Just starting this thread as I am sure I will need more advice. Thanks to Neville at Lonely Spoon for letting me inspect his setup for inspiration and ideas.
I live in the bush west of the NSW Central Coast so not perfect conditions but it will have to do. Our paddock floods so the observatory needs to be at least 1.5m up to keep dry if situated with a reasonable arc of sky to view. Will need remote power which I plan to supply via battery and a couple of repurposed solar panels. Roll-off roof not supported by management due to footprint, so a dome it is.
A bit slow getting out of the ground with a progress pic here if I can work the upload. Started just before Christmas.
I printed these as something of an experiment (PETG, fairly solid infill). They support roller skate bearings sitting radially on a 34mm rolled steel tube - which will be attached to the underside of the dome ring.
I was going to use Aluminium angle, but the geometry is not optimal to clear the peak of the angle.
They look pretty solid in printed plastic but just wondering if anyone out there has tried this - and what filament did you use?
Pity about the rain but hoping for better weather when back from a trip in a few weeks. Will be exciting to actually get some optics installed.
I am very impressed by the occasional blog mention of observatories built in as little as a week. Clearly I have spent too much time head scratching.
Next to automate the dome rotation. I am thinking 3d printed gears, perhaps with the lonely spoon option of a plywood ring gear if the plastic cannot cut it.
Thanks Michael. I have been keeping an eye on the dew point overnight with no obvious condensation to date, but it is a big risk, I agree. I have not got around to setting anything up yet but am thinking about leaving the scope under a cover and adding a small heat pad based heater to the pier to keep the temperature under that cover a degree or two above ambient. wrapping a dew heater around the pier and running it overnight after the scope is parked is another thought.
How about you? Have you implemented any solutions for condensation?
That's an impressive build. All you need is one of those swamp boats to get to it when it's high tide.
Do you have any sort of isolating vibration reducing rubber between the flooring and the pier?
The pier is independent of the floor, of course. I have tried to close the small gap with some foam rubber. And the swamp boat looks great but I may have to settle for a lowly kayak!
The 3d printed ring and driver gears seems to be holding up and working well to date (inspired by seeing Neville's plywood gears). Happily, the Levesdome ascom driver and USB extension board were uncomplicated to set up and are working well.
Next step is to mechanise the shutters so I can be lazy and warm at the end of a session and remotely close the dome up.
I also get a lot of condensation on the dome (3mm ply and one layer of fibreglass mat). Wondering whether to ignore it or look at applying some form of insulation??
If the condensation is at risk of wetting/soaking and damaging your equipment I think insulation would probably be a good thing.
I don't know what is considered a good option for a dome because I don't have one but I did take the glass covered insulation out of an old gas hot water heater to put in the garden shed above a lathe to stop condensation dripping down on it. I bought polystyrene foam stuff for the rest of the small shed I'm yet to put up but I like the glass covered aluminium foil (much thicker than standard foil). No waste, the old tank got plasma cut into 2 halves and is the water and slag tank for my plasma cutter.
The 3D printing looks so much neater than my laser cutting, Campbell!
How many rolls of filament has that taken?
I really like the encoder mount, too. I don't know why I didn't use a 3D printed approach for mine, to be honest- just a woodworker at heart, I guess...
The ring gear needed to be printed in 30 segments to fit on my print bed and to divide sensibly. I printed it fairly solid - 70% infill. Each weighed 130gm, so around 4kg of filament.
I could have made the encoder a bit more compact - but it works, so likely to stay as is.
