topic Re: flatten a double curve plate in Inventor Forum

flatten a double curve plate

Shane_M35 — Wed, 15 Feb 2023 00:14:48 GMT

hi all, I have been passed a project and cannot unfold or flatten this part attached, it was originally drawn in 2018 by someone else. I suspect a someone may have had a play trying to flatten the part as well.

I haven't done much with sheet metal or plate fold/unfolding so any help would be great.

The end result I am after is a flat pattern for a laser cutter.

please see attached ipt

cheers

inventor 2023

Re: flatten a double curve plate

SBix26 — Wed, 15 Feb 2023 01:02:59 GMT

Well, the very first problem is that the active sheet metal rule doesn't match the thickness of the part. The part is 12mm thick, and the active rule has the thickness as .500mm. Sheet metal flat patterning won't work unless the entire model is uniformly the thickness of the active sheet metal rule.

So, I changed the active sheet metal rule to 12mm thickness, and to my great surprise, it flattened... mostly. The original loft surface is made up of two faces. When thickened and flattened, one of the faces, presumably conical in form, flattens nicely. The other does not.

To get a completely flat pattern, you will need to use the Unwrap tool, which will produce a flat surface of the part, but with no account taken of stretch/compression as the sheet metal flat pattern does-- use at your own risk.

Note that while your message says "Inventor 2023", the file you attached is Inventor 2019 format.

Sam B

Inventor Pro 2023.2.1 | Windows 10 Home 21H2

Re: flatten a double curve plate

Shane_M35 — Wed, 15 Feb 2023 01:43:02 GMT

hi Sam and thankyou
But, I changed the sheet metal defaults to 12mm from .5 and is much the same unflatten outcome, I have only been using inventor for a few months so i'm still very green and getting familiar with the way it works, obviously it isn't the active rule which I can't locate? any change you could attach the file?
and the version I have is 2023 pro why it's as 2019 format I have no idea.

Re: flatten a double curve plate

johnsonshiue — Wed, 15 Feb 2023 02:05:10 GMT

Hi! Inventor Flat Pattern has very limited ability to unfold spline geometry. It is built to handle cylindrical (or conical) bends. For this case, you need to use Unwrap command to flatten the face. Please note that the flattened surface does not obey K-factor or any material deformation. It is just an geometric approximation.

Many thanks!

Re: flatten a double curve plate

SBix26 — Wed, 15 Feb 2023 02:34:18 GMT

Here you go.

Sam B

Inventor Pro 2023.2.1 | Windows 10 Home 21H2

Re: flatten a double curve plate

Shane_M35 — Wed, 15 Feb 2023 03:02:51 GMT

Awesome thanks Sam was a great help the unwrap as you and johnson have said works ok as well

Re: flatten a double curve plate

Shane_M35 — Wed, 15 Feb 2023 03:03:16 GMT

thanks Johnson that works well