Here you will find answers to a number of
Frequently Asked Questions (FAQs) about the Telescope
Making class itself. If you have questions that are not answered here, please either enquire at
the class or submit them by e-mail via the telescope
making class discussion list.
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Q: Who can
attend?
A: Members of the ASSA Johannesburg Centre.
If you are not
already a member, we would prefer you to join the Astronomical Society, as
the class is run under the auspices of the Society and there is a degree
of cross-subsidisation. See the About section of this web site for details
of what else the Society does, how to join, etc.
We try to cater
for both the beginner (who has not yet completed a telescope) and the
advanced (those who have successfully completed at least one telscope).
If you do not wish to join
the class, but would like to know what is involved in building a
telescope, you are welcome to drop in and observe. We will try to
answer any questions you might have, but remember that the class
members have priority when it comes to having our attention.
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Q: Where?
A: The class meets in the Design Technology centre of Parktown
Boys' High School.
This is situated on the corner of Jan Smuts and Empire
roads, Parktown, Johannesburg. Entrance is from Wellington Rd. (parallel
to Empire). Go in the gate and follow the driveway to the right - it makes a
right-angled bend to the left just as it hits some buildings. The
technology centre is the building immediately to the left of the alleyway
marked No Parking. Find a map
here>>.
Don't park in a no-parking
zone: your wheels may be clamped, the car could be towed away.
Besides, it would annoy us.
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Q: When?
A: The class runs most Saturday afternoons, starting at
about 2:30 PM. You can begin now!
Our classes are pretty much ongoing, though we
sometimes have a day out if there are other events on, and around major
public holidays.
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Q: How
much?
A: The class fees can vary from time to time according to
the costs of materials, and of course according to the size of the
telescope mirror you want. Please ask at the class for the current
prices.
All other costs are to your own account, but typically it is possible
to build a suitable instrument for about R2000. The money goes out slowly
over time, and the actual cost is a function of your expertise, scrounging
ability, ingenuity and of course the standard of finish you desire. To put this in perspective: you should end up with a scope that would
be the equivalent in performance of one that would cost you at least 3x as
much to buy commercially.
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Q: Who
do I talk to?
A: When you arrive at the class, ask for
Vincent Nettmann,
who looks after the beginning stages. He will provide the materials and
initial guidance. If he is busy, don't worry - just ask anyone and they
will steer you to someone who can anwer your questions and get you
started. The class is run on an
informal basis and discussion is encouraged. This is a
"mutual benefit" situation, so you are expected to interact with and help each
other as a matter of course.
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Q: What is
included?
A:
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The materials for making the mirror (i.e. glass,
abrasives, polishing agents). Glass disks are usually available in a
number of sizes, ranging from 4" to 8".
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A set of notes.
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General instruction.
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Use of the workshop facilities, which you are expected to treat with
respect and help keep clean.
Since we help each other, the group also accumulates other materials
that can be shared out among the members, either free or for nominal cost.
If you have any special
skills or materials to contribute to the group, or feel that you
may be able to assist in any way in running the class, please volunteer them.
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Q: What are we
building?
A:
Typically a Newtonian reflecting telescope on a Dobsonian
alt-azimuth mounting.
If you have any doubts as to which
size you want, we recommend going for a
6-inch (150mm). This is the ideal beginners scope, manageable in size and
easy to build. It will give you access to the craters on the moon, the
belts and moons of Jupiter, Saturn's rings, the polar caps of Mars, and
more deep-sky objects than you can comprehensively observe in a lifetime.
As to further technical details, please don't expect the course conveners to communicate them by e-mail: they too must work and somehow
still have a life! Come to the class and all will be revealed.
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Q: How long will it
take?
A: This is up to you: perseverance and commitment are the
key determinants. Typically you should be able to complete your telescope
in about 6 months of spare time, and still have a life. Constant
attendance at the class is not mandatory, but is HIGHLY recommended if you
actually expect to complete your instrument. Building a telescope is a
time-consuming and occasionally frustrating business, but the
class is your support group. As long as you are prepared to
persevere, and listen to instruction, you can do it! (If, on the
other hand, you give up easily, you will probably soon drop out - so why bother?)
There are those
... admittedly advanced, experienced telescope makers ... who
have completed entire telescopes, from first deciding to build it right up
to observing with the fully functional instrument, in one week of spare
time. Then, there are many who take 25 years (literally), and many more
who NEVER complete their first scope. It's really all up to you.
In
the final analysis, no home-built telescope is ever really
"finished". You will always find something you would like to
add, change, improve... in the end, you call it "done" and move
on to enjoy it. In all probablility, if you do get your scope to this
point, you will revisit these details later, or build another one
incorporating the ideas that come to you over time. If the bug bites, you
may find yourself building telescopes forever. You have been warned!
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Q: What do I need to
bring?
A: For your first visit, it would be helpful to have a
notebook and pen, but that's all. We will explain all, at the time!
Wear casual clothes that you don't mind getting a little dirty.
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Q: Anything
else?
A: All
participation in any of the Centre's activities is at your own risk. You will be expected to
sign an indemnity at the class, because we shall have access to potentially
dangerous tools and materials (don't worry: we haven't lost anyone yet!)
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