My Monster 6+ watt Laser Build Has Started !

[Alaskan]

I have some of those Linos beam expanders, they are nice. Roberto in Italy bought some too, but he somehow burned the AR coating off of one of them, be careful not to focus the beam on the input lens too tightly.

 

[RedCowboy]

Yea I am afraid of that but I want to run my corrected beam of 7mm by 1mm into the expander and get a tight spot at my target distance, I would not defocus a G2 down to 2mm x 0.25mm into an expander like some have done with the jet 10X.

I burnt one of my 25mm projection TV lenses with the raw output of a De-Canned NUBM06 and it looked like about a 1/4 inch long slot where it scorched it, these are vis coated I think.

They are a 3 element set up and the coating is fairly light, maybe I got smoke or dust on the lens then burned that because it was zooming across the room popping out an open flame kernel from the raw output of that 06, of course now I know I can't run the 06 open like that, but the result was sweet.

I think maybe the lens was contaminated and that's what burnt, I will keep the linos very clean, but you would think a quality BE would use a fused silica input lens anyway, but again it could be the coating or a contaminant, hell you can see finger prints and bits of black crap on these in my lens box, they need to be cleaned.

These are not dark, the VIS coating is light and the 52 inch TV passes a lot of light energy through this lens.

 

[Alaskan]

I put 4 watts of 532nm into one of those Linos beam expanders and burned the input lens with a 5mm wide beam, if I can do that with a beam that is so big at infinity focus, it won't take much power. I also accidentally shot the beam inside the expander at too much of an angle and vaporized some of the grease inside used on the threads and that coated the inside of the input lens too

I can understand a projector lens burning, but I didn't expect that to happen to the Linos, then Roberto reported the same thing with his. Those projector lenses you have look nice. Great photo's.

 

[RedCowboy]

They make a fantastic zoom lens right off of the raw output of a M-140 diode, but too much gets clipped with the 44, I lose 40% of the NUBM07 but what goes through focuses to a nice burning point, but again I will never run an 07 can less, I have 4 dead ones now.......maybe I could correct the NUBM44 short so that it fills 80-90% of the width of the 25mm 3 element, maybe I need a sanwu style 7X that's 50mm wide or a 10X that's 75mm wide, that would work.

Maybe we could get up a group buy and have a bunch made, it would tighten up the far field.
Yes the beam coming out of your device would be 3 inches wide, but the far field point would be well worth it to me, I would use the standard 3 element and a new oversized sanwu with a higher magnification rate and wider objective.

Actually I would correct a 44 and pump that through the 75mm :eg: Now that could be tough, but at some point we just need more horsepower, I am ready for more watts, have cash in hand, bring on the 40w diodes.

 

[Alaskan]

I don't think 75mm is too wide, I have gone up to 150mm/6 inches with my higher power lasers and for night time beam shots there is plenty of glow in the beam and ability to focus to a tiny spot, when taken out of infinity focus. Only thing is the laser pointer gets a bit tip heavy Yep, we could correct for a higher power laser and expand to make the divergence work out, bring them on

 

[RedCowboy]

I've been squawking about it for a while, maybe if enough of us showed an interest podo would make us a double to triple size and strength expander.

I will put up 200 dollars or more if needed for a pair up front.

 

[Alaskan]

I can find 25mm expanders easy enough, but 50.8 or 75mm, not so common.

 

[RedCowboy]

We may have to make our own.

 

[Alaskan]

Easy enough to get a fat beam, just a big PCX lens in front of a bare diode with a long enough focal length so the beam from a NUBM44 fills 75% of its diameter. However, better at 50% fill because then the wings that are normally present with that diode are gone. I know you like to expand that slow axis so the beam is better squared up, I do too, but adding a pair of cylinder lenses to correct the beam requires a real beam expander then, so now you need a concave lens in front of the PCX lens.

Although beam correction is not required for burning if focused to a point, who cares what shape the tiny little beam is when that small

 

[Accutronitis]

I wonder how well the Wicked Lasers Beam Expander works ? For $400.00 I'll never know...............

 

[Jhop]

Its not worth $400 I can tell you that.

I got the Sanwu 3x BE for my spiker, and it is really awesome how much faster I can burn stuff with it. i have an old wood toy truck collecting dust in my basement so i use it as target practice. With the BE on the spiker, which is only a 1.6w+g7 lens, so its probably closer to 2watts, i can draw on the wooden truck from as far away as 10 feet or more, no problem. I just focus it down to the best point I can get and bam it starts smoking that wood. Its fun :eg: and smells good

 

[Accutronitis]

Maybe we could get up a group buy and have a bunch made

YOU CAN COUNT ME IN !

I'd love take part in the creation of the ultimate NUBM44 Beam Expander for maximum burning at long distances !!!

Its not worth $400 I can tell you that.

I got the Sanwu 3x BE for my spiker, and it is really awesome how much faster I can burn stuff with it. i have an old wood toy truck collecting dust in my basement so i use it as target practice. With the BE on the spiker, which is only a 1.6w+g7 lens, so its probably closer to 2watts, i can draw on the wooden truck from as far away as 10 feet or more, no problem. I just focus it down to the best point I can get and bam it starts smoking that wood. Its fun :eg: and smells good

Have you tried the same thing with the Wicked Lasers Beam Expander to compare the two ?

 

[RedCowboy]

I correct the rapidly diverging axis to slow it down, if you do the math there's no better way with these diodes insane divergence to get a concentration of power over distance, even with an unlimited lens diameter, unless we correct that rapid divergence, then the further we focus the longer in relation to the height the spot will be, maybe we can get it really tiny, but it would be a tiny long long long line.

That also creates other problems in focusing across the entire distance range, correcting the divergence first is the right way.

Now if all we ever want it to go 50 feet and the new diode is a 50w GBall then a great big expander may be what we go with, it may be our only real choice to start, I have tested the 3X on the NUBM06 with GBall intact and it's useable to ignite the bag to about 20 feet as a bulky lineish blob, but that's it, however the 08's GBall is much worse.

We may have to reverse engineer the GBall then fix the divergence and use round lenses from there when the next diode is a 50W GBall that projects like a floodlight.

 

[Accutronitis]

For the moment and just speaking for myself I'd like to concentrate on solutions for the NUBM44, focusing on two aspects,

With the 1st - being the best achievable burning power out to a distance

And the 2nd - being the best achievable beam profile without excessive loss of power

And I'd like to have two categories,

1st - practical (can be done without excessive cost or the need for a machine shop)

2nd - unlimited (anything go's but must be achievable by an average person)


I don't know, I'm just thinking out loud....... :thinking:

 

[RedCowboy]

A quick fix would be a wider longer FL lens and module, you will have a cone shaped beam so this is not for the projector builder, rather the hobbyist who wants a quick way around the horrible divergence of the nubm44 with minimal add effort, not that a 3 ele and 3X is that big of a deal, but an expander could be used with this as well.

Also with a proper single element lens more power and less lenses, although a 25mm 3 element would give the best far field results.

What could do is use a G2 to set the divergence of the NUBM44 to a little less spread than a M-140, maybe 1/2 the spread of a M-140 which is 1/3 that of a NUBM44 anyway, them employ my scavenged 25mm 3 elements, I have about a dozen of the lens packages they come in, that may actually work and it would spread the power across the lens.....why have I not done this yet??? Oh yes, it wont address the factory super aggressive axis issue that will remain, although 3X BE type results could be obtained it's hard to get around correcting that aggressive axis for truly good far field results, but for a quick fix....hell it's about as much trouble as doing it right, but for the casual customer a wider longer focal length lens would be a good stop gap to make the 44 more useable.

Really the existing set up with a 3 element and sanwu 3X fixes it well enough for most, but any way we go to really get the power out there will mean correcting the aggressive axis first.
Now we can test some super big expanders, both lens only and with a primary, but a power meter test at range will show what works and what is clipping most the power and only looks good.

I think we need some big SOB expanders that we can use with axis correction or without.

 

[Accutronitis]

Do you have any M25 x 0.5 lens ? Can you post a picture of one ?