April 2nd, 2005 - Reassembly and First Light


Saturday April 2nd 2005 was an eventful day.  We lost a Pope, gained a telescope, and witnessed a convincing Illini victory against Louisville.

The weather was cool, sunny (later with puffly clouds), and very windy.  Gusts were 35-40mph in our observatory amongst the farm fields.  I arrived with the fork and tube cradle in the back of my truck, and we unloaded them into the observatory.  Present were Mike Conron, John Stone, Cliff Maduzia, Guy Hampel, and myself.

The fork went on with no trouble at all, and after an hour and a half of work we had the fork installed and the cradle installed in it.  Here's a photo of the unloading, and then a picture of the fork and tube cradle.

UnloadingFork and cradle

There was a great bit of "club spirit" displayed during the reassembly, with too many humorous comments flying around to remember.  Time flew by and parts went on quickly, and the day warmed.  The winds got a bit stronger, and bits of birds' nests were blown from the open slit into the dome.  The air whistled through the dome vents in the walls.

By noon, we were out of parts to reassemble, so we took a lunch break at Nero's Gyros in Champaign.  We ate, talked telescopes and travel to darker skies, and made a list of stuff that we needed to bring out in the afternoon for "phase two" of the reassembly.  We went our separate ways to pick up various items, including the tube, optics and other parts.  Then we met again at about 1:30 pm.

Next, attention turned to "demousing" of the observatory.  A family of field mice was evicted from the telescope's cover (now partly eaten) and the entire place was Shop-Vacced by John Stone and Dave Leake.  Amidst the cleanup, two pulleys on the dome slit mechism were repositioned by Guy Hampel (first photo below).  To clean out the bird's nest remnants from the slit, John and Dave became "bell ringers" (second photo below) by alternately pulling on the open and close handles for the slit.  Quite a bit of nest debris fell out, and the slit could then be opened with much less than 200 lbs. hanging on the handles!

Pulley adjustmentDave and John

With the slit now operating properly, and the inside of the dome the cleanest it has been in years, we continued reassembly.  The beautiful gloss-white tube was carefully guided into place and attached to its brackets.

Tube

The secondary mirror was installed, and the mirror cell (without the mirror) was installed so that the baffle tube and focuser could be aligned.  While these were in, a laser collimator was used to align the secondary mirror.  Finally, the primary was installed and roughly collimated.  Here are a couple pictures of the back and front of the scope, with John checking the scope motion on the left and Guy providing scale for the scope on the right.

scope 1scope 2

We paused for a bit to examine the scope, check its motions, and figure out how much of a counterweight was needed at the front of the tube.  At that point we covered it up, closed up the dome, and went home to watch the Illini beat Louisville in the semifinals of the NCAA tournament.

Not 5 minutes after the game ended, I was out the door, having already spoken to Mike Conron on the phone.  The night was clear and the winds much calmer.  Willard Brinegar was already there, viewing with his 18" Obsession.  Mike C. arrived and the three of us added the small lead counterweight to the top of the scope.  This very weight was made in a "Miracle Whip" jar lid, of melted lead from tire weights and was used on my 10" F/6.8 for 10 years before I rebuilt it.  We mounted a Telrad and aligned it, with first light of the scope being in the general vicinity of the easter part of Leo, as I sought out a moderate-brightness star to tweak the primary mirror collimation.

I adjusted the secondary position to move the focal plane out so that a diagonal could be used for more convenient viewing, and recollimated.  Finally, we trained the scope on Saturn and then Jupiter, and enjoyed some nice views, though blurred by dome-induced turbulence.  Final collimation was achieved using Saturn and the moons of Jupiter.

All in all it was a very good day.  Our club once again has a permanently mounted telescope for members to use.  Here's Guy Hampel's summary of the day:

Fellow club members

Hey yesterday was a work day for the reinstallation of the 16” cass in its home in the dome.  It actually started on Friday with most of the club rebuild committee meeting at mike L’s house to hoist the mount out of the basement and then into the delivery truck for a Saturday morning drive to the dome.  The tough task was to get a 200 lb fork and 4 guys up a 3 foot wide stair and door with out killing any one. As a side note have you ever witnessed or participated in move requiring 3 mikes and a guy (hey mike lift your corner or hey that guy lift).  It was humorous to say the least , it reminded of those stories involving Daryl, Daryl and their other brother Daryl. Upon the forks seeing daylight it was determined that a little blue paint was needed to touchup some spots and of course when you then pickup something that has been touched up and rotate it and shove it into the back of a truck “to dry” you get what? Yea that’s right blue paint on your hands and the comedy starts all over again.  Well I guess you had to be there. 

Saturday morning came and it was partly sunny and (I thought that it was April) windy, you can’t keep the door open windy.  It was the first time this year that the dome roof had been opened and rotated.  That was funny too, to see grown men, hanging from a cable trying to use all their weight to open it.  The laughter started early as we thought of Jeff and all those others that are not blessed with near 200 lb mass to sling at these handles.  Finally the dome opens and sunlight streams into the dome, I did not know that sunlight came in chunks, turns out that the birds had been back to join the field debris in the cracks and gaps of the dome slats.  This debris side tracked us with thoughts of later having to bring out a fleet of shop vacuums and clean out the cracks of the dome.  Out went the old cover for the scope to be shaken and on the way a family of mice was evicted and thrown to the wind.  As you can tell there were lots of distractions to occupy 5 adults as we hoisted the forks back into place.  The new tube cradle and dec bearings were next and Mike L was trying to educate us on the finer points of assembling the cradle and bearings, as he went on he noted that we need to get many assorted sized stainless screws to replace the those that were not, hopefully one of us has a good memory as no paper or pencil could be found.

Time for lunch and to get the rest of the scope for assembly, well what’s a good place to eat on the west side of town, 5 answers or more then 2 minutes of debate and finally okay that’s good and were off.  Some one call Dave because he is to meet us out here at 1:00.  Lunch was a picnic including are the Illini going to win, we will be done before game time and did anyone find a piece paper.  List of items was made and we were off to get the rest of the stuff and the shop vacs. 

We the converged on the dome to do some spring cleaning, it is amazing what shop vacs, a generator, brooms and a 30 mph wind will do the debris of a season of unuse will do.  With all the stuff out of the dome everyone decided that they liked it that way, well maybe we need to keep it that way and build an addition onto the storage building.  We rotated the dome to loosen it up and reopened the slot to let in the sun.  Here is one for you, How many astronomers does it take to clean out the track and shelf around the dome, that is easy 5 cause that is how many were there, one do the vacuuming, one to hold the vacuum, two to rotate the dome and one to photo it and not believe its happening, home movies at 11:00 compliments of Mike C.  The stories go on and on, fun was to be had by all. While the cleaning continued the slot tracks and cables were looked at, as a side note did you know it is windier at the top of the dome that at the base.  It was voted on and passed unanimously that we need a sun deck at the top of the dome and are presently seeking volunteers to do the construction of that and a roll-off roof building.  If you were not there you missed it. It was also voted on that we need to have a barbeque, restroom, cooler, and a bunch of the other things out there, oh yes the number one item was a roll-off roof building with a ‘warm’ room.  The scope assembled well thanks to excellent pre-assembly work done by Mike L, who again tried to educate us on the finer points of assembling the scope.  I think that Mike was hoping that someone else would also know something about how the scope works, Mike we were actually paying attention, but individually we would not pass your final exam.

First light for the newly rebuilt scope was decided upon as just after the Illini victory that night, so back we came to check it out.  The word simply is wow and I think Willard summed it up later that night after Mike L tweeked the collimation “I never thought that this scope would be a planetary scope or be used at high magnification”.  Both were observed last night between 10:00 and 1:00.  We tried the club 50mm and eye relieve was way more than one could handle at the time, next came Willard’s 35mm panoptic “simply fantastic” views of Saturn and Jupiter. We got as high as 11mm Nagler with excellent results.  The dec axis is now much looser, easier to handle and almost needs to be locked to control RA movement.  The scope is now ready for the continuing work on RA and then better alignment in that axis for even better manual tracking.  Good work everyone.

I brought my IR thermometer to do some quick checks on temperature variations and change over time.  To sum up daytime temp was in the 50’s and the temp at 1:15 was 28deg F and frost on everything.  I checked the temp regularly but did log individual temps. The inside of the dome started at 50deg with the mirror within 2deg the outside temp was 40deg.  The mirror stayed within 2-4deg with no fans just holes all night of the inside the dome temp but the dome temp was as much as 15deg above outside temp.  The dome walls were 42deg on south side and 40deg on the north at 1:00.  A more documented log will be kept the next time.  But the general point here is the mirror will be able to be at ambient of the dome easily but the dome temp will be tough to get keep up with the temp swings of the day because of its mass. 

The scope is now capable of keeping up with seeing conditions.  Come out next weekend to the club’s dark sky night and check it out for yourself, oh yea now it is definitely worth the $15 for a dome key.

Guy

Well, that's all for now.  We'll be adding ventilation fans to the scope soon, and doing more work on the building.  Now all we have to do is USE IT!

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