Hi, I am Yusuke. This is my first time to E-mail to this homepage.

I am now planning to make a 12.5" dobsonian telescope(f/6) and this is my first try to build a telescope. I am intersested in observing planet and galaxies.

Before finishing to design my telescope, I would feel comfortable if the following matters are made clear to me.

1)How does the baffle work and how can I decide the position of baffle?

2)I am going to cut 2.2m tube in 3 pieces, first piece with primary mirror(0.3m), second piece tube itself(1.2m), and third piece with secondary mirror/spider/focuser(0.7m). When I use it, I have to connect these pieces firm. This is because I have to bring this telescope by normal 4 door car(not wagon). Are there any good ways to connect the tube firmly?

3)What is the merit to induce 2" focuser compared with smaller focuser?

4)As for secondary mirror size, which is better to choose a mirror which is a little bit larger than the ideal size or a little bit smaller than the ideal size to observe planets.

5)Merits and demerits of curved spiders.

Any replies for my any questions are much appreciated.

• Re: Some questions about telescope making - bobmay - April 6, 1998 - 20:21 UTC
  • Speaking of Spiders - Tony Dunlap - May 28, 1998 - 15:21 UTC