3 Replies Latest reply on Aug 14, 2014 11:18 AM by Jamil Snead

    Is there a way for SolidWorks to mate points as a "Best fit"

    Taylor Bohach

      I have two parts that I am trying to mate. Each has three points on their own individual planes. both sets of points are near identical, but the positioning is slightly different. Because these points can not align perfectly, I would like to mate them as best as possible. Is there a way to do this?

      I would like to mate the centerpoints of the following as best as possible:

      1. "(-) engine original position...", Sketch18 mated to "(-) engine moved redo1...", Sketch1

      2. "(-) engine original position...", Sketch19 mated to "(-) engine moved redo1...", ( - ) Sketch2

      3. "(-) engine original position...", Sketch20 mated to "(-) engine moved redo1...", ( - ) Sketch3

       

      Thanks for the help!

        • Re: Is there a way for SolidWorks to mate points as a "Best fit"
          Jamil Snead

          I don't know of a method to optimize it perfectly, but I came up with something pretty darn close. First I edited each part and made a plane using the three points you want to mate. Then I put both parts in an assembly and mated those planes coincident to each other and aligned the corresponding points somewhat close to each other. Next I edited "engine moved" in context of the assembly and started a sketch on the plane I made in that part. In that sketch I put a sketch point on each of the points in the "engine original" part, deleted the in-context coincident relation that got added automatically, and dimensioned the distance between the points without moving them. So now I have a set of points that match the "engine original" locations in a sketch in "engine moved". Next I drew a line between each of the points I want to match up, so 3 lines in total, and make them equal length. This guarantees that the error of each point pairing is the same for all three pairs, which I believe would be the case for the ideal solution. Once those lines are equal you can drag the sketch points around and get them very close to the matching points. Once I dragged them really close, then I dimensioned one of the lines and kept decreasing the dimension incrementally until the sketch couldn't solve. This is the limit where the error can't be reduced further. In the end the distance between each point pair is .213 mm. Now the points in that sketch can be mated coincident to the actual points on "engine original" back in the assembly. You only actually need to mate 2 of them to fully constrain it, because you already have the planes mated.

           

          Hopefully that was clear enough for you to understand it and try it out. I would attach my files except I am using SW2014 so you wouldn't be able to open them.

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