Re: ATM Advice on Large Spherical Mirror?

["Richard Schwartz" <richas@earthlink.net>]

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.
>
>