Re: [ATM] Mirror cell ramblings re: thin plate glass3/4-inchx24-inch

["Bill Wheaton" <junkwheaton@gmail.com>]

I find your stuff on ATMPage.org fascinating, inspiring and useful,
Davey.  You should post it there with your other stuff.  Be careful though
-- you may give "Okies" something to live up to :)

-Bill


On 5/30/08, David Harbour <stainless_steel@suddenlink.net> wrote:
>
> Bob, Dale, and all:
>
> I briefly, quickly searched my archives of articles and found my article,
> with four hand drawn (very well, I should tell you) of my "Giant Measuring
> Engine" for mirror testing. There are four very clear illustrations in it.
> Now: what does this have to do with the current thread?
>
> Just this: mirror and tester were always connected with 4,500 lbs of
> masonry
> walls, on which were the rails for the testing table trolley. The distance
> between the mirror, and the test set up (whether Foucault or Caustic- I
> eschew interferomtry, being from the old school, and believe Irwin
> Schroeder
> when he says one can measure accurately enough with caustic, that after
> reducing the data with the formulae, one can easily come up with an
> accurately inferred wavefront of up to one fiftieth of a wave)- however, I
> am thinking of you guys- this "optical bench" would not allow the distance
> between mirror and test set up to change. If I am not mistaken, that is
> what
> your debate is about.
>
> The "guide rail" for the trolley was arrow straight, and perfectly round;
> it
> had to meet these criteria to do what it originally did: go up and down
> through a sleeve, or sleeves, to suck oil out of the earth. That is why
> they
> call it "sucker rod"- I used it for the kinematically arranged
> bearing/wheels for the guide rail, and it performed beautifully. They
> trolley would not "run out" laterally, by even a thousandth of an inch.
> "Sucker Rod" (was- probably still is) available in diameters between one
> and
> three quarters up to 2 and three quarters of an inch in diameter, and was
> only pennies per foot. Almost as hard as diamonds; will make the older
> machinists curse when they try to part and face it.
>
> If stacking up (no mortar is necessary) about 140 concrete blocks frightens
> you, intimidates you, then don't ask for the article. A cheapie plastic
> level, 48" length, and some stuff to shim the blocks with (a big jar of
> coins is handy) made the jop delightfully easy. Of course, a garage or a
> basement is handy. When you get ready to move up into that dream house, or
> down into that pup tent, because of the coming great depression, it is very
> easy to just take the blocks apart. They are not glued together.
>
> You are wondering: "All that sand!!!! He must have scratched a lot of
> mirrors!!!! As I told you all, individually and severally, before, I NEVER,
> EVER, scratched a mirror that I ground, (or polished) after my first eight
> inch. I've already conveyed to you the secret of how to keep sand from
> getting between tool and mirror, and it goes for concrete blocks. Leave the
> loosely bonded sand lying where it is; do not caress the blocks with your
> hands, while working a mirror. Gravity will keep the loser surface sand
> pieces where they are. And, with the design of the bench, they are way
> below
> the level of the trolley, which rides on guide/outrigger, well above the
> top
> of the block walls.
>
> Ask for the article. It is an HTML email, illustrated, and all I have to do
> is forward it. Kind of a miracle, that I have it on the new machine; three
> previous machines I had melted down, that that article was on. But I back
> up
> my files.
>
> "FORTUNE FAVORS THE BOLD"
> (and the innovators)
>
> R-101/
> Col. Vincent Richmond/
> Davey/
>
>
> ----- Original Message -----
> From: "Bob May" <rmay@nethere.com>
> To: <atm@atmlist.net>
> Sent: Thursday, May 29, 2008 3:55 PM
> Subject: Re: [ATM] Mirror cell ramblings re: thin plate
> glass3/4-inchx24-inch
>
>
> >I have trouble doing the Foucault test on benches and
> > interfrometry is even worse for vibrations.
> > Then again, if the seperate parts are sturdy enough, you can get
> > away with it.  I also note that you mention using fast shutter
> > speeds to get the vibrations out of the interfrograms tho so you
> > do have some problem with vibrations.  It does help tho to have
> > nobody walking about vibrating the floor.
> > Bob May
> >
> > rmay at nethere.com
> > http: slash /nav.to slash bobmay
> > http: slash /bobmay dot astronomy.net
> >
> > ----- Original Message -----
> > From: Dale Eason <atmpob@yahoo.com>
> > To: <atm@atmlist.net>
> > Sent: Wednesday, May 28, 2008 2:33 PM
> > Subject: Re: [ATM] Mirror cell ramblings re: thin plate
> > glass3/4-inchx24-inch
> >
> >
> >> Sorry Bob but I have to take exception to that
> >> generalized statment.  I use two tables and it works
> >> very well. Actually a table and a tripod.  I have also
> >> taken Igrams on the second floor of a building and was
> >> successful because I used a fast shutter to stop the
> >> vibration.
> >>
> >> However air current induced see is much more of a
> >> problem but that is taken care of by averaging many
> >> analysis sets.
> >>
> >> There are usually ways to address all of the issues.
> >>
> >>
> >> Dale Eason
> >>
> >> --- Bob May <rmay@nethere.com> wrote:
> >>
> >> >  I'll also note that
> >> > you do need to
> >> > have a stable support for the system - no doing the
> >> > work with the
> >> > interfrometer on one table and the mirror on another
> >> > table.
> >>
> >>
> >>
> >>
> >> _______________________________________________
> >> ATM mailing list http://www.atmlist.net/
> >>
> >
> > _______________________________________________
> > ATM mailing list http://www.atmlist.net/
> >
>
>
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