TRO_30inch_figuring_log

 Knife edge readings for the following notes can be seen here: [|TRO+30inch+F4_remake_R2.00.xls]

Note that readings have not been taken for all figuring sessions. time__** || **__Total time__** || **__Date__** ||
 * **__Figuring work done__** || **__Work
 * Center 20 inches figured using an 11 inch star lap. The lap was too hard and caused a rough surface on the mirror. The pitch was removed and replaced with a medium new pitch with a less pronounced star pattern. || 75 mins || counted as 0 mins || 11/06/08 ||
 * 11 inch star lap. Full stroke with 2 inch overhang slightly off center || 50 mins || 50 mins || 29/06/08 ||
 * Central zone worked. slightly off center and keeping 3 inches from the edge || 45 mins || 95 mins || 29/06/08 ||
 * 11 inch star lap. Full stroke with 2 inch overhang slightly off center. See image [|TRO_30inch_figuring_140mins_a.jpg] || 45 mins || 140 mins || 29/06/08 ||
 * 19:19 to 19:34 - Dave Thomson did 15 minute session using the motorised turntable and moving the 11 inch star lap across the mirror, slightly off-centre, with an overhang of about2 inches. 15 minutes tonight.

19:35 to 19:46 - Geoff Regan did another 10 minutes using a similar full diameter stroke, slightly off-centre, with about a 2 inch overhang. 10 + 15 = 25 minutes tonight.

19:47 to 1952 - Geoff Regan did 5 minutes, slightly off-centre, with about a 4 inch overhang. 5 + 25 = 30 minutes tonight.

19:52 to 19:57 - Geoff Regan did 5 minutes, slightly off-centre, with a 2 inch overhang. 5 + 30 = 35 minutes tonight.

20:00 to 20:10 - Dave Owen did 10 minutes, slightly off-centre, with an overhang of about -2 inches, i.e., not polishing the edge of the mirror. 10 + 35 = 45 minutes tonight.

20:15 to 20:25 - Dave Thomson did 10 minutes. Sorry Dave, I have no note of what work pattern you used for this 10 minute session. 10 + 45 = 55 minutes tonight.

20:35 - Mirror rinsed and dried, for Rhonchi/Foucault testing.

20:51 - Mirror adjusted in strap. "Rhonchi lines less astigmatic" - Dave Thomson.

Mirror was then rotated about 45 degrees. "Still has astigmatic Rhonchi pattern but not as bad as before" - Dave Thomson/Geoff Regan/Dave Owen.

Mirror was then rinsed with bottled water, from supermarket.

21:24 to 21:30 - Geoff Regan did 6 minutes polishing, 4 inches off-centre, with -3 inch overhang. 6 +55 = 61 minutes tonight.

21:30 to 21:34 - Geoff Regan did 4 minutes polishing, 4 inches off-centre, with 2 inch overhang. 4 + 61 = 65 minutes tonight.

21:35 to 21:43 - Geoff Regan did 9 minutes polishing, 4 inches off-centre, with -3 inch overhang. 9 + 65 = 74 minutes tonight.

21:43 to 21:47 - Geoff Regan did 4 minutes polishing, 2 inches off-centre, with 2 inch overhang. Mirror rotated about 45 degrees. Mirror was usually rotated at the end of each session, when the timer stopped the turntable. 4 + 74 =78 minutes tonight.

21:47 to 21:53 - Geoff Regan did 6 minutes polishing, 5 inches off-centre, with -3 inch overhang. 6 + 78 = 84 minutes tonight.

21:53 to 22:00 - Geoff Regan did 7 minutes polishing, 2 inches off-centre, with 2 inch overhang. 7 + 84 =91 minutes tonight.

22:01 to 22:15 - Dave Thomson did 14 minutes polishing, 5 inches off-centre, 2 inch overhang. 14 + 91 = 105 minutes tonight.

22:03 - Temperature 20.5 degees centigrade inside the garage and 17.5 degrees outside. Door kept partly open to reduce temperature difference between inside and outside.

22:16 to 22:26 - Dave Owen did 10 minutes polishing, 4 inches off-centre, with 2 inch overhang. 10 + 105 = 115 minutes tonight.

22:26 to 22:31 - Dave Owen did 5 minutes polishing, 10 inches off-centre, with 2 inch overhang. 5 + 115 = 120 minutes tonight.

22:32 to 22:37 - Dave Thomson did 5 minutes polishing, 5 inches off-centre, with 2 inch overhang. 5 + 120 = 125 minutes tonight.

Mirror was then tested in telescope. Lack of proper collimation was a problem but mirror did seem slightly better than before tonights session.

See image [|TRO_30inch_figuring_265mins_a.jpg] || 125 mins || 265 mins || 01/07/08 ||
 * Tue 8 Jul 2008 – TRO II Figuring Notes

19:20 - Arrived at Dave Thomson’s with Geoff Regan and Dave Robinson. Dave Thomson had already done 20 minutes polishing with 11 inch star lap, 3 inches off-centre. Machine turntable used for all polishing sessions tonight.

19:18 – 19:28 - Dave Thomson did 10 minutes polishing using chordal stroke, about 8 to 10 inches off-centre. “Lap skipping” (Dave Thomson). 30 minutes polishing tonight.

When lap was lifted from mirror it was noticed that the micro facets had mostly closed up, but not in a completely uniform way.

19:29 - Dave Thomson started to re-cut the micro facets with a Stanley blade.

19:38 – 19:48 - Geoff Regan started polishing 30 inch f4 mirror using diametrical stroke, 3 inches off-centre with a -4 inch overhang, to concentrate the figuring action in the centre of the mirror. “Lap not skipping” (Geoff Regan). 10 + 30 = 40 minutes polishing tonight.

19:49:36 - Mirror spun about 20 degrees.

19:49 – 19:56 - Geoff Regan using diametrical stroke about 2 inches off-centre with 2 inch overhang. 7+ 40 = 47 minutes polishing tonight.

19:57 – 20:13 - Geoff Regan continued with diametrical stroke about 2 inches off-centre with 2 inch overhang. Three micron cerium oxide, mixed with water, used so far. 16 + 47 = 63 minutes polishing tonight.

When mirror was put on test stand, with thinner strap, Rhonchi lines looked twisted. The lines seemed less twisted when a 1 inch thick strap was used to support the edge of the mirror.

21:52 – 21:58 - Dave Thomson started polishing with BM 304/water (average particle size of 7 microns). At this point Dave Thomson confessed that he had not been shaking the cerium oxide/water bottle before applying this mixture to the mirror! Therefore, we had been polishing with too thin a mixture? Diametrical stroke about 2 inches off-centre with 2 inch overhang. “Lap not skipping now” (Dave Thomson). 6 + 63 = 69 minutes polishing tonight. Mirror was then spun about 20 degrees.

21:58 – 22:04 – Dave Thomson continued with diametrical stroke about 2 inches off-centre with a 2 inch overhang. 6 + 69 = 75 minutes polishing tonight. Mirror was then spun about 20 degrees.

22:06 – 22:12 – Geoff Regan used diametrical stroke about 5 inches off-centre with 2 inch overhang. Mirror was then spun about 20 degrees. 6 + 75 = 81 minutes polishing tonight. 22:12 – 22:18 – Geoff Regan used diametrical stroke about 2 inches off-centre with a 2 inch overhang. “Lap not skipping” (Geoff Regan). It was noted that, with the BM304/water mixture, both Geoff Regan and Dave Thomson were able to move the lap across the mirror much more quickly, without skipping, than with the 3 micron cerium oxide/water mixture. 6 + 81 = 87 minutes polishing tonight. Mirror now to be Couder mask tested.

22:27 – Rhonchi lines not as twisted as before.

22:37 – 22:42 – Dave Thomson used diametrical stroke about 4 inches off-centre with a 2 inch overhang. “Lap contact still good” (Dave Thomson). Mirror was then spun about 20 degrees. 5 + 87 = 92 minutes polishing tonight.

22:43 – 22:48 – Dave Thomson tried to polish the crest of the high zone near the 50 per cent radius using a chordal stroke with a 2 inch overhang. 5 + 92 = 97 minutes polishing tonight.

22:49 – 22:54 – Geoff Regan used diametrical stroke about 2 inches off-centre with a 2 inch overhang. 5 + 97 = 102 minutes polishing tonight.

22:55 – 23:01 Geoff Regan tried to polish the crest of the high zone near the 50 per cent radius using a chordal stroke with a 2 inch overhang and some increased pressure on the left hand side of the lap, i.e., the side that was closest to the centre of the mirror. 6 + 102 = 108 minutes polishing tonight. Time for a Couder mask test. || 108 mins || 373 mins || 08/07/08 ||
 * We had not done any figuring work since July due to teh warm weather. The temperature in the garage was now quite stable and around 17 degrees. We used the 11 inch star lap and concentrated around the middle of teh mirror. 3 inches from teh edge. The results of which can be seen in the image taken by Dave Robinson below. Knife edge readings are yet to be taken to see how much actula work has been done.

Most work was slightly off centre using striaght strokes with not too much pressure. 10 minutes of edge to edge work (2 inch overhang) was done to blend.

19:15 - Arrived at Dave Thomson's with Geoff Regan and Dave Robinson. Lots of preparatory work to resume figuring TRO II 30 inch f4 mirror. First session since 8 Jul 2008; cutting carpet, hot soaking pitch lap etc.

21:35 - Still need another 15 minutes of lap lying on mirror, with intermittant hand pressure, before figuring can start.

21:43:30 - DT doing centre over centre work with 11 inch star lap. Overhang = about -3 inches, staying away from the edge of the mirror. Centre of lap kept about 2 inches off centre. Slight down force used, "finger pressure only".

21:54:22 - Motorized turntable stopped. Mirror spun about 20 degrees anti-clockwise. Turntable is moving in clockwise direction.

21:55:16 - GR doing centre over centre but actually about 3 inches off centre. Overhang = about -3 inches. Mirror turned about 20 degrees anti-clockwise at the end of each of the 8 10 minute sessions tonight.

22:01 - Temperature = 18 degrees inside garage and 15 degrees outside.

22:07:24 - DT COC, slightly off centre, with -3 inch overhang.

22:29 - End of DO 10 minute figuring session, COC about 2 inches off centre with -3 inch overhang.

22:30:28 - DR COC, about 4 inches off centre with -3 inch overhang.

22:42:25 - GR COC, about 2 inches off centre with -3 inch overhang.

22:53:30 - GR COC, about 2 inches off centre with -3 inch overhang.

23:17 - End of last 10 minute session by GR. 6 minutes of W strokes and 4 minutes of COC, about 2 inches off centre with -3 inch overhang.

Mirror sponged off with tap water, then bottled water, then dried with kitchen roll.

23:23 - Mirror back on test stand. Rhonchi test shows that 80 minutes figuring has dug hole in middle of the mirror. Couder mask measurements, tomorrow, should show how deep this hole is.

Above image to the left on the figuring page was after 453 minutes of figuring: TRO_30inch_figuring_453mins_a.jpg. It was taken only a short time (20 mins maybe) after coming off the lap.

The image to the right of it (TRO_30inch_figuring_453mins_b.jpg) was taken 2 days later after NO more figuring was done.

The differerence is clear to be seen. It appears that the amount of work done is less. In fact, we think that the glass has re-bounded over time. Exactly how long is not sure.

[|TRO_30inch_figuring_453mins_a.jpg] [|TRO_30inch_figuring_453mins_b.jpg] || 80 mins || 453 mins || 14/10/08 ||
 * Varied work. Some long strokes slightly off centre and some at te 50% zone. One 10 minute session tagental to the edge with the centre of the lap positioned 3 inches in from the edge. Ian Baker and myself.

When put on the test stand, we had problems with the Ronchi lines being very bent (S shapped) in the middle. This reduced over time and appeared to reduce when settled in the support.

Temperature and support appeared to be the problem. || 80 mins || 533 mins || 16/10/08 ||
 * Wide W stroke for 10 mins. Edge work with the tool centered 2 inches from the edge with indside hand pressure 10 minutes. 50% zone work 20 mins and the rest long strokes slightly off center.

The edge looks slightly better. More noticeable visualy rather than on the image [|TRO_30inch_figuring_583mins_a.jpg].

The S shapped Ronchi lines where not visible.this time when put onto the test stand!!

After leaving the mirror overnight it did settle a little but not by much. See the spreadsheet for figuring work and image [|TRO_30inch_figuring_583mins_b.jpg] that was taken at the same time. || 50 mins || 583 mins || 17/10/08 ||
 * The mirror is slowly beginning to repsond. The edge is getting better too.[|TRO_30inch_figuring_819mins_b.jpg]

The same types of stoke have been used. Center edge to edge, 20%, 50% and some edge work. The figure is slowely moving out towards the edge.

The back of the mirror must be DRY before being put on the test stand. This, along with torque induced stress from lifting the mirror on the strap, are causing the bending of the Ronchi lines. The bubble pack is 'sticking' the back of the mirror!!

Dave Owen notes:- TRO II FIGURING NOTES – SAT 18 OCT 2008

13:30 – Arrived at Dave Thomson’s with Geoff Regan and his son Christopher. Dave Robinson (b4 14:30), Lew Brown (about 16:00) Ian Baker (about 16:30), arrived later in the afternoon. DT had already done 70 minutes figuring work before we arrived.

14:39 – 3 micron cerium oxide/water put on 30 inch f4 mirror.

14:41:18 – GR doing chordal stroke, about 2 inches off centre with 2 inch overhang for 10 minutes.Mirror spun about 20 degrees anti clockwise at the end of each 10 minute session today. Machine turntable turning clockwise. Session I total = 70 minutes. Session II total = 10 minutes.

15:09 – End of DO 10 minutes session using chordal stroke, 2 inches off centre with 2 inch overhang. Session I total = 70 minutes. Session II total = 20 minutes.

15:11:20 – GR doing chordal stroke, about 2 inches off centre with 2 inch overhang. 15:12:40 - GR doing chordal stroke, about 6 inches off centre with 2 inch overhang. 15:22:18 – End of GR 10 minute session. Session I total = 70 minutes. Session II total = 30 minutes.

15:25:35 – DR doing chordal stroke, about 6 inches off centre with 2 inch overhang. 15:36:02 – End of DR 10 minute session. Session I total = 70 minutes. Session II total = 40 minutes.

15:36:50 – DT doing chordal stroke, about 12? inches off centre, working edge of mirror. 15:49:12 – End of DT 10 minute session. Session I total = 70 minutes. Session II total = 50 minutes.

15:50:40 - DT doing chordal stroke, about 7.5 inches off centre with 2 inch overhang. 16:02 – End of DT 10 minute session. Session I total = 70 minutes. Session II total = 60 minutes.

16:16 – End of DO 10 minute session using chordal stroke, 2 inches off centre with 2 inch overhang. Session I total = 70 minutes. Session II total = 70 minutes.

16:18:17 - GR doing chordal stroke, about 5 inches off centre with 2 inch overhang. 16:27 – End of GR 10 minute session. Session I total = 70 minutes. Session II total = 80 minutes.

16:29 – Mirror sponged off with tap water then sprayed with bottled water then dried, front and back, with kitchen roll.

16:31 – Mirror put on test stand.

16:40 – Rhonchi lines twisted about 10 degrees in clockwise direction, possibly due to mirror being lifted in strap by bolt on left hand side of mirror?

17:16:48 - GR doing chordal stroke, about 5 inches off centre with 2 inch overhang. 17:27 – End of GR 10 minute session. Session I total = 70 minutes. Session II total = 80 minutes. Session III total = 10 minutes.

17:37 - End of DO 10 minute session using chordal stroke, 2 inches off centre with 2 inch overhang. Session I total = 70 minutes. Session II total = 80 minutes. Session III total = 20 minutes.

17:40:50 - GR doing chordal stroke, about 6 inches off centre with 2 inch overhang. 17:51 – End of GR 10 minute session. Session I total = 70 minutes. Session II total = 80 minutes. Session III total = 30 minutes.

18:06 - End of DO 10 minute session using chordal stroke, 3 inches off centre with 2 inch overhang. Session I total = 70 minutes. Session II total = 80 minutes. Session III total = 40 minutes.

18:09:08 - GR doing chordal stroke, about 6 inches off centre with 2 inch overhang. 18:18:58 – End of GR 10 minute session. Session I total = 70 minutes. Session II total = 80 minutes. Session III total = 50 minutes.

18:19:44 - DT doing chordal stroke, about 12? inches off centre, working edge of mirror. 18:22 - DT doing chordal stroke, about 16? inches off centre, working edge of mirror. 18:24 – DT doing “semi chordal stroke”, (video snippet taken), to work zone 3 inches in from edge with lap movement of +/- 6 inches. DT might be able to describe this beter than I can. 18:29:40 – 10 minute timer ping. Reset to 6 minutes. 18:30:10 - DT doing chordal stroke, about 3 inches off centre with 2 inch overhang. 18:36 – Stop. Session I total = 70 minutes. Session II total = 80 minutes. Session III total = 66 minutes.

18:37 - Mirror sponged off with tap water then sprayed with bottled water then dried, front and back, with kitchen roll.

18:41 – Mirror put back on test stand. DT will try Couder Mask measurements later tonight or tomorrow morning. || 236 mins || 819 mins || 18/10/08 || [|TRO_30inch_figuring_889mins_a.jpg] taken just after figuring [|TRO_30inch_figuring_889mins_b.jpg] taken the following morning with no more work done!
 * See images:-

20:00:34 – GR doing chordal stroke about 3 inches off centre with -3 inch overhang. Only applying finger pressure to the 11 inch star lap. We are worried about warping this very thin 30 inch plate glass mirror.

20:14 – Stop. Session time = 13 minutes.

20:14:43 – GR doing chordal stroke about 1 inch off centre with -3 inch overhang.

20:19:43 – GR doing ½ W stroke with -3 inch overhang. A W stroke that only goes from the edge to the centre of the mirror then back to the same edge, ignoring the table rotation of about 1 rpm.

20:24:35 – Stop. Mirror spun about 20 degrees anti clockwise at the end of each “10 minute session”. Session time = 13 + 10 = 23 minutes tonight.

20:38 – End of DO 10 minute session. 50% 0 inches off centre with -3 inch overhang and 50% 3 inches off centre with -3 inch overhang. Session time = 23 + 10 = 33 minutes tonight.

20:40:24 – GR doing ½ W stroke with -3 inch overhang.

20:46:00 - GR doing chordal stroke about 0 inches off centre with -3 inch overhang.

20:50:46 – Stop. Session time = 33 + 10 = 43 minutes tonight.

21:04:30 - End of DO 10 minute session. 50% 0 inches off centre with -3 inch overhang and 50% 3 inches off centre with -3 inch overhang. Session time = 43 + 10 = 53 minutes tonight.

21:06:18 - GR doing chordal stroke about 0 inches off centre with -3 inch overhang.

21:13:12 - GR doing ½ W stroke with -3 inch overhang.

21:18:30 – Stop. Session time = 53 + 12 = 65 minutes tonight.

21:19:23 - GR doing chordal stroke about 5 inches off centre with -3 inch overhang.

21:24:20 - GR doing chordal stroke about 3 inches off centre with -3 inch overhang.

21:29:30 – Stop. 65 + 10 = 75 minutes tonight. Mirror sponged off with tap water, then rinsed with bottled water and dried with kitchen roll. The back of the mirror was also dried with kitchen roll as we think that dampness may result in the mirror sticking to the bubblewrap on the test stand and inducing torsional stress that can be easily seen on the Rhonchi pattern as it can amount to about 5 to 10 degrees. This torsional stress can keep the same orientation, even when the mirror is rotated in the opposite direction.

21:36 – Mirror on test stand strap, supported by bubble wrap behind the mirror. Rhonchi lines twisted about 5 degrees clockwise. Mirror rotated about 10 degrees anti clockwise. Rhonchi lines still twisted about 5 degrees clockwise. We therefore concluded that this torsional strain was not actually an inherent property of the mirror but an artefact of the support system used in the test stand.

22:29 – Mirror put back on carpet for some more figuring.

22:32:11 - GR doing chordal stroke about 5 inches off centre with -3 inch overhang.

22:37:05 - GR doing ½ W stroke with -3 inch overhang.

22:41:56 – Stop. 75 + 10 = 85 minutes tonight.

22:42:18 - GR doing ½ W stroke with -3 inch overhang.

22:46:58 - GR doing chordal stroke about 0 inches off centre with -3 inch overhang.

22:48:10 - GR doing chordal stroke about 4 inches off centre with -3 inch overhang.

22:49:00 - GR doing chordal stroke about 2 inches off centre with -3 inch overhang.

22:51:58 – Stop. 85 + 9 = 94 minutes tonight.

22:52:46 - GR doing chordal stroke about 4 inches off centre with -3 inch overhang.

22:53:30 - GR doing chordal stroke about 4 inches off centre with -3 inch overhang but with rounded ends to each semi stroke. Video snippet, 40 seconds taken.

22:57:20 - GR doing chordal stroke about 0 inches off centre with -3 inch overhang.

23:01:40 - GR doing chordal stroke about 7 inches off centre with -3 inch overhang.

23:02:20 – Stop. 94 + 9 = 103 minutes tonight.

23:02:55 - GR doing ½ W stroke with -3 inch overhang.

23:10:50 - GR doing full W stroke with -3 inch overhang. WW.

23:12:40 – Stop. 103 + 9 = 112 minutes tonight.

No meaningful Couder Mask measurements can be taken until the mirror has reached thermal and isostatic equilibrium. At least 1 and maybe several hours? It does appear that this very thin mirror bends on the polishing table as we are pressing down with the lap. However, if we don’t apply some pressure than the lap might just skate over the glass and do very little polishing action?

Dave Owen Wed 22 Oct 21:55 || 70 mins || 889 mins || 21/10/08 ||
 * My notes for this session are as follows:

18:45 - Arrived at Dave Thomson's with Geoff Regan.

Had long discussion on why figuring is going so slowly. Tentative conclusion was that too much work was concentrated near the 70% zone. This is the radius that contains half the surface area of the mirror. Therefore, too much work here planes down the mirror too evenly!? Different tactics to be tried tonight - mainly a lot of W strokes.

19:50 - Ian Baker arrived.

19:54 - Dave Thhomson re-cutting microfacets on 8 inch star lap with Stanley Blade knife.

20:00 - Cerium Oxide/water mixture put on 30 inch f4 mirror.

20:02:14 - Geoff doing chordal stroke, about 2 inches off centre with -8 inch overhang.

20:11:50 - Stop. Mirror spun about 20 degrees anti-clockwise. 10 minutes figuring time tonight.

20:12:02 - Geoff doing chordal stroke, about 2 inches off centre with -8 inch overhang.

20:21:45 - Stop. Mirror spun about 20 degrees anti-clockwise. 10 + 10 = 20 minutes figuring time tonight.

20:23:36 - Ian doing W strokes with about 2 inch overhang. Slight downforce used, to overcome lateral drag. "Lap moving with even drag" IB.

20:35:23 - Stop. Mirror spun 20 degrees anti-clockwise. More Cerium Oxide/water mixture put on mirror. 10 + 20 = 30 minutes figuring time tonight.

20:36:24 - Ian doing W strokes with about 2 inch overhang.

20:47:02 - Stop. Mirror spun about 20 degrees anti-clockwise. 10 + 30 = 40 minutes figuring time tonight.

21:15 - End of Dave Owen 20 minute session, using W strokes with about 2 inch overhang. 20 + 40 = 60 minutes figuring time tonight.

21:16:36 - Dave Thomson doing W strokes with 2 inch overhang.

21:26 - Stop. End of DT 10 minute session. 10 + 60 = 70 minutes figuring time tonight. Mirror spun 20 degrees anti-clockwise.

21:30:15 - Geoff doing W strokes with 2 inch overhang.

21:40:30 - Stop. Mirror spun 20 degrees anti-clockwise. 10 + 70 = 80 minutes figuring time tonight.

21:41:15 - Geoff doing W strokes with 2 inch overhang.

21:51:01 - Stop. 10 + 80 = 90 minutes figuring time tonight. Mirror sponged off then dried with Kitchen Roll.

21:59 - Mirror put in strap on test stand. Rhonchi lines look less severe in first few minutes of testing than in previous session.

The mirror was not tested with a Couder Mask until Sat 29 Nov 2008. Dave T had to go to Hawaii for a few weeks. The following readings give a figure error of 5.7 waves in Figure XP:

1 0.0 2 0.0 3 0.0 4 0.0 5 0.7 6 2.6 7 4.3 8 6.1 9 7.8 10 9.2 11 9.2 12 8.9 13 10.0 14 13.5

Owen || 90 mins || 1079 mins || 6/11/08 ||
 *  Here are my notes from Sat 29 Nov 2008:

13:02 - Arrived at Dave Thomson's with G Regan and Dave Robinson. Most recent knife edge readings put into Figure XP - giving error of 5.6 wavelengths:

Zone 1 0.0 Zone 2 0.0 Zone 3 0.0 Zone 4 0.0 Zone 5 0.7 Zone 6 2.6 Zone 7 4.3 Zone 8 6.1 Zone 9 7.8 Zone 10 9.2 Zone 11 9.2 Zone 12 8.9 Zone 13 10.0 Zone 14 13.5

14:08 - 6 degrees centigrade inside garage, 2 degrees centigrade outside.

14:10:18 - GR started moving l1 inch star lap across 30 inch f4 mirror. Lap has not been used for several weeks. Will be using it with no cold or warm pressing before start of figuring work.

14:10:20 - Stop!!! Almost 1 cm^2 of pitch broke off edge of lap.

14:11:30 - Lap "skipping" - (GR). Not yet bedded in.

14:12:30 - DT moved lap across mirror - checking for poor contact in particular areas of the mirror. DT then continued with chordal stroke - 1 inch off centre with 1 inch overhang.

14:16 - Stop. Decided to heat lap with blow torch, to speed conformance of lap to mirror.

14:19 - Blowtorching lap.

14:21:30 - "Better contact" - GR. No anomalous edge effects.

14:22:50 - DT leaning on lap, on mirror, in order to speed up conformance.

14:24:10 - Lap lying on centre of mirror.

14:35:40 - DT moving lap around mirror - better contact.

14:36:32 - GR doing chordal stroke, 0 inches off centre with 1 inch overhang. "Much better contact" - GR.

14:51:01 - Stop. End of GR 20 minute session. Mirror spun about 20 degrees clockwise.

14:52:16 - GR doing W strokes, (6 half strokes to traverse the mirror). Good lap contact. Light hand pressure, sitting down.

15:03:45 - Stop. End of GR 15 minute session. 15 + 20 = 35 minutes today.

15:04:20 - DT doing W strokes, (13 half strokes to traverse the mirror). "Having to slow down due to grabbing/skipping of lap" - DT. This may be a sign of better contact.

15:20:40 - Stop. 15 + 35 = 50 minutes today.

15:45 - End of DO 15 minute session. W strokes, (8 half strokes to traverse the mirror). 15 + 50 = 65 minutes today.

15:47:25 - DR doing chordal stroke, 0 inches off centre with 1 inch overhang.

15:55 - DR doing W strokes, (8 half strokes to traverse the mirror).

16:01 - Stop. End of DR 15 minutes. 15 + 65 = 80 minutes today.

16:02:48 - DT doing W strokes.

16:17 - Stop. End of DT 15 minutes. 15 + 80 = 95 minutes today.

16:35 - End of DO 15 minutes. W strokes used. 15 + 95 = 110 minutes today.

16:37 - GR doing chordal strokes, 1 inch off centre with 1 inch overhang.

16:43:55 - GR doing W strokes.

16:51:25 - Stop. End of GR 15 minutes. 15 + 110 = 125 minutes today. Mirror rinsed with tap water and sponge. Mirror then rinsed with bottled water. Front of mirror dried with Kitchen Roll. Back of mirror dried with Kitchen Roll.

16:58 - Mirror put in test stand strap. || 125 mins || 1204 mins || 29/11/08 ||
 * Here are my notes from Tue 2 Dec 2008:

20:00 - Arrived at Dave Thomson's with Geoff Regan and Dave Robinson. Couder Mask measurements taken, as follows:

Zone 1 0.0 mm Zone 2 0.0 Zone 3 0.0 Zone 4 0.0 Zone 5 1.1 Zone 6 3.1 Zone 7 5.2 Zone 8 6.8 Zone 9 8.2 Zone 10 9.2 Zone 11 9.8 Zone 12 9.8 Zone 13 10.3 Zone 14 14.2

Figure XP calculates error of 5.45 waves.

20:10 - Temperature is 5 degrees inside garage.

20:43:40 - DT doing chordal stroke, 0 inches off centre with 2 inch overhang. DT standing up, to apply extra downforce.

20:52 - 8 degrees inside garage. Fan heater on since knife edge readings taken, about 40 minutes ago.

20:54:50 - Stop. Pushing lap while standing up is much harder than when sitting down. Therefore, each person will, after DT, only do 5 minute sessions. 10 minutes, so far, tonight.

20:55:05 - GR, standing up, doing chordal stroke, 2 inches off centre with 1 inch overhang.

21:00 - Stop. End of GR 5 minute session. 5 + 10 = 15 minutes tonight.

21:06 - End of DO 5 minute session. Chordal stroke, standing up, 2 inches off centre with 1 inch overhang. 5 + 15 = 20 minutes tonight.

21:06:30 - DR doing chordal stroke, standing up, 3 inches off centre with 1 inch overhang.

21:12:20 - Stop. 5 + 20 = 25 minutes tonight. Mirror spun about 20 degrees anti-clockwise. More Cerium Oxide/Water mixture added.

21:14 - DT doing W stroke. "Can't apply sufficient downforce sitting down". DT.

21:16 - 9 degrees in garage. 3 degrees outside. "Trying not to press down too much on 70% zone". DT.

21:20:00 - Stop. 6 + 25 = 31 minutes tonight.

21:21 - GR doing W strokes.

21:26 - Stop. 5 +31 = 36 minutes tonight.

21:31:30 - End of DO 5 minute W session. 5 + 36 = 41 minutes tonight.

21:33:14 - DR doing chordal stroke, 3 inches off centre with 1 inch overhang.

21:38:48 - Stop. 5 + 41 = 46 minutes tonight.

21:39:13 - DT doing chordal stroke, 2 inches off centre with 2 inch overhang.

21:45:10 - Stop. 5 + 46 = 51 minutes tonight. More Cerium Oxide/Water mixture added.

21:46:00 - GR doing W stroke.

21:51:35 - Stop. 5 + 51 = 56 minutes tonight.

21:57:10 - End of DO 5 minute session using W strokes. 5 + 56 = 61 minutes tonight.

21:58:01 - DR doing W strokes.

22:03:15 - End of DR 5 minute session. 5 + 61 = 66 minutes tonight.

22:09:10 - End of DR 5 minute extra session. Chordal stroke used, 3 inches off centre with 2 inch overhang. 5 + 66 = 71 minutes tonight. More Cerium Oxide/Water mixture added.

22:10:01 - GR doing chordal stroke, 3 inches off centre with 1 inch overhang.

22:15:20 - Stop. 5 + 71 = 76 minutes tonight.

22:21:40 - End of DO 5 minute session. Chordal stroke used, 2 inches off centre with 2 inch overhang. 5 + 76 = 81 minutes tonight.

22:22:20 - DR doing chordal stroke, 2 inches off centre with 1 inch overhang.

22:27:40 - Stop. 5 + 81 = 86 minutes tonight. More Cerium Oxide/Water mixture added.

22:28:28 - DT doing W strokes.

22:33:15 - Stop. 5 + 86 = 91 minutes tonight.

22:33:40 - GR doing W strokes, with reduced downforce.

22:39 - 11 degrees inside garage, 4 degrees outside.

22:39:50 - Stop. 5 + 91 = 96 minutes tonight.

22:45:55 - End of DO 5 minute session. Chordal stroke used, 2 inches off centre with 2 inch overhang. 5 + 96 = 101 minutes tonight.

22:46:15 - DT doing chordal stroke, 3 inches off centre with 2 inch overhang.

22:51:24 - Stop. 5 + 101 = 106 minutes tonight. Time for Rhonchi Test. Mirror sponged off with tap water. Front of mirror dried with Kitchen Roll.

22:54 - Back of mirror dried with Kitchen Roll.

22:55 - 12 degrees inside garage, 4 degrees outside.

22:58 - Mirror put on strap in test stand.

22:59 - Fan heater unplugged. Couder Mask measurements of "warm mirror":

Zone 1 0.0 mm Zone 2 0.0 Zone 3 0.0 Zone 4 0.0 Zone 5 0.6 Zone 6 2.1 Zone 7 4.8 Zone 8 7.1 Zone 9 8.6 Zone 10 10.2 Zone 11 10.9 Zone 12 11.0 Zone 13 12.6 Zone 14 15.0

Figure XP calculates a wave error of 4.32 waves. However, when the mirror relaxes back to thermal equilibrium how much of this improved figure will, literally, evaporate? || 106 mins || 1310 mins || 2/12/08 ||
 * Here are my notes from Thu 4 Dec 2008:

19:35 - Arrived at Dave Thomson's with Geoff Regan and Dave Robinson. "Mirror has relaxed almost 100% since last session" - DT. Therefore, last session produced almost no change in figure, in relaxed state.

20:05:30 - End of DO 5 minute session. Chordal stroke used, 0 inches off centre with 2 inch overhang.

20:05:50 - GR doing chordal stroke, 0 inches off centre with 1 inch overhang.

20:11:45 - Stop. 5 + 5 = 10 minutes tonight.

20:12:20 - DR doing chordal stroke, 0 inches off centre with 2 inch overhang.

20:13 - 7 degrees inside garage, 4 degrees outside. Heater put on.

20:18:03 - Stop. Mirror spun about 10 degrees clockwise. 5 + 10 = 15 minutes tonight.

20:19:00 - DT doing chordal stroke, 0 inches off centre with 2 inch overhang.

20:25:54 - Stop. 5 + 15 = 20 minutes tonight.

20:31:40 - End of DO 5 minute session. Chordal stroke used, 0 inches off centre with 2 inch overhang. 5 + 20 = 25 minutes tonight.

20:32:10 - DR doing chordal stroke, 0 inches off centre with 2 inch overhang.

20:38:00 - Stop. 5 + 25 = 30 minutes tonight.

20:38:22 - GR doing chordal stroke, 0 inches off centre with 2 inch overhang.

20:43:30 - Stop. 5 + 30 = 35 minutes tonight.

20:45:13 - DT doing chordal stroke, 0 inches off centre with 2 inch overhang.

20:50 - 11 degrees inside garage, 5 degrees outside.

20:50:10 - Stop. 5 + 35 = 40 minutes tonight. Mirror spun 10 degrees clockwise.

20:58:10 - Stop. End of DO 5 minute session. Chordal stroke used, 0 inches off centre with 2 inch overhang. 5 + 40 = 45 minutes tonight.

20:58:40 - GR doing chordal stroke, 0 inches off centre with 1 inch overhang.

21:04:00 - Stop. 5 + 45 = 50 minutes tonight.

21:04:25 - DT doing chordal stroke, 0 inches off centre with 2 inch overhang.

21:05 - Lew Brown arrived.

21:10:00 - Stop. 5 + 50 = 55 minutes tonight.

21:10:27 - DR doing chordal stroke, 0 inches off centre with 2 inch overhang.

21:12 - 12 degrees inside garage, 5 degrees outside. Heater turned off.

21:16:18 - Stop. 5 + 55 = 60 minutes tonight. Mirror sponged off with tap water.

21:18 - Front of mirror dried with Kitchen Roll. Rim and back of mirror dried with Kitchen Roll.

21:19 - 12 degrees inside garage, 5 degrees outside. Back of mirror dried, by hand wiping - GR, DT and LB.

21:22 - Mirror put in strap in test stand.

21:25 - Lining up mirror with laser pointer.

22:02 - Couder Mask put on mirror. Readings:

Zone 1 0.0 Zone 2 0.0 Zone 3 0.0 Zone 4 0.0 Zone 5 2.4 Zone 6 5.3 Zone 7 8.4 Zone 8 10.1 Zone 9 12.5 Zone 10 13.0 Zone 11 14.3 Zone 12 14.3 Zone 13 15.9 Zone 14 17.6 or 19.0, say 18.3

Figure XP gives 4.09 waves error.

22:23 - Mirror put back on turntable.

22:24 - Mirror rinsed with bottled water.

22:25 - Cerium Oxide/Water mixture put on mirror. 11 inch Star Lap put on mirror.

22:25:56 - DT doing chordal stroke, 2 inches off centre with 2 inch overhang.

22:32:06 - Stop. 5 + 60 = 65 minutes tonight.

22:33:01 - LB doing chordal stroke, 2 inches off centre with 2 inch overhang.

22:38 - Stop. End of LB 5 minute session. 5 + 65 = 70 minutes tonight.

22:44 - End of DO 5 minute session. 5 + 70 = 75 minutes tonight.

22:44:30 - GR doing chordal stroke, 2 inches off centre with 2 inch overhang.

22:46 - 10 degrees inside garage, 5 degrees outside. So cold that I decided to put hand warmers in my shoes - they worked very well.

22:49 - Stop. 5 + 75 = 80 minutes tonight.

22:50 - DR doing chordal stroke, 2 inches off centre with 2 inch overhang.

22:55:55 - Stop. 5 + 80 = 85 minutes tonight.

22:56:15 - DT doing chordal stroke, 2 inches off centre with 2 inch overhang.

23:01:34 - Stop. 5 + 85 = 9- minutes tonight. Mirror sponged off with tap water.

23:03 - Mirror front dried with Kitchen Roll.

23:04 - Rim and back of mirror dried with Kitchen Roll. Back of mirror dried by hand wiping - GR and DT.

23:07 - Mirror put on strap in test stand.

23:08 - Mirror aligned with laser pointer.

23:09 - Mirror image found bt DT. Rhonchi lines show about 5 degrees of clockwise twist - may need to be reset on strap. || 90 mins || 1400 mins || 4/12/08 ||
 * 6 inch star lap made. 1 hour before any work done after making the lap.

15 mins in the centre (10 inch diameter) 20 mins with the centre of the 6 inch lap 175mm from the outer edge (10 inch tangental movement) || 30 mins || 1430 mins || 10/12/08 ||
 * Here are my notes from Thu 11 Dec 2008:

20:15 - Arrived at Dave Thomson's with Geoff Regan and Dave Robinson. Seems like 11 inch star lap is too well matched to 70% zone of 30 inch f4 mirror - possibly part of explanation of why figuring is proceeding so slowly. Therefore, will use a 6 inch star lap tonight. This has already been used for 30 minutes on Wed 10 Dec 2008.

19:00 - 6 inch star lap used, for 15 minutes, on 50% zone, using a 10 inch stroke.

19:15 - 6 inch star lap used, for 10 minutes, on 70% zone, using circular strokes.

21:15 - Mirror tested, with Couder Mask:

Zone 1 0.0 Zone 2 -8.0 Zone 3 -5.6 Zone 4 -2.3 Zone 5 1.2 Zone 6 2.7 Zone 7 4.0 Zone 8 5.5 Zone 9 7.3 Zone 10 8.2 Zone 11 8.9 Zone 12 9.5 Zone 13 10.2 Zone 14 12.9

Figure XP gives error of 4.95 waves.

21:45 - DT started 20 minute session, sitting down, using circular strokes on 225mm zone with 6 inch star lap.

22:05 - DO started 10 minute session, sitting down, using circular strokes on 225mm zone with 6 inch star lap.

22:17 - DR started using chordal strokes with 11 inch star lap, 3 inches off centre with 1 inch overhang.

22:23 - End of DR 6 minute session.

22:24 - Start of DO 6 minute session, using chordal strokes with 11 inch star lap, 3 inches off centre with 1 inch overhang.

22:30 - Start of DT 6 minute session, using chordal strokes with 11 inch star lap, 5 inches off centre with 1 inch overhang.

22:37 - Mirror sponged off with tap water. Front of mirror dried with Kitchen Roll. 8 degrees inside garage, 3 degrees outside. Rim and back of mirror dried with Kitchen Roll.

22:41 - Back of mirror dried by hand.

22:42 - Mirror put in strap in test stand.

23:01 - Couder Mask put on mirror.

23:20 - Knife edge readings:

Zone 1 5.0 Zone 2 0.0 Zone 3 5.0 Zone 4 8.6 Zone 5 11.7 Zone 6 14.8 Zone 7 16.4 Zone 8 17.8 Zone 9 19.6 Zone 10 21.2 Zone 11 21.9 Zone 12 22.6 Zone 13 24.0 Zone 14 27.0

Figure XP gives error of 3.73 waves. || 103 mins || 1533 mins || 11/12/08 ||
 * Here are my notes from Saturday 13th December

13:00 - Arrived at Dave Thomson's with Geoff Regan. Dave Thomson, starting about 12:00 today, has done 40 minutes work on 175mm zone, using circular strokeswith 6 inch star lap.

13:52 - Couder Mask put on mirror. 9 degrees inside garage, 6 degrees outside. Door to garage currently open. Readings:

Zone 1 0.0 Zone 2 0.0 Zone 3 0.0 Zone 4 3.5 Zone 5 5.5 Zone 6 7.2 Zone 7 9.8 Zone 8 11.2 Zone 9 13.1 Zone 10 14.5 Zone 11 15.2 Zone 12 16.1 Zone 13 16.8 Zone 14 19.6 "This zone very difficult to measure" - DT

Figure XP gives error of 4.12 waves.

14:17:10 - DT using circular strokes with 6 inch star lap on 175mm zone, avoiding central 3 inch radius and keeping 3 inches from edge of mirror.

14:32 - DO using circular strokes with 6 inch star lap on 175mm zone, avoiding central 3 inch radius and keeping 3 inches from edge of mirror.

14:50 - DT using chordal strokes with 6 inch star lap on 50% zone with -3 inch overhang. "Lap movement seems much smoother" - DT.

15:00 - DO using chordal strokes with 6 inch star lap on 50% zone with -3 inch overhang.

15:10 - Mirror sponged off with bottled water - less likely to thermally shock the mirror than tap water - DT. Mirror dried with Kitchen Roll and hand wiping back of mirror.

15:21 - Mirror put in test stand.

15:51 - Couder Mask put on mirror. Readings:

Zone 1 0.0 Zone 2 0.6 Zone 3 0.6 Zone 4 3.5 Zone 5 4.2 Zone 6 7.5 Zone 7 10.0 Zone 8 11.2 Zone 9 13.5 Zone 10 15.3 Zone 11 16.1 Zone 12 17.1 Zone 13 17.8 Zone 14 19.8

Figure XP gives 3.68 waves error.

16:13 - 11 inch star lap, after being trimmed at edges, put on mirror.

16:14:30 - DT 1doing chordal strokes, 3 inches off centre with 2 inch overhang. 1 degrees inside garage, 6 degrees outside. Lew Brown here since 15:00. Ian Baker from about 16:00.

16:30 - DO DT 1doing chordal strokes, 3 inches off centre with 2 inch overhang.

16:52 - Mirror put back on test stand.

17:35 - Readings:

Zone 1 0.0 Zone 2 0.0 Zone 3 3.5 Zone 4 3.5 Zone 5 6.6 Zone 6 9.2 Zone 7 12.5 Zone 8 14.0 Zone 9 15.7 Zone 10 17.8 Zone 11 18.6 Zone 12 19.6 Zone 13 20.8 Zone 14 23.5

Figure XP gives 3.13 waves error - best so far?

17:58 - Start of DT 15 minute session. 4 inches off centre, with 2 inch overhang, using 11 inch star lap.

18:06:05 - "Going through centre for 1 rotation" - DT.

18:15 - Start of DO 10 minute session. 4 inches off centre, with 2 inch overhang, using 11 inch star lap.

18:29 - Mirror put on test stand. || 50 mins || 1608 mins || 13/12/08 || See image [|TRO_30inch_figuring_1728mins_a.jpg]
 * 6 inch star lap between the 150mm and 325mm zones followed by the 11 in star lap (now heavily cut into a star) on the 50 % zone edge to edge to smooth.

Daves notes:- 19:30 - Arrived at Dave Thomson's with Geoff Regan and Dave Robinson. DT has aready started doing 15 minute session with 6 inch star lap on 200mm to 325mm zone. [DT - are these measured from the edge or the centre of the mirror?].

19:33 - End of DT 15 minute session. DT doing another 5 minutes with 6 inch star lap, using tangential stroke on same zone. First 15 minutes was with circular strokes.

19:39 - Start of 11 inch star lap work on 50% zone, chordal stroke with 2 inch overhang.

19:41 - 10 degrees inside garage, 8 degrees outside.

19:49 - Stop. Mirror wiped with Kitchen Roll. Back of mrror also dried by hand wiping. 20 minutes work tonight with 6 inch star lap. 10 minutes work tonight with 11 inch star lap.

19:59 - Mirror put in strap on test stand. Couder Mask measurements:

Zone 1 0.0 Zone 2 0.0 Zone 3 2.6 Zone 4 4.8 Zone 5 6.5 Zone 6 8.3 Zone 7 10.1 Zone 8 12.0 Zone 9 13.8 Zone 10 14.9 Zone 11 15.7 Zone 12 16.6 Zone 13 17.5 Zone 14 20.0

Figure XP gives 4.36 waves error.

Mirror rinsed with bottled water. 6 inch star lap to be used by GR on 150mm to 225mm zone, counting from edge to centre of mirror.

21:03:04 - GR started circular strokes with 6 inch star lap.

21:16:20 - Stop. 13 + 20 = 33 minutes work tonight with 6 inch star lap. 10 minutes work tonight with 11 inch star lap.

21:16:48 - GR using 6 inch star lap with tangential strokes on same zone.

21:31:55 - Stop. 15 + 33 = 48 minutes work tonight with 6 inch star lap. 10 minutes work tonight with 11 inch star lap. Mirror spun about 20 degrees anti-clockwise.

21:35:46 - DR using 11 inch star lap on 60% zone, chordal strokes with 1 inch overhang.

21:45:30 - Stop. 48 minutes work tonight with 6 inch star lap. 10 + 10 = 20 minutes work tonight with 11 inch star lap.

21:46:00 - DT using chordal strokes with 11 inch star lap on 55% zone, 2 inch overhang.

21:50 - 11 degrees inside garage, 8 degrees outside.

21:52:18 - Switch to 2 inches off centre with 2 inch overhang.

21:54:12 - Switch to 50% zone with 2 inch overhang.

21:57 - Stop. 48 minutes work tonight with 6 inch star lap. 20 + 11 = 31 minutes work tonight with 11 inch star lap. Mirror wiped with Kitchen Roll, to remove cerium oxide/water mixture. Mirror sprayed with bottled water. Front of mirror dried with Kitchen Roll. Rim and back of mirror dried with Kitchen Roll.

22:05 - Mirror put back on strap on test stand. Measurements:

Zone 1 0.0 Zone 2 0.0 22:44 Zone 3 1.4 Zone 4 3.8 Zone 5 5.5 Zone 6 7.2 Zone 7 8.8 Zone 8 10.1 Zone 9 11.5 Zone 10 12.5 Zone 11 13.7 Zone 12 14.5 Zone 13 15.7 Zone 14 18.0 22:55

Figure XP shows 4.53 waves error.

23:07 - Washing up liquid put on mirror. Bottled water used to rinse mirror. Cerium oxide/water put on mirror.

23:08:35 - GR using circular strokes with 6 inch star lap. Edge of lap moving between 150mm zone and 225mm zone, measured from edge to centre of mirror.

23:14:55 - Switch to chordal stroke on same zone. Overhang = about - 3 inches.

23:21:37 - Stop. 13 + 48 = 61 minutes work tonight with 6 inch star lap. 31 minutes work tonight with 11 inch star lap.

23:22:48 - DT using chordal strokes with 11 inch star lap on 55% zone with 2 inch overhang.

23:23 - DT standing up but not pressing down too hard on lap.

23:30:18 - DR took over from DT, still standing up.

23:36:36 - Stop. 61 minutes work tonight with 6 inch star lap. 14 + 31 = 45 minutes work tonight with 11 inch star lap. Front of mirror wiped with toilet roll. "Using less water to clean mirror should lessen thermal shock"? - DT. Hopefully, this should lessen time it takes for mirror to reach thermal equilibrium after polishing. Back of mirror and rim dried with Kitchen Roll. Back of mirror dried by hand wiping. Mirror put on strap on test stand. || 120 mins || 1728 mins || 16/12/08 ||
 * 10 minutes with a 6 inch lap on the 175mm zone.

20 minutes with the 11 inch lap edge to edge 3 inches off centre.

Correction has improved in Figure XP from 4.6 waves to 2.8 waves. The mirror is now close and will not take much more correction to complete. See image [|TRO_30inch_figuring_1758mins_a.jpg] || 30 mins || 1758 mins || 19/12/08 ||
 * Geoff and myself did 2 x 30 minute sessions using the 11 inch cut back star lap. We used long straight strokes slight off centre (between 3 inches and 6 inches off centre) with a 3 inch overhang.

The mirror appeared to have smoother correction overall but with a slightly rougher surface. You could see radial lines from the work completed. These were faint and would not take much to remove. This could be due to the very cold weather and hard lap as a result. Daytime has been 0 deg. Night down to -7 deg.

No great improvemnet in the figure was seen on the graph. || 60 mins || 1818 mins || 04/01/09 ||
 * 19:15 - Arrived at Dave Thomson's with Geoff Regan. 0 degrees outside garage, 5 degrees inside. Couder mask measurements:

Zone 1 0.0 Zone 2 0.3 Zone 3 2.7 Zone 4 3.5 Zone 5 3.9 Zone 6 5.5 Zone 7 7.8 20:20 Zone 8 9.1 Zone 9 10.6 Zone 10 11.7 Zone 11 13.3 20:25 Zone 12 14.3 20:26 Zone 13 16.0 20:26 Zone 14 19.0 20:27

Figure XP gives 3.56 waves error.

20:45 -John Leek arrived.

21:10 - Mirror rinsed with bottled water.

21:12 - Cerium oxide/water mixture put on mirror.

21:14:35 - GR using W strokes 6 inch star lap, from centre of mirror to 4 inches inside rim.

21:25 - Stop. 10 minutes tonight.

21:25:30 - DT using W strokes 6 inch star lap, from centre of mirror to 4 inches inside rim.

21:30 - DT switched to chordal stroke, with 6 inch star lap, about 5 inches off centre with -4 inch overhang.

21:35 - Stop. 10 + 10 = 20 minutes tonight.

21:36 - DO using W strokes 6 inch star lap, from centre of mirror to 4 inches inside rim.

21:46 - Stop. 10 + 20 = 30 minutes tonight.

21:46 - GR using W strokes 6 inch star lap, from centre of mirror to 4 inches inside rim.

21:51 - Stop. 5 + 30 = 35 minutes tonight.

21:51 - DT using chordal stroke, with 6 inch star lap, about 5 inches off centre with -4 inch overhang.

21:56 - Stop. 5 + 35 = 40 minutes tonight.

21:57 - DO using W strokes 6 inch star lap, from centre of mirror to 4 inches inside rim.

22:02 - Stop. 5 + 40 = 45 minutes tonight.

22:56 - Couder mask put on 30 inch f4 mirror:

Zone 1 0.0 Zone 2 0.0 Zone 3 0.0 Zone 4 1.2 23:06 Zone 5 1.4 23:08 Zone 6 2.2 23:08 Zone 7 5.5 23:09 Zone 8 8.2 23:11 Zone 9 10.2 23:11 Zone 10 12.5 23:12 Zone 11 14.0 23:13 Zone 12 15.7 23:14 Zone 13 17.5 23:15 Zone 14 20.8 23:15

Figure XP gives 1.2 waves error!!!

See image: [|TRO_30inch_figuring_1893mins_a.jpg] Figure XP: [|TRO_30inch_figuring_1893mins_a_figurexp.jpg] Spreadsheet: [|TRO_30inch_figuring_1893mins_graph.jpg] || 75 mins || 1893 mins || 06/01/09 || 11:55 – Arrived at Dave Thomson’s with Geoff Regan. Dave Robinson arrived about 15:00 and Ian Baker arrived about 16:30. 12:09:15 – DT using circular strokes with 6 inch star lap on 70% zone. 12:14:30 – Switch to chordal stroke on 70% zone with -3 inch overhang. 12:20 – Stop. 10 minutes work today. 12:21:10 – GR using chordal stroke with 6 inch star lap on cental zone, +/- 3 inches. 12:27:58 – Switch to circular stroke, 6 inches in from rim of mirror. Circle diameter about 12 inches. 12:32 Stop. 10 + 10 = 20 minutes today. 12:33 – DO doing W strokes with 6 inch star lap, keeping about 3 inches from rim of mirror. 12:43 – Stop. 10 + 20 = 30 minutes today. 12:49 – Mirror on test stand, after rinsing with bottled water and drying with kitchen roll. 12:50 – 11 degrees inside garage, 10 degrees outside. Couder Mask measurements: Zone 1 0.0 Zone 2 0.7 13:39 Zone 3 1.6 13:39 Zone 4 1.7 13:39 Zone 5 3.1 13:40 Zone 6 3.9 13:41 Zone 7 6.3 13:41 Zone 8 8.3 13:42 Zone 9 10.0 13:43 Zone10 11.8 13:43 Zone11 13.5 13:45 Zone12 14.7 13:46 Zone 13 16.1 13:46 Zone 14 19.4 13:47 Figure XP gives 2.51 waves error. Decided to wait another hour to see if shape of mirror changes significantly:
 * TRO FIGURING NOTES – SUN 11 JAN 2009

Zone 1 0.0 15:09 Zone 2 1.2 15:09 Zone 3 2.3 15:09 Zone 4 2.9 15:09 Zone 5 3.8 15:11 Zone 6 4.6 15:12 Zone 7 7.4 15:13 Zone 8 9.2 15:15 Zone 9 10.8 15:16 Zone10 12.7 15:16 Zone11 14.1 15:19 Zone12 15.5 15:19 Zone 13 17.0 15:20 Zone 14 20.3 15:21 Figure XP gives 2.61 waves error. Almost no change. 15:35:08 – DT using chordal stroke on 50% zone with 6 inch star lap with -3 inch overhang. 15:40:30 – Switch to elliptical strokes on 50 % zone. 15:42:55 – Back to chordal strokes on 50 % zone with -3 inch overhang. 15:45 – Stop. 10 minutes in Session II today. 15:46 – DO using chordal strokes with 6 inch star lap, 3 inches off centre with -3 inch overhang. 15:51 – Switch to W strokes with -3 inch overhang. 15:56 – Stop. 10 + 10 = 20 minutes in Session II today. 15:56:30 – GR using circular strokes with 6 inch star lap on 50% zone. 16:03:45 – Switch to W strokes with -3 inch overhang. 16:04 – 13 degrees inside garage, 10 degrees outside. 16:08:01 – Stop. 10 + 20 = 30 minutes in Session II today. 16:12:45 – DR using chordal strokes with 6 inch star lap, 3 inches off centre with -3 inch overhang. 16:16:55 – Switch to chordal stroke through centre of mirror with -3 inch overhang. 16:19:30 – Switch to chordal stroke, on 50% zone with -3 inch overhang. 16:23:20 – Stop. 10 + 30 = 40 minutes in Session II today. Waited about 50 minutes to test mirror: Zone 1 0.0 17:11 Zone 2 2.0 17:12 Zone 3 2.0 17:12 Zone 4 3.5 17:13 Zone 5 3.9 17:14 Zone 6 5.3 17:15 Zone 7 6.8 17:15 Zone 8 9.3 17:17 Zone 9 11.3 17:17 Zone10 13.2 17:18 Zone11 15.0 17:20 Zone12 17.0 17:20 Zone 13 18.4 17:21 Zone 14 21.1 17:23 Figure XP gives 1.74 waves error.

Dave Owen Sun 11 Jan 2009 21:40 || 70 mins || 1963 mins || 11/1/09 || 40 mins with 6 inch on 225mm zone and centre plus some off centre. 30 mins with 6 inch lap. 10 mins on centre 12 inches. 10 mins on the 225 zone out to 1 inch from edge. 10 mins all mirror narrow W stroke. 15 mins 6 inch lap 3 inch off centre edge to edge. 5 mins at the 225 zone also. 15 mins 6 inch lap 150 zone, 15 mins 6 inch lap at 220 zone. 20 mins recut 6 inch lap on the centre. || 100 mins || 2063 mins || 13/01/09 ||
 * More work with the 6 inch lap:
 * Restesting only after FTS trip || 0mins retest only || 2063 mins || 10/02/09 ||