So you want a telescope? Or perhaps you just want a better telescope than the one you already have.
Should you make your own telescope?
Making you own telescope is often abbreviated as ATM (amateur telescope making) and it has quite a following of enthusiasts.
Great Astronomers Used To Do It
If you read about the history of astronomy, you will see that many of the great astronomers in the past built their own telescopes.
They sought to improve on what was available and also, to build an instrument that was designed for the work they wanted to do.
You can justify a DIY (do it yourself) telescope similarly now. I like the idea of getting a custom solution, together with perhaps getting more for my money.
Also, the idea of creating something with your own hands, that you then use to explore the Universe, is fantastically attractive to me, at least.
But, Times Have Changed?
When I was first getting into astronomy, it was fairly common to make your own telescope. As a teenager, I was tempted to try, although I did not.
Nowadays though, there is a much wider range of good-quality, commercially produced telescopes, available at fairly inexpensive prices.
The industry has been led by a small number of large companies. They have taken advantage of mass-production techniques and manufacture in the currently low-cost area of China, to provide some very good value equipment to amateur astronomers.
So Why Would You Make Your Own Telescope Now?
I know that many keen astronomers would think that you were a bit bonkers, if you announced you were going to make your own DIY telescope today.
They would tell you to go for the good commercially available stuff, I have just mentioned.
Generally, I agree with them.
However, I would suggest there are two situations when it is perfectly sensible to consider the DIY (or ATM) telescope making approach.
These are:
Firstly, if you want a large aperture telescope (say over 12 inches/300mm aperture) and cannot afford thousands of pounds or dollars to buy one “off the shelf”
Secondly, if you would really enjoy the project of creating a telescope yourself and would get real satisfaction, from using an instrument built specially to your requirements.
I personally fall into the second category.
So How Would You Go About It?
So if you decide to give amateur telescope making a try, how would you start?
The first thing is to settle on building a reflecting telescope, based on a mirror, not any other type of telescope. Don’t think about refractors or hybrid designs (for example Schmidt Cassegrains), these use large lenses and are too hard to make.
The most favoured telescope for DIY build is a Newtonian reflector, on a simple Dobsonian mounting. There are many plans available to show you exactly how to go about it.
Then comes the big decision – will you make your own main mirror?
This is exactly what DIY telescope makers always used to do.
The advantage is that you CAN get a good mirror at low cost, by physically grinding and polishing a blank disc of glass into a parabolic telescope mirror.
The disadvantage is that it takes a long time, is a lot of hard work and requires a high level of technical skill to get the correct profile on the mirror surface.
I have to admit, I’ve never made a mirror, but people do and they seem to enjoy the experience.
I would recommend instead, buying a ready-made mirror set. This is a matched pair, consisting of the large main mirror together with a flat secondary mirror, which is what you need make a telescope in the Newtonian configuration.
Commercially-made mirror sets are not too expensive, although the price goes up rapidly with size.
Most importantly, buying a mirror set should ensure that you have high quality optics as the basis of your telescope.
Then you will need to check your plans and make or buy all the various other components and get started!
Here is a simple online spreadsheet to look at the various items and costs involved. ATM Cost Spreadsheet
Summary
It is perfectly possible to build a DIY telescope and many people do.
If you are keen to own a large reflector and would enjoy the project, it can make a lot of sense.