From: "Russell Jocoy" 
To: bader{at}hydroblendinc.com, greg.emery{at}mohawkcollege.ca
Cc: atm{at}shore.net
Reply-To: "Russell Jocoy" 


>From: Byron Ader 
>To: 'Russell Jocoy' , greg.emery{at}mohawkcollege.ca
>CC: atm{at}shore.net
>Subject: RE: ATM Figuring problems
>Date: Wed, 23 Jul 2003 08:58:08 -0600
>
>Thanks Russell, I will give it a go.  Figuring .. a term used only in the
>application of creating a parabolic center on the mirror, correct?  I
>definitely need to do more homework.  One thing is for sure, I am glad that
>I was advised to start with a small mirror before tackling anything big!!
>


("atm{at}shore.net")

  Byron,     I think you said you were working on an 8" disc,..am I wrong?
This size mirror is not small
by any standards. If figured correctly and done well it would exceed most
10" commercial brand
mirrors...   Just think get this one right then move on to a 12"!!!!! Keep
polishing and looking at your
surface, (often..don"t forget cool down time) you will see the surface
change before your eyes.
   Just remember that when figuring not to over shoot your parab..   It is
better to figure in short sessions
and check your progress than to try to get to the destination all at once,
you might pass up the exit
you need to get off on and have to go back...

Russ Jocoy
("atm{at}shore.net")
>-----Original Message-----
>From: Russell Jocoy [mailto:russjocoy{at}hotmail.com]
>Sent: Tuesday, July 22, 2003 6:29 PM
>To: greg.emery{at}mohawkcollege.ca; bader{at}hydroblendinc.com
>Cc: atm{at}shore.net
>Subject: Re: ATM Figuring problems
>
>
> >From: Emery Greg 
> >Reply-To: Emery Greg 
> >To: Byron Ader 
> >CC: atm{at}shore.net
> >Subject: Re: ATM Figuring problems
> >Date: Mon, 21 Jul 2003 19:56:51 -0400
> >
> >
> >Hi Byron:
> >
> >I had a look at the sketches.  I'm not very experienced with looking at
>the
> >doughnut shadows.  I have no experience with an f/4.
> >
> >  My initial guess ( and that may unfortunately be the accuracy of it all
>)
> >is that there is a central hill ( you said the knife was from the left,
> >correct?).  The outside shadows at least look to be in the right areas.
> >You really should make a Coude Mask (4 zones or so) and collect the data
> >that way.  You can then analyze the data and have a more reliable
>estimate
> >of the mirror surface.
> >
> >Personally, I would do the Coude mask and analyze the data before I
>touched
> >the mirror again.  You can read about zonal testing in ATM 1, ATM 2 and
> >Texereau.
> >
> >Anyone shed more light on this than I can (sorry for the bad pun)?
> >
> >ttfn
> >greg
> >
> >----- Original Message -----
> >From: Byron Ader 
> >Date: Monday, July 21, 2003 5:53 pm
> >Subject: ATM Figuring problems
> >
> > >
> > > I just wanted to confirm my test results, I would hate to move
> > > forward an
> > > increase my problems.  Has anyone had a chance to review the
> > > results of my
> > > Focault test at www.astrothuse.com ?  If you had any feedback, I would
> > > appreciate it.
> > >
> > > Thanks,
> > > Byron
> > >
> > >
> >
>
>
>
>("atm{at}shore.net")
>
>     I had  the same image in my Ronchi tests very close to ROC. I think
>you
>need to polish more  and
>test after  sessions to see changes. Don't think that you are in the
>figuring stage when you are going
>towards a sphere. If you have a raised or depressed center you have not
>completed your task of creating
>a sphereical surface. There is information on the net and in books on how
>to
>get there from where you
>are but most say , get the sphere and then figure... I would suggest to
>polish more on your regular
>stroke and rotate as before until the surface changes, if it doesn't than I
>would check your lap for
>closed gaps or irregular contact to the mirror's surface. Ain"t no big deal
>the images you see through
>your tester are just telling you the micro surface images, These can be
>fixed and harmony of reflection
>restored!! Keep polishing and look at the mirrors surface to see changes,
>because it will.... Check your lap
>give it some micro-fauceting (sp)...
>       Russ Jocoy
>("atm{at}shore.net")
> >
>
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