Pro Engineer sheet metal - Elliptical cone / frustum offset - flat pattern?

[MJW]

Hi All, First post so sorry if this has fallen into the wrong category!

Could you please provide guidance on generating the sheetmetal plate development for an offset elliptical cone.

I have tried to tackle this by first modelling the cone as a standard solid part. From my knowledge, it is not possible to roll an ellipse so the top and bottom footprints were approximated into radii. I then switch to sheetmetal in the applications drop down menu, shell the solid so as i'm left with the plate (5mm thick mild steel.). This is where I get stuck.

I have tried various different ways to flatten the plate but it always fails to regenerate and will not create the flat state. Part of the problem seems to stem from not being able to select an edge to fix. I get the message "Inappropriate Edge"?

Any help greatly appreciated.

Matt

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[CallBobB]

Hey Matthew,

Welcome to the "Planet"! If you can, post some pics of your part or attach a file that we can look at... Also,

let us know what pro-e version you are working on!

When you get a chance add some detail to your profile!

Thanks,

Bob Barker

[MJW]

Hi Bob, thanks for your speedy response.

I'll try and attach the pro engineer *.prt file for the undeveloped plate. I assume you will be able to open it and work back through my part generation process? It's at the point where I now need to flatten it to get the development.

I'll also try and attached a PDF file showing how the complete geometry is set out and general arrangement drawing showing the finished article. Unfortunately, I'll have to remove alot of the notes and dimensions for confidentiality.

It's actually now a segment of a cone as we need to assemble the complete geometry with bolted joints. Also, it now has a flat side to it which is required for the final fabricated geometry. Hopefully this will become clear if you can open the attached PDF files. It was easier to ask how to develop an offset cone than try to explain the attached geometry and I thought once I knew how to do the offset cone I could apply it to the attached part.

Let me know if you need more information.

I've been working with Autodesk Inventor for the past seven or so years and have now started a new job using Pro Engineer so i'm a beginner again! The version we are using is Wildfire 5.0 Date Code M020.

[CallBobB]

FYI - Matthew did you check for other discussions of the same topic? Just off to the right of the discussion window is a

heading called "More like this". There are a couple of other discussions regarding bending or unbending a cone...

Take a look there first - I will look at your work later today...

Bob

[MJW]

Thanks Bob, really appreciate yours and everyone else's input.

I had a quick look at the links there, yes. However, I am able to get the development of a regular cone which the posts I found were discussing.

I don't think Pro Engineer likes that it is an offset (oblique) cone or perhaps it's to do with material deformation which would happen in practice but is what is not considered in Pro Engineer?

I just don't know what I am doing wrong???