MikeMike Sharps

My thanks to all that have replied - some good suggestions that I will follow up. In response to sky badger, the picture below depicts the mechanism. Lower rail Is where the dome is mounted onto & allows 360 rotation. Above is another frame mounted on casters which allows the centre split roof to open. The rotating rail is set a fair bit outside of the internal observatory walls, making it difficult to mount a direct drive. A motor driven wheel could be mounted in a similar way to the castors but would rotate with the roof - care needed for control & power wires. I have looked at some of the popular GRP domes & drive mechanisms connected & controlled through ASCOM, but cannot see a way to emulate with this observatory design., hence a linear actuator. my requirements spec is fairly basic; need to rotate the roof in short ( few second) intervals & have a time delay of several minutes. If these times need to be easily varied (to allow for different scope elevations. I am looking for about 2 -3 hrs / 30 -45 degrees of rotation for a typical photography session. Many thanks again for all contributions.

Hi, I am lucky enough to have a fabulous ‘Home Observatory UK’ hexagonal observatory I am looking to simply automate the dome for extended Astro-photography sessions. I currently move the dome by hand every 20-25 mins. I have acquired a 330mm linear actuator- which is powerful enough. I can work the mechanical aspects but looking for help on the electrical side of timing & switching. I need to operate a 30v DC motor (750w) every 10mins for a few seconds. Don’t seem to be able to find a suitable timer switch off the shelf, looked at Ardunio / Raspberry PI, but quickly got out of my depth. looking for simple ideas, anyone done similar thing or can provide some help. I’m a retired mech engineer so only have basic electronic skills. All help appreciated. Mike