Quote:
Originally Posted by Orion
All the best with it and I'm sure it will turn out great.
Your not making cell yourself Steve?
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Thanks
Orion, I just sat down and looked at every component of the scope which I have to construct, and I made a decision to have some parts ready-made, and the mirror cell was one of them. I could make it, no problem, but I want to concentrate on the timber work. And I'm confident the mirror cell will be first class.
Quote:
Originally Posted by AstroJunk
Oversize the secondary because you WILL do some imaging sooner or later
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Hi
AstroJunk, I pretty scratchy when it comes to calculating this sort of thing, but I'm working from
Kriege's book, page 95. Here is what I've calculated so far (all in inches) using a 20mm eyepiece:
- Secondary cage I.D. = 19", or 9.5" radius from centre of cage to inside surface of cage.
- Focuser board thickness = 0.75"
- Focuser = 2.5" (haven't decided on either Feather Touch or JMI)
= 12.75 distance from seconday mirror to focal plane.
using the equation, the result is 3.49" secondary mirror minor axis! Or 3.5".
Now that's fine for a 20mm eyepiece, but what if I use a different eyepiece? all these parameters change. Did Kriege use 20mm because it is usually in the middle of the range for eyepieces?
Quote:
Originally Posted by AstroJunk
...and pre-drill the rocker box for ServoCat as it is easy to do on the build, and a complete pig to do as a retrofit (and yes, you will get that too, eventually).
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Ohh yeah, no problems here. I will start researching ServoCat, Argo Navis and encoders when I even start on the mirror box. I'm going to take up Gary (Wildcard Innovations) offer for some advise on this when the time comes.
hoo roo
Steve