I am trying to add a circle to a spline at a certain diameter so I can determine a height based on a ball size on a spline.  I basically just need to drop a circle at a specific size right in between these teeth until the circle makes contact, and then I can measure from the middle of the circle to the other features I need.  Whats the best way to do this?  This also needs to be at a Ø60 diameter from the top view, so I already have the circle at that point.  I just need to be able to move it up and down until it falls into place making contact on both sides.