Here's a DIY CDK but i wouldn't call it the average DIY. This one is amazing! and check out the mount he has made also.
http://www.zytratech.com/category/zy...ologies/cdk17/
I would love to make a planetary imaging scope using one of Royce's dall-kirkham mirror sets. They wouldn't be good for deep sky imaging at f18 though.
http://www.rfroyce.com/cass_sets.htm