Servorised Spider

2008

 
 

A fellow astronomer is building an incredible rig. It is basically two newtons on a common mount. The thing is that he want to use several cameras on the tubes so the idea was to attach an additional focuser on each tude. In order to use the different cameras a motorised secondary mirror holder that could turn the secondary mirror so that the light would exit through the different cameras had to be made.

I was asked to make the holders and below is the result and some pictures on the way.

The final application uses electronics that monitor the current of the rotating motor to determine when the mirror has rotated to one of the end positions. The ratio of the gear and a slightly flexible connection between the motor and the rotation centre axis makes for a stable position when the motor is stopped.

The solution is actually quite handy even for the strict visual newton as it could substitute for a rotationg tube solution. If you are using a camera you could keep one focuser for visual observation and keep the camera setup on the tube.