It is somewhat difficult to machine them as they are brass and very fragile.
You need to make a cutting tool that cuts all the angles and diameter of the tips at one time and the lathe needs to be set up so you can duplicate the tip length as well.
The cutter must be in exact alignment with the rods are they will not cut well when you get down to smaller diameters.
I use an old metering rod to set up the lathe with a few practice cuts, and already have a custom made cutter for the included angle an taper of leading up to the tip.....Cliff