22 Replies Latest reply on Oct 18, 2016 7:38 AM by Xuno Gildelamadrid

    Windows on cylinder (sheet metal)

    Xuno Gildelamadrid

      So I don't know what is happening here. I've tried so many things and watched so many videos but no matter what I do I cannot get reproducible results with this.

      I am trying to add two adjacent windows to a sheet metal cylinder. I made the cylinder, unbent it, then extruded my windows. Well now it will not let me bend the cylinder back. I know I have been able to bend it back after making circular windows, is there something about square windows that will not let it work?

       

      The second thing is that I want to add some edge flanges to the edges of the window. Will I be able to do that and then bend the cylinder again?

      I know that there could be issues with keeping the integrity of the flanges after the re-bend but I feel there has to be a way of accomplishing this, any Ideas?

       

      Thanks all.

       

      I have attached a sample of what I am trying to do.

        • Re: Windows on cylinder (sheet metal)
          Xuno Gildelamadrid

          Holly dam!

          Ok, disregard the folding and unfolding section of the question...

           

          The flanges issue I am stiff trying to figure out the best way to do.

          • Re: Windows on cylinder (sheet metal)
            JOHN GEORGE

            Xuno,

            I think the file you attached is a flat pattern

            You have to create the cylinder in sheet metal, then unfold, make the cut, fold again

            It should look something like this, if I am correct.

              • Re: Windows on cylinder (sheet metal)
                Xuno Gildelamadrid

                Sorry, yes I figured it out and got to that.

                 

                My current issue is that I want to add flanges to the window edges. Ideally, I would like to have a 1" flange to the window edges that is recessed about 2mm to the inside of the cylinder. I see how this would be very hard to fabricate and that is why maybe it is not easy to do on SW?

                I would like to hear opinions on this, thanks.

              • Re: Windows on cylinder (sheet metal)
                Rob Edwards

                very strange it worked for me.

                At first it wouldn't because stupidly I was trying to 'unfold' it twice.

                I couldn't get an edge flange on the unfolded body, the tool tip said 'selected edge is on non planar face' so I grabbed the unfolded state in a sketch and recreated another base-flange and applied the edge flange to that.  I have no idea if this is good practice, but it yields a flat pattern.  Hopefully someone will show the better way

                  • Re: Windows on cylinder (sheet metal)
                    Xuno Gildelamadrid

                    This is funny because that was what I was doing wrong too. I was unfolding twice instead of folding but I figured it out now.

                     

                    Not about the flange edges though

                    • Re: Windows on cylinder (sheet metal)
                      Xuno Gildelamadrid

                      I am sorry I didn't see that you had those flanges there, I am having mixed success with the vertical ends but no success with the horizontal ones (which will be the ones that might cause trouble when the part gets re folded.

                        • Re: Windows on cylinder (sheet metal)
                          Dennis Bacon

                          If you do indeed want 1" flanges on the window edges I don't think you can do this with strictly sheet metal features. You may want to consider using sheet metal features and the flex feature. I put the flanges in your model flat then used the flex command. This does give you a good representation of the folded part. There are several things that need consideration like the angle of the vertical bends (not sure how you want that) and a neutral bend axis. This can all be worked out. Not sure what your cylinder OD is supposed to be but we do know the flat pattern length from your file.

                          You do need 2 configurations for this. One for the formed and one for the flattened state (the flex needs to be suppressed.

                          • Re: Windows on cylinder (sheet metal)
                            Rob Edwards

                            I don't know how it would be possible.  If this were my job I would be pragmatic and not expect SW to do it for me all at once.

                            For example

                            I would break the problem down into the small parts that SW can handle and look at the results of each flat pattern, and then construct my own flatpattern directly depending how it was to be manufactured.

                             

                            That was my approach before in doing the job in two.  Constructing a second base on the results of the flat pattern of the first 

                             

                        • Re: Windows on cylinder (sheet metal)
                          Elmar Klammer

                          Hi Xuno,

                           

                          Here is a model that flattens. One little quirk. SW looses the window edge flange when flattened. I just added a parametric patch. The window itself can be unfolded and works fine if you had to add holes or otherwise.

                           

                          Not a 100% but close enough...

                          • Re: Windows on cylinder (sheet metal)
                            Dennis Bacon

                            I'm curious Xuno,,, When you say flange recessed to the inside (2mm) are you thinking of something like this?

                             

                              • Re: Windows on cylinder (sheet metal)
                                Xuno Gildelamadrid

                                Sorry guys, I have been away for the weekend.

                                Dennis, that is exactly what I am looking for. I have some good information to go through thanks to all the replies but yes that is exactly what I am looking to do on my part. Ideally, I am looking for two adjacent 10cmx15cm windows with a 3cm gap between them. But I want the whole 23cm x 15cm (two windows plus gap) recessed 2mm to the inside. Then I would also need to put some holes on the flanges. This will be for a piece of Lexan that will serve as a viewing window.

                                 

                                So Dennis, since you made that drawing I am to assume it can be done? Did you use the methods described by the other members above or was there other processes involved? Also, these flanges would be able to support hole wizard inputs?

                                 

                                Thanks a lot everyone, all the help is great to see!

                                  • Re: Windows on cylinder (sheet metal)
                                    Dennis Bacon

                                    Yes Xuno, it can be done but probably not as easily as you would like to see. I made a tool for the emboss then used that in combination with the indent feature. This gives you a good representation of the formed cylinder but will not translate to the flat. So for the formed cylinder you can add the cutouts and holes (yes the hole wizard will work well for this) then do the indent. I initially tried to use a form tool which would also include the cutouts, holes, and emboss, but SW requires a flat surface for the stopping face. Could have done that in the flat then used the flex feature for the formed model but I'm sure there would be some issues translating the exact hole and cutout locations from one to the other. It's difficult to say exactly how far off the locations would be do to the material flow when embossed and SW can't figure this out for you, but it would be fairly close with a 2mm deboss. If I were making several of these, and needed it to be accurate, I would make a tool (horn) to emboss and pierce the holes after forming but not everybody has the equipment for that. Since you plan on doing the cutouts and holes in the flat, I do believe you can make a couple of configurations of this and have the exact locations in the formed view and approximate hole and cutout sizes in the flat. Then by trial and error (shouldn't take much) alter your flat dims until you get it really close. Withing a couple thou"

                                    If you give me the OD of this I can come up with something for you to start with since I have a pretty good idea of what you want now. Would not be able to get to it until later in the week. What version? How much flat do you want to the outside of the holes? If you are an educator or student as this post is tagged I would be hesitant to send you a file and urge you to look into the indent feature and or form tool. Lots of info on this on YouTube.

                                      • Re: Windows on cylinder (sheet metal)
                                        Xuno Gildelamadrid

                                        Dennis, yes I am using the 2016 education edition as I am building the part for a lab at a university. I will try and see what I can find in YouTube on this but it does sound like a lot of work on something I would have to learn. (I don't think they will allow me limitless time to get the part exactly how I would want it.) I have a version where I just have the windows drawn onto the cyclinder with holes patterned around them, it is just that I feel that is sloppy and I would really prefer a design like the one we are discussing.

                                         

                                        The OD of the cylinder is 72cm so I feel adding a flatter surface could be doable without changing to much of the shape. That being said I would like to keep the flat area outside of the holes to a minimum.

                                         

                                        Thanks for the help here! Love to hear what you think.

                                          • Re: Windows on cylinder (sheet metal)
                                            Dennis Bacon

                                            If you are building the part for the lab I would imagine that you are going to send this out to a shop for fabrication. If that is the case I wouldn't worry about the flat pattern. That is the for the fabricators to figure out. I would give them as generous of a tolerance as you can and still have your Lexan holes line up for riveting or whatever) I would do as you described and put the holes and cutouts in the cylinder (doesn't have to be sheet metal) then use the indent tool. You can easily model your tool for this, indent, then hide the tool. Fairly easy to figure out if you have some SW modeling experience.

                                            • Re: Windows on cylinder (sheet metal)
                                              Elmar Klammer

                                              What you are trying to do is unrealistic. If you stamp your part before rolling, then you can't roll it anymore. If you roll it first, then you can't stamp it anymore (or only with difficulty). Either way, something like this is simply crazy, unless you make 10000 and can afford specialized tooling. Ask yourself how you are going to make this first, then all your questions regarding modeling will answer themselves.

                                                • Re: Windows on cylinder (sheet metal)
                                                  Dennis Bacon

                                                  I don't agree with you Elmar... I have done this sort of thing many times in my career. Since the depth of the emboss is only 2mm deep this should not be a problem if you emboss the flat prior to forming. This is frequently done.

                                                    • Re: Windows on cylinder (sheet metal)
                                                      Elmar Klammer

                                                      Sure you can do that with thin gauge material...before rolling...the question is why would I be so concerned with the flat pattern.

                                                      That is the stupid part. It's a die formed feature and your flat layout will only be approximated. Even the edges won't be truly straight at the end of your process.

                                                      We are talking two things here. Stressing over something so trivial is simply wasted time.

                                                        • Re: Windows on cylinder (sheet metal)
                                                          Xuno Gildelamadrid

                                                          As I noted before, I know that adding flanges that go along a curved end are very difficult to fabricate and that is why I was wondering if there was a way to design it considering the emboss depth to the over radius of the cylinder. Now is it simply wasted time trying to design such a thing? I guess depends who you ask, for me I was wondering if there was a fairly simple way that could be easily fabricated. Probably my boss would say it is not worth the time unless it is a simple thing. If I was making the part of myself, it would bug me because it is not exactly how I wanted it.

                                                           

                                                          Either way it comes down to choices, I was just curious if there was a fairly simple way of designing it, from the fabrication side

                                                          I figured someone could do it considering the depth vs radius. But yes, imagining a flat piece of sheet metal being forced to arc along it's plain sounds impossible, but hey I think that with the arc angle I am working with it would not be to hard to simply keep the "holed" section flat and make the rest of the sheet metal do the job of completing the cylinder, This is after all a small portion of the surface area of the cylinder.

                                                           

                                                          But I am no fabricator!