid.

 

[TheTick]

Most CAD programs (including SW) do not have the ability to flatten forms with compound curvature. There are some sheet metal blank development packages available.

Check out Forming Technologies at

http://www.forming.com

for information about BlankWorks and FastBlank products.

If you need this done as a service, you may be able to broker the work to a tool shop that is running this software.

 

[Arlin]

This seems to be a very common question here. It seems that most do not understand how complex and involved forming really is.

The truth of the matter is that some CAD packages DO have the ability to flatten non-gaussian (compund curvature) surfaces...BUT DOING SO IS USUALLY NOT ACCURATE!! Flattening such surfaces requires EXTENSIVE knowledge of the material's physical properties as well as the forming process. In those few CAD programs that can flatten such surfaces, neither material properties or process is specified (adequately).

FEA and specialized forming software is available and can be used for such processes, but they can be expensive and the results of these are only as good (or worse) than the data that goes in (physical properties).

I think many surface modelers can flatten compound curvature surfaces (Rhino, Alias...). But, I would seriously question their accuracy based on my above comments. The primary uses of flattened surfaces in those tools deal with texture mapping and other 'visual' needs. Flattening in these programs are not meant to produce a blank pattern suitable for manufacturing purposes.

All that being said, SWX2003 does have a nifty little feature called a lofted bend that can be used to create and then flatten a non-gaussian type shape. But, this feature is pretty limited and SWX even includes tools to analyze the resulting flat pattern and its errors.

In summary, flattening non-gaussian surfaces is a VERY complex and involved process that is beyond the scope of most modern CAD programs. Some programs can flatten these types of surfaces, but their use in a manufacturing environment is questionable at best. Your best bet is to find some sort of specialized flattening sofware that specializes in you type of work (BlankWorks, for example).

 

[JNR]

On the nail, Arlin!! And the reason that CAD programs do not go to the extreme lenghts required for this function is that only a tiny percentage of customers require it, so it is not cost effective. You will have to invest in specialized software for this. Unfortunately it will be expensive - because the problem is difficult and expensive to solve and the market for it is small.

Not much help, but maybe it can help focus your search.

There have been several post on similar issues, including textile stretch fabric patterns (even worse problem?). Perhaps if you do find some potential solutions you could add a brief report of your findings to this thread? It might be helpfull to others.

Good luck.

3/4 of all the Spam produced goes to Hawaii - shame that's not true of SPAM also.......

 

[tristram]

Thanks for the responses, at least I know to stop trying. I was able to unroll the surfaces in Rhino3D, so I will have to check the accuracy.
Figures, my next project is with textile stretch fabric patterns.