Autodesk Inventor

[#1]

I have attached a simple model to detail what I am having trouble with.  

I have constructed a sheet metal tube by first creating a flat sheet face and then by folding the sheet with two, 180 degree bends and large radius.  I am doing it this way in order to simplify the drawing of the cutouts that are required in the "real" sheet (with many more cutouts than in the sample I have provided.)

When I try to add work points or work axis to the holes shown in the sample, only the holes on the second bend will accept the work features, the holes on the first bend will not - giving the error:

TEST.ipt: Errors occurred during update
Projected loop failed because of multiple vertex solutions
Work Point8: Could not build this Point Copy Point
Zero or multiple solutions for Point Copy Point. Use Redefine Feature to change its definition.

I am using the work point as reference to the center of the hole in order to position a rod.

Thanks for your help!

[#2]

Please, please add the version of Inventor you are using!

Instead of the flat and 2 bends, draw a circle with a small gap at 1 point representing the gap in the sheet ends. Then use Contour Flange to create the solid the length you want. Then use Unfold, create a sketch to represent your holes, refold it and cut the holes through. I have attached a sample file in 2013 format.

If you have a more complicated set of cutouts there is another method where you create a solid or surface representing the inside (or outside) of what you want (including the cutouts) and thern using Sheet Metal Derive to bring in this solid (or surface) and then Thicken as this will can include the cutouts automatically.

[#3]

Oops. Process should be CUT before REFOLD!

[#4]

Thanks Brendan,

Your solutions are great; however, I am supporting models done by a colleague - no longer with the company and the cutouts are numerous and time consuming to create so I'd rather not re-make this part if at all possible.

I have been able to create a plane perpendicular to the tube axis and through the center of the hole because I know the hole's dimension from one of the primary work planes.  In this way I've been able to create a sketch of the hole center and place a work point on the sketch.  When I do this Inventor complains a lot but the point remains.  I don't like this method but it works for now so until someone has a better idea it'll have to do.

Inventor Professional, 64-bit, Build: 176, Release 2013 SP1.1