tilbrook@rbe.ne
14-04-2012, 11:01 AM
Hi,
What do you do when your observatory dome isn’t designed to use a conventional drive setup, such as a drive roller or chain drive.
My dome has a split door which makes it difficult to use any of these options, so I decided to make a threaded rod setup which drives for 3.5 hours. I was limited to this because of the circumference of the dome.
The 12V DC unit simply clamps on to the base track of the dome, with a shaft that slots into one of the roller arms, it only takes a minute to get up and running! I have a rheostat in the observatory hut to control the speed and a timer to switch it off in case I forget. The drive speed can vary from the sidereal rate to as slow as I like, and have reversing switch for when the dome is pointing North or South.
I gave it it’s first real test last night imaging Thors helmet, it ran for two and half hours and kept fairly central to the scope. It doesn’t matter if the drive rate is a little off because there’s a minimum of half an hour before the scope is vignetted by the edge of the dome.
It’s certainly better than climbing into the dome to rotate every half hour or so, it means there’s no chance of bumping the scope or tripping over the many usb cables.
Cheers,
Justin.
What do you do when your observatory dome isn’t designed to use a conventional drive setup, such as a drive roller or chain drive.
My dome has a split door which makes it difficult to use any of these options, so I decided to make a threaded rod setup which drives for 3.5 hours. I was limited to this because of the circumference of the dome.
The 12V DC unit simply clamps on to the base track of the dome, with a shaft that slots into one of the roller arms, it only takes a minute to get up and running! I have a rheostat in the observatory hut to control the speed and a timer to switch it off in case I forget. The drive speed can vary from the sidereal rate to as slow as I like, and have reversing switch for when the dome is pointing North or South.
I gave it it’s first real test last night imaging Thors helmet, it ran for two and half hours and kept fairly central to the scope. It doesn’t matter if the drive rate is a little off because there’s a minimum of half an hour before the scope is vignetted by the edge of the dome.
It’s certainly better than climbing into the dome to rotate every half hour or so, it means there’s no chance of bumping the scope or tripping over the many usb cables.
Cheers,
Justin.