5 Replies Latest reply on Jun 13, 2018 9:24 AM by Erik Bilello

    Swept Cut & Bend Lines

    Ethan Ably

      When a flat pattern is activated, why does my perimeter swept cut profile (crowned edge detail) omit at the bend line (but still continues as it should around perimeter of the sheet metal part)? I want to avoid gap showing without additional operations.

        • Re: Swept Cut & Bend Lines
          Rubén Rodolfo Balderrama

          hey pal could you attach your file?

          • Re: Swept Cut & Bend Lines
            Kevin Chandler

            Hello,

             

            Not in front of SW, so did you unfold the bend before making the edge? (w/fold after)

            When unfolded, a "regular" cut is all that's required. Not a swept cut.

             

            Also, the inside radius looks quite small. What's your K factor?

             

            Cheers,

             

            Kevin

            • Re: Swept Cut & Bend Lines
              Solid Air

              When I un-check merge faces and flatten your part, the gap matches your bend allowance (which I am not familiar with) of 0.031.  My best guess is that SolidWorks does not know how to calculate what you are trying to do.  Bends at edges normally flare (bulge) out on the inside of the bend area and in on the outside of the bend area.  I tried unfolding your part and adding the "crown" but SolidWorks would not re-bend it.  My recommendation would be to add another crown in the area where it is flat just for drawing purposes (how the part actually looks bent will not be as you modeled it).

              • Re: Swept Cut & Bend Lines
                Kevin Chandler

                Hello,

                 

                From a fabrication perspective, a inner radius of 1/64 on .236 thick material may be problematic.

                If you're going to crown after forming, then I suggest creating a configuration that unfolds the part and has the crowning suppressed so the blank has square edges at the original size. Use this config in place of the normal flat pattern.

                 

                On an unfolded part, SW won't cut the crown, it instead, cuts at the chord even though there's nothing there to cut with.

                So SW won't let a sheet metal blank get a dressed edge prior to forming.

                 

                Also, I'd recommend when making sheet metal parts, to start with a base flange and add the sheet metal features from there, such as an edge flange.

                Also, instead of the "regular" cut, I would do the unfold/cut/fold shown in the image (or incorporate it into your base flange sketch if known at the time).

                 

                Lastly,I don't recommend creating sheet metal using edge-on already bent sketches.

                This workflow doesn't tend to scale well.

                Just typin'.

                 

                Cheers,

                 

                Kevin

                • Re: Swept Cut & Bend Lines
                  Erik Bilello

                  Ethan,

                   

                  I don't think SW is going to figure out that sort of geometry for you.  ANs, as has been pointed out, in "real life" the area in the bend is going to distort in ways aren't shown by SW anyway.

                  You have a couple of choices that I see.  Easiest is to just suppress the crown cut in the flat pattern, unless you really need to show the crown on the flattened part for some reason.  Alternatively, if you do really want to have the crown in the flattened part, is to use the DeleteFace feature to fill in the little notches in the Flat-Pattern. It's not really hard, but fiddly, especially if you have a lot of bends.

                   

                  Erik,