Flatten part guidance

[dave.mooney]

I've managed to get a hatch door made for a curved surface but i need to flatten this for a CNC machine to be made out of flat plate aluminium. I've used the sheet metal function but it doesnt seem to fatten the part, i have explored many videos but i havent been able to find one that explains how to do such a thing to just a curved surface rather than boxes, 

[JDMather]

Part not modeled correctly.

I assume the mating part was not modeled correctly either - but didn't check.

See Attached.

For additional help - you will need to agree to follow all of my instructions (starting with fully defined sketches).

[SBix26]

Along with what @JDMather  wrote, Inventor's sheet metal tools are unable to flatten curved sheet forms that are not conical (or cylindrical, a special case of conical). The processes used to create conical forms are bending (e.g. press brake) or rolling.

Your hatch is created by a spline curve, so definitely not a conic form.  However, Inventor also includes a non-sheet metal tool called Unwrap, which flattens nearly any curved surface.  It doesn't obey sheet metal rules and is limited to creating a surface from a set of contiguous faces, but may give you a very usable surface form for your purposes.

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Sam B

Inventor Pro 2023.1 | Windows 10 Home 21H2

[johnsonshiue · Accepted solution]

Hi Dave,

I have a different opinion on this case. The base geometry is fine. It is actually the Extrusion was wrong. I think the intent was to create a 2mm thick plate. But, Extrusion goes in one direction, which may not be normal to the curvy face. Instead, Thicken should be used. Use Thicken command to create a uniform thickness body. Then the flat pattern will work.

Many thanks!

[dave.mooney]

Thanks John, that helped a lot 🙂