Welcome to Laser Pointer Forums - discuss green laser pointers, blue laser pointers, and all types of lasers

LPF Donation via Stripe | LPF Donation - Other Methods

Links below open in new window

ArcticMyst Security by Avery

HELP!!! Need to find lens!

Jollyrajer73

Jollyrajer73

0
Joined
Nov 4, 2010
Messages
404
Points
18
So just got a 230mW laser from Skylasers that I bought from a member here.

While cleaning the lens I was careful not to use too much force but somehow after hearing a loud pop sound I looked at the lens and found a chip in it. I dont know if it was just a defective lens or something else but

I would like to know or if anyone has a lens that I could replace this broken one with? Or maybe someone knows where to get a new lens?

Please if you can help PM me
This is so upsetting :confused::(:confused::(

Here are some pictures of what has happened


1413wo2.jpg


2nlznlt.jpg
 





Trevor

Trevor

0
Joined
Jul 17, 2009
Messages
4,386
Points
113
When you remove the lens, how divergent is the beam?

How big is the aperture of the laser head?

-Trevor
 
Last edited:
chipdouglas

chipdouglas

0
Joined
Dec 23, 2008
Messages
3,948
Points
63
i looks like swirl marks. try rubbing the lens and see if the pattern changes. if it does, then you need to find a better way to clean it.

michael.
 
Jollyrajer73

Jollyrajer73

0
Joined
Nov 4, 2010
Messages
404
Points
18
IDk how big it is but here i cant remove the lens completely with out breaking it off. I dont understand your question...???

Trevor said:
When you remove the lens, how divergent is the beam?

How big is the aperture of the laser head?

-Trevor
Click to expand...
 
Trevor

Trevor

0
Joined
Jul 17, 2009
Messages
4,386
Points
113
Jollyrajer73 said:
IDk how big it is but here i cant remove the lens completely with out breaking it off. I dont understand your question...???
Click to expand...

This assumes the lens needs replacement:

The level of divergence of the beam will tell you where your point source and what focal length lens you'll need to use.

The diameter of the laser aperture will tell you what range of focal lengths you can use, as the aperture restricts the beam diameter.

-Trevor
 
Jollyrajer73

Jollyrajer73

0
Joined
Nov 4, 2010
Messages
404
Points
18
EDIT: the hole is exactly 1/4th inch in diameter


hmmm well on the box it says 1mrad but im sure that, that is when the lens that now needs replacement is focused to infinity.

How can i figure this out with out breaking the lens completely?

The hole that the lens sits on is about 4cm is that what you are asking for?

Trevor said:
This assumes the lens needs replacement:

The level of divergence of the beam will tell you where your point source and what focal length lens you'll need to use.

The diameter of the laser aperture will tell you what range of focal lengths you can use, as the aperture restricts the beam diameter.

-Trevor
Click to expand...
 
Last edited:
Trevor

Trevor

0
Joined
Jul 17, 2009
Messages
4,386
Points
113
The angle of divergence of the beam without the collimating lens is the important part. This will allow us to figure out what focal length lens to replace it with.

You need to make an important choice here. Are you going to keep the laser as-is and not worry about it, or are you going to remove the lens and provide relevant information so that we can help you replace it?

Relevant: What the hell were you cleaning that lens with?!

-Trevor
 
Last edited:
Trevor

Trevor

0
Joined
Jul 17, 2009
Messages
4,386
Points
113
Surplus shed in all likelihood. But you have to know what focal length to use.

So you need to figure out the angle of divergence before the collimating lens.

Or you could buy a giant assortment of lenses and test each one.

-Trevor
 
Jollyrajer73

Jollyrajer73

0
Joined
Nov 4, 2010
Messages
404
Points
18
Just a qtip and yes i was careful
So how do i figure out the angle of divergence of the beam once i have removed the lens?


Trevor said:
The angle of divergence of the beam without the collimating lens is the important part. This will allow us to figure out what focal length lens to replace it with.

You need to make an important choice here. Are you going to keep the laser as-is and not worry about it, or are you going to remove the lens and provide relevant information so that we can help you replace it?

Relevant: What the hell were you cleaning that lens with?!

-Trevor
Click to expand...
 
Trevor

Trevor

0
Joined
Jul 17, 2009
Messages
4,386
Points
113
You'll have to measure diameter at the aperture and diameter a little farther away. Then you'll divide the difference in diameter by the distance. This will give you a rate of divergence.

If you used millimeters and meters as your units of measure, that will be in milliradians. This can then be plugged into some triangle math to figure out what focal length lens you need.

Only remove that lens if you're absolutely sure you want to attempt this fix yourself.

-Trevor
 
Last edited:
Jollyrajer73

Jollyrajer73

0
Joined
Nov 4, 2010
Messages
404
Points
18
The beam at the aperture is 1/4th inch how far away should i measure now?

Trevor said:
You'll have to measure diameter at the aperture and diameter a little farther away. Then you'll divide the difference in diameter by the distance. This will give you a rate of divergence.

If you used millimeters and meters as your units of measure, that will be in milliradians. This can then be plugged into some triangle math to figure out what focal length lens you need.

Only remove that lens if you're absolutely sure you want to attempt this fix yourself.

-Trevor
Click to expand...
 
Trevor

Trevor

0
Joined
Jul 17, 2009
Messages
4,386
Points
113
Okay. Try measuring about 1m away.

It is important that these measurements are precise. Make sure you're measuring the most intense portion of the beam for both diameter measurements, and try to make your meter as accurate as possible.

If the difference is not very large, move out to 2m.

-Trevor
 
You must log in or register to reply here.




Top