Ad Astra Observatory

An exciting development! But first, the news.

When we last left Hilltop Observatory, I had just gotten the encoder assembly hooked up to a dome wheel, and was thinking about how to make the wheel turn 100% of the time when the dome was turning. Also, I had hooked up control switches downstairs, so I could manually rotate the dome from the desk, below.

First, the encoder wheel. I had a flash of inspiration, and decided to install the wheel directly to one of the drive wheels; they have extra-long mounting bolts, and of course they would be turning the whole time the dome is turning, right?

…

Well, not exactly. That is, the encoder wheel now turns the whole time the motor turns. However, there is a “dead spot”, where the motor turns for awhile, but the dome doesn’t spin. It happens in the same spot every time, but I don’t know exactly what the dome is getting caught on. Anyway, this means that there are now “extra” ticks coming through; I am starting to wonder if figuring out how to read the actual DSR, like it was intended, might not be a better idea.

Until I get the home switch and the rotation encoder installed, I cannot start even attempting to do dome automation. So the encoder (one assumes that hooking wire to the home switch will be fairly trivial) is what is keeping me turning the dome by hand.

I made the command decision that getting to first light is higher priority than getting to dome automation, so I tabled the encoder installation until later.

Installing the extra switches downstairs similarly turned into a boondoggle; since I started messing with the 12v wiring, the dome has been harder to open, close, and rotate. I even had to resort to closing the shutter by hand on one occasion (touching the battery leads to the shutter motor leads, how embarrassing). Again, I decided that this can wait, so I disconnected the downstairs switches, and moved on towards First Light.

I moved a bunch of furniture, in preparation for receiving the new observatory machine, more on this later. I moved the grungy desk from Observatory 1.0 in, along with the desk chair (also from Obs 1.0) and the super comfy chair (which we inherited here in WA, and has been waiting in the shop for this moment). Suddenly, the construction area feels like a working observatory!

In the middle of all of this, I was finally able to re-engage my friend The Astronomy Jedi, who has done some amazing things to mounts and telescopes over the years (If you’ve followed this blog at all, you’ll have heard of him). He has spent a lot of time figuring out how to make telescopes, cameras, and mounts work to the best of their ability, and occasionally, if I present him with an interesting enough problem, he will drop by himself to poke at my rig, and always leaves it in better shape.

So, I induced him to come over a couple of times. The first time, he taught me how to remove the “twist” from mount balancing (he calls this “the 3D problem”), and got the mount really nicely balanced all over the place. He left with a suggestion that I get the scope completely cabled up and balanced, and he took my bare-metal Windows 7 machine to start prepping it for becoming an astronomy machine.

Cabling and balancing the mount took two evenings; I spent a good long time making sure that all the wires were run just so, taut enough to stay out of the light path, with a loose loop that won’t catch on moving parts on the mount. Balancing was also a bit interesting, because of course I disrupted the previous balance while adding in the motor focuser and camera and shifting all the cables around, and of course I added back in some twist :S

All’s well that ends well, though, and I was able to get the scope balanced really, really nicely. It will now stay put in any position.

I will document getting the observatory computers ready in another post, since that’s pretty long and involved, and I will likely want to refer back to it in the future.

The clouds are supposed to roll in over the weekend, so I must be getting close to being ready. 🙂