---------- Forwarded message ----------
From:
Jerry W
Date: Mon, Jun 3, 2013 at 10:20 AM
Subject: Mid course correction.
To:
Tim C, Dmitrii Z, Tom T, Tom W, Chuck M, Ed
K
People
It seems
another ATM "rule" needs to be discarded. Here's an
interesting quote from
Mel Bartels discussing the benefits of 1. Not
keeping the channels of a pitch lap open, 2. Not pressing and 3. Using
an oversize pitch lap, all to get a perfect mirror.
"...developed a new technique.
Many years ago, back in the age of over the air TV and phones with cords that connected to walls, I decided to teach that 12 inch mirror a lesson and furiously keep polishing despite the pitch lap's channels gradually closing in and the pitch lap expanding beyond its normal size.
You see I had partially burned off a tiny portion of my left eyebrow in a home chemistry experiment (I was in 6th grade at the time) that I conducted I never figured out if she was more curious about my eyebrow or about the smoke that had wafted upstairs.
So when I say that I raised my eyebrows at the mirror's surprising figure - you know I mean it - a perfect edge and ultra-smooth surface. From that day forward I never channeled a lap again and I always made over sized laps.
Being a student of history and a great admirer of elderly people with all their wisdom, I asked an old time pro optician about the oversized lap. I raised my eyebrows yet again when he didn't (where is Spock when I need him). It turns out that this was common knowledge - no big whoop (a phrase that ought to be making a comeback any day now thanks to the all-powerful and all giving INTERNET).
Researching further, I found that Brashear mentioned oversized laps as a standard technique in the late 1800's. You see, during that era, there was an explosion of pamphlets and small books on how to do things. Telescope making was a 'big deal' back then. Holcombe had formed the first USA telescope company in the early 1800's (to the surprise of leading European intellectuals who maintained that Americans were not up to the task), followed by Fitz and Clark which was followed by Brashear and others.
The reason that oversized laps were lost to amateur telescope making is because the ATM world fell into the trap of promoting glass tools as the same size as the mirrors.
Centuries ago, right after the adoption of the Keplerian telescope, astronomers stalled out because the images were upside down. They didn't know what to make of it and shied away. It took a younger generation of astronomers to declare that it didn't matter that the Moon was upside down in the telescope.
The same conceptual moat and lack of imagination exists today. Amateurs apparently cannot conceive of how an oversized lap would be made and how it would work. Maybe it is time to singe an eyebrow and get mad at a mirror that's not polishing out very quickly and 'get her done'.
Believe me, there is no secret and this is not new.
Mel Bartels [
http://www.bbastrodesigns.com/tm.html ]"
Very interesting, eh?
Jerry
W
Sent from my iPad
