Equatorial Wedge Installation
During my first attempt at assembling the wedge (see blog entry for Sunday, 14 February), besides the missing parts or wrong installation instructions, I noted that neither the wedge documentation nor the LX200-ACF manual had instructions on attaching the telescope to the wedge. The wedge documentation only discussed attaching the wedge to the field tripod. I pointed out this oversight to Meade. On Monday, OPT sent me a link to a different set of assembly instructions from Meade. It seemed to better describe the wedge I received and had the telescope attachment information as well.
Monday night, 15 February, there were some high thin clouds covering a lot of the sky. I briefly got to see a very thin crescent moon low in the western sky before it was covered by some clouds. I decided to not open up the observatory that night.
On Tuesday, 16 February, at 0845 MST, temperature in the POD = 45°F, I began the wedge assembly again using the different Meade instructions supplied by OPT. It only took about 15 minutes to assemble the wedge. Amazing what having the correct instructions will do!
I then unparked the telescope, set the AutoStar II for Polar Mount, and powered off the telescope. I removed the telescope from the tripod. I had to rotate the tripod to get it in the right orientation for Polar Mounting. I checked that the tripod head was level and made some small adjustments in the leveling. Then the wedge was attached to the tripod. The next step was to attach the Azimuth Control and this is where things got interesting. I had to use the supplied spacer bar as the rim of the wedge was not flush with the rim of the tripod head. The “new” instructions did not discuss this but the “old” instructions (that came with the wedge) did. Unfortunately, Meade did not supply the hex key for the longer screws to attach the spacer bar; I eventually found one in my tool chest and attached the Azimuth Arm and spacer bar to the wedge. Next, the Azimuth Base was attached to the tripod, or rather, I attempted to attach it. The supplied screws were a VERY tight fit in the pre-drilled holes in the tripod. In fact, I started to strip the head on one of the screws while trying to tighten the screw down so that the Azimuth Base would be secure against the tripod. And then DISASTER struck! The screw broke in half!!! Nasty words were said. I discovered that the supplied screws were too long to be fully inserted without using a couple of washers (which were not supplied nor mentioned in either set of instructions). Of course, I still had the challenge of getting the broken screw out of the hole in the tripod. Luckily, about a 1/4” still protruded and I was able to unscrew it using pliers. I located a replacement screw and was able to successfully attach the Azimuth Base to the tripod. The photograph at the top of this page shows the wedge mounted on the tripod. Whew, what an experience!
One other thing to note about the wedge assembly: it is necessary to position the tilt plate to your Latitude (approximately, at least) using the Latitude Scale on the side of the wedge, but the large knob hides the Latitude Scale, making it difficult to set the angle. I got it as close as I could; I’ll refine the Latitude when I do the Polar Alignment at night.
I rechecked the level (since I had to move the tripod to work on the Azimuth Control screw problems) and made some refinements. Then it was time to mount the telescope on the wedge. This was not too difficult for one person with the 8” LX200-ACF. But it would be more difficult for one person with a larger telescope. Here you can see the telescope in its “Polar Home” position:
The control panel on the fork-mount base is at the bottom of the orientation, as are the finderscope and eyepiece on the telescope tube.
I then did an “ops check” of the position of the polar mounted telescope. When the telescope was mounted in Alt/Az, the tripod was centered inside the POD. Now that it is mounted on a wedge, I needed a little more room on the north side to view objects low in the south. So, I shifted the tripod about 6” southward of POD center to make more room on the north side of the tripod. I then rechecked the leveling and made some adjustments. Here you can see the telescope in a more natural position:
Now that the telescope is mounted on the wedge, the next step will be to align its polar axis to the Earth’s rotational axis. I plan to do that tonight using the “Drift Method”.
I left the observatory at 1125 MST, temp=70°F.
Tuesday, February 16, 2010