Re: ATM pitch mold, opinions needed

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

I would back up what Tom recommends:  only trust what you read in published
books; advice you get on the ATM list is only correct to the extent that it
agrees with books.  Remember that older books have withstood the test of
time.   The years of the great depression of the 1930's were a golden age
for telescope making.  That was when they discovered the correct way to do
everything.

P.S. Good luck with home foundary and machine shop you will require!   In
the 1930's, every farm boy had one so he could make horse shoes.


> [Original Message]
> From: <tkrajci@san.osd.mil>
> To: <atm@shore.net>; <atm@atmlist.net>
> Date: 1/23/2004 8:51:02 AM
> Subject: Re: ATM pitch mold, opinions needed
>
>
> >From: "c f" <quantemlp@hotmail.com>
>
> >...I was totally unaware that a mold existed until last night 
> >when it was suggested to me from a person on the board.  sounds like a 
> >good thing.
>
> Another good thing is to read several books on ATM'ing.  You will find 
> some of them mention pitch lap molds.  If your local library has back 
> issues of Sky and Telescope magazine...they are worth reading for ATM 
> articles...even back to the 1950's.
>
> one source of ATM books:  http://www.willbell.com
>
> ATM Books are often chock-full of useful info...gathered from 
> experience...and you can benefit from that...which I consider better than 
> reinventing wheel.  Also, books are usually reviewed for content and 
> accuracy...posts to lists such as this are not.  Be careful with all 
> the 'free' advice you get...it may be worth every penny!  ;-)
>
> I have never used a pitch lap mold...from 4 inches to 16 inches.  I do
not 
> channel with a bar or heated solder iron.  I channel with a sharp nail or 
> razor, holding the lap under running water, and then use a brass brush to 
> remove chips and freshen up the surface.  I also do not trim the edge of 
> the lap.
>
> I also measure my pitch hardness...which, sadly, few other ATM's do.  
> Measuring pitch hardness puts you in control of another process 
> variable...which is a good thing.
>
> See ATM archives:
> http://astro.umsystem.edu/atm/
>
> some examples:
> http://astro.umsystem.edu/atm/ARCHIVES/JUN99/msg00535.html
> http://astro.umsystem.edu/atm/ARCHIVES/MAY99/msg00569.html
> http://astro.umsystem.edu/atm/ARCHIVES/APR01/msg00493.html
>
> I hope this helps.
>
> Tom Krajci
> Tashkent, Uzbekistan
>
>
>