First [Red] light in the observatory.

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I was able to fit the new plate, with the lens already mounted, as dusk fell. The I used the pulley system to lift the folded OTA onto the mounting. Only to discover that the balance was all wrong. I shifted the sliding weights forwards and things settled down. More to do on getting both axes balanced with the worms freed. Refitting the modified OTA was a bit rushed but I was able to overcome the difficulties. The pulley system allowed most of the weight of the OTA to be taken up while I aligned and dropped the fixing bolts through the cradle.

As I was slewing the OTA to the Moon the drive pulley started slipping on the axle of the RA stepper motor. Grrr! I had fitted a second clamping screw during the first build but it obviously wasn't enough. Or the grub screws had simply worked loose. Not much I can do about that without removing the motor from its housing.

Nevertheless I managed a couple of hours looking at the Moon and Mars while I fiddled with optical alignment and compared different drive speeds.

Still quite a bit to do in the alignment department too. The Cheshire EP suggests the objective was already quite well aligned but the mirrors are off after the removal and refitting of the OTA.

The 1W red LED light bulbs are proving about right once I am dark adapted. The trapdoor is flooded with red light from the LED bulb inside the pier to show whether it is open or closed at a glance. I could add some white paint or similarly reflective surface to the underside of the hatch to emphasize when it is open in poor light.

The chain of red Xmas lights is proving handy to delineate the edges of the space available. They do produce a useful glow once I am fully dark adapted. Only just enough to see if I have put something down on the top ring.

I think I shall hang one red LED light bulb up high to supplement the white one. Which is normally turned off but handy for maintenance work. A red, even glow might be best without having the bulb too close to my eyes. I was able to dark adapt despite the red bulb [temporarily] hanging off the mounting but a more general red light might be worth trying. Provided I hang it beyond the top crossbar there should be no conflict with seeing the night sky through the open slit.

I used the familiar "North pole pointing" alignment so that the OTA wanted to rest naturally on the cradle. The tightness of the lifting pulleys prevented easy lowering but the new pulley  system will hopefully help here. I'm glad I ordered a 3x3 system again because having fewer pulleys would take away the relaxed hold needed on the rope.

Remembering to hold onto the rope while manhandling a very awkward, 40lb telescope, high above my head should not need to increase the difficulties. I'm still supplementing the stepladder with an old beer crate. A plywood box with three different working heights would be preferable. The crate offers only one and is finally falling apart. The stepladder is too bulky and awkward in the dark but essential some of the time.

All in all it was valuable experience in using the observatory in the dark for the first time. Until I actually tried it I had no idea about some of the problems I'd face. A red cover for the torch would help.

Now I need to remove the RA stepper motor and drill and tap the small timing pulley boss for a third grub screw. Then bore a deep hole right through from the edge of the front plate. This will allow a long series hex driver to tighten the grub screws without unnecessary dismantling. I did this for the larger pulleys and it has proved invaluable. The pulley grub screws would otherwise be completely unreachable. Dimpling the shafts with a drill might help too if I can keep the swarf at bay.

Update: I dismantled the entire RA worm/motor assembly and drilled the front plate on edge to allow easy tightening of the small pulley grubs screws with a hex key. There were already three grub screws which I had forgotten about since building the mounting. The larger pulleys already have tightening access holes. I replaced the motor and have just spent an hour looking at a rather soft Moon. Thin cloud is moving in.

I also fitted the 1W red LED bulb overhead and it is proving just right for flooding the dome with dim red light. Handy for seeing what is happening to the telescope during slews. I can still see faint stars when looking just past the red bulb. I shall hang the white light on the other side of the top crossbar for maintenance moments in the dark or when the shutter doors can't be open. It is odd how different the dome looks and appears inside in changing light.

Click on any image for an enlargement.

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