Finally--a scope update

I'm sure you're wondering what's become of my homemade spotting scope. I haven't had much time to play with the scope or anything lately, what with my class, my job, and my work on the little cottage in the backyard. Here is an update, though there's very little news to relate.

Remember that I ended up with a huge objective lens, 80mm in diameter. Right now, I'm trying to figure out how to go from my 1-1/4-inch eyepiece/image-erecting prism to that giant diameter. Before, I had just kept the smaller diameter tube from when I had the crazy non-color-corrected objective (remember the full-bore horror show?), then added a big adapter for the big objective. However, I had a big problem with vignetting, which Astronomy Boy reminded me meant that somewhere, my focal path was being interrupted. I figure it was somewhere in the barrel/eyepiece.

So I need to go get a bigger barrel (a little over 3 inches), then figure out how I'm going to bring that down in diameter to accommodate the prism and eyepiece. Perhaps something like this? (excuse the horrible MS Paint drawing you're about to see--I wish I had access to Adobe Illustrator or even PhotoShop, so I could create some decent graphics)










So--basically, I'm wondering if I can find some sort of adapter that sizes down in one step between a 3-inch-ish PVC pipe and a 1-1/4-inch pipe. I also have to find a pipe that's only slightly smaller than the 3" pipe in order to create the two-piece sliding barrel that will enable me to focus. This will require some hard time at the hardware store, playing around with all those crazy adapters and pipes and things.

I'm hoping to get down to the hardware store this weekend. Wish me luck, and if you have any suggestions at all--bring 'em on! I could use all the help I can get.