Cloudy today but not raining. I worked in the dome much of yesterday and today, and finished the cabling of the gear – at least for now. (I suspect this is one of those chores that is never finished.)
- All the multitude of devices with wires on the scope (cameras, guider, focuser, filter wheel, etc.) are cabled along the scope and mount body to minimize dangling.
- The platform between the plates on the SkyShed Pier top section makes a great place to put permanent connection points, so in there I put a USB hub (which means I only have to one run USB cable to the computer), the focuser hub, the USB-to-serial convertors, etc. Each is fastened in place with velcro.
- This left only 6 cables that need to go from the mount to the electronics bay – several power cables and the single USB. These all run down the side of the pier, held in place with peel-n-stick cable guides, then through “wiring channels” fastened to the floor.
It required lots of hand rotation of the mount on both axes to work out the right amount of slack in the cables so the mount can go through its range of motion without snagging. I’m very pleased with the results – the interior seems much tidier and more spacious without all the dangerous dangly bits.
I also checked various optical surfaces for cleanliness after the terrible spotting I saw on last week’s image tests, and carefully cleaned a few.
Next clear evening I’m looking forward to some new test images, this time with the filter wheel and flat frame box back in action.
We’ve had several days of rain, so it was a good test for the dome. I left the cover off the whole time, to evaluate the water-tightness of the structure itself. No more water intrusion around the floor or the 1/2 dome seals. However, there was a fairly large splash of water under the pivot point on one side. Inspecting why this would be so, I found the gasket between the primary and secondary domes had folded back the wrong way – it was inside the dome instead of outside it, and was allowing a clear channel for rain water. So I fixed that, and am pretty sure it will be fine – the other side of the dome, where the gasket was sitting properly, had no leakage.
It’s clear tonight and no moon, temperature about 0 C. I used the evening to start testing out the wide-field imaging train.
I eventually plan to image with the C9.25 and, for that, will use the Van Slyke off-axis guider to avoid differential flexure of a guide scope. I tried that tonight with the SV80 refractor. It didn’t work – there isn’t enough back-focus in the refractor to hold the large VSI OAG. I tried the old Mead OAG and it works ok, except I couldn’t find a way to attach it to the filter wheel – so I did some tests of straight monochrome imaging and OA guiding. Continue reading
It was clear tonight and won’t be for the next few nights, so it seemed wise to get some dark time when it’s available. I set up the 80mm imaging scope to start some polar alignment.First it took rather a long time just to get all the software and hardware connected – it’s been about 8 months since I used the imaging setup, having spent available time either doing outreach or planning the observatory. Eventually I remembered what connects to what and got Maxim, one camera, and PEMPRO running. Continue reading
I did a quick observing session tonight, only about 90 minutes, to generally check things out. Setup took about 5 minutes. Since this included balancing the scope, which I won’t have to do again, it’ll be even less time next time. The dome nicely blocks house lights, and I did a quick calibration of the mount and observation of a half-dozen favourite objects: M27, M57, NGC869/884, Albireo.
Tonight was about testing out the setup, not observing, so no observing reports. I did find the scope’s dew shield got in the way of the dome in certain sky positions, so I’ll trim it a bit shorter (or maybe just not use it and permanently install the heater strips instead). I am starting to understand the mount/dome geometry that determines what sky can be seen and cannot be seen. I also found a couple of cases where doing a meridian flip opened up another strip of sky. I’ll give it a few sessions to get used to this, but the thought of the PZT accessory, next spring, entered my mind. The pier is nice and sturdy and I tried powering-off the mount then doing a one-star re-synch to start up again – something that only works with a permanent mount. Worked like a charm.
I definitely need to spend a couple of sunny days in the dome organizing where to put things – running cables out of the way, etc. I lost things a couple of times and need to develop some routines on where everything goes. The real treat was at the end of the session – I decided I was cold and wanted to go in the house. Park the mount, dust cap the scope, pull in the extension cord, lock the dome, done. Shutting down took about 3 minutes, and is done in a way that can be easily restarted next time. This – instant start-up and shut-down – is the reason I wanted a permanent installation. Clear skies forecast for tomorrow night again, so I’ll have a chance to do some more testing. Now I need to put together a plan so I’m not making it up as I go.
Today was a holiday, and sunny & warm (10 degrees), so I completed the basic assembly of the POD. Got the walls and dome done, taking most of the day, and installed the pier and G11 mount. To test things out I quickly put the C9.25 on the mount, set up for visual, and will go outside for first light tonight. Still lots to do, furnishing the interior, running cables more neatly, polar alignment, etc. But first light tonight will be pretty exciting.
The POD arrived today, in 4 large packing boxes. Everything seems in good condition. It took an hour to unpack the boxes and fold up the packing material for disposal, then I started assembly. I finished assembly of the two dome halves before the afternoon ended, and decided to stop there. Tomorrow is a holiday so I’m home all day, and the weather forecast is for another sunny and warm day, so finishing assembly tomorrow should be easy.