Constructing a Tri-Beam laser pointer for a telescope...

[chicagoastronomer]

Hi laser kids,

Cool site and a great data/knowledge base.

I have a question.....

I have been using 50Mw+ Green lasers in my astronomical public outreach sessions, both in-hand pointers and mounted on the Telescope via a Zhumell laser holder. Using it to slew to celestial targets is a great tool and impressive for the visitors. Don't know how I managed without one before.

But I was thinking.....

I would like to mount three Green laser modules, (or similar), along the outside far rim of the telescope tube, (C11 SCT) - and have the three beams converge into space and unto my selected object. Not only helping to find my objects, but it would look so cool.

Something Dr. No would use.

Any insights on how I could construct such a Tri-beam like this...controlled with a single switch and perhaps powered by a 12V power center via inverter or something like that?

Thank you.

Respectfully,

Astro Joe

 

[magonegro]

Check for a black tube of aproximate diameter of the telescope's tube. Use three laser holders on the black tube. If you can attach 3 50mw modules to the holders you are done, simply one set of batteries for the three lasers, and some soldering on the switchs to become only one. I am talking about modules like this: DealExtreme: $16.43 50mW 532nm Green Laser Module (3V 11.9mm)
Once assembled protect it as you want. It could have an awesome look...

 

[AstroLaser]

I would like to mount three Green laser modules, (or similar), along the outside far rim of the telescope tube, (C11 SCT) - and have the three beams converge into space and unto my selected object. Not only helping to find my objects, but it would look so cool.

Hey Astro Joe !

Welcome to the forum !

Neat idea, that would indeed look cool !

(please post some photos of the 3 beams converging if and when you do build it !)

I'm still learning more about laser technology so I'll defer to other much more laser tech savvy members of the forum to offer tech advice as far as wiring on that type of setup, but I was wondering - since those 3 converging beams would be in the field of view when you look thru the eyepiece, would it be safe to look thru the eyepiece with them on, or is that something you would turn off before looking thru the eyepiece ?

 

[chicagoastronomer]

Magonegro,

I was looking at those at DE a few weeks ago, and thought that perhaps I could utilize the exact same ones for my project. I'm pleased that you think so too, but wouldn't I need more than just one set of batteries, (2x 1.5v), to run all three?

Astrolaser,

This is what I have on my C11 presently:

The Chicago Astronomer - Zhumell Laser Finder Holder

The laser holder works very well. In observing, the beam can be seen in the finder scopes and the main eyepiece with no ill effects. It's greatly diffused by the time it reaches the target area and cool to view it in the field of view - confirming the desired area.

I'm pretty anxious about making this over the winter, but do encourage the input from our great laser minds here.

 

[magonegro]

You can also try with one 18650, (or two or more in parallel for increased runtime) For sure juice enough! I power one of my modules with a 18650 and no problems so far. The same applies to 16340's 14500's etc. Use ALWAYS protected batteries. You have several models of suitable rechargeable lithium batts. If you are in R/C control you could aso use LiPo batts like this: DealExtreme: $17.33 Mystery 7.4V 2800mAh Lithium Polymer Rechargeable Battery for R/C Helicopters This will give you in parallel 5600mah at 3.6v !! I use things like this for my labbies.

Magonegro,

I was looking at those at DE a few weeks ago, and thought that perhaps I could utilize the exact same ones for my project. I'm pleased that you think so too, but wouldn't I need more than just one set of batteries, (2x 1.5v), to run all three?

 

[Petacat]

Hi Chicagoastronomer Welcome!
I did a lot of observing in Alaska and had trouble with keeping the laser warm in cold weather. The batters on hand helds would get cold and the laser would go dim. I had to stick the laser up my artic parka sleeve to keep it warm untill I needed it. When using a lab laser powered by an extention cord the cold would over come the power supple . It would struggle to mantain it's tempture and I blow one up.
Also More than 5mW would interfer with my night vision. Three 50mW lasers would be very bright. Nice scope by the way! I'm observing with a 9.25" and and old orange 5". Had to leave the big Dob with the grandson when I retired and left Alaska

 

[chicagoastronomer]

Petacat,

Yes, I have encountered the "chill" factor with lasers here in Chicago, but if I can keep a chemical hand warmer on the batteries, it may be enough to keep them toasty for a pubic session. Are the working parts of the laser affected as much as well?

And....

I dig the 9.25s. It's the sweet spot between aperture and portability...but I set-up my C11 everywhere and have had thousands peer through my scope. And that's the reason for three targeting lasers - for the "oooh" factor. I get compliments on the single 50 mw laser on the C11 as it is - and it's only one for brief seconds at a time. I woinder if I could pulse them...hmmmmm.

Magonegro,

This is encouraging to read.

I have some more questions, but later on tonight. Thank you.

 

[Petacat]

The night sky is so wonderful by it self that you don't need high power lasers
to get the WOW factor from the uniniated. Their first look a Saturn, Jupiter,
the moon - Luna, or our Sun - Sol, through a big scope always gets a WOW.
I used the high power lasers for a while to get people to come over to my scope
at star parties, but many of the other astronomers complained. Now days it's
smart not to use more that a 5mW laser in public as it is illegal without certification,
and if someone gets hit in the eye, you could get sued. I had stopped using them
altogether, because of airplanes and the flap about people shining lasers at them.
But [Tech Junky] informed me 5mW was still legal to use for star pointing.
I also have a 40mm solarmax for viewing Sol. It changes every day, and has
become my favorite stellar body to view. :wave:

 

[chicagoastronomer]

Petacat,

Light Pollution.

Must punch through the orange blanket of muck.

Those H-Alpha scopes are indeed a window to a hidden world.

Very cool.

 

[Cyparagon]

it may be enough to keep them toasty for a pubic session.

Freudian slip spotted! :shhh:

Srsly tho. One beam is enough to aim your telescope. Any more is redundant because of the distance between the lasers and distance to the object. If you're doing it so it looks cool, that's a different story.

I'd recommend powering three in series with a 9V source.

 

[chicagoastronomer]

Cyparagon,

In all reality, lasers are a more recent addition to the gear and astronomy has been successfully experienced forever. I do use the 50mw for quick aiming and locating, but in public astronomy, it's all about the presentation and show - more than just plopping down a scope and lookin'.

Three converging lasers put on a show and builds anticipation for the views. Needed, no, but would look cool and memorable.

The 9v is a good idea.

Toasty Joe

 

[Benm]

I guess it could be a nice visual aid in some demonstrations, but it would effectively be a source of light pollution on its own. If you point 3 lasers around whatever you want to observe, keep in mind that the divergence of those lasers isn't zero.

 

[chicagoastronomer]

Benm,

For a few seconds of operation, the light pollution is minimal and remember...this is not a countryside setting, but Mercury Vapor soaked city skies, where a 5Mw laser is a weak beam at best.

Often, after viewing objects in the eyepiece, visitors usually ask where it is in the sky and it has been a simple matter of pushing a button and lighting up exactly where they just looked.

But I'm digging the tri-laser pointer and will be a crowd pleaser.

 

[millirad]

I'm relieved to find out that city skies are not literally soaked with "mercury vapor", as I misread your statement. It's light pollution as you obviously stated. Mercury vapor is what made the mad hatter, mad. LOL But, I can see that the mercury vapor spectral emission lines ruin astronomical observations near cities. Those lines are intermixed in this spectrum/signature of a galaxy observation......

 

[chicagoastronomer]

Hehe...

Breathe deep, the gathering gloom...

50 mw seems to be the sweet spot for good visible beams, (which is probably actually lower), and for group instruction.

I'm this close from ordering the DX ones.