Gina

I might go for this if I decide to build another pier for telescopes. Much cheaper than a Skywatcher Pillar mount at over £200!

Is your pillar drill that big??? ? Mine isn't. I do have a decent mains hammer hand drill though and have drilled concrete quite often.

Good luck with drilling the concrete. I hate drilling concrete the stones tend to make the masonry drill wander off course.

I some respects, the direct connection of Peltier TEC to cooler seems simpler though it means other components of the ASC need rearranging. Using a copper or aluminium strip bent at right-angles means the cooler can be arranged in it's most efficient orientation with free air flow in at bottom and out at the top. It may also mean that the other ASC components can be arranged much as now. My intuition tells me that a better air flow over the cooling fins should outweigh the increased thermal resistance from using an intervening strip between TEC and cooler.

I've taken the cooling apart on the ASC and realised a small problem with the first arrangement above - how to attach the camera to the cooler. The present arrangement is that the round aluminium block has holes drilled through to take Nylon screws that screw into the four mounting holes in the camera body and counter bored to take the heads of the screws. Whether it would be possible to drill the new cooler remains to be seen. Otherwise I shall have to make a clamp that goes over the camera body to the top of it. That wouldn't really be a problem as I could easily print something. The other arrangement can simply have holes in the copper or aluminium strip for the nylon screws. At the other end I can drill and tap holes in the cooler.

The alternative to having the heatsink directly against the TEC would be to use a copper or aluminium strip to conduct the heat from the TEC to the heatsink. What I don't know is whether the increased cooling provided by having the base of the heatsink/cooler vertical, giving improved air flow results in better cooling that would more that counteract the reduced thermal conductivity from the TEC. I guess the only way to tell is by trying both arrangements. Unless someone who has more experience of cooling than I have can tell me. These diagrams show the two arrangements.

If this cooler has the same size pad as the other (fan cooled) units I have, the Peltier TEC will fit nicely directly onto the heatsink. This arrangement would provide the best thermal conductivity to the fins and hence maybe the best cooling even though the airflow isn't optimum. But the only "proof of the pudding is in the eating". This cooling method will mean a completely new case but that is no problem - have 3D printers, can make any number of new cases ? The Raspberry Pi will need turning from vertical to horizontal to get it in the space.

I think this passive cooler might be suitable. Ideally with a copper plate from the underside of the Peltier TEC to the outside and this mounted on top for maximum convection but I think it might be possible to put it underneath, directly onto the TEC and mount the ASC on an arm. ARCTIC Alpine 11 Passive - Silent Intel CPU Cooler for all Intel CPU'S up to 47 Watts

This seems to be the main problem that needs to be resolved. There are several ways of getting rid of heat from fins relying on convection through air blown over the fins to water cooling. The problem with using a fan is that this is out in the open and subject to damp or even horizontal rain. The fan would have to be water resistant. A large finned heatsink might be sufficient. Water cooling is something I have some experience of and it works well but the problem is the height of the ASC - the water reservoir needs to be at the highest point. I think this puts water cooling out of court.

Here's the casing and dome.

I'm back on this project and it seems I have a couple of things to sort out before the unit can be set up outdoors. I've decided to separate the ASC from the weather station and put them on separate masts. As far as the ASC is concerned, this means simply removing the arm that took the weather station wind measuring parts - the ASC casing needs no other modification.

I have my latest all sky camera on the table to put back together and test. I think if you don't use a Raspberry Pi, the alternative is a long USB cable for the camera and other wires for the focussing, dew heater, etc. The focussing and dew heater could be controlled by an Arduino but you'll need to write your own code.

Separating the weather station from the ASC means either a small or a large redesign of the wind measuring unit. With a small change I could simply mount the unit on a new bracket from the side of the mast. This will look decidedly odd I think. The other idea is a redesign of the wind vane mechanism so that both sit atop the mast with the anemometer above the wind vane on the same axis, as I had on an earlier design. Then again there's a common arrangement of a bar across the top of the mast with wind vane on one end and anemometer on the other.

I've removed the broken weather station mast and old vane and anemometer. I have a 35mm x 5m aluminium pipe which I thought might be suitable to take the ASC and weather station wind instruments but having stood it up on end I think it's too whippy particularly with all that windage on the top. So it's back to the 44mm diameter x 5m pipe. I've been thinking about the height of the wind instruments and come to the conclusion that enormous height is not essential. It's not as if this is going to be a Met Office site with a 10m high wind instrument standard. All I need to know is approximate wind force and direction. Currently, I have a combined ASC and wind instruments unit but I'm having second thoughts. The wind instruments want height but having the ASC on a high mast, particularly with the extra windage of the wind units, means it's going to sway in the wind (and we get plenty of that at times) and mess with the image. The main reason for the combination was to have the ASC above the wind instruments and avoid having them in the ASC view. But I'm thinking that is less important than a steady mounting for the ASC.

The float was inadequate. Placed float plus pump and nozzle on pond, it floated so I powered up. Small jet which grew but as it did the assembly gradually sank! More bouncy required. Not a problem. The two planters I ordered from Amazon arrived this morning and look fine. I've started filling them with soil.

I too have used SharpCap but now use KStars/Ekos/INDI. KStars/Ekos on my Linux Mint desktop and INDI drivers and image capture with Ubuntu MATE on Raspberry Pi 3 on the camera and WiFi. So I only need power to the remote setup atop a 2.5m and soon a 5m mast.

I have a similar design but with a higher apex and have had no problem of that sort. What could be on the roof and fall off into the scope room anyway? Mind you, mine has a gutter on the end away from the warm room roof. Water from the sloping part over the warm room simply deposits rainwater onto the warm room roof and into the warm room gutter. There are ridges on the sides of both roofs to stop water running off the sides. Actually, because the ROR is wider than the warm room roof, there are short pieces of guttering to collect water from the ROR not over the warm room and deposit it onto the warm room roof.

Mine was folded so needed plenty of settling time. Think I left it a couple of days. Then to glue it I lifted one end and rolled it back half way, applied glue as I gradually unrolled it, smoothing out any bubbles as I went (important). Then, having done one side, rolled up the other etc.

I've designed a lily pad shaped float for the fountain pump and now printing it.

In that case the camera shutter will be closed during daytime and the sensor is safe anyway. I find clouds fascinating during daylight and an ASC may be useful to watch out for clouds during solar imaging. Regarding photo-reactive coatings, I gather these respond to UV but I don't know what the pass spectrum is like except that the grey coatings look neutral. I have photo-reactive coatings (grey) on my glasses as I have over-sensitive eyes.

That would limit your view of the sky. An optical dome with reactive coating would work though. Or maybe an optically flat piece between lens and sensor. OR... Get the lens coated with a reactive coating as long as it doesn't affect the anti-reflective coating.

It does overload and could do with some way of reducing the brightness during bright daytime. Fine if cloudy. Unfortunately, the lens doesn't have an aperture control. Some sort of arrangement to introduce a neutral filter into the light path would be good but I haven't been able to devise anything (yet).

No. It's fine. Here's an image from last year in full sunlight. Exposure of 32 microseconds. I'm just about to put my ASC back out having been doing a few upgrades.

I had funny corners on my observatory too. Some of my rubber does some very strange contortions! ?

I might get one or other of those Amazon plastic planters. For one thing I already have plants that want planting before they die. I may replant the ones from round the wildlife pond into a planter. I could get a plank and put it on a couple of concrete blocks to carry a planter (or two). One thing I like about my own design printed plastic planter is that nobody will have the same and I do like to be different!