Introduction: Green Laser Pointer Mount for Your Telescope

Picture of Green Laser Pointer Mount for Your Telescope

Greetings!
This is my first instructable. I hope it goes well.

As an avid astrnomer on a very tight budget, I have to make do with what I have. I star hop to my targets and have no motorization on my scope. But I have found an easy way to shorten the time it takes to reach my targets. I have attached my green laser pointer to my scope and use it to aim my scope.

If you have visited a star party or sidewalk astronomy session you may have seen how wonderful these green lasers are at pointing out the wonders of the night sky. It seemed only natural to put it on my scope. This instructable will tell you how I did it.

Step 1: Tools and Materials

Picture of Tools and Materials

Ok, Heres what you need:

Strong Magnet(s) big enough and strong enough to hold your laser stable on your telescope. (I used a big speaker magnet but a rare earth magnet should work as well.)
1/4" aluminum U channel about 6 inches long
sheet tin or steel (as long as it's magnetic)
1/8" wall aluminum angle with 1" sides
brass strip 1/2" wide
#4-40 allen screw about 3/4" long
#2-56 wing nut
#2 nylon washer
#2-26 steel nut
#2-56 brass nut
#2-56 machine screw (2)
green laser pointer

tools:

hack saw
drill and bits
epoxy glue
pliers
soldering iron
4-40 tap

Step 2: Start Building

Picture of Start Building

Sorry, I don't have a good picture for this step.

First, we need to make a few pieces

Aluminum channel

1. Make the aluminum channel by drilling 2 holes to accept 2-56 screws and one additional to tap for 4-40. Make sure the holes are placed to match the function of the screw.
2. Cut two tabs in the aluminum channel and bend them slightly out to accommodate the brass assembly.

Brass assembly

1. Cut a strip of brass shim long enough to wrap around the laser housing plus just enough to allow the ends to be soldered to the brass nut. (see the exploded picture in the previous step)
2. Solder the nut to the brass strip. Any standard soldering iron should be able to accomplish this. It will be easier to solder if the brass pieces are tinned (a thin application of solder is applied to the surfaces to be joined before the actual solder process)

Mount

1. Cut a 1" long piece of aluminum angle and drill a hole to accommodate a #2 screw in the vertical side near the top edge.
2. epoxy the magnet to the bottom of the mount assembly. ( I was fortunate that the magnet i found was able to be screwed to the aluminum angle, but I don't think this is necessary.)
3. I applied electrical tape around the magnet to protect it, but again, this is not strictly necessary.
4. epoxy a 1.5" square piece of tin or steel to a flat spot on your telescope tube. (if you use steel, be sure to protect it with paint to prevent rust)

Step 3: Put It Together

Picture of Put It Together

1. Insert a 2-56 machine screw into the middle hole of the u-channel to the threads point out the back. Use a nylon washer between the angle and u-channel and fix it together with a wing nut.

2. Slide the brass collar on the laser and position it to line up with the second hole. Insert a 2-56 screw through the channel and engage the brass nut. If the collar fails to pull tight , an additional nut may be required on the outside of the u-channel. If it still fails to pull tight, re-soldering the brass assembly to fit more closely will fix the problem.

3. screw in the 4-40 screw and align it to hit the momentary switch on the laser.

Your laser mount is ready for use!

Step 4: Use It!

Picture of Use It!

Ok, slap that laser on your scope and point! Take time to align the laser with a known naked eye object that the telescope is pointing to.  Simply turn the entire assembly against the steel/tin plate to adjust the relative azimuth and adjust the channel relative to the angle aluminum to adjust the relative altitude. For greater usefulness, use your binoculars to view fainter stars and increase your pointing accuracy. You can also pull the laser off and use it hand-held or put it on a different scope, just make sure to re-align when you put it back.

Clear Skies

Comments

georgeATM (author)2011-07-11

Kelsey: indeed, safety is very important with all lasers. I only specified a green laser to be used because the wattage and brand can,change with equal effectiveness. As far as misuse, anyone who would misuse it will likely not get much advantage using this mount.

kelseymh (author)2011-07-11

You haven't provided any guidance on what kind of laser pointer to use with your mount, nor have you indicated any knowledge or understanding of the legal limitations on pointers which can be used in this manner.

While your build is technically excellent, the lack of any recognition of the legal and safety issues involved raise concerns about how it could be inadvertently misused by people who are not themselves aware of those issues.

You should read the following (and the referenced links).

http://www.laserpointersafety.com/laser-hazards_aircraft/laser-hazards_aircraft.html

meeware (author)2013-01-08

I've tried a similar though less elegant project recently, and ended up getting a £10 mount of the internets when I hit a couple of snags- firstly, my scope isn't ferrous, so I needed to add a metal plate to stick the finder onto, and the magnets didn't have as reliable an attachment, so would easily be knocked and require a recalibration. Secondly (and also magnet related) I found it very difficult to glue to rare earth magnets- granted I tried cyano acrylics, but the little blighters just wouldn't stick. I de greassed, I sanded, I dremelled to rough up the surface, but I have found rare earths to be really hard to work with.
I'll probably give this another go though, as I have a teeny 76m reflector that I fancy lasering up.

gmartin2000 (author)2012-05-14

I'm a little late to the party but having done something similar, I can say that the 5mw lasers sold by astronomy outlets are recommended. See links below.

Keep the lasers warm. Below about 50 degrees f they fail. When its cool out, I keep mine warm in my breast pocket till I need it.

Alignment is too easy: The beam can be seen in a low power eyepiece so there is no need to find a star or object on the horizon like you would need for a typical optical finder. Loosen the mounting/alignment screws of the holder and slowly move the laser around. It will pass through the field of view and you can lock it down. A bit tricky till you get the hang of it.


here are a couple of links:
http://tinyurl.com/laserpointersafety
http://tinyurl.com/Astroscan-laser-finder

chichimus (author)2011-10-01

this is just what I am planning to do. I have a small Dobson that is a pain to orient. Thanks for the ideas.

Dannne11 (author)2011-08-07

Warm batteries are dying batteries :D

georgeATM (author)Dannne112011-08-07

Cold batteries too. Its not like I am keeping them "warm", just "less cold"

thirtyfivefox (author)2011-07-12

Is this really that effective for aiming a telescope? It would be crazy difficult to zero a laser for the huge distances you would have to cross.... especially if you are using a radio tower. The geometry doesn't make sense. I also wouldn't recommend putting a laser in the sky over 15mw... unless you want to start popping up on DHS and FDA blotters... pilots report lasers in flight increasingly and that stuff gets reported around. (still high altitude aircraft should be fine as long as you stay under 15mw, most off the shelf is less than 5mw)... also check a map of where ever you set up to make sure you are not near an municipal airport or something. Also I would recommend fashioning a momentary on push button switch on a wire lead that could be used to remotely turn the laser on and off from somewhere that wont affect alignment. That way you can turn it on when you need it and it stays off when you don't! like one of those camera shutter release buttons you see on high end photo setups...

http://www.nytimes.com/2011/01/22/us/22lasers.html

http://www.theregister.co.uk/2005/01/06/laser_man_charged/ (not the most reliable source but meh... looks like the guardian..)

georgeATM (author)thirtyfivefox2011-07-13

Yes this is good for aiming a telescope. The alignment suggestion is workable & good for alignment. The beam can be seen and due to perspective it appears to end in a point. My laser is spec'd for just shy of two mile range. there is no way to actually hit a distant tower(much less anything outside of the atmosphere) so the beam is all that is being used for alignment.
Again, lasers and planes dont mix. If you are responsible, it wont be a problem. I only leave the laser on long enough to aim my scope. For heavy handed individuals, a remote switch is an excellent idea.

dimtick (author)2011-07-11

I really love this. gonna have to make one for my scope.
one question....How do you align the laser once you have in mounted to your scope? You kind of explain it, but I didn't understand it.

georgeATM (author)dimtick2011-07-11

The key to alignment is simply making sure your scope and laser are pointed at the same thing. A radio tower in the distance is a good example. The mount is very intuitive to align by moving it left-right, then adjusting it up-down. I hope you complete one to see how simple it really is.

dimtick (author)georgeATM2011-07-11

that makes sense. I'll let you know how it goes.
I have always used the moon to align the spotting scope. Didn't seem like that would work with the laser. Using something "local" like a radio tower makes a lot more sense.

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Bio: Tinker, astronomer, father, busy body.
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