First completed build! And a learning experience

[trephanation]

As I promised in my introductory thread, I'd be posting about my first attempt at building one of these things. My name's Jack, I'm 27 and work in manufacturing so I'm very familiar with EHS and OSHA regulations and safety standard operating procedures when handling hazardous materials and environments. This is my first run-in with lasers though.

I used a Survival Laser S4 host, a Nichia NDG7475 diode from DTR's shop, a driver supplying 1.8A current, and the DTR-2EG lens. The "learning experience" part is that I should have done more research on the lenses first. Unless I'm mistaken, this particular one is incapable of adjusting the focus. However, even completely unfocused, this thing is bright as hell and I was still able to get some pictures of the beam outside. Sometime soon I'll probably be getting a new lens, and it's a toss up between the G-2 and G-8, of which I'm not sure I understand the differences completely. Any recommendations there?

Anyways, this thing was very easy to assemble. Self explanatory, just solder the driver to the ring, solder the wires, and screw everything together. Thanks to Gary for answering my questions over the phone as well as making sure I had the goggles first before any of the other components, as well as DTR for the extremely quick shipping on the diode module. Enjoy the pics, but I apologize for the crappy picture quality.

-edit- Also, please see last attached pic. Are grainy artifacts like this (at the top of the picture) inherent to unfocused lenses or is there possibly something wrong with the diode? Thanks in advance

 

[Blades and Photons]

Nice job! If you go to the lens page on DTR (link below) and scroll down you will see a comparison of spot sizes and how much light passes through them. Just my opinion but i would go with the g8.

https://sites.google.com/site/dtrslasershop/home/glass-lenses

 

[WizardG]

Those 'grainy' artifacts are most likely reflections of the edge of the beam from the inside of the lens barrel. A different lens should cure this.

 

[paul1598419]

You can also mask them out to an extent. That means to put a tube around the aperture of the laser to keep the "grainy" parts out of the FF beam profile. You know that you can focus the beam better than you have in your photos?

 

[trephanation]

Thanks guys!

You can also mask them out to an extent. That means to put a tube around the aperture of the laser to keep the "grainy" parts out of the FF beam profile. You know that you can focus the beam better than you have in your photos?

Do you have any instructions or tips for focusing it? I only ask because it seems like it would be obvious, but what appears to be the "focus ring" is really just a cover for the lens that screws right off and doesn't change the beam at all. Sorry if this is a really stupid question.

Just to clarify, it's the DTR-2E-G 500nm-600nm AR Coated Two Element Glass Lens:

 

[GSS]

Trep, all the lenses focus and the little knurled ring is the focus knob.
The best way is to put the knurled ring on the lens first and tighten it a little firmly by hand, then screw the lens on the module.
There's always the chance of putting the lens on backwards and you won't like the focus but then you just put the lens in the other way.

 

[trephanation]

Trep, all the lenses focus and the little knurled ring is the focus knob.
The best way is to put the knurled ring on the lens first and tighten it a little firmly by hand, then screw the lens on the module.
There's always the chance of putting the lens on backwards and you won't like the focus but then you just put the lens in the other way.

Thank you GSS, I'll take another look at it after work today. I got the module and lens already pre-attached from DTR and like I said, it seems that knurled ring only acts to provide some protection for the glass lens itself. Twisting it does not change the beam and it actually twists off completely rather quickly.

 

[GSS]

The knurled ring has kinda a small hole so it might look like a protector of some type.
What happens is sometimes the focus rings don't come snug on DTR's modules and is just spinning some on the lens barrel when you turn it and can come right off.
You have a G2 right? When you take off the lens from the module be careful because behind the lens there might be a small spring behind it that is there to help put some pressure on the back of the lens to hold the focus better. They can pop out and sometimes you might lose it.
Be careful to seat the spring back on over the diode.
The part of the lens thats closest to the lens barrel itself, goes towards the module/host.
This is simple stuff and self explained when you see it itself in hand so need to worry
Like I had mentioned it's better to have the lens off to snug fit the knurled focus ring with you fingers on the lens barrel.
Have fun focusing! you will like it!

 

[trephanation]

The knurled ring has kinda a small hole so it might look like a protector of some type.
What happens is sometimes the focus rings don't come snug on DTR's modules and is just spinning some on the lens barrel when you turn it.
You have a G2 right? When you take off the lens from the module be careful because behind the lens there might be a small spring behind it that is there to help put some pressure on the back of the lens to hold the focus better. They can pop out and sometimes you might lose it.
Be careful to seat the spring back on over the diode.
The part of the lens thats closest to the lens barrel itself, goes towards the module/host.
This is simple stuff and self explained when you see it itself in hand so need to worry

Thanks and no it's not the G2, it's the 2E-G. It was the cheapest option available, like I said I should have done more research and picked the G-2 or G-8 lol

 

[GSS]

Still a 2E -G is decent and many like it with a 520 green..
I saw the pic but thought you were thinking about getting it instead of having it

 

[CRX]

Very nice.

 

[paul1598419]

Thanks guys!

Do you have any instructions or tips for focusing it? I only ask because it seems like it would be obvious, but what appears to be the "focus ring" is really just a cover for the lens that screws right off and doesn't change the beam at all. Sorry if this is a really stupid question.

Just to clarify, it's the DTR-2E-G 500nm-600nm AR Coated Two Element Glass Lens:

I have this same lens on one of my 520nm lasers. It seems to be the best at removing any artifacts, rectangular, from the beam profile. To mask it, remove the focus knob and place a tube, paper if you have nothing else, to limit stray reflections from getting out around the primary beam. It is also important to realize that your mask should not be able to cause internal reflections either.

 

[trephanation]

I figured out how to focus the beam! I'll post some beam shots later on tonight when it gets dark out. That "focusing ring" seems best suited to protecting the lens, as I still can't get it to actually adjust the beam, but it definitely focuses when you twist the lens itself. It's absolutely terrifyingly bright! Thanks for all the help, guys.

-edit- Here are some beam shots from similar angles as last night, with the beam focused to infinity. She's so beautiful... :O

 

[paul1598419]

If you remove the lens and then tighten the focus ring down onto it I think you will find it will work much better for you.

 

[trephanation]

If you remove the lens and then tighten the focus ring down onto it I think you will find it will work much better for you.

You're right about that. I feel pretty stupid but it's working as intended now. Thanks

 

[GSS]

Glad you got it focus, but you find out soon the focus ring is there to help protect your fingers from burning while focusing