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Parameter input for n-sided polygon in sketches

imants_smidchensimants_smidchens Member Posts: 9 EDU
I found myself designing a configurable 3-sprocket chain for a robotics project, and as I read up on how chain pitch works, I found the simplest way to generate a variable n-toothed sprocket was to define a polygon with n sides and a side length of the chain pitch (seen below)

Currently the polygon tool does not allow for parameter-driven polygons, as variables are not considered valid expressions.

I realize this is likely because the input for such a polygon must be a natural number, but being able to configure this would be nice.
I also realize I could just define the diameter of the circle to be (# of sides)*(pitch length)/(pi) and call it good enough, but my brain prefers the geometric visual solution ¯\_(ツ)_/¯

Thanks for your time!


  • imants_smidchensimants_smidchens Member Posts: 9 EDU
    i found out that the polygon feature acts much like the pattern tool and thus enters a gray area in terms of how it can be edited and create dependency issues - if i delete one face of a pentagon, then change the parameter to be 4 sides, then back to 5, what happens to the deleted face? (and other such issues)  
    Perhaps a more robust solution (in my case, at least) is to define the circle with an isosceles triangle.

    definitely works well enough, at some point i'll get around to writing a featurescript that doesn't have this bothersome intersection issue between chain links

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