ATM - Amateur Telescope Making.


I've been building telescopes since I was 15. Initially because when I was at school I couldn't afford to buy one, and then because I realised that I could make better ones than could be bought, and it was better value for money.

I've made some 40 mirrors which corresponds to roughly one a year, but averages are certainly deceptive. Not all mirrors were for me - some of the mirrors were for friends, some I've done for work (which is a big thrill for an amateur), and I've even been paid for some. I don't know if that makes me a professional - I don't feel like one.
Me making lensThis photo (35Kb) is me holding a 21cm lens which I was making for use on the AAT. It was the collimator/camera lens used in an ultra-high resolution spectrograph (called the HBS) specifically built for SN1987A. The only spectrographs which have higher resolutions than this one are intended for use on the Sun. (On the left is Peter Gillingham, the engineer who designed and organised the HBS. He also did some of the grinding and polishing of the lens.) Barely visible in the background is the traditional ATM grinding stand I was using - an old 44-gallon drum.

I plan to include on this page short articles on ATM topics that are of particular interest to me, or are perhaps comments on general aspects of telescope making.


My Telescopes

I have made many telescopes over the years. Most were of the Newtonian design, but I've done a Cassegrain and some lenses. I've sold or otherwise disposed of most of them so I only ever have a few at any one time. Here I describe my current (and some previous) telescopes that I've built.


My Observatories.

I have the luxury of living under dark skies and so don't need to travel to observe. The obvious need therefore is an observatory. I initially built a simple roll-off roof design which did me for many years. It has since grown a control room for CCD imaging and a 6-m diameter, 2 story dome has been built for visual observing.

Roll-off roof observatory - AKA the skyshed. This is my original building made by converting a commercial garden shed.

Control room extension. The skyshed was originally designed for visual observing and astro-photography, but since the mid-90's I've been doing CCD work and it wasn't quite so suitable as it left the computers and electronics exposed to the damp night air while observing. A control room was needed.

Remote control. The skyshed's use grows - now it needs to be controlled from the other side of the world. How I automated the Skyshed.

The dome. Nice as a roll-off roof observatory is, you can't beat a dome for visual observing. Here's the story of how I built my 2-story, 6-m diameter steel dome.


A faster way to grind mirrors.

I believe that the beginning ATMer is more likely to create some new revolution in telescope making than old hands. New innovations are to be encouraged. I wish that when I was 16 I had the guts to follow through with some of my ideas instead of being put off by experts. Here is one of my ideas which may be of interest to mirror makers both new and old. It has saved me many hours of grinding time since I started to use it.


Things that annoy me!

I'm a pedant. I dislike the way exact terminology has become perverted and lost its true meaning. So what really is a Serrurier Truss? What does Prime Focus really mean?


Colour Filters and CCDs.

Photometric filters; filter transmission characteristics; how they relate to CCDs; and how to assemble filters from Schott coloured glass.


A Filter Wheel.

I have made a motorised filter wheel to hold my colour filters. Here is a description and some photographs of it.
Me holding large filterwheel
(This isn't it! It's the filter wheel from the AAT prime focus camera, currently used for WFI - our Wide Field Imager - which is an 8192×8192 mosaic CCD camera. The filters I'm loading are 165mm square - a standard UBVRI set (only the UBVR are loaded).)


Cutting glass

How to cut glass circles for filters, which is also applicable to cutting the hole in mirror for a Cassegrain.


A 6-inch RFT

A description of a simple and very cheap telescope - a 6-inch short-focus Newtonian, usually called an RFT (for Richest Field Telescope). It is made almost entirely from spare parts from my large junk box and yet incorporates many good features not often found on expensive telescopes.


The best portable telescope? A ballscope

I think that a ball-scope is the best design for a portable, medium-sized telescope. they're a little more effort to build than a standard Dobsonian, but I think it's worth it. I've sold my ball-scope because I don't really need a portable telescope, but I've put an updated description of it here so that it can live on.


Current projects

In an attempt to motivate myself, I'm listing some of the many plans I have for equipment modifications. Not that anybody will be interested until they're done, but I might get suitably embarrassed at how long it takes to do them!

Updated 2006 February - the 31cm has been re-built as a portable Dobsonian.


hometo Cookbook CCD


Page last updated 2011/05/21
Steven Lee