Dudes,
Not a biggie, and even I can do something like this, just curious about opinions on strategies.
For an electrical fixture part.
5/8-27 nps thread -- try finding DAT on a drill chart! About .5" of thread, will mill/drill hole .650 deep.Basically the OD of the tap measures .630, and we will start with a .590 hole (.020 thread depth), and finagle from there, mating-wise, with the test fitting.
Because of the shitty set up (only 2pcs per cycle), I want to minimize tool changes and dispense with a pilot drill, and drill (or helix) down with a
5/16 2-flute end mill. About 260 pcs.I see two ways to do this:
"Drill" straight down in z close to the circumference, and do rough/finish passes. The Q here is: how many pecks in the rough? (no pecks in the finish, I presume). Or: Helix down in rough, then a full depth finish pass. The Q here: what Z per helix revolution?
Which will give the fastest hole? Suggested speeds/feeds?
I've already programmed in the helix method, as I have an idea this is better for chip clearance (and ergo higher overall feed?), but I'll go with any consensus here.