Curved SpidersPosted By daniel gillis |
Hello Tom,
I have built a curved support for my homebuilt 12.5"
dob (Parks primary). I prefer the lack of spikes in the images I see--especially when the seeing is steady.
I must also say that some ATMers I have talked to think that the first defraction ring is enhanced as well as increased "glow" from having a curved vane. I do not think so from my limited experience.
I know that ProtoStar sells secondary mounts w/o the supports that you can then add a curved vane to. Sky&Telescope had an article in the April 2002 issue (I believe) that described building a whole assembly. I built my whole secondary assembly out of wood, some bolts, a nylon screw, and a stainless steel strip. Its not too hard especially if you have built four scopes--this 12.5" was my first.
Daniel
I have built a curved support for my homebuilt 12.5"
dob (Parks primary). I prefer the lack of spikes in the images I see--especially when the seeing is steady.
I must also say that some ATMers I have talked to think that the first defraction ring is enhanced as well as increased "glow" from having a curved vane. I do not think so from my limited experience.
I know that ProtoStar sells secondary mounts w/o the supports that you can then add a curved vane to. Sky&Telescope had an article in the April 2002 issue (I believe) that described building a whole assembly. I built my whole secondary assembly out of wood, some bolts, a nylon screw, and a stainless steel strip. Its not too hard especially if you have built four scopes--this 12.5" was my first.
Daniel