cassegrain

Hey whats up everyone?

I am trying to find out how to make a 10 inch cassegrain, mirror, tube assembly and mounting.

Does anyone know if there is any software or plans that I can download?I need to know how to calculate the parabola, size of the hole in the primary mirror, the size of the secondary mirror,the distance between them and general dimensions.
I am finding it hard to find any book on subject.

Anythng information would be cool.

Brian, Try any of the following referance books:

How to Make a Telescope by Texereau is a classic

A Manual for Amateur Telescope Makers by Jean-Marc Lecleire is easy reading

Advanced Telescope Making Techniques by Allan Mackintoch book 1 & 2 are more advanced.

Any of these books provide very useful information.

I would presume that you already have experiance grinding and polishing several parabolic mirrors already. If not, your in for a lot of learning.

Regards,

Preston

Hello:
Jean Texereau's "How to Make a Telescope, second edition" has details on designing a cassegrain telescope, including the equations to get the mirror size, spacing, and conical consstants. The size of the cental hole is determined by the size of the primary mirror baffle. This, in turn, is easily determined by making a scale drawing of the light path through the telescope. As mentioned before, and in Texereau's book, you should have some experience making mirrors before taking on a cassegrain. For a cassegrain you'll need to make a fast paraboloid and a convex hyperboloid, and test both of them! Most of the telescope making parts for sale are for Newtonians, but many can be used on a cassegrain such as the tube, focuser, and spider. Cassegrains are also well suited to a truss tube design. You may need to make the secondary mirror holder yourself. For the primary mirror cell, make sure you get one that can hold the mirror in all orientations. As for the mounting, I'd recommend a good solid german mount since you'll probably be doing a lot of high magnification work.

Cheers
Mike Connelley

Try here:
http://freeware.intrastar.net/telescope.htm
Lots of Astronomy freeware here. Look for "Cassegrain Application"
Hope this helps.