Re: Machining / Lathe questions

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "marc metlicka by way of Terry Fritz <teslalist-at-qwest-dot-net>" <mystuffs-at-orwell-dot-net>

Hi captain,
  If you're going to produce large quantities of balls drilled, one good
way is to use a 3/4" square hardwood block of 1/2" thickness. Then glue
four 1/4" square "sticks" around the bottom edges, find the center of
the square by drawing a line across from corner to corner and drill your
pilot hole.

  then as you clamp each ball in the vice, just hold the jig on top of
the ball and drill through the pilot hole slowly. Once a good hole is
started you should be able to drill to the required depth with nice
straight and true centered holes. This has worked well for me,


Tesla list wrote:
 >
 > Original poster: "by way of Terry Fritz <teslalist-at-qwest-dot-net>" 
<DamDeName-at-aol-dot-com>
 >
 > In a message dated 3/19/03 4:21:13 PM Pacific Standard Time,
 > tesla-at-pupman-dot-com writes:
 >
 > >1.  My first question is that I want to drill and tap a large number of 1"
 > >steel spheres which I am going to using as
 > >corona balls (spark gaps actually).  Anyone have suggestions on how to 
clamp
 > >these spheres properly.  I guess the proper way to do this to ensure proper
 > >centering would be to use a lathe (see next question), but precision 
isn't a
 > >hard requirement as they are only going to be used for spark gap balls.  I
 > >was thinking maybe taking some material putting perpindicular V-Slots and
 > >having the sphere rest in the intersection point.
 > >
 > >2.  Secondly, I'm finding that lathe work is becoming a requirement on
 > >almost all my new tesla and high voltage projects (as well as others) and
 > >I'm finding the very high prices of out-of-house machining to be very
 > >restrictive so I think its in my best interest to invest in a lathe and
 > >start practicing.  Are there any lathes out there for under $500.00 that
 > >would be okay for practicing and would be tabletop sized (not a huge floor
 > >mounted lathe)???

  There are many hobby lathes out there and used ones aren't that
expensive. My craftsman 6" metal lathe (24" long) was picked up at a
flea market for $125. including all the gear sets for speed changes and
threading.
Marc M.