Andrew Thompson

driven dims + sketch relations + equation = quandary

Discussion created by Andrew Thompson on Sep 11, 2012
Latest reply on Sep 12, 2012 by Andrew Thompson

This came up while creating set up sketches for an eight-arm square umbrella. In order for the umbrella to open and close the combined length of the upper and lower pivoting arms of the side arms (A + B dims) and the corner arms (C + D dims) must be equal (A + B = C + D). See attached part with 3d sketch. Side arm geometry is 100% defined within the context of the umbrella canopy size (the square); corner arm geometry should be driven by the side arm setup.

This umbrella will be subject to custom configurations based on client needs. If we change the dimension of the umbrella canopy or the pivot point location in the side arm setup, it would be helpful if SW would calculate the lengths and pivot point locations of the corner arms. This way we will know that it will open and close without binding.

It seems this should be solvable by SW:

1. We know one end point of each of the C and D segments.
2. We know that the other ends of these segments are coincident with each other and another known line.
3. We know the combined length of these segments.
4. There is only one solution.

I've gone over this with my VAR but we were unable to find a solution. I submitted an ER, but figured I'd throw it out here to see if anyone's got a way to make this work.


Many thanks in advance.



EDIT: Having trouble uploading the file. Will keep trying. And accidentally double posted. I got an error for the upload and thought it was for the post as well. Sorry