22 Replies Latest reply on Nov 4, 2011 3:44 AM by Erik Bilello

    CUTTING HOLES THRU AN ARC?

    CHRIS HOLSKE
      I am trying to put holes every 13 deg on an acr. I can unfold the part first but my dimension on print are every 13 deg and when in the flat I don't have the dimensions? I guess I could figure out the length of the 13 deg arc but if I need to change my K factor later my arc length in the flat will change so I'm not sure this is the best way to handle this?
      I have attached the part with no holes if anyone can help that will be great!

      Thanks, Chris
        • CUTTING HOLES THRU AN ARC?
          Kevan Chapman
          Hi Chris
          Take a look at the attached.
          I am not sure what size or where you want the holes but this method uses a plane on the cylindical face to create the hole sketch then cut thru and pattern as required. The plane can be created elsewhere on the cylinder (at 13 degrees) if necessary.
          Hope this helps.
          Regards: Kevan
          • CUTTING HOLES THRU AN ARC?
            Dave Bartholomew
            Kevin,
            Brilliant minds think alike, I was just uploading my rendition when I saw your reply!
            • CUTTING HOLES THRU AN ARC?
              Kelvin Lamport
              Here's an alternative using the Hole Wizard.
                • Re: CUTTING HOLES THRU AN ARC?
                  CHRIS HOLSKE

                  Just looking at some of my old posts now that I have learned much more about SolidWorks.  I use this method described here quit a bit with the holes on the acr but the drawing will not let me dimension the holes in the flat, I usually cheat and add text but there must be a better way?

                    • Re: CUTTING HOLES THRU AN ARC?
                      Kelvin Lamport

                      The method of creating the model should reflect the method of creating the hole in the actual part. Will the holes be created when in the flat, or after forming?

                        • Re: CUTTING HOLES THRU AN ARC?
                          CHRIS HOLSKE

                          The holes are created in the flat but most of my customers drawings are dimensioned all formed up and they are using an angle so it is much easier to  put the holes in the formed part given the customers dimensions but I find when I make an inspection sheet for the laser operator I have to cheat when dimensioning the flat.

                            • Re: CUTTING HOLES THRU AN ARC?
                              John Stoltzfus

                              Good afternoon Chris,

                               

                              With a slow computer I won't be able to open and change something or make an example.  I also didn't see what the other guys did, however I thought I would throw my two cents out there and you can choose what ever method works for you.

                               

                              This is what I do:

                               

                              1.  Create your arc or circle in Sheet Metal

                              2.  Add your hole  (smaller then the finished size) if you use 1/4" go with a 1/8" hole

                              3.  Cut through all

                              4.  Flatten

                              5.  Add a reference geometry point at each hole or just two and measure then use that to pattern

                              6.  Add the correct size circle sketch at each point or pattern

                              7.  Extrude cut

                              8.  Fold

                               

                              This might not be the best or quickest but it works fine,

                               

                              Later,

                               

                              John

                                • Re: CUTTING HOLES THRU AN ARC?
                                  CHRIS HOLSKE

                                  John,  This sounds great, just tried it but I can not locate the center of the hole in the flat to insert a 'ref' point.  I think if I could get to the center of the hole that way it would also work to dimension it in the flat which is my initial problem.  Maybe I am doing something wrong?  Do you have an example I could look at?

                                    • Re: CUTTING HOLES THRU AN ARC?
                                      John Stoltzfus

                                      Good afternoon Chris,

                                       

                                      In the flat state you should be able to select the hole edge or the hole face when making your reference geometry selection.

                                       

                                      I have computer issues or I would send you a sample part.  If you can hang on till mid next week bump this post and I do a sample for you.

                                       

                                      Later,

                                       

                                      John

                                        • Re: CUTTING HOLES THRU AN ARC?
                                          CHRIS HOLSKE

                                          John,

                                           

                                          Any luck with a sample part?  I have been struggling with this one.  I did add holes and tried to add ref point in the flat but it still doesnt recognize the feature as a hole in the flat so the ref point is just floating in space, not at the exact center of the hole?

                                           

                                          Chris

                                            • Re: CUTTING HOLES THRU AN ARC?
                                              Anna Wood

                                              Add a construction line to the hole (ellipse). Add the point to the center of the construction line.

                                               

                                              Cheers,

                                               

                                              Anna

                                              • Re: CUTTING HOLES THRU AN ARC?
                                                John Stoltzfus

                                                Good morning Chris,

                                                 

                                                I didn't forget about you, but.....

                                                 

                                                My computer issues have only gotten worse.  Last week I had to go back to 2004 and yesterday our IT guy came in my office and said that my new computer won't be finished till mid week.  So I had a lot of issues because my co-worker needed to open my newer SW files and save it as an Iges file so I could work on a new assembly, etc....

                                                 

                                                I am going to try it with 2004 and I'll try to up-load it,

                                                 

                                                Later,

                                                 

                                                John

                                                  • Re: CUTTING HOLES THRU AN ARC?
                                                    CHRIS HOLSKE

                                                    John,

                                                     

                                                    Sounds like your having fun.  When ever you find time, no problem.

                                                     

                                                    Chris

                                                      • Re: CUTTING HOLES THRU AN ARC?
                                                        John Stoltzfus

                                                        Good morning Chris,

                                                         

                                                        Here they are one is different from the other and I did miss a few steps I see.  You need to select the Face of the Hole and also add a sketch point to center the hole,

                                                         

                                                        I will be out a few hours this afternoon and if you have any additional question email me at johns@afsproducts.com

                                                         

                                                        Later,

                                                         

                                                        John

                                                         

                                                        PS: The IT guy just said the computer is done and will ship today, yippeeee

                                                          • Re: CUTTING HOLES THRU AN ARC?
                                                            CHRIS HOLSKE

                                                            OK, This does seam to work but doesn't it seem like this is a little backwards or the long way to get there?

                                                             

                                                            Thanks, Chris

                                                              • Re: CUTTING HOLES THRU AN ARC?
                                                                John Stoltzfus

                                                                Good afternoon Chris,

                                                                 

                                                                You didn't tell me you wanted something simple and nice

                                                                 

                                                                I know it is a backwards, long way out around approach, but it does the job for me.  It's not something that I do a lot of here, so for me time isn't the issue, it's about having correct information. 

                                                                 

                                                                I haven't come up with something better, yet. 

                                                                 

                                                                Later,

                                                                 

                                                                John

                                                                  • Re: CUTTING HOLES THRU AN ARC?
                                                                    Dean Viviani

                                                                    Is there no way of just transferring a 3d sketch point/s (indicates hole centre) from a curved surface on to the corresponding flat pattern using mates. This would help for those things which are formed with slight curvatures (skinned structures etc.) where small dimensional differences need to be taken into account.

                                                                      • Re: CUTTING HOLES THRU AN ARC?
                                                                        John Stoltzfus

                                                                        Good afternoon Dean,

                                                                         

                                                                        You can try it.

                                                                         

                                                                        If you insert a 3D sketch in the part you can add sketch points, however for me they stay at their original location rather then follow the edge that they were attached to in the sketch.

                                                                         

                                                                        What Chris was asking for is a way to dimension the holes in the drawing.  If you add the sheet metal to a circular part and then go to flatten, the hole edges show up as a spline instead of a true circle and therefore he can't dimension from the hole centers.

                                                                         

                                                                        Unless SW changes the way the hole is shown in the flat pattern, this is what I know works, unless someone else has a better way,

                                                                         

                                                                        Later,

                                                                         

                                                                        John

                                                                          • Re: CUTTING HOLES THRU AN ARC?
                                                                            Erik Bilello

                                                                            I just came across this posting and will admit to not having read the whole thing carefully.  At a glance it doesn't look like anyone else has posted this "trick" yet so I will.

                                                                             

                                                                            It's been awhile, but what I used to do to get hole locations to transfer from the formed to the flat was to cut a square in the formed part. Make it slightly smaller than the desired round hole.  In the flat pattern you will have a rectangle or diamond (depending on how you orient the square). Then put a construction line across two corners and the midpoint will be the center of your desired round hole.  The end result is the same as Anna's suggestion but I find it is quicker to grab the points of the square than the quadrants of an ellipse.

                                                                            If you need the hole to show in the formed part use "unfold" and "fold" to put the circular cuts in the part.  If you just need to show the correct hole size and location for your flat pattern drawing and/or DXF for manufacturing, save a couple of steps and just make the circular cut in the flat pattern configuration.

                                                                             

                                                                            This situation comes up often enough in sheet metal work that it seems like there should be an option to "keep hole round in flat pattern".  What do you think? ER anyone?

                                                                              • Re: CUTTING HOLES THRU AN ARC?
                                                                                John Stoltzfus

                                                                                Good morning Erik,

                                                                                 

                                                                                That is also a good idea, however it is still a work around.

                                                                                 

                                                                                Yes an ER is what is needed, are you going to do it??

                                                                                 

                                                                                Later,

                                                                                 

                                                                                John

                                                                                  • Re: CUTTING HOLES THRU AN ARC?
                                                                                    Erik Bilello

                                                                                    John,

                                                                                     

                                                                                    I've never submitted an ER and it looks like I'm not going to anytime soon.  I'm "403 Forbidden, Access denied to this resource." for submitting enhancements, just at present.

                                                                                     

                                                                                    I'd feel bad, but I gather the 403 is actually a pretty popular club (check it out if you can't find the 404), and not as exclusive as the name might suggest.

                                                                                     

                                                                                    I can find my products, and it says I'm paid up until next year.  I can see fixed SPRs and lots of other stuff, but no KB or ER for me.  I gather the answer to this is to find a minute and call my VAR, who will call SW and they will somehow fix it.

                                                                                     

                                                                                    If someone else wants to submit an ER I'll be happy to vote for it when access is permitted.

                                                                                     

                                                                                    Erik,