The Starry Night, 240

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12/6/2022. I've been turning an adapter to put the LXD-55 head on a tripod smaller than the mighty Linhofs, the better to haul it and a short OTA (either the TMB92SS or the 105mm Sigma) more casually to open and perhaps darker skies. Among other projects, I'd like to revisit some of Barnard's "selected fields" and be properly prepared for a fly-and-gaze trip to the 2024 solar eclipse. I excavated the "smaller tripods" I hoped to use, and they were all, it seemed to me, at least marginally too small. My Gitzo 320 "Studex" is enjoying an extended stay Out West; my next heaviest is a "Reporter," and then there's my 3rd party carbon by another maker which I suspect would work better than the Reporter under the LXD-55 but which I really do not want to use for that application. While Christmas shopping for Amy, wouldn't you know that a really cheap set of used Gitzo 1345 legs would leap into my shopping cart and refuse to leave? It really was an extraordinary bargain from Roberts Camera and includes a new flat top plate to which I could attach the work-in-progress adapter -- pure luck in that I wouldn't have known to look for that detail. The moon and clouds say it doesn't matter very much when the legs arrive, but they're on the way.

How many ways can a lathe go wrong? I am not a machinst so much as a guy who sometimes whittles on metal with power tools. I was looking forward to using some new carbide-insert tools which were indeed a real improvement over previous cutters. The small pulley on the shaft of the lathe's belt-driving electric motor had loosened and began making a large noise. When I fixed it, I discovered that it had likely been loose-ish for some time. Tightened, the lathe works much, much better. I'm guessing that slippage in the pulley had been letting the lathe bog down under modest loads; without slippage, cuts are far surer and smoother. Between the lathe and drill press, part of the adapter for the LXD-55 is finished. Tomorrow, the rest of the metal should be in hand. I should need only to tap one hole and drill three more to call the adapter ready for the sky.


12/8/2022. And... done! Good God, can I make a mess? I drilled nine (nine!) holes in the adapter to get three within a sixteenth of where I needed them. But they're all hidden within, so they don't count. The 3/8-16 tap was easy to use. And the whole thing works great. I have the LXD55 set up on Gitzo "Reporter" legs just for plausibility's sake. It looks fine, and might even work in a pinch, but it is by no means "solid." Standing on a stone floor, it rings like a bell. That's without the counterweight or any camera or 'scope attached. It might be better out in the wild, on dirt, but I think at best the word would be "marginal." The Gitzo 1345 "Studex" legs will have at least 22 lbs of capacity rather than 13, and from my experience with another heavy-duty Gitzo (a vintage G320, which I used with OK success under the 6" F5.9 with a heavy Giro Alt-Az mount with a counterweight), 22 pounds is conservative. I'm sure it will be fine for photography with LXD-55 and 105 Sigma. We'll see about pushing it harder soon. Once it all proves out, I'll go over all the internal threads in the adapter with Loktite -- it would be a pain to re-tighten them in the field.


12/10. Whoa, Roberts was fast and the legs are perfect! The tripod won't be the weak spot. I'm pretty sure I could put the G11 on this thing and it might be pushed but it wouldn't be overwhelmed. I'm impressed. It is heavy and it is gawky but nothing like as heavy and hard to fling around as the Linhofs are, so all is proceeding apace. The idea to remake the bottom of the adapter in brass or steel sneaks into my thinking, but so far it's just an itch. I was planning how to make lighter counterweights using scraps of brass or steel, when I decided just to try one of the 10-pounders that came with the mount. Which is exactly right: in close it balances the 105mm Sigma and farther out it takes care of the TMB92SS. So just stop thinking about it all so much and make some pictures. As for 2024, a rolling duffel should hold the key bits and can either be checked or shipped ahead.


12/13. I loaded an 8-posiiton EFW for the 1600MM and re-assigned the the 5-position mini as a high-resolution lunar/solar wheel for the 178MM. For planets, use the 462MC instead of the monochrome cameras.

Here's what's in the slots, listed here the better to configure software without opening up the wheels to see which filters are where. In the EFW, all slots hold Baader filters:

1. Luminance
2. Red
3. Green
4. Blue
5. H-a
6. Oiii
7. Sii
8. IR (685)

In the EFW-Mini, slots 1-3 contain Baader filters. Slot 4 holds a Zwo filter:

1. Luminance
2. Clear
3. Solar Continuum
4. IR (850)
5. empty


I've been reconfiguring the ASI software with this new arrangement (because it's simple) and messing with N.I.N.A. because it's not, which is to say it offers lots of useful features and options and upgraded controls. It's going to be a while before I use a significant fraction of N.I.N.A.'s features. At first I just want it to take a series of filtered sequences, naming and saving the files where I want them. Eventually, I'll coordinate PHD2 through N.I.N.A.'s interface and add dithering. Then there's the focus assist screens. And there's the plate solving tools, followed by plate solving and syncing and slewing.


12/16. Well, damnit! I snagged the LXD-55 with the neck strap of a camera I was carrying outside on the TMB92SS for some focus tests (anticipating two ISS transits and a rocket launch). How long have I been doing this? Listen, tripods are not at their most stable in their lowest positions, especially with heavy stuff like the LXD-55 and its counterweight up top. The triangular footprint is smallest when the legs are least extended, and it's easy to nudge the CG outside that triangle. Anyway, the LXD-55 on the new-to-me Gitzo hit the porch hard and snapped the Dec axis, messily. Fortunately, there was no OTA or camera attached.

I've yet [12/24] to get the mount to run in RA mode only, and have had some adventures shopping for a functional replacement. An LXD-75 on AstroMart proved too prciey to ship; a CGEM-II at B&H was mis-described; and at the moment, a SkyWatcher Star Adventurer package is enroute from a seller on eBay. Each option had its virtues and liabilities. More when I know more.


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                   © 2022, David Cortner