Re: ATM Advice on Large Spherical Mirror?

["Ken Hunter" <kb7h@onemain.com>]

Richard...

Take a piece of brass or aluminum round stock a bit larger than the
threaded rod you want to machine and bore and tap a hole down the
center. (This is done in the lathe). Thread the threaded rod into the
threaded hole and lock it down with a threaded nut. Machine the end of
the threaded rod to the size of the hole in the un-threaded bearing.
Do the same on the other end.

Let's hope this isn't the beginning of another long thread.

Ken Hunter

----- Original Message -----
From: "Richard Schwartz" <richas@earthlink.net>
To: <atm@shore.net>
Sent: Thursday, December 06, 2001 11:58 AM
Subject: Re: ATM Advice on Large Spherical Mirror?


>
> It is my shame to admit that the first version of my foucault tester
used a
> $95 Japanese micrometer head to push and measure the carriage.
Since that
> time, I have learned to lap screws and make cheap hardware store
threaded
> rod into a very accurate tool.  I also learned to make great knobs
with 50
> divisions with scrap plywood, my computer printer, a 2" hole saw,
white
> paint, and epoxy.  My knobs are much easier to read than the mike
head!   I
> no longer use expensive mike heads.  Am I redeemed?
>
> Today I will go to the community college with Strong's book in hand
to ask
> about ways to machine a shaft concentric with pre-existing threads.
I
> thank this list for the bushing method, but I am just curious what
they will
> say.   (I will probably get a parking ticket there; that is their
main
> business activity.  They won't give me free parking for blood like
UCLA
> does.)
>
> . . . Richard
>
> ----- Original Message -----
> From: "Vladimir Galogaza" <vladimir.galogaza@zg.tel.hr>
> To: "Patrick St. Jean" <stjeanp@pat-st-jean.com>
> Cc: <atm@shore.net>
> Sent: Thursday, December 06, 2001 7:36 AM
> Subject: Re: ATM Advice on Large Spherical Mirror?
>
>
> >
> > Ever since I red  ATM books 1,2 and 3, I noticed a habit
> > of ATM-ers of Russel Porter times to mention ( proudly) if they
> > obtained some part for their telescope for $0.3, or so. With years
> > and inflation this sum has raised to somewhere in the $ 18,5 range
or
> > so, but not much more.
> > This is so even today, our List is witnessing the phenomena.
> >
> > But if our fellow ATM-ers will acquire something in the orders of
> > magnitude higher price class, as a rule, there will be no
mentioning
> > of the price as if this is obviously not interesting for anybody
or even
> > indecent. Milling , turning, and other machines are discussed  as
they
> > are for free or obvious.
> > People are working with 20 " blanks not mentioning the damage to
the
> > wallet they suffered, but they found it necessary to announce they
bought
> a
> > scrap pipe
> >  for  1$.
> > Everybody is salivating on the recent " scrap yard " buy of 16",
3.5"
> thick,
> > probably Pyrex mirror. Nobody dared to ask for the price nor the
proud
> > owner find it worth mentioning in a good old ATM tradition .
> > Interesting habit. Is not that so?
> > But why?
> >
> > So David, please satisfy my curiosity ( may be off List).
> > What was the price for the beauty?
> >
> > Vladimir.
> >
> >
>
>