The 8" f/4 Guide Scope

The guide scope is an 8" f/4 OTA from Orion Telescopes. The optics in this scope are not the best but with a little work on the primary and secondary mirror mounts I was able to get reasonable performance from the scope. The rubber retaining clips on the primary mirror needed to be loosened to just touch the mirror. The secondary mirror holder required some sanding to get the mirror to just fit in the base support without any stress on the mirror. I removed the back cover plate exposing the primary mirror to help it cool down faster. I also installed a JMI Crawford focuser.

Wooden Ring Mount	Assembled Guide Scope	Guide Scope on the Mirror Box
Another View	The Counterweight Box	The Collimation Bolts

Future updates to the guidescope will include a modified mount that will allow slow motion movement of the guide scope alignment. This would make it possible to center a good guide star while keeping the desired image frame in the camera on the 25" telescope. I will also be implementing autoguiding with a webcam.

Updated 03-25-2006