Posted 18 August 2013 - 03:52 PM
240mm mirror with a -1.00230 conic constant, and a 576mm focal length.
Yes, those are Hubble's optics, but at 1/10 scale.
I have experience making Newtonians, I've made an 8", 10" and 14", but I wanted to make a Cass for my 4th scope, and I figured I'd go all out and make a scope that as much a detailed scale model as it is a telescope. I'm just not sure what things to look for, optically, that is different in the design.
Posted 18 August 2013 - 04:12 PM
Which begs the question, which conic are you going for, the intended one or the one it launched with?
And what about those solar panels?
Posted 18 August 2013 - 06:20 PM
Posted 18 August 2013 - 06:46 PM
Whereas the typical Ritchey pushes the image plane out a significant distance. Thus the curve of both the primary and secondary are slightly different for a usable scope.
But in any event, you can puruse:
To figure out the question.
Posted 18 August 2013 - 10:43 PM
Besides, the mirror at cc = -1.0023 is a praboloid. With that you can only get a Classic Cassegrain solution, not a Ritchey-Chretien Cassegrain.
Posted 19 August 2013 - 07:52 AM
SRF RADIUS THICKNESS APERTURE RADIUS GLASS SPE
1 -1.1040e+03 -490.000000 120.000000 REFLECT -1.0023
2 -137.140000 647.000000 15.616303 REFLECT -1.497
Primary is a very mild hyperboloid, and the secondary is still moderate. At 25mm off axis it is just diffraction limited over its best field, but the field curvature is very strong: -65mm.
Posted 19 August 2013 - 10:47 AM
As to how I'm going to do it? I'm not sure yet. Probably trial and error a few times first.