Discussion of how you rotate your dome.

[steve000]

Hi Folks.

I would like to start a discussion of various methods people use to rotate their domes. Please include as much info as possible such as approximate cost, where stuff was purchased from, effectiveness of the mechanism etc etc. Pictures also tell a thousand words.

Steve

[sheeny]

I have a POD, so rotation is provided by a bipedal carbon based cognizant life form powered by a mixture of proteins, carbohydrates, water and air... oh, and I added a couple of handles made from small trowels.:D

Al.

[steve000]

Got pics? hahaha

[sheeny]

Um... no, not of the trowels actually. I should take some. Here's the thread on my obs.:)

http://www.iceinspace.com.au/forum/showthread.php?t=35747

Al.

[Barrykgerdes]

I used the same method with the addition of an extension rod on the dome.

Barry

[bloodhound31]

I'm using small, tuff-plastic roller wheels from Bunnings rated at 40kg each. I took the weight of the completed dome, divided it by 40 and bought the appropriate number of wheels, plus added a few extra for over-engineering's sake.

So the dome sits on these vertical wheels and is guided by four, heavy-duty horizontal wheels with bearings to stop it rolling off the side.

[scopemankit]

I used 75mm aluminium V belt pulleys with bearings inserted with an 8mm centre. They were mounted in rectangular stainless steel section which had down holes for 8mm bolts. These holes were oversize to allow fine adjustment. The dome has a 3500 mm diameter ring of 50 mm X 50 mm steel angle (bent professionally). The bolts to attach the pulleys are sunk into the wooden ring foundation by drilling 6.5 mm holes, partially filling with resin, locking two nuts as a driver and bolting them into the base ring. The dome turns very easily but the wind does not manage to move it. There are six pulleys supporting the dome. Bit of a weird shape but works a charm!

[bloodhound31]

What a magnificent setting Chris! Astronomical HEAVEN! :eyepop:

Where is this?

Baz.

[scopemankit]

Baz, This is in the Cederberg mountains, about 175 Km North of Cape Town. Fantastic skies and quite cold in winter and hot in summer!

[Tandum]

I got this stuff from Bert (brett) on these forums.
There's more info on http://starshed.net/ about the build.
Yes it's automated and driven from POTH via ascom and uses the lesve dome driver (http://www.dppobservatory.net/DomeAutomation/DomeDriver.php).
POTH does the geometery to sync the scope and the slot.

I should add that it is accurate enough for me with my current scopes, it work fine across the entire sky, but adding a grey scale rotation sensor would make dome pointing more accurate.
If I ever get a mount that can handle a 12" plus scope, I'll need that accuracy as the dome slot is only 600mm wide.

[cohiba]

My right hand