NX plunge helix toolpath

[Midwest2004]

Good afternoon gents, have a question on the best tool path to Plunge on a helix to create a ramp following a single arc. Basically half of. Thread but it is creating a ramp in a part on a slight radius. Any help would be great on how to overcome this as currently it kicks out lots of linear code and bogs down old machine. I would prefer it to be an arc if possible