I have a feature that I want to extrude cut along another feature (curved profile) which needs to be 90 deg maintained to the curved profile.
I created a plane 90 deg to the profile, but the extrusion cut is not perpendicular to the curved profile.  I have attached a couple snap shots illustrating the geometry that I am trying to cut into the .360” dia profile. 

Thanks guys for any help you can offer.