Autodesk Inventor

[#1]

Suppose we have a plastic part modeled as bent around a cylinder with an x-axis. Because the material is plastic and the manufacturing method is injection molding, part stretch is not a concern.

Suppose further that the part is a solid part that will be converted to a straight spring. The part needs to be flattened to obtain the correct spring dimensions--the part may have variable width in the x direction.

What is the best way to flatten this part?

[#2]

Follow the steps for the first two "Folds" but use 179.9 degrees (can't have it intersecting/colliding with itself) for each fold.

You will need to work out the material length that you require.

This was just an exercise to have  the holes in a flat pattern before bending, but the "Fold" principle is the same.

You really could increase the length of the base item and create a clamp with holes on the end flanges.

[#3]

I can't open the attachment:

   Database schema for file C:\Users\xxxxx\AppData\Local\Temp\Flange.ipt is (17.0 (Build 170095000, 95)), which is newer than this version (16.0 SP2 (Build 160219200, 219)) of the software

[#4]

It is done in IV2013, as noted in my post signature. The only way to get this into IV2012 is to export to a neutral format which would loose all the detail in the model tree.

[#5]

I'm taking the opportunity to update my installation to 2013.

[#6]

Install the SP1.1 as well.

[#7]

Now that I can see the part you posted, I think there is some miscommunication. I'm not trying to bend a part. Instead, I have a part modeled as bent around a constant curve -- cylinder around x-axis. What I need to do is straighten the part or unwrap surfaces so I can model the part as straight. I've read that others have had some success with using the sheet metal environment, but I'm hoping for a more direct and less klunky approach. The part has spline curves (as mentioned in the original description) that lead to variable width in the x direction and make ripping a shelled version of the part laborious.

I've attached two pictures. One shows the part shelled and gives a good example of the variable width I mentioned. The other is a side view showing the curves I want to straighten. Projecting from the curved surface to a 2D plane does not produce the desired result.

[#8]

Not as you have modeled it is it within the scope of Inventor. It could be done as Sheet-Metal in four pieces and then joined together to form an assembly (weldment) for the singe tube piece.

[#9]

I was able to get the desired result as a flat pattern (see image with strategic use of SHELL. I've yet to find a way to convert the flat pattern into a 3D editable solid.