[Normsthename]

I have been given a job to make a small batch of vacuum formed parts. They already have the mould made by a another company so the forming part is dead easy.
I also have a original sample part
But I need to trim the formed part to the shape shown in the attachment. One part of it is a half circle, but the other half slopes down at an angle.
I want to trim the part on my CNC Router using a 1/2" Cove cutter for instance
I drawn the part in my 3D CAD system and I then transferred the plan view into my machining software and the CNC router will machine the shape with the 'Z' set at a constant level. I thought about tweaking the Z Movements of the part that slopes down, but it sounds very hit or miss.

Any ideas?

TIA

Andy