Re: Machining / Lathe questions

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

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)???


Hi Captain---

Clamp the sphere in a small machinests vice --- set up in drill press 
---slowly --- bring down a pilot sized drill to the approximate center of 
the sphere ---- use very light
pressure --- the drill bit will tend to walk away from center ---- when you 
find the
center of the sphere the drill will stay & drill the pilot hole ---

Very light pressure & safety glasses a must -------

I do machining & welding etc-etc .
I'm in Altadena , California ----
Been with Chip & the list for a  few years now ---

Regards,

Sandy