the 3kg travel telescope made by Patrick Woitala, I started longing
for a similar device. Since no such telescope is commercially
available, what else could I do but building a small altazimuth
mounted telescope myself.
Here are some pictures of the finished
additionally here are the results of different
optical tests (including interferometric and ronchi-tests) before
and after the refiguring of the mirror by Stathis Kafalis: optical
and here are some images of the building
process: building the 6-inch dob
Because I am new to amateur telescope making,
I wanted to keep the financial risk low and ordered a used 150mm
parabolic mirror of "average quality" (1/4 Lambda p/v
Strehl ~0,8) together with the main mirror I bought a used secondary
mirror. I paid 90 € for both mirrors together.
here is a short list of my design goals:
- portability (holiday)
- easy to use
- interesting project
after some thought and many scribbles I
decided on a design which allows a 45 degree angle for the eyepiece
and uses only four trusses. After obtaining aluminium tubes (12mm)
I found 6 and 8 mm carbon tubes intended for kite-building and
decided to use those for my project.
I have to thank a lot of people who provided
tips, plans, ideas or presentation of their own telescopes, here
is an incomplete list: Patrick Woitala, Stathis
Kafalis, Martin Trittelvitz, Chuck Fellows, Barry Leger, Dirk
Here are some images of the telescope (click
on the images for enlarged version):
The first observations with this telescope
included M3, M51, M13, Jupiter, M44, NGC4565. During this first-light
observations I found out that something was wrong with the optics.
The images are not sharp. On Jupiter only two cloud bands were
visible, and M13 was only mottled, far from resolved (see the
optical bench report). My 130mm
Vixen Newton telescope has much better optics, and the Vixen was
interferometrically tested, and I know it has a lambda/2 mirror...
Stathis Kafalis has kindly refigured the mirror, and now the
quality is quite good.
I have added another page with some images of the construction
process: building the 6-inch dob.