Hello, I hope someone can help with my issue.

I am trying to build a variable fillet around the base of a part. The part is simply a extruded rectangle (rounded) with equal fillets in each corner. I need to have a variable fillet that smoothly transitions from two radii (radiuses). The radii need to be specified at the mid-point of each edge.

The problem that I have is that I only want to specify a radius at 8 different points (4 for each radius size) and let the rest be the result of a tangent smooth transition, however when using the variable radius feature I must specify a radius at every vertex. This causes a problem as I do not know the radius at these vertices- I have calculated an approximate but the transitions are not fluid. I would like Solidworks to simply fill in the blanks and create a smooth consistent transition. I have sucessfully done this many times in another program (ZW 3D) and the results are quick and perfect. I have also tried this in Inventor LT - although it allows me to do what I want the results are inconsistent. Any idea how I would do this?

This is a picture of what I need (from ZW3D): Base Dimensions are approx. 140mm x 150mm with a 50mm corner fillet

Thanks for any help