Hi All

I'm surprised I haven't run into this before.  Here is a simplified version of my sketch - the left half of a 4 center arch.

For model reusability I was hoping to be able to make the radii equal (a 2 center arch) but SW refuses to play ball

Here I tried to make the 100R = 50

It will accept slightly above or below 50 but not equal.  Anyone any ideas what the problem is?

Thanks for looking

2016 attached