Saturday, July 19, 2008
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 w
here 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.
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.
. 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 w
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.
Tuesday, July 08, 2008
Monday, June 30, 2008
Saturday, June 28, 2008
Cold Start
I seem to recall a time in my life where I was "smart" - i.e. had a crapload of learning at my disposal along the lines of higher mathematics, physics, literature... all those things they cram in your brain in university. Problem is I never put that to use beyond the final exams, so now when I encounter my lecture notes, conveniently stored in cardboard boxes down in the spidery depths of the crawlspace, I marvel at the cryptic scribblings I used to understand.
I had occasion to recall some of these arcane spells when I went on my annual Lynden, Washington trek for the Rhinoceros teacher seminar.
Here's the problem: Wanted to generate a stereoscopic rendering of a 3D model. This involves the following process:
10:00 am: Google "Rhino scripts" to recall how to reference camera postion
10:30 am: spend significant amount of time deciphering how Rhinoscript deals with vector notation. It should be A, why am I getting errors?
11 am: recall vectors and arrays are declared as a variant, which has to be initialized. Oh yeah.
11:30 am: lunch at Eastside Deli : Awesome sandwiches.
12:30 pm: try to remember my vector transformations. do a *lot* of uugling ( useless Googling).
1:30 pm: finally remember enough vector transformations to scrape a vague script together.
2:00 pm: discover Rhino plugin called "Monkey" - IDE fro Rhinoscript. Life is made 90% easier.
2:30 pm: discover many, many built in vector transformation functions in Rhinoscript already exist. Using these removes 5 "For-Next" loops, and reduces script volume significantly.
3:00 pm. prototype script works. Looks stupidly simple. This took me five hours? Minus Lunch?
I'm embarrassed.
It's the mental equivalent of this
I had occasion to recall some of these arcane spells when I went on my annual Lynden, Washington trek for the Rhinoceros teacher seminar.
Here's the problem: Wanted to generate a stereoscopic rendering of a 3D model. This involves the following process:
- render image, save as "left.jpg"
- shift camera axis a factor of 1/16 the camera/target distance to the right, along a line perpendicular to the axis, preserving z coordinate
- render image, save as "right.jpg"
- ????
- profit!
10:00 am: Google "Rhino scripts" to recall how to reference camera postion
10:30 am: spend significant amount of time deciphering how Rhinoscript deals with vector notation. It should be A, why am I getting errors?
11 am: recall vectors and arrays are declared as a variant, which has to be initialized. Oh yeah.
11:30 am: lunch at Eastside Deli : Awesome sandwiches.
12:30 pm: try to remember my vector transformations. do a *lot* of uugling ( useless Googling).
1:30 pm: finally remember enough vector transformations to scrape a vague script together.
2:00 pm: discover Rhino plugin called "Monkey" - IDE fro Rhinoscript. Life is made 90% easier.
2:30 pm: discover many, many built in vector transformation functions in Rhinoscript already exist. Using these removes 5 "For-Next" loops, and reduces script volume significantly.
3:00 pm. prototype script works. Looks stupidly simple. This took me five hours? Minus Lunch?
I'm embarrassed.
It's the mental equivalent of this
Sunday, June 15, 2008
Wednesday, June 04, 2008
Convergence

Required knowledge:
One of my favourite rockets of all time was the Estes Orbital Transport.
Fun to build, looked very cool, flew great... awesome.
It was the only one I kept from my younger rocketry days, and it began to decay - broken fins, crushed body tube, dented nose cone....
Eventually, the damage was too far gone. Bye Bye....
Current Events:
Last week, three things happend:
1. I found this site
2. The local hobby store had a 25% off sale
3. Free time on a laser cutter
...the omens are clear....
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