I decided to try to use the ASGT for autoguided long exposure photography. To do so, I needed to add a guide scope, and I just happened to have a short tube 70mm spotting scope that I got for free. The spotter scope has three tripod mount holes on the mounting block, so I needed a way to attach it to the C8. I decided to build a mounting rail out of aluminum “L” shaped stock. A three foot section is about $4 at Home Depot, plus a couple M6 machine screws, nuts, and the tripod mount screws all added up to just under $6.
I measured the length of the mounting bar and cut the proper length out. I also cut a smaller horizontal bar for the rear cell mounting points since on these C8’s, the front and rear mounting holes are not in a straight line. You end up having once screw mount on the front and two at the rear of the scope.
I used a tiny bit of “JB Weld” quick setting epoxy to mate the guide scope mounting bar and the rear cell mounting plate (see photo). After that, I marked and drilled the location of the holes required to mount it to the C8.
For the guide scope, I cut two short lengths of the “L” stock, and drilled mounting holes to attach the guide scope. After mounting the guide scope, I drilled holes on the sides where it will mount to the mounting rail, sliding over the rail. I then drilled holes in both the guide scope mounting plate, and the rail. I used a simple repeating pattern so I could adjust where the guide scope mounts. I filed the edges round so that there weren’t any sharp edges to catch on in the dark.
Quick and easy design, this took about 30 minutes to build and seems to be plenty sturdy for my light weight 70mm spotter scope.
