Mirror Making Log
Randolph Center Sky Clock -


Here's a log of the time I put into making my mirror.
 - Samantha 

Now, if while working 47.0 hours, I'd been paid $10/hour, the mirror's value would be $470.00. :-)

Date Hours Description
ALL 47.0 Total Working Time
5/19/07 0.5 Mirror Class #8 - Let the mirror temperature equalize to the room, and then Dave K. tested it.  Viola!  A PARABOLA!!!
4/14/07 2.0 Mirror Class #7 - Fletcher House, Chester - After the Foucault Testing lecture, I had Phil test the mirror, and worked with him to do a little figuring today.  Unfortunately, the tester wasn't quite set up as well as Dave K normally can set it up when it's at the McGregor, so Phil didn't want to say for sure, but was leaning toward call it finished, when we got done.  
Post Class Assignment:  Don't Touch It!!!!
3/17/07 -- Mirror Class #6 - Cancelled - Snow
2/17/07 -- Mirror Class #5 - Cancelled - Snow
1/21/07 2.0 Mirror Class #4 - Figuring - Stared out with the Figuring basics lecture.  Then after having my polish and sphere checked, I started doing some figuring today.  Lots and lots of hurry up and wait time, as it only takes 2-3 minutes for a couple passes around the mirror, and then wait for a while for a turn at the tester.  It did allow for some fun time talking with others, and seeing what and how they are doing.  By the end of class, Dave was saying, "It's getting very, very close.  Probably next class."
Post Class Assignment:  Don't Touch It!!!!
1/15/07 1.0 Homework - Figuring - Set up the Stellafane tester, and checked the figure.  Overall, it looks very good.  A nice flat surface that 'blinks' all at once.  A nice sphere!
1/13/07 1.5 Homework - Polishing - A little extra polishing to ensure that it's well polished and spherical.
1/7/07 1.0 Homework - Polishing - All polished out!  Clean all the way to the edge.
1/7/07 4.0 Special Project - Today we built our own Grinding/Polishing bench.  It came out really well, and is very sturdy.  :-)  Will work well for polishing out my mirror.
12/28/06 1.5 Homework - Polishing - Getting closer.  About 0.25" from the edge.
12/16/06 6.0 Mirror Class #3 - Polishing - Set up at the McGregor, and then went down to the bunkhouse for the polishing lecture.  Then, back up at the McGregor for the day to do some polishing.  Everyone was impressed with my pitch lap, as we used the 'official' Dave Kelly diamond shaped channels, instead of the standard square channeling.  It's getting very close to being polished out, as the laser shows no reflection up to about 0.5" from the edge.
12/11/06 2.0 Homework - Polishing Tool - De-pitched the tool, and discarded the burgundy pitch.  Jay had given us some extra Gugolz 64, just in case at the last class, so we re-poured using that.  Turned out to be a great success.  New possession, a nice looking pitch lap.
11/26/06 2.0 Homework - Polishing Tool - Poured the burgundy pitch that came with the kit today.  Not sure if it was bad pitch, or if we got it too hot, but it really went poorly.  Way too mushy and ran down over the sides of the tool.  Too thin to use on top, now, so we'll have to re-pour.  Another good 'learning experience. :-)
11/23/06 0.5 Homework - Polishing Tool - Applied Epoxy to the outside of the plaster for waterproofing and strength.  Even though it's 5 minute epoxy, we'll let it sit overnight to dry.
11/15/06 2.0 Homework - Polishing Tool - Have more plaster.  Time for trial #2.  Much better this time, using lessons learned from trial #1. 
11/12/06 1.0 Attempted creation of a polishing tool.  Found that we weren't fast enough in mixing the plaster, and it clumped up before we had it mixed and poured, so we're chucking that one up to a 'learning experience'.  Will have to pick up more plaster before trying again.
11/11/06 6.0 Mirror Class #2 - Fine Grinding - Set up in the newly renovated 'enclosed' porch to grind.  Worked through 12 micron grit and 9 micron and 5 micron.  Ready to polish! :-)
11/8/06 1.5 Homework - Fine Grinding - Completed 25 micron grit
11/4/06 1.5 Homework - Fine Grinding - Completed 40 micron grit
10/27/06 1.5 Homework - Fine Grinding - Completed 220 grit.
10/25/06 1.5 Homework - Fine Grinding - Completed 120 grit.
10/22/06 2.0 Homework - Fine Grinding - Completed 80 grit..
10/21/06 6.0 Mirror Class #1 - Edge Beveling and Rough Grinding - First worked on edge beveling.  Then we had our grinding lecture today, then right into the 80 grit.  By the end of the day it was already at depth!  Looks like it's going to be a 4.25" f/4.25 mirror.  The f/4.25 might change a bit, as polishing goes on, but should be fairly close.




(c) 2007 by the Randolph Center Stargazers
Site was last updated on: 12/01/2007