Thursday, July 17, 2008

Mai Telescopes - Let Me Show U Thems

I have two telescopes, both with stories.

The stories start with a desire to have a telescope. I got one when I was a kid, a little 3" Tasco refractor with a crappy alt-azimuth mount, single magnification and a wobbly tripod. I would have loved it, except for its flaws.

There's a definite catch-22 to any interest in that, they all seem to require an initial investment that has to be enough to break above the "craptacular" quality level. My Tasco ( as are pretty much all "department store Christmas telecopes" ) was below that point. But if it turns out that the interest ends up waning in a few months/years, then its a bit of a waste of money.

This is probably one of the main reasons I like to make things. I know in my heart I will never develop a true passion for anything, but I want to at least experience it. So although I want a $1500 8" goto scope with GPS, I'm happy to settle for making my $75 4-1/4" Dobsonian.

"Dobby" started out with plans from The San Francisco Sidewalk Astronomers
. I decided to go a little more modest and scaled things down to a 4-1/4" mirror that I picked up on ebay. I suppose I could have ground my own mirror, but that's getting into the whole passion thing again. Dobby saw first light in 2004. I was concerned that optically, I would have garbage - the precision is pretty important and this is just plywood and brass wire. But the optics are great. The mount is a bit crappy though. The box is about 1/8" too big for the tube, which means I have to wedge it in there, and the altitude tracking is very sticky, which means when I want to nudge it up a bit, it ends up flying way past where I want it to go. One Day I'll get around to fixing it.

This 6" reflector came from a garage sale, oddly enough about the same time as I was half way through constructing Dobby. I haven't got a name for it, although I've considered "Neville". It came with a behemoth of an equatorial mount that was pretty worn out. I tried repairing it, but it was so poorly designed in the first place I ended up just bailing on it. It seemed to be a home made contraption, judging by the 50's era Soviet Engineering style construction ( Aluminum? What is Comrade? Using best quality gauge 3 pig iron - is good! More bolts here! And here! )
Anyway, I finally broke down last week after seeing a mount on ebay for a reasonable price. It's terribly underweight and there's more vibration that there should be, but it works well enough to pass my quality/price ratio.

Of course, I still want one of these.