Newbie has some dumb (for anyone who knows about boring) questions. I
am using an off-set boring head (APT) with "spoon type" cutters on a
vertical mill to drill a number of odd size holes (eg .342", .543",
etc), all between .3" and .75"; some shallow, some 1.3" deep, in
carbon steel FS 1141 (heat treatment: normalize @1200F air cooled,
hardened @ 1525F, oil quenched & drawn @ 700F) w/ Rockwell hardness @
A60-70.
1) Do these boring cutters plunge into the steel like a
center-cutter?..., or do they need a pilot hole to enlarge?...would it
be good practice to run a slightly smaller endmill down through the
center anyways?
2) Would you suggest boring these holes out in one pass?...or more
than one pass with increasing diameters? If so, what is a good
incremental increase per pass?
3) The surface where the hole will go is irregular, ie. not flat:
within the hole I want to bore the surface probably has up to three
different levels, and I have parallel holes partly within the target
hole. Does this present a problem for these standard boring cutters I
am using?
4) Does anyone have any suggestions rpm and quill feed rates
for what I'm describing? Without knowing any better, I would tend to
use 300-400 rpm and feed by feel.
5) My mill (Bridgeport Series 1) has an auto quill feed which I
have not used nor know much about. Should I be using that mechanism
either automatically or manually?...or is the standard quill feed
lever handle just as good?

As you can tell, I only know enough to be dangerous. Any advice would
help me lower the danger factor. Thanks for looking!

BTW if any of you have helped me out in the set-up phase two weeks
ago, I got this 25 year old machine up and running great! Shimming
with steel plates and a rubber anti-vibration pad under each corner
did the trick...and the VFD phase converter from that outfit in
Brooklyn, NY for my single phase source seems just perfect; and Harold
the tech was above and beyond: we got it running at 6:30 Friday nite
over the cell phone while Harold was stuck in NYC traffic.

I am missing one of the 6 copper electric contacts in the motor
reversing switch, just a ~3/8"x1+" piece of copper, no tools needed to
remove or install. What's a good source for parts?

Fred