2 Replies Latest reply on Jul 26, 2016 9:09 AM by Peter Ham

    Mate Components to Punched Belt

    Peter Ham

      This is something I have looked at on a number of occasions, and I've yet to come up with a satisfactory solution.

      We regularly attach components such as paddles to timing belts. The timing belt is punched with a series of pairs of holes. Each pair of holes has a mounting block screwed to it. See the attached picture for a better understanding.

       

      At the moment, I typically create one pair of holes, then use a Curve Driven pattern to create regularly pitched pairs of holes around the belt.

      Each attachment is brought into the assembly as a sub-assembly, and mated to the holes using Concentric mates.

      Where the holes are on a flat portion of belt, I then use a co-incident mate between the underside of the attachment and the belt surface.

      If the holes are on a radius, I use a tangent mate instead.

       

      This is kind of functional, but I want to be able to move the holes to any position within their cycle. Say I have a 70mm hole pitch, I want to be able to move +/- 35mm from the datum position.

      The issue I have is that as soon as a hole that was on the flat moves onto a radius, the coincident mate fails. And vice versa.

      If the holes are half on the flat, and half on the radius, that's even more of a pain.

       

      Any suggestions on the best way to achieve this in a robust manner would be appreciated.

        • Re: Mate Components to Punched Belt
          Peter Ham

          Since posting this I've had a another go at something I've attempted before, and its been more successful.

           

          I've create a new sketch with a series of construction lines, with co-linear relations to the axes of the holes.

          These are then used as the basis for a series of Reference Axes, which are then used for a concentric mate.

           

          Then use intersection to create a series of points on the surface of the belt, one on each reference axis.

          These are used for coincident mates on the underside of the mounting block.

           

          The only 2 issues I've seen so far are:

          Original pair of holes must be on a flat surface - Not really a problem

          The points can occasionally jump to the 'return' side of the belt

          • Re: Mate Components to Punched Belt
            Jeremy Zuvich

            If your belt is created with a sketch that is a closed loop, you can use a Path mate to keep the part on the surface of the belt. You would need to go into the path sketch and use the Make Path command to join all of the sketch segments. Keeping the block tangent might be a trick, but if you don't mind a little interference between parts, you can mate the forward edge of the block to the same path. Once you have one block mated in place you can use a curve driven pattern in the assembly to pattern the parts. There is a function in the pattern dialog that allows you to rotate the parts in the pattern to remain tangent to the path.

            You might also be able to use the Cam mate in the Mechanical mates section, but I've never used it, so I'm not sure how it works.

             

            JZ