telescope build : intro

Alongside day-to-day work, I like to involve myself with longer term projects which challenge my knowledge and ability and act as a source of new learning. These projects invariably reflect my various interests such as machine tool restoration and building small stationary steam engines.

My current longer term project reflects a lifelong interest in astronomy and takes (or will take) the form of an open tube 6 inch f-15 refractor.

The telescope will be based around a 150 mm f-15 achromatic doublet objective made by Istar, which is pictured above. Due to the long focal length of this lens, the telescope will be very big – the finished instrument will be somewhere between eight and ten feet long. In order to make this practicable in terms of storage and portability, the telescope will be built in three sections which will be stored separately and bolted together for use. I’m sure that I’m not the only person who has designed a telescope based on this type of arrangement, but personally I haven’t seen any examples of it so to all intents and purposes this jointed aspect of the design is my own contribution. The sketch below (not to scale) hopefully gives an idea of how the two main joints will be constructed.

An aspect of my approach to complex projects such as this, or for example steam engine builds, is that I usually document my work in progress on a relevant forum. This serves as a build log for my own use, but it also enables me to discuss arising issues and get help from experienced makers on the forums. The forum on which I am posting the build log for this telescope is Stargazers Lounge. However, I shall also post regular brief updates on the build via blog entries on the this page. Feel free to follow along if you are interested, and indeed to contact me should you wish to share an interest in this build, a scope build of your own, or in telescope building in general.