Has anyone else out there ever had to model a higbee cut on a thread? Also known as a blunt start. (This is popular for fire hose fittings).

I'm trying to use a sweep cut. by putting a round extrusion into the part (not merged) and do a sweep on a spiral - to simulate an end mill plunging down in a spiral. I keep getting error: "Operation failed due to geometric condition"

Keep in mind that I'm still using SW2011. I'll try to post a sketch soon if my description is not clear.

Thanks,

Pete