Hello guys and girls,
I've decided that I'm going to build a 254mm f/4 reflector for imaging - at least a few years off but I would like to start off with some preliminary costings and designs.
My first question relates to the size of aluminium tube required - I'm assuming that one would allow for the circumference of the mirror (2xpixR), but how much extra is required to actually join the rolled sheet together? Similarly, what would be an acceptable amount of "overhang" at the opening of the tube past the secondary?
As you can tell this is going to be a loooooooooooooooooooooooooong project
Cheers,
Ben.