Question About Corrective Optics

[RedCowboy]

HPO, my NUBM44 with sanwu 3x expander and 3-element lens does not appear to project a line at any distance. At short distance it is a stubby bar and at long distance it looks like a dot.

Your 3 element may be out of focus, try setting it to 5 meters and lock it down.
-------edit------
Also over time it seems the AR coating on 3 elements can burn into little black balls when using 5W lasers that you can see under magnification, removed from the laser of course. NEVER LOOK INTO A LOADED LASER. When my 3 elements start to get fuzzy if I see those black specks inside I just replace them, it's part of the cost.

Also you cant see the bar at distance without your laser safety glasses on.

At 75feet I see a big spot, but with my glasses on I can zoom the hot center bar to it's tightest.

I cant hold still enough with my camera zoomed in and holding the glasses in front of the camera, I will take a tripod pic later after I feed the cats and myself, but with your glasses on you can adjust to a tight burning bar that you cant see unless you have your amber/orange laser safety glasses on.

I did not hold still, but there is a bar long ways top to bottom but I jiggled it, the cam took a longer exposure on it's own, yea I didn't try to set it right, just set it on normal mode.

 

[HighPowerObsession]

Red Cowboy, I really appreciate that explanation, but there's not even a slight chance that I'm going to do any of that on my own especially considering I have never build a lase in my life.
I would be paying someone to do all that and I can't imagine it costing anything reasonable. Like I said before, I'm already getting my NUBM07E laser from JL so now I have a NDG7475 and a burning laser left on my list and I'm planning on having both of those custom made. That burning laser will likely be a NUBM44 and if you could make me a dual NUBM44 build (that's insane btw), I would be willing to pay a premium for that. That's if you could make it have a very low divergence and the dot shape is perfect or close to perfect at all distances. PM me if you are willing to build me something like that.

 

[HighPowerObsession]

HPO, my NUBM44 with sanwu 3x expander and 3-element lens does not appear to project a line at any distance. At short distance it is a stubby bar and at long distance it looks like a dot.

That's pretty cool, but that laser you have probably isn't putting out anything more than 5W and since I'm already getting a PL-E Pro 4W 465nm (NUBM07E), it wouldn't be worth it for me to get a burning laser that's only 1W more than my PL-E Pro. At that point, I would just use my PL-E Pro for long distance burning and popping 10 balloons in a row almost instantly. That's why I was wondering if a NUBM44 with a G2 lens and 10X BE would give the same outcome as what you have going on. Then I would have a 8W+ (with 5.5A driver) burning laser and that would be worth it.

 

[RedCowboy]

I can't risk building anything dangerous for anyone, there are people here who might and could build components and even finished stuff for you as long as they trust you, but that's between you and them, I share hobby info as I think it's mostly still legal, soon it may not be.

We may all be responsible if we say gas burns with a match and someone burns something, or talking target shooting becomes an ITAR violation online.

Sigh, and what really kills me is so much could be retroactive, i.e. that cowboy guy called her majesty a witch last year, put him on the no fly list and xray his house daily until his head grows tumors....sounds crazy huh.....I wish it was.

You can do anything you want to work at, it's easier than you think, it just takes some practice time.

 

[HighPowerObsession]

Well I fully understand the dangers of these lasers and I would be as responsible as one could be with it, but I can understand why me being new to this forum could get in the way of that. If you truly wouldn't build that for anyone then I guess there is no point in asking any further. Would you be willing to build anything with corrective optics? Maybe something like the NDG7475?

 

[RedCowboy]

This setup is simple, it's just a nubm44 with a 3 element and a sanwu 3x expander, this diode is a year old and still kicks it out.

You could buy one on flebay from rick and attach a sanwu expander.

My point was you can't see what the focus is doing without the safety glasses on and shouldn't look at it at 25 feet like in this video anyway, it's too bright.

p.s. I have fire extinguishers all over the place here, front and back hoses and it's in a burn pit on top of dirt and ash for any safety sally's.

I can burn through small twigs and leaf stems, but stuff like 1/2 inch branches, no way, I need more power, this is a fun paper burner, but you must protect your eyes and anyone else's.

 

[HighPowerObsession]

You guys dont seem to be getting my point...

I have zero interest in using the 3-element in the NDG7475 or NUBM44 build. It dims the brightness too much in the NDG7475 (take 400mW off the 1.4W) and if I used it in the NUBM44 it would take nearly 3W off and id get a 5W output which wouldn't be enough of a difference from my 4W PL-E Pro. I keep asking this question but if i used a G2 lens and 10X BE in the NUBM44 would that be enough to get the spot shape and divergence seen in that thread with the guy and the tower???

 

[Sta]

HPO, the NUBM44 @5A with 3-element is much closer to 6W than to 5. G2 and 10x BE, I think, will not be as nice as 3E/3x, nor as good for burning.

 

[RedCowboy]

Just by the way, This nubm44 is near 1 year old and has a lot of time on it, and it's always been at 4.5 amps. It only wears a 3 element and a sanwu 3X expander.

Now when I use the 6X cylindrical correction first that makes it much more potent and extends ability at distance.

The Jet 10x has too small of an exit lens for our MM diodes so you have to de focus your G2 to make it work, I have done it at 10 feet with a NUBM07 but across the yard it eats a lot of the power by clipping the beam.

Lietime17 posted a shirt he burned a hole in at 32 feet with the 10X, and I tested a nubm44 with just a 6X pair, no expander and it burned through pretty fast.
I also have it with the G2/6X/3X and so far that burns the best at 75 feet.

The only real test is a LPM at distance and test each set up's power and spot size.

I have not wanted to burn up my Jet10X so I am saving it for a nice 500mw - 1w dpss 532 that's the type of beam it's made for because the input is 5mm and the exit 25mm so any beam over 2.5 mm wide would clip unless defocused, but that reduces it's intended effect.
Maybe it could come out to 5X, that's about what my defocused NUBM07/G2 test with the 10X looked like.


This is a NUBM07 with a defocused DTR G2 and the Jet 10X expander at 9 feet vs a cardboard cat food box.

OOPS SORRY that was my scavenged 25mm lens.

Here's the Jet 10X

This is a NUBM44 with a sanwu G2 and 6X Cyl correction followed by a 3X expander from sanwu. vs a wood stich thicker than a penny.

 

[HighPowerObsession]

I cant have a corrective optic laser if no one builds me one and i havent found anyone who will do that yet. My only option is to use a NUBM44 with G2 and a BE for burning. I guess ill also be using a G2 and BE for my NDG7475 laser as well...

Oh and do JL BE not last long or something? You also mentioned how your NUBM44 is a year old and still works great...do these lasers not last long??

 

[RedCowboy]

Honest answer, I don't know if defocusing the 44 will hurt the coating on the Jet 10X or not, I know I burned the coating off one of my 25mm scavenged lenses with the raw beam out of a GBalled NUBM06.

I work my lasers hard, I use them a lot, and I drive them past factory spec and no doubt get them too hot.

That said the NUBM44 is a TANK and takes a beating, just don't get any junk on the little window, it will burn it through.

My NDB7875's have been robust diodes too, GBalls don't like me, I need to clean my dusty old house or just not take the lenses out.

All the N brand diodes are good, but we do overdrive them so we can't expect they will last 20,000 hours.

I will say a good heavy heat sink and not pushing past the recommended hobby max will give you good diode life, the NUBM44 is a little stronger at 5 amps it seems, I can see it burns stuff at distance a little faster it seems, but they last very well at 4.5 amps.

You choose how hard you want to push yours, but along with that can come reduced lifespan.

p.s. The 3 element seems to be worth the little power cut in exchange for a tighter divergence in my opinion when paired with the 3X.

 

[HighPowerObsession]

Yeah based on DTR's testing with the NUBM44, it seems you should be pushing at least 5A and if you really want to get the diode's full potential then 5.5A.

I don't think I'll be using my lasers as much as you use yours, but I just got worried when you made it sound like you were surprised that your NUBM44 is still working well after a year.

I am way more concerned about my NDG7475 than I am my NUBM44 since I'll be using the NDG7475 for everything (shining it up at the sky, shinning it at things miles away, showing it off to people, taking pictures with it and occasionally burning with it) and with the NUBM44 I'll just be using that for burning only. I hope a G2 lens and 3X or 10X will be enough for the NDG7475.

Btw I just saw those videos you attached a couple messages back; they didn't load earlier or something, but thanks for posting those. Not sure if you have ever used a SW 3X BE on the NUBM07E, but if you have which beam looks better, the 10X or the 3X?

 

[RedCowboy]

I like the way it looks with the G7 lens.

 

[CDBEAM777]

As I mentioned a few replies back, round cylindrical optics would be a better solution.

Hmmmm....??? I thought a round Cylindrical lens (see pic) still requires a specific radial orientation to expand the slow beam axis. See how the lens has two (2) thinner edges....and two (2) thicker edges.

Now...one COULD mount this round geometry lens in a Kinematic mount which accepts a round lens(see pic)....but round or rectangular....the beam must enter the lens at the correct radial orientation.

We barely have room for the rectangular Cylindrical lens...epoxied to a Aluminum flat ....let alone some big honking Kinematic mount ???
I will stick with the rectangular cylindrical lens sets.

These Cylindrical (Rectangular) lenses are not all that difficult to align. The distance between the lenses is what must be spot on....+/- .05mm....SO....I use a machined mount that slides back an forth....but.....I machine my own.

Such a sliding/trombone style mount....(See pic)while nice.... is NOT necessary to achieve optimal results. Just us the Brass independent mounts as supplied by Laser Show parts.....or...make your own.....this whole alignment issue is being made into way to big a deal !!

Beam out.

 

[HighPowerObsession]

If I used just the G2 lens and the SW 3X BE on my NDG7475 build, will I have issues with the BE cutting off part of the beam like the JL 10XBE does sometimes?

 

[Sta]

Re: Proper 16340 Batteries for my 445nm 4W Laser

Hey CDBEAM777, if I used just the G2 lens and the SW 3X BE on my NDG7475 build, will I have issues with the BE cutting off part of the beam like the JL 10XBE does sometimes?

7475/G2/3X is fine, the beam will not be cut off.