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(not so simple) Simple Beam Collimator reviewed

Zander

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Well, after 1 weeks shipping time, I finally assembled the beam collimator.

http://www.laserpointerforums.com/forums/YaBB.pl?num=1179242523

The hardest part about this whole thing was getting the LEN1 to fit in the PVC tubing. This took me more than 2 hours and would take anyone else probably a whole day; this being that my dad is a jeweler. I have the access to drills and other tools that an average guy would not have. Those were needed to get the inside of the PVC tube exactly the right diameter for the LEN1 and to make that diameter in the right place down the tube so that LEN1 would fit snugly. After many attempts, Mr. LEN1 started to slowly chip away after each adjustment of the inside of the PVC tube.

Making LEN1 fit in LTUB1 was nearly impossible. This is the first reason you should not buy this kit.

After the LTUB1 was fully put together, now LEN2 had to be positioned at exactly _____ inches away from LEN1. The PDF file recommends 2.15 inches. The 2.15 inches part was also hard as I had to guess where LEN1 was inside LTUB1. It would be so much easier if they made clear PVC tubing. I know that my LEN1 and LEN2 are more than 2.15 inches away, I would say they are 3-4 inches apart. I got the exact length by trial and error.

Now that my collimator is fully assembled, I am now ready to experience this "5-7 times" smaller dot. Okay, I'm ready to be amazed!

I shine my laser at a brick wall across the field, and see no difference.   :-?

"It's only a tiny tiny bit smaller, nothing special and hardly noticeable," my friend said while standing a few hundred feet away from me.  :mad:

Wait, WTF? I just spent $30+ dollars and nearly half my day making something that does not work? F_CK! This "5-7 times smaller" bullshit turned out to be around 1.5 times smaller, not noticeable unless you have someone standing next to the dot measuring it for you. This is the other reason you should not buy the kit.

Attached are all the parts laid out and a comparison shot from a few hundred feet away taken with a 70-300mm Nikon lens zoomed all the way in.




DO NOT BUT THIS PIECE OF CRAP!
1/10

**EDIT** removed F-bomb {SenKat}
 

Hemlock_Mike

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Re: (not so simple) Simple Beam Collimator reviewe

Is it possable to adjust the focus on this "telescope"?? Seems it should do better than that. I thought it was adjustable for range.

Mike
 

Zander

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Re: (not so simple) Simple Beam Collimator reviewe

I guess it is, you can always twist and untwist ADJMALE from ADJFEMALE. But why would you have it anything from the most focused point.
 
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Re: (not so simple) Simple Beam Collimator reviewe

I think his point is that you should try turning it to see if the dot gets any smaller at that range. It really wouldn't take much more than a fraction of a mm change in distance between the lenses to throw the dot size completely off.
 

steve001

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Re: (not so simple) Simple Beam Collimator reviewe

Let start off by saying clear PVC pipe is available.
What you have is a 3x expander
It looks to me that both lenses are have positive focal length 25 and 75 mm added
together =100mm so the correct spacing is 3.9 inches or 100mm. If the the expander lens is -25mm then the correct spacing will be somewhat less than 75mm. If I were you I'd by a -6mm plano-concave lens that will give you 12.5x expander.
You can determine what the approximate divergence will be with the new lenses if you know what the beam diameter is and the beam divergence is coming from the laser originally.

It seems that you might have access to a lathe if that is so I'd machine parts to fit into your laser.
Any other questions just ask.
 
K

kingzilla

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Re: (not so simple) Simple Beam Collimator reviewe

Wow, glad you posted this, I was JUST about to buy that! :mad:
 

Zander

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Re: (not so simple) Simple Beam Collimator reviewe

steve001 said:
Let start off by saying clear PVC pipe is available.
What you have is a 3x expander
It looks to me that both lenses are have positive focal length 25 and 75 mm added
together =100mm so the correct spacing is 3.9 inches or 100mm. If the the expander lens is -25mm then the correct spacing will be somewhat less than 75mm. If I were you I'd by a -6mm plano-concave lens that will give you 12.5x expander.
You can determine what the approximate divergence will be with the new lenses if you know what the beam diameter is and the beam divergence is coming from the laser originally.

It seems that you might have access to a lathe if that is so I'd machine parts to fit into your laser.
Any other questions just ask.
clear 1/5inch inside diameter schedule 40 PVC pipe?

I'd rather not spend/waste any more time/money with this thing anyway.
 

steve001

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Re: (not so simple) Simple Beam Collimator reviewe

Zander said:
[quote author=steve001 link=1181189702/0#4 date=1181256167] Let start off by saying clear PVC pipe is available.
What you have is a 3x expander
It looks to me that both lenses are have positive focal length 25 and 75 mm added
together =100mm so the correct spacing is 3.9 inches or 100mm. If the the expander lens is -25mm then the correct spacing will be somewhat less than 75mm. If I were you I'd by a -6mm plano-concave lens that will give you 12.5x expander.
You can determine what the approximate divergence will be with the new lenses if you know what the beam diameter is and the beam divergence is coming from the laser originally.

It seems that you might have access to a lathe if that is so I'd machine parts to fit into your laser.
Any other questions just ask.
clear 1/5inch inside diameter schedule 40 PVC pipe?

I'd rather not spend/waste any more time/money with this thing anyway.[/quote]

Look online or the old school way in the yellow pages directory
 

Kenom

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Re: (not so simple) Simple Beam Collimator reviewe

steve001 said:
Let start off by saying clear PVC pipe is available.
What you have is a 3x expander
It looks to me that both lenses are have positive focal length 25 and 75 mm added
together =100mm so the correct spacing is 3.9 inches or 100mm. If the the expander lens is -25mm then the correct spacing will be somewhat less than 75mm. If I were you I'd by a -6mm plano-concave lens that will give you 12.5x expander.
You can determine what the approximate divergence will be with the new lenses if you know what the beam diameter is and the beam divergence is coming from the laser originally.

Wow! I totally understood that. NOT! gonna haf to read it slowly to myself about 30 times to start to understand that. :)
 

steve001

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Re: (not so simple) Simple Beam Collimator reviewe

Kenom said:
[quote author=steve001 link=1181189702/0#4 date=1181256167] Let start off by saying clear PVC pipe is available.
What you have is a 3x expander
It looks to me that both lenses are have positive focal length 25 and 75 mm added
together =100mm so the correct spacing is 3.9 inches or 100mm. If the the expander lens is -25mm then the correct spacing will be somewhat less than 75mm. If I were you I'd by a -6mm plano-concave lens that will give you 12.5x expander.
You can determine what the approximate divergence will be with the new lenses if you know what the beam diameter is and the beam divergence is coming from the laser originally.

Wow! I totally understood that. NOT! gonna haf to read it slowly to myself about 30 times to start to understand that. :)[/quote]

Look up Galilaen beam expanders or Keplerian beam expanders, so you know and understand the differences between the two. BTW it not hard to understand especially if you do hands-on experimentation. Edmund Scientific has an inexpensive optical bench that would be great for collimation experiments.
 
S

SenKat

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Re: (not so simple) Simple Beam Collimator reviewe

[RANT]Edmund is filled with crooks, liars, and theives.  They completely lied about receiving an RMA I sent them, and held up my $100.00 order for over a month while they sat on their collective asses.  I will NEVER deal with those jackasses ever again, and I will do whatever possible to ensure that my information about my horrible experience goes out to every forum, every newsgroup, and every discussion anywhere to make sure that those clowns know that they pissed off the wrong FORMER customer. Their smug attitude while discussing my missing RMA was infuriating, and they did nothing to diffuse the situation at all. They only completed a partial refund as their solution, which is unacceptable.[/RANT]
 




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