Contour Roll - Creating a Flat Pattern

[chris.barrie]

Hi All, 

Can anyone help with an issue I'm having using the "contour roll" function. 

I am modelling a conical canvas seal with different diameters top and bottom. The top and bottom diameters then have a "flap" or a flat for bolt holes. So my profile looks something like this. 

When Im then creating the flat pattern, the shape of the flat pattern isnt a curved radius as expected, its a rectangle. 

It seems to be the "flats" that are causing the issue on the unfold, without them the model looks like this, with the corresponding flat pattern below, which is what I was expecting. 

However, with the flats added in the contour roll profile, the model looks like this (as expected), but the rectangular pattern is shown below. 

Can anyone help with what I might be doing wrong? 

Many thanks 

[JDMather]

You are not doing anything wrong.

Those two flanges are deformations - Inventor will not unfold those correctly (are you sure you can manufacture them).

[johnsonshiue]

Hi! JD is right. The Contour Roll was meant to create the elbow portion with linear extensions on both ends. The roll creates non-cylindrical bends. Inventor Flat Pattern cannot unfold it. It can unroll it linearly.

You may use Unwrap command to flatten the shape. Please note that the flattened surface is an approximation. It does not consider any material property like K-factor.

Many thanks!

[chris.barrie]

Thanks guys, most helpful as always. 

[JDMather · Accepted solution]

@chris.barrie 

I suspect your liner material is very flexible and not close tolerance.

I did an Unwrap on similar geometry and I suspect this operation would be fine for your needs.