Weatherproof Telescope Home

[roundycat]

Dark knight, no worries about being patronising, now it's my turn ;-)!! I actually understand about dew point and such but when I covered my tripod outside it had to be fairly tight or it would have ended up next door. I frequently found dampness under the cover, deposited on the cold metal parts. I don't believe air temp in or outside the bag comes into it. Merely the fact that the metal is colder than the air does it. The counterweights in my obs are frequently soaked in the morning for the same reason.

Dennis

[dark knight]

Air temp is as important as any other factor (relative humidity, temp and dew point are all related) as they are all relative. The warmer the air the more moisture it can contain. For example tonight the air temperature is going to be about 3degrees c and the relative humidity tonight for my location is 78% using a set of tables the dew point will be 1 degree c. therefore only if the surface of metal parts reach 1degree c can condensation form. Not sure if the metal parts can reach 2 degrees lower than the ambient temp, I would need maths too complicated for me.

Using the same data but substituting the relative humidity to say 20% the temp of the metal would have to be about -17 degrees c.

Sorry if this is all going off topic.

[ollypenrice]

Hi,

If you have room to leave your scope out you almost certainly have room for a roll off because it does not have to be much bigger than your scope. You don't have to leave room for the observer to work at the scope in this design. Some people call these little devices 'kennels'.

I have made three and am a reluctant DIYer, not an enthusiast. I had to teach myself to weld but any local mechanic or fabricator will knock you up a steel frame in no time. In fact I wonder if the steel frame from a camping loo tent might be just the thing as a near-ready frame? You just bolt on a cladding (ply?) and a tin roof.

You can see mine on my website at www.lesgrangesastro.talktalk.net

Olly

PS David Arditti's book Setting Up A Small Observatory is full of good ideas.

[ollypenrice]

Sorry - another good idea is to be found in Phil Harrington's Star Ware book. This is scope-moving dolly or 'sled' . I happily used one of these myself in the UK. You make a simple triangular wooden base just bigger than the triangular footprint of your tripod. You raise it from the ground by fitting wooden blocks at the three corners. You attach the tripod feet securely to the base. Then you use a hand truck (L shaped frame with 2 wheels as used for moving suitcases and sold in garden centres etc) to run under the base and scoop it up so you move the whole base-mount-scope as one.

Refinements include - adding a wooden support to the hand truck somewhere so as to support the mount safely and using a quick release strap for peace of mind.

- having a locator of some kind at the observing site so that when you put the dolly-sled down it is always in the same place, so preserving your polar alignment.

Olly

[Astrosurf]

this may also be useful

Accessories for Meade LX SCT range of telescopes Telescope Moving Dolly

Good idea! Would it be sturdy enough when locked for astrophotog??

I think I'll go for a small shed!

Many thanks all!

XXX