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.
This
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.
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.
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.
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?
Photometric filters; filter transmission characteristics; how they
relate
to CCDs; and how to assemble filters from Schott coloured glass.
I have made a motorised filter wheel to hold my colour filters. Here is
a description and some photographs of it.
(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).)
How to cut glass circles for filters, which is also applicable to
cutting
the hole in mirror for a Cassegrain.
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.
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.
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.
home
to
Cookbook CCD
Page last updated 2011/05/21
Steven Lee
This
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.
