| Date |
Hours |
Description |
| ALL |
91:00 |
Total Working Time |
|
|
|
| 11/22/07 |
2:00 |
Beveling & 80 grit hogging. |
| 11/24/07 |
4:00 |
Beveling & 80 grit hogging |
| 11/25/07 |
0:50 |
Beveling & 120 grit fine grinding (Bad Grit.
Left pits bigger than 120 grit. Need to get rid of it before using
again.) |
| 11/25/07 |
2:10 |
Beveling & 220 grit fine grinding |
| 11/26/07 |
1:30 |
220 grit fine grinding |
| 11/26/07 |
0:25 |
Beveling & 40 micron fine grinding
- It's coming out closer to f/4. It's a little faster than I
was planning, but I think I'll go with it at this point. |
| 11/30/07 |
1:15 |
40 micron fine grinding |
| 11/30/07 |
1:20 |
25 micron fine grinding - Almost finished fine
grinding! |
| 12/01/07 |
1:15 |
12 micron fine grinding - Sooo Close! |
| 12/01/07 |
1:30 |
5 micron fine grinding All done fine
grinding! Now to make a pitch lap and start with polishing! |
| 12/08/07 |
6:00 |
Mirror Class 3 - My first! - (Polishing
Lecture) - Started off with a quick test by John Martin of the focal
length. Turns out we were off by a power of two on the calculations,
and I've actually got an f/2 instead of an f/4 mirror. That's way
too fast for me, so I think I'll try to bring it back to the f/6 range I
was originally planning.
Started out grinding, then stopped for the polishing lecture, then back to
grinding.
Stopped part way through the day to make my patch lap. I'm using the
same tool that Samantha used on her 4-1/4" mirror, but the pitch has
been removed, and it's ready to pour a fresh coat. The tools ready
to go, and just waiting for fine grinding to finish again. |
| 12/9/07 |
1:30 |
220 grit fine grinding |
| 12/10/07 |
2:45 |
220 grit fine grinding |
| 12/14/07 |
2:15 |
120 grit fine grinding |
| 12/16/07 |
3:00 |
120/220 grit fine grinding - Finally back to
where I'm happy with it, although it took a while. It's looking more
like it's about an f/7.5, but that's ok. A little easier to get
magnification with a bigger eyepiece, and a good contrast to Samantha's
f/3.88. About half way through with the 220 grit. That should
finish up quickly. |
| 12/17/07 |
1:30 |
220 grit/40 micron fine grinding - done with 40
micron |
| 12/19/07 |
1:00 |
25 micron fine grinding |
| 12/20/07 |
1:30 |
12 micron/5 micron fine grinding - All done fine
grinding! (Again!) |
| 12/27/07 |
1:30 |
Polishing |
| 12/29/07 |
2:00 |
Polishing |
| 1/2/08 |
2:00 |
Polishing |
| 1/4/08 |
1:15 |
Polishing - It's all polished out. I'll
find out from Dave Kelly on Sunday how it looks. |
| 1/6/08 |
6:00 |
Mirror Class 4 (Figuring Lecture) - Started out
warming and pressing, then attended the figuring lecture.
Afterwards, had Dave Kelly test my mirror, and he said that it's polished
out well, but has a very deep zone in the center. A super deep
hyperbola. Focal length difference was about .75" to .8",
so it's extremely deep. (Total correction for my mirror should be
about .020".) Dave suggested pressing a small piece of paper
between the mirror and the lap, so that the center of the lap was lower,
and would allow for polishing in the outer zones, without continuing to
push down the center. Polished this way through the day, and had
brought it back to around .675". Homework is to get rid of the
hole. |
| 1/19/08 |
1:30 |
Polishing - Changed from a piece of paper to a
piece of overhead transparency shaped like a circle, about 2/3 the
diameter of the mirror. This will help as the paper keeps
deteriorating. - Still ~ .600" to go. |
| 1/20/08 |
1:30 |
Polishing & Testing for spherical - Still ~
.525" to go. |
| 1/25/08 |
2:00 |
Polishing & Testing for spherical - Still ~
.450" to go. |
| 2/1/08 |
3:00 |
Polishing & Testing for spherical - Still ~
.350" to go. |
| 2/2/08 |
1:30 |
Polishing & Testing for spherical - Still ~
.275" to go. |
| 2/4/08 |
2:45 |
Polishing & Testing for spherical - Still ~
.150" to go. |
| 2/8/08 |
3:15 |
Polishing & Testing for spherical - getting
spherical, but with an odd figure. Will talk to Dave about this
tomorrow. |
| 2/9/08 |
6:00 |
Mirror Class 5 (Testing Lecture) - Pressed
while attending the lecture. Afterwards, had Dave Kelly test my
mirror, and he said that it's looking much, much better, but has a raised
ring around the outer zones. He suggested taking the transparency
circle, and trimming it like a star, and continue with the pressing using
it. Polished this way for a while, and by the end of the day, Dave
said that I had improved a lot. Homework is to continue doing this,
until the zone is gone, then do center over center to smooth everything
back out. |
| 2/16/08 |
2:30 |
Polishing & Testing for spherical |
| 2/17/08 |
1:30 |
Polishing & Testing for spherical |
| 2/22/08 |
3:00 |
Polishing & Testing for spherical |
| 2/23/08 |
1:45 |
Polishing & Testing for spherical |
| 2/28/08 |
1:30 |
Polishing & Testing for spherical |
| 3/8/08 |
1:30 |
Mirror Class 6 (Constructing a Telescope
Lecture) - Missed this class due to freezing rain, but decided to work on
my scope a little anyway. - Polishing & Testing for spherical |
| 3/22/08 |
1:45 |
Polishing & Testing for spherical |
| 4/5/08 |
6:00 |
Mirror Class 7 (Final Class) - Pressed for a
while, then had Dave Kelly test to see how things looked. He was
very impressed with the improvement of the mirror, but said that it still
has a touch of a turned down edge, left over from the outer raised
ring. Keep pressing with the star, don't worry about the center
raising up, and polish the edge out before doing anything else. By
the end of class, it was looking much better, but the TDE was still
slightly there. I am getting a central hill like Dave had mentioned, but
will ignore it for now. Homework - Finish working out the edge, then
attack the central hill with a 1/3 to 1/2 Center over Center stroke.
Call him when finished, and he'll bring his tester to the next Stellafane
meeting, and check it out. |
| 4/14/08 |
2:00 |
Polishing & Testing the TDE. It's
almost gone. Another couple hours, and I should have a good edge
again. |
