Dome for a GPCAM

[MarkS]

I want to put one of my recently acquired GPCAMs into service as a 24hour "all-sky" camera on my observatory.  To be precise, not quite all sky because it has only a 150 degree field of view.

Any ideas where I might be able to source a protective dome?  I would also put a small heater in there to prevent the outside dewing up or icing up.

Mark

[RobertM]

This is what I have (unfinished) but I think Duncan has a better container even if it does have more humble origins.



I found them ridiculously expensive but in the end I tracked something down at a reasonable cost.  The dome is one hemisphere of one of these:  http://www.polycraftsupplies.co.uk/index.php/clear-plastic-balls-c-22; I used the 100mm diameter version (Duncan used the other half for his).

Hope that helps.

Robert

[The Thing]

Looks like it needs legs and wheels coming out the sides Robert!

My version is in a Wickes plumbing fitting as seen at Astrofest in the Atik room. Thin ply would probably be easier as the polycarbonate CD is hard to work. The dome is siliconed to the CD, which is also flocked. There is a heater in progress as well.

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[MarkS]

I'm not quite sure how the Duncan version fits together - is the pipe the same diameter as the dome?

Mark

[The Thing]

The dome is a little smaller than the pipe there is a 2mm gap all round. The CD needed reducing to fit into the slotted rubber seal. The lens is inserted into a hole in the CD. The dome is siliconed onto the CD which is flocked to minimize reflections off the dome. There is a ledge in the pipe which takes another CD with a hole and its this that has the heater and the camera fixed via two parfocalising rings, one above and one below (QHY5L-II is eyepiece sized). There is a ring which clips on over the rubber seal which is part of the pipe assembly and that holds it all together. A picture of the commercial version is shown for comparison

110mm domes with flanges to fit the pipe properly are available and would be better but they are a stupid price and Robert had half a dome going spare....