Here is a photo of the finished parts. The filter body was also programmed using HSMXpress and machined on my Syil CNC Mill. I would not have even attempted to program this with my previous methods.
Right pain of a job, the cavities are 14mm deep with only 4mm of clearance between the centre posts and the walls. I ended up using a 1/8" 2 Flute long series cutter with 15.875 cutting edges and going very, very slow with light cuts. Each cavity took 15 minutes.
The customer was desperate. I advised them the correct way to do this job was to make the posts separately and bolt them in after the cavities were machined.
Regards
Chrisjh