My first injection mold and the Rabit HY-4 injection molder

[mekanik]

Yes first op is drill the hole, you then want to remove the bulk of the material as you would probably break the engraving tool if you tried to open it out with that, also just checked the angles the 60 deg is refering to the larger opening that blends with the 45deg, the taper that opens out the hole has an included angle of 30 deg so you need an engraving tool that size, so remove the bulk machining the 45deg taper then go in with your 8mm dia ball nose cutter then just blend out with the 60 deg taper and tickle out the 30 deg taper with the engraving tool. FYI a "D" bit is just a form tool you basically turn the required profile with the drive dia slightly offset then machine away the profile leaving it flat topped to the centre line of the driving diameter, this gives the profile a "D" shape and a cutting clearance.
Regards
Mike
Reg

[gavztheouch]

the taper that opens out the hole has an included angle of 30 deg so you need an engraving tool that size,

I think the 30 degree taper is not part of the mold but instead part of the machine that injects the plastic. My thoughts are this is a heated tip and the plastic will flow around this?

[mekanik]

That makes it relatively easy to make then, carry on number one.
Mike