Instructables
Picture of Laser Starfinder
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I've always been interested in astronomy, and often thought I'd like to get a telescope.  Last year was the International Year of Astronomy, marking the 400th anniversary since Galileo first pointed a telescope at the heavens, and learned that there was so much more to discover there.  There were a lot of astronomy related events going on, and it spurred me to delve into the subject again.

By fortunate happenstance, I managed to acquire a somewhat dirty and disused, but quite serviceable 10" newtonian telescope.  Since then I've had great fun finding nebulae, examining planets, and gazing in awe at the detail that can be seen on the moon.

I've had some trouble finding things though.  Using a finder scope (the small telescope mounted on the side of your larger one) is a big pain in the rear.  At one of the monthly star parties hosted by our local astronomical society I saw that someone had a green laser mounted to the side of his telescope in place of a finder scope.  It was amazing!  He didn't have to mess around with anything, he just turned on the laser, pointed it where he wanted to look, and there it was!

I of course thought to myself, "I can make one of those!"  So here I'll show you how you can as well, and save a few bucks off the cost of buying one of them new.  This is a very simple and cheap fix that will definitely make amateur astronomy a lot more fun!


If you should decide to make one of these yourself, make sure to post a picture in the comments section below, and I'll send you a digital patch!


 
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dorkpirate5 months ago

neat! but I would find out if its legal in your area to fire green lasers skyward. some people especially near airports might get onto trouble

depotdevoid (author)  dorkpirate5 months ago
I'm pretty sure it's okay as long as you're not actively pointing them at airplanes, but you're right--people should definitely check their local laws.
everyone don't do that. at least the laws in the area I live clearly state even if there is no air traffic you can still be finned the minimum fine of $10,000 and a 5 year sentence in jail. and secondly the only civilian laser able to be purchased that can enter our atmosphere is stupid expensive and can only truly be seen on the moon.
edrisamiry5 months ago
wow thanks
berfraper5 months ago

I use a regular green laser for that, it has enogh power to see the beam and it costs about 15€ ($10~).

meeware1 year ago
Looks really easy to knock the laser out of alignment, don't you have to keep recalibrating it? Like the use of sugru though!
depotdevoid (author)  meeware1 year ago
It's not really for precision work, just to get you pointed at the right area. It IS really easy to knock out of alignment!
tinker2343 years ago
wow cool
hottroc4 years ago
I don't quite get this? It's a great idea for improving your telescope but.....Seems like you have just taken apart a laser pointer you had to buy then reassembled it exactly the same but in a less neat/compact format. Have I missed something here? Would be more useful if you had started from more basic components perhaps.
depotdevoid (author)  hottroc4 years ago
Whoops, sorry looks like I missed your comment! I usually try to get back to people the same day when they've got questions, but I guess this one slipped under my radar.

It is true that the new assembly is less, as you say, neat and compact, but it has been reconfigured for a different purpose. There are several advantages to the new design:
  1. The new shape allows it to be conveniently strapped to the telescope
  2. The new shape also is aligned so that it will be immediately useful when attached to said telescope
  3. It now has a click on, click off switch (like a flashlight) rather than a momentary switch.  This allows you to turn on the laser and then use both hands to point the telescope, rather than keeping on hand on the laser to keep it on
  4. It now uses AA batteries instead of AAA's.  This allows for much longer battery life.
I hope that answers your questions.  Also, what do you mean by it being more useful if I'd started from more basic components?  I don't understand what you're saying there.
cefn4 years ago
Wow I'd never heard of this before, but I've always been fascinated by the way a laser goes off forever into space and wanted to do something with it. Just using the parallax to help your perception of stars is genius.

Don't annoy the little green men too much.
depotdevoid (author)  cefn4 years ago
Hi Cefn, thanks for the comment!

Unfortunately, this little greenie laser probably doesn't keep going up to space, it's weak enough that the atmosphere would absorb it before it got that far. You should check out how observatories use yellow lasers in their work, they actually use them to create an "Artificial star" to help their telescopes compensate for air currents and temperature gradients.

I'll try not to annoy the LGM's, I don't want to get the dreaded anal probe!

If you've got a moment, I'd love a vote in the Sugru and Gorilla Glue contests!
'Tis done. Crazy to vote against myself but I need new insights like this once in a while. Also I've been collecting high-powered lasers for no visible reason for some time, and I should damn well do something with them.
depotdevoid (author)  cefn4 years ago
Ah, but collecting high-powered lasers is its own reason! I only collect low power lasers, just in a variety of colors, because I'm too cheap for protective eyewear and I'm scared for the integrity of my eyeballs.

By the way, I cast a vote your way for the calendar, it's a great project and a great write up! Don't forget to vote for yourself as well, I saw I was the first vote on it!
You can vote for yourself. Yuk, I feel dirty. But I did it anyway. Thanks for the advice.

I just got featured! Had to tell someone who'd know what it means to me. My family and colleagues will just look at me blankly. I was almost hoping I wouldn't get featured, as it makes me think I'll have to do something even bigger and better next time to make the grade - maybe no bad thing.

Out of interest do you have access to a laser cutter? Do you know who I should recommend to people stateside?

I got lucky and found someone in the next village (Suffolk, UK) who has one and isn't too busy so I get a pretty good service - same day often.

The first proto of the tacticalendar I went through Ponoko UK which was a truckload of cash and they took more than three weeks! Can't speak for the other Ponoko making centres around the world though.
depotdevoid (author)  cefn4 years ago
Yeah, I used to feel bad about voting for myself until I realized I could vote as many times as I wanted, so I make it a point to vote for lots of people as well as myself.

Congrats on the feature! I remember the first time I got featured and I told my girlfriend about it. Her reaction was, "Oh, that's nice."

Unfortunately I don't have access to a laser cutter. I'm kind of poor and haven't really looked into the options available in the US. Of course, I've not yet had a project where I felt like I really needed one, but if I had easy access I'm sure I'd come up with some sort of excuse!

I know a guy through work who runs a plant where they have a 4 kilowatt laser that cuts 3/4" plate steel. I got a tour once, which was awesome. As cool as the giant laser was, the super duper high pressure water jet cutter was actually more impressive. They cut a 2" diameter slug out of a solid steel gear 5" thick with that thing!

It's cool, but there's no LED here.
depotdevoid (author)  fungus amungus4 years ago
Laser LED? That's how cheap lasers are built these days, take a look at the wikipedia page.  Still, I admit I was stretching the definition a bit!  It doesn't hurt to try, right?