Telescope Mountings, Drives, and Electrical Equipment

Abstract

The current trend toward larger and more powerful instruments is mostly limited by the size, type, and quality the mounting. The telescope mounting is a complex structure of many parts and is far less easily comprehended than the optical path in the telescope; some parts are even more difficult for the amateur telescope maker to manufacture than a primary mirror.

The emphasis of this chapter is placed on design principles. Practice-oriented publications — Amateur Telescope Making, Sky and Telescope, Telescope Making — and many other periodicals and books are available. Innumerable mounting types have been presented over the years in these publications, and in fact there is no type, no concept, no detail of manufacture which has not been described. Mostly lacking, however, has been a treatment of the criteria for the design and layout of a telescope mounting. Amateur ideas regarding telescope vibrations and kinematic principles are similarly vague. But technology needs measurable and calculable quantities. The chapter contains a discussion of basic criteria for statics, kinetics (vibrations), and the kinematics of the structure. From these, the technical principles which are relevant for determining design and layout will be derived. In order also to help the practice-oriented telescopemaker with some systematic guidance, the primary consequences of the theory have been condensed into the fundamental principles. A similar treatment of the basics of electrical equipment is included. A substantial difference between mechanical and electrical telescope problems is that the latter are much more easily dealt with. In an electrical circuit, components may be replaced simply and at low cost, or even the entire circuit changed, whereas a mechanical structure with serious faults and weaknesses can be corrected only with prodigious effort and expense. It is for this reason that careful designing and layout are supremely important for telescope mountings.