Ad Astra Observatory

With the OTA all together, I spent some time collimating. With Cheshire collimation complete, I tried the autocollimator again. I totally lucked out! The two images that you are supposed to line up using the secondary were already lined up! Apparently, my secondary-aligning skills are in shape. So, with only primary mirror movements to do, I had my first successful autocollimation. It took a little time, but it was very happy to see all those triangles disappear.

So I took the newly collimated scope outside to chase suckerholes and confirm that my focal length is OK.

I popped in an eyepiece, and things were tough to get into focus. I finally decided that the bright-but-setting moon was my best shot at figuring out the focus thing. So I fired up the “Harris mount” (that’s me, holding the scope with my hands, and tilting it around until the mirror shows something bright, then trying to hold the OTA steady with one hand as I focus with the other), pointed at the moon, and got a small shock.

The eyepiece wasn’t coming into focus; it ran out of “backfocus” (inward movement of the focuser). I played around and got the eyepiece to focus finally, but I was dreading putting the camera on, because…

Yep, the camera wouldn’t come to focus at all. It came close, but no dice.

Bummer.

I started thinking about what I could modify; putting brackets under the mirror cell, replacing the focuser board with sheet metal, replacing the focuser drawtube, …

and I decided that I needed to recollimate the scope with the bolts pushed forward, to see whether I could get that to work.

So, back inside, loosen all the collimation bolts as far as they’ll go, go too far on one and have to mess around to get it biting on threads again, determine which direction was the only “safe” one to go (future reference: CCW is tighten, CW is loosen), redo the Cheshire collimation (took about 5 minutes), work the autocollimator (this went more quickly, too), and back to perfect collimation again, this time (hopefully) with the mirror far enough forward to let the camera come to focus…

…

and it worked. 🙂

The camera can now go “past” focus before bottoming out in the focuser. And that means that somewhere in there is the point of perfect focus, and *that* means that I have an astrograph again.

w00t!

The moon, as always, looked awesome. It’s about 11 days old now, and there was a really gorgeous crater southeast of Copernicus that I need to look up. It was right near the terminator and looking awesome. Big and round with a peak in the middle and some rubble in the floor.

I didn’t get to see anything else. The “mount” was too shaky, and the clouds started rolling in.

There were thrills and chills, and I only got to see the moon, but there’s nothing quite like a first light.

Welcome back, Trixie. May this be the first of many nights under the stars. If you flex this time, I’m selling you on Astromart, you thankless hunk of glass. 🙂