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Here is a little tip for anyone with a "303" type laser with lens problems

Steppenwolf

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The cheap "303" type lasers are all over ebay but they have barely acceptable plastic lenses and if you make the mistake of even looking at them sideways you've already damaged them, But this is how you can replace them with glass for pretty cheap...

https://www.ebay.com/itm/M8-Frame-Beam-Expander-Collimation-Lens-DIY-Green-Laser/261110312646?ssPageName=STRK:MEBIDX:IT&_trksid=p2057872.m2749.l2649

The "303" type lasers use a oddball size M8 lens threading which is not all that easy to find, I hope this can help anyone with "303" laser lens woes...
 

RedCowboy

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Re: Here is a little tip for anyone with a "303" type laser with lens problems

Usually the Gradient index lens is glued on top of the crystal holder and the focus lens is placed into the threaded barrel. It is a tiny beam expander because what comes out of the crystal is needle thin but diverges faster.

I assume the glass pair go together so you will need to remove the concave lens or gradient index lens and glue on the new one to work with the new glass lens, any misalignment can be a problem.

Something I do is to use a bigger longer FL lens in a tube and slide to focus without removing the factory concave/GRIN lens, just the final focus lens, you can get a really tight dot in the far field.

NOTE: If your module has an IR filter and you choose to omit it you do so at your own risk, although many don't have one some do and IR leakage can vary.



 
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paul1598419

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Re: Here is a little tip for anyone with a "303" type laser with lens problems

The "303" laser do use acrylic lenses, but since they are mostly below 100 mW or in red maybe 175 mW, there is no good reason to replace them unless you scratch them or use a solvent that destroys them. I have "303s" that still work fine from years ago and I keep them in an air tight bag and boxed to prevent anything happening to the lenses. Those glass lenses are almost the price of a new "303" laser. I have used acrylic lenses on many builds up to 300 mW with no problems at all. If I had a high powered 532nm laser that was over 500 mW and happened to have acrylic lenses, I might consider replacing them, but not in a "303".
 

deadshadow

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Re: Here is a little tip for anyone with a "303" type laser with lens problems

i agree with paul,the cost of the lens you posted is similar to the cost to buy a new laser,i would't bother to try to remove the lens as some are have strong glue on the threadings
 
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Lifetime17

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Re: Here is a little tip for anyone with a "303" type laser with lens problems

Hi
I’m amazed at how many 303 threads are developing with lens issues

Rich:)
 
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GSS

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Re: Here is a little tip for anyone with a "303" type laser with lens problems

Agreed,
They all seem to be after someone tries cleaning the lens?, trying to get the almighty dot and not understanding that all dots have some type of splash.. or by being taken apart just from curiousity?
There not much of a burner so I can't see residue being an issue?
Trolls or spammers?
 
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Lifetime17

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Re: Here is a little tip for anyone with a "303" type laser with lens problems

HI GSS,
Yes you are correct the only upgrade i would do to a 303 is replace that dull host , or machine really cool sink for it or change the host and machine a cool sink and fake non focusable adapter so it doesn't look like cyclops .

Rich:)
 

GSS

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Other than the thin wide artifact, the spot looks good. Could be a dust in the corners where the lens meets the barrel.
I would leave it be..
 

paul1598419

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That is very unusual as the splash is not concentric with the beam profile. The spot looks very good.......Gaussian. I would look into masking the beam as that should eliminate any splash you are getting from reflections behind the lens.
 

BowtieGuy

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I wonder if the laser was held at an angle to that surface, that may be why the splash isn't concentric with the dot?
 

paul1598419

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I had thought of that, but the spot is sure round. That seems to indicate it wasn't.
 




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