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Dragon Laser Viper Series

CHCKLS

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Hi guys, new to the forum after browsing around the last few days and thought I would give this a try.

I have this 95mW Viper from 2006 (I think that's when I purchased it).

I haven't used it in years but wanted to use it this past week for a camping trip now that my kids are getting into astronomy more and more.

I noticed the beam is not as focused as it was before. Opened the end cap and noticed the lens that is convex on one side and flat on the other was loose.

Cleaned it up and the middle lens and the lens for diode itself and I still get a pretty decent size "dot" 10 ft away as seen in the photo. Pointing into the sky the beam is much wider than what I remember ..

Is this to faulty lenses? Or a diode going bad.. can still feel the burn when pressed to my palm bit that's about it.

BTW, dot on tree is about 2 inches on diameter and fuzzy on the outter edges.
Any thoughts?

Thanks!
 

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Razako

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The diode is fine or it wouldn't work, you just need to adjust the collimating lens for the focal point you want.
 

CHCKLS

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Do you mean you cleaned the diode window??
Yes, and playing around with it last night a little more I removed the lens in the cap body and just held the cap with the outter lens and can see the beam getting more narrow than before so that tells me there is something going on with the lens in the cap body.
 

RA_pierce

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The problem is likely incorrect lens adjustment as Razako stated.
Any chance you have pictures of the laser?
I have some experience repairing these and can probably walk you through repair and adjustment (if the design of your lasers is the same as the ones I've worked on from the 2000s).

Note that when you glue the lens in place, you should never use cyanoacrylate adhesives because the vapors leave a residue that forms a film on optics that disperses the beam.
 

CHCKLS

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The problem is likely incorrect lens adjustment as Razako stated.
Any chance you have pictures of the laser?
I have some experience repairing these and can probably walk you through repair and adjustment (if the design of your lasers is the same as the ones I've worked on from the 2000s).

Note that when you glue the lens in place, you should never use cyanoacrylate adhesives because the vapors leave a residue that forms a film on optics that disperses the beam.
I have this one and can take more when I get back home this weekend if that will help.

You see to the right what I have been calling caps. Cap body that is about 1/2" long and black and then cap itself gold color.
 

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Cyparagon

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A small optical spanner might have enough torque to break the glue that holds the threaded lens-mount in there. It may be better to leave it alone.
 

CHCKLS

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Morning :)

So back home and in a more controlled environment. Have these pictures and noticed something. The lens between the diode and the end cap is loose and turning. I am guessing this is my issue since the beam got "tighter" or less divergence in a certain distance. I guess from here I can play with it and keep making adjustments till I am happy but would love to know what tool I need to get in there. My spanner screw driver set has square edges on there and not wide enough.. anyone tell me the size and type I need?
 

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CHCKLS

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Ah, didn't even think of that. Thanks.

Is there a good starting point for this? Example certain mm from edge of casing to face of lens holder.. wondering if these adjusted individually as they were sold or just placed inside the casing at a certain distance for all of them.
 

Encap

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Is all going to be trial and error--take it apart and clean the lens properly--put it back together --test then adjust if possible etc.
Maybe it is as good as it gets---who knows? Try cleaning and adjusting the pen lens for best focus.
Really nobody here is going to know or have all the details of that laser much less the manufacturers practices from 2006 ---DL never and still does not actually made/manufactured anything --they were/are just resellers of CNI China made items.

Here is one guys take on cleaning. a DL Viper
https://www.instructables.com/id/How-to-clean-a-laser-pointer-lens/

While Dragon Lasers still exists they stopped selling any hand held laser a while ago---you can email them and ask if they have any advice or details they can share to resolve your dilemma.
 
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CHCKLS

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Sweet. Article helped a bit. I'll mess with it over the next few days.

Thanks to everyone who responded!
 

CHCKLS

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Ugh, one more question.. I dropped the gold end cap and knocked the lens loose. There is a slight convex side and a flat side.. which way should this go back in.. I would guess convex facing diode and flat side secured to cap inside.
 

RA_pierce

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Ugh, one more question.. I dropped the gold end cap and knocked the lens loose. There is a slight convex side and a flat side.. which way should this go back in.. I would guess convex facing diode and flat side secured to cap inside.
Beam should enter the flat side and exit the convex side.
A lens like this is called a plano-convex lens.
Was the lens originally attached to the gold cap?
 

Cyparagon

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^A more general rule for optics (e.g. also applicable to telescopes, photography, beam expansion, et al.) is the collimated side of the beam is on the curved surface of the lens, and converging or diverging side of the beam is on the flat surface of the lens. I don't remember why. It does work the other way around, but not as well.
 




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