Opt Lasers 6X Cylindrical Testing

[RedCowboy]

Yes the 2 axis still don't match after correction, not at all, they are a lot closer and looking into the sky look a lot better, but you still have a stretching rectangle.

I have to say I like your design using the rails to tension the metal ruler that your convex cylindrical lens is attached to, for many people keeping that lens in 3D orientation while adjusting it forward and back would be an issue, I would use larger parts such as an inch wide channel for an aluminum block to slide in, but I tend to overbuild.

How tight can you get a spot at 50 feet? Can you ignite a paper bag at 50 feet.

I know you can burn like hell up closer, but have you explored the useful limits of those lenses and seen how they run out, it's amazing what it takes to burn through a 1/4 bush branch at 50 feet, one problem is our starting beam quality, if we had 7 watts in a 2mm beam like a 660nm red diode single mode makes people would have been setting neighbors curtains and car upholstery on fire causing all kinds of problems, accidentally, carelessly that is, it's the crap divergence that makes these blue diodes no big deal, just green dpss pointers are a much bigger boo-hoo because of pilots.

I have thought of combining and converging and maybe pumping crystals is a better way to go, these multi mode projector bulbs have a lot against them, hell the truth is your best spot at 100 feet with a G2 and your cyl correction is huge next to a 660nm red with a single element acrylic lens. Actually its at best half the size of a NDB7875 with a simple 3 element, have you done a side by side at distance on a target ( plywood ) ?

Now add an expander that will fit your beam, I use a sanwu G2 and lsp 6X then it's a tight but very rewarding squeeze into the 3X BE, you could probably go with 4X Cyls and the DTR G2, I am going to build some wider expanders or buy some, but the 3X is something you want to experiment with, try a 3 element and 3X, it's fun, hell a 3X makes a burner out of the better focused GBalls with GBall intact, did I mention the 3X ??

 

[Accutronitis]

Yes the 2 axis still don't match after correction, not at all, they are a lot closer and looking into the sky look a lot better, but you still have a stretching rectangle.

I have to say I like your design using the rails to tension the metal ruler that your convex cylindrical lens is attached to, for many people keeping that lens in 3D orientation while adjusting it forward and back would be an issue, I would use larger parts such as an inch wide channel for an aluminum block to slide in, but I tend to overbuild.

How tight can you get a spot at 50 feet? Can you ignite a paper bag at 50 feet.

I know you can burn like hell up closer, but have you explored the useful limits of those lenses and seen how they run out, it's amazing what it takes to burn through a 1/4 bush branch at 50 feet, one problem is our starting beam quality, if we had 7 watts in a 2mm beam like a 660nm red diode single mode makes people would have been setting neighbors curtains and car upholstery on fire causing all kinds of problems, accidentally, carelessly that is, it's the crap divergence that makes these blue diodes no big deal, just green dpss pointers are a much bigger boo-hoo because of pilots.

I have thought of combining and converging and maybe pumping crystals is a better way to go, these multi mode projector bulbs have a lot against them, hell the truth is your best spot at 100 feet with a G2 and your cyl correction is huge next to a 660nm red with a single element acrylic lens. Actually its at best half the size of a NDB7875 with a simple 3 element, have you done a side by side at distance on a target ( plywood ) ?

With the OPT 3X plus 6X combo I'm using right now it is very close to a small thin rectangle that is slowly squeezing towards a square as it go's up and out of sight with the one axis looking very close to the other axis shot up in the night sky which was one of my primary goals with this 44, One of the other goals was across the room burning along with insane up close burning and I nailed those as well with this adjustable convex cylindrical lens pair setup ! With the laser pre-set for the range of across the room black plastic will immediately start rolling smoke and most times in less than a minute it will catch on fire that I have to put out !!! I'm very happy with this setup !

Now how well could this work at 50 ? Well i'll tell you this, the farther you want to keep the light traveling together the better and more closer to perfectly aligned all your lenses will need to be and right now my alignment is not flawless when adjusting it BUT at the point I'm at right now this was much more of a proof of concept to prove to myself that a adjustable convex cylindrical lens pair setup could do what I expected it to do and it did !

I'll try a paper bag at 50 later on tonight for you and we'll see what she can do, How's that sound ?

 

[RedCowboy]

I think you have done well, we squeeze all we can out of the 44 on a budget, but I want more.

Yes, do a test and see what you get, I am curious. Just lighting up many feet of air sucks down power, on a foggy night it eats it up fast. :beer:

 

[CDBEAM777]

Very interesting discussions.....thanx to all for sharing !!!

My understanding....maybe flawed...BUT...The Cylindrical lens optics...actually expand the 044 SLOW axis...not the Fast axis...I know....this statement sounds A__ backwards....as in....Why do we want to expand anything. ??..we want shrink the beam...correct it....adapt it ....make it NOT a line....but a spot....a rectangle....surly NOT a line !!

And....one would think....that the " Fast Axis " is the problem here....the divergence is expanding...to FAST....right ??? Nope !!! The " Slow Axis " is the problem....

Now....when one expands or multiplies the Slow Axis....THAT is were the correction takes place. That is why these Cylindrical lenses are named....2X, 3X.....6X...because they expand one axis....that being the Slow Axis.

OK...When the Slow Axis is expanded....THAT is when the beam divergence is reduced...that is when the Far field geometry goes from a " line "....to something more like a round cornered rectangle !

I am fairly sure this is what is going on optically....but then....maybe....I am FOS !!!

OK....as to the issue of focal length....where the beam has the greatest power density....burns the best.....well...there at always trade-offs in Optics.

To have the ability to select this distance....yes....the last optics in the C-Lens set up ....the Plano Convex lens would need to be made.....adjustable.....but....even here....there are practical limits.

Even beam propagation....thru seemingly clear air....will eventually reduce power.....due any dust or moisture particles in the air....

SO.....there are always limitations....we just need about 1K Watts.....that'ill ...." Lite'em UP " !!!!

Later...Beam Out

 

[Alaskan]

CDB, let's do a PBS combined, corrected and expanded NUBM44 someday, if you are interested.

 

[Accutronitis]

This is all I can say for sure, When I focus the G-2 lens at 12 feet it creates a well defined horizontal thin line on the wall 2'' wide by 1/4" thick, I then setup the first cyl lens (the concaved 6X cyl lens which is flat on one side and concaved on the other) on the wide horizontal axis which makes that 2" line diverge even more to 12" wide by 1/4" thick, Then I add the convex cyl lens and adjust it which converges the 12" wide axis down to about 3/8" wide and the 1/4" thick axis stays the same.....

But if I add a concaved 3X cyl lens right after the concaved 6X cyl lens that makes that 2" line diverge even more to 36" wide and about 1/4" thick, Then when I add the convex cyl lens and adjust it then converges the 36" wide axis down to about 5/16" or less wide and the 1/4" thick axis stays the same.....

 

[RedCowboy]

Cool, sounds like you're having fun, speaking of fun I would like to correct 3 separate NUBM44 diodes in some square bar stock and bolt the center one down to an aluminum plate and the others on each side but make them articulated and rotated 45 degrees and 90 degrees one each side, then all 3 could be converged at the target, just for fun.

3 corrected beams each rotated would look like a * sort of shape and make a fun 20W burner, plus I love the look of multiple beams.

This would have looked a lot cooler at night. FYI the paper/cardboard target was destroyed. :eg:

 

[Accutronitis]

That's called the "Pre-Death Star" arrangement !

 

[RedCowboy]

6 lasers would be really cool, I had thought about a 6 sided large bazooka type tube with lasers corrected and mounted in the far end firing back at galvo mirrors on the user end, but it gets expensive, maybe I could do 3 mounted in a triangle shaped hand held so the beams are all very close, hollow triangle made from 1/4 inch aluminum plate with the lasers mounted on the inside, as they diverge they would cross kinda like a bio hazard symbol.

 

[Accutronitis]

WARNING YOU HAVE ENTERED A SUPERFUND SITE ! LEVEL 3 CONTAINMENT PROTOCALS ENACTED !

 

[CDBEAM777]

Alaskan....YES...A dual 044....as I the Dual NDG7475...Verde Volcano........Just a factor of Time and $$

Beam Out

 

[Accutronitis]

With the OPT 3X plus 6X combo I'm using right now it is very close to a small thin rectangle that is slowly squeezing towards a square as it go's up and out of sight with the one axis looking very close to the other axis shot up in the night sky which was one of my primary goals with this 44, One of the other goals was across the room burning along with insane up close burning and I nailed those as well with this adjustable convex cylindrical lens pair setup ! With the laser pre-set for the range of across the room black plastic will immediately start rolling smoke and most times in less than a minute it will catch on fire that I have to put out !!! I'm very happy with this setup !

Now how well could this work at 50 ? Well i'll tell you this, the farther you want to keep the light traveling together the better and more closer to perfectly aligned all your lenses will need to be and right now my alignment is not flawless when adjusting it BUT at the point I'm at right now this was much more of a proof of concept to prove to myself that a adjustable convex cylindrical lens pair setup could do what I expected it to do and it did !

I'll try a paper bag at 50 later on tonight for you and we'll see what she can do, How's that sound ?

Sorry it took so long but I broke my mouse and had to get another one, At 50+ feet the spot is 8mm x 16mm (it's really smaller than that but I want to error on the side of too big) and a bag catches on fire in around 4 or 5 seconds....



The dot looks bigger than it really is in person, You can see the actual size reflected on the garbage can.....

And my latest mRad cal.....

 

[Alaskan]

Impressive!

 

[RedCowboy]

Thanks Alaskan, I often brace against my window seal bottom and side to get an X-Y adjustment when aiming downward and a solid hold but these are so high up that I use a block and the shelf I attached outside the window to feed birds to get a very stable hold at the angle I need because when bracing against my hand just my pulse will cause the dot to bounce, yes my blood pressure is good, also I have to wait for the wind to stop blowing the leaves, but to see steam shooting out of those little leaves and burn a hole through when they are so far out of reach is so cool, the only other way to reach out and touch those high leaves would be with a rifle ( I would not do that ), but this is fun and it's been raining so it's very safe as everything is soaked.

 

[Alaskan]

The thought had crossed my mind regarding shooting holes through tree leaves could start a fire, but green leaves? I've only been able to make them smoke, never a fire. If wet, even more room not to worry.

I still don't understand how Acc. is getting such a low divergence with such a small aperture when using the NUBM44, expansion is expansion whether one or both axis, the same thing. Surely the pointer must be focused to that small of a spot instead of at infinity, if so, you cannot use the spot size to calculate divergence. To get under 1 mRad would require a lens which is close to 2.75 inches diameter with that diode. IDK, maybe larger, what is the divergence using a 6 mm diameter collimating lens, 11 mRad?

 

[paul1598419]

You are absolutely right, Chris. It is pointless to try to calculate the divergence of a laser that is beam expanded and focused to a point down field. In all likelihood, it would be a negative number.