Re: [ATM] Ronchi interpretation and corrective action for high zoneatedge

["Polk, Tom" <TPolk@decatur-al.gov>]

-----Original Message-----
From: Jerry [mailto:wa4guu@verizon.net] 


>>SNIP<<
As for the corrective action, just wait until the mirror is fully
polished
and then you will (should) go to shorter work sessions for figuring. The
shorter work session might straighten it out some. 5 to 10 minute
sessions
will not heat the work as much as long polishing sessions. I am assuming
that your polishing sessions are longer than that by a large margin.

REPLY: Using a laser pointer, the surface is fully polished except an
area ~2.0 diameter at the center. This area follows closely behind.

Last night the polishing sessions were:
15 minutes TOT; hand pressure and stroke as described by Mike Lockwood
site (great information, thanks!).
15 min MOM; hand pressure and stroke as described by Mike Lockwood site
*Cold Press* 45 minutes
Repeat the above set twice (one hour polish time).
*Cold Press* 1 hour
Repeat first set twice (one hour polish time).

This morning's Ronchigram (both outside focus, 133 lpi):
4-04-06:
http://www.atmlist.net/contrib/tpolk-at-decatur-al-dot-gov/Tom%20Polk/04
-04-06/Outside%20Focus%201.jpg

Compared to previous session:
4-02-06:
http://www.atmlist.net/contrib/tpolk-at-decatur-al-dot-gov/Tom%20Polk/04
-02-06/outside%20focus%201%20GS%20.jpg

Looks like progress to me (right? ;-).

Are my polishing sessions to long? 
Can I go longer between cold presses? 

>>SNIP<<
>>What are you using as a base for the lap? 
Dental Stone. My old grinding tool.
>>How thick and heavy is it?
~1.5", approx 10lbs.
>>I saw your last post about 28 pounds of weight on the center of the
lap.
>>I have never worried about uneven hand pressure except to try not to
do it >>by accident. The extra weight might be fine for polishing but
for figuring >>it could be too much weight.
Thanks, since I'm close to fully polished, the weights are gone.

Thanks for all the help!





_______________________________________________
ATM mailing list http://www.atmlist.net/