Dome and Shutter Motorisation and Automation

There are three stages of dome rotation available. The basic form is to move the dome by hand. One finger will do the job on a 2.3m (7' 6") Home model, one hand on a 3.5m (11' 6") School model.

The second stage is motorised - this adds a 12 volt DC motor which provides continuous clockwise or counter-clockwise rotation at the flick of a switch. The motor, gearing and battery are housed within a strong fibreglass case. This case is permanently bolted to the top of a wall panel within the observatory (or to the mounting ring in the case of a ‘Dome only' installation). The switch is on a long cable that allows you to stand beside your telescope in the center of the dome and rotate the dome in the direction of your choosing. The dome is driven by a laser cut toothed track - so no dome slipping. The motor is very quiet and can be powered from an AC transformer if you wish. Battery re-charging is via a solar panel (standard) located on a sealed platform outside the observatory and adjacent to the motor case. An optional mains-powered battery charger is available.


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The third stage is MaxDome which adds computer control to the dome rotation. The MaxDome software and controller card allows the shutter aperture to be "slaved" to the telescope position - hence the dome rotates to the telescope's position following a slew, and then tracks along with the telescope. MaxDome works by counting the revolutions of the dome drive shaft and using this in conjunction with the "geometry" of your dome and telescope mount to know where the aperture is. Obviously you must already have a motorised dome before you can add MaxDome to slave your 'scope to the shutter.

In addition to dome rotation, these three stages apply to the dome's shutters as well. You can open them manually, you can have a motor open them at the flick of a switch, or you can have your computer open them (even from a remote location) with MaxDome. Once under computer control a cloud or rain detector can close them as well via a wireless FM radio link between the observatory wall mounted transmitter and the dome mounted receiver.

The lower shutter is opened and closed using a 12-volt worm-driven mechanical actuator with limit switches to ensure that there is no over-ride. In the School Model, the lower hinged shutter has an additional spring-tensioned rigid arm mechanism which provides stability in strong winds.



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The sliding upper shutter is operated by use of a 12 volt DC battery powered, positively geared drive. The motor, gearing and battery are housed within a strong fibreglass case which is permanently bolted to the dome and consequently rotates as the dome is rotated. By operating a toggle switch inside the dome, the upper shutter (which is independent of the lower shutter) can be opened or closed fully or stopped at any intermediate position. The battery, which powers the shutters, is charged via a solar panel situated on the outside of the dome. Again an optional mains-powered battery charger is available.

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