PBSing 2 NUBM07E in a compact set

I started to make this set months ago, but now the time has come to start testing.

First I received 2 12mm modules with LDs from DTR: one with G-ball, other with G-2. The collimation by both lenses seemed pretty similar, one with G-2 gave a little more output, but the spot (line) was also a little wider.

Unfortunately, both seemed to be underspec - instead of expected 2.9W at 2.3A LPM has shown 2.42 and 2.55W. But I do not know which proper laser drivers can work at 8-9V output and used B3603 from dx.com. Yes, the experiment was also to test how LDs behave if driven in series from only one CC driver. Maybe current from this driver pulses and median current value passing through LDs is lower than 2.3A set?

Then I started to make a small device to PBS them. It should be:
-small enough to pass ino gun-like hosts
-modular (should allow to replace 12mm modules with any type of blue LDs and lens)
-produce round spot (using Milos results in taming 44s)
-work from 12V Ni-Cd, lead or Li battery in hosts like portable handdrills or spotlights

The parts used here I have already listed in the midnightchime´s thread about Combining 2 NUBM44.

Here are the pictures of the tested model with all optics glued except C-lenses. I set 2.3A, 8.5V limits because B3603 is limited at 3A. The additional Voltammeter in the two LDs circuit shows 2.28A at 8.3V what could mean that the driver holds its promise.
The spot at 5m (picture taken through safety googles) looks round and less than 1cm in diameter. Interesting that the position of last PCV lens has strong effect of spot shape - if it is only a little rotated by side, instead of squeezihg horizontal line into round spot I get vertical or diagonal line!

Bad thing is the total output only 4.6W. You would say Alien Laser has got 6W from only one such LD. But that was at 5A and I only test 2.3A, where according to graphs the effieciency of this LD is maximal! More is yet to come.

Abarnett, will you answer me at end, if X-wossee driver (or one you have with external potentiometer) is suited for output at 8-9V?

Thanks for your attention!

Hi, sweet setup. Are you running them at that amount of current for longevity?
+rep
-Danny

Not yet. I slowly increase current. Think to stop at 3.5A (max rating for 07e), but need to choose another driver.
If there would be these 35mm Cu modules before, I would be less conservative.

But I accidentally attached this setup to a driver which gave them 5.5A current. Very bright beam for couple of seconds but LDs did not die. This is a good sign.

The 9mm stuff is tough and the 35mm cu modules are great heat sponges.
-Danny

I swear soon LPF members a gonna be caught running around stealing copper pipe so they can make bigger and bigger heatsinks for their lasers

If i was to stoop so low as to steal it, i would nab solid copper!:evil:

Note to self, stockpile slabs of copper and wait for higher power diodes too make lpf members desperate, get rich.

I like the way you set this up. Nice job. I think you can get away with much higher current if you are concerned about the lower power level. +Rep.

If I had a way to drill exact 12mm holes for 12mm modules, I would buy copper bullion (20EUR for 500g one from Germany) instead of stealing copper pipes !

Even silver bullion heatsinks would not essentially increase the cost of high powered setups ... What as investment strategy!

Very cool device you got there! How long did it take you to create? +rep!

Thank you.

Yes it took pretty long by trial and error and it is not yet finished. There will be more features added in due course. Just as an experiment.

The longest part is to wait for ordered pieces, find that they are not as they looked on pictures, finding better passing ones, rinse, repeat...

Light superglue said:

If I had a way to drill exact 12mm holes for 12mm modules, I would buy copper bullion (20EUR for 500g one from Germany) instead of stealing copper pipes !

Even silver bullion heatsinks would not essentially increase the cost of high powered setups ... What as investment strategy!

Click to expand...

I use a 12mm drill bit, but copper is grabby, aluminum is much easier to drill and tap.

RedCowboy said:

I use a 12mm drill bit, but copper is grabby, aluminum is much easier to drill and tap.

Click to expand...

I've tried a 12mm drill bit and a 12mm milling bit in aluminum. But there still seams to be more slop with an aixiz module then if I buy an already made pill. Most of those pills have some sort of anodizing on them. But I wouldn't think it would add that much material bulk to it?

I ordered a couple 12mm high speed steel bits from flebay and they are fine, set your drill speed so you get a curl of material and let the tool do the work, don't press too hard.

Sometimes I pre drill with a smaller bit say 2mm, then a 5mm bit then the 12mm.

I use a dab of heat sink compound but my modules fit pretty close.




You can try a 15/32 because that's 11.9063 mm, but I bought 12mm, the ones in the 2nd link.

http://www.ebay.com/itm/Irwin-67830...hash=item1a131e8a5b:m:m5YUBMSODPCfxnE-PQgUBAA


Here's the ones I bought below

http://www.ebay.com/itm/12mm-2-piec...579250?hash=item53f4b1cf72:g:Rd4AAOSwPcVVukR3


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Thanks RC! I'll try that 12mm bit out.

Here some update on the project:

I finally found a "driver" capable to hold exactly 3.5A at 8.7V at least for a minute. It is not a specially designed for laser diodes one, but a cheap and relatively new DC-DC downstep converter sold at dx maybe for driving LEDs. I checked several (they only cost 4-8 EUR), but this one held 3.5 A the best (SKU 375823).

Then I made a hole in one of the heatsinks to insert a thermal sensor of a "Car volt/thermometer", so it would touch copper module inside close to where LD is.

And finnally added 4 screws around the front PCX lens (the one which has strongest effect on the shape of the beam) to adjust its rotational positioning and lens separation. All lenses are attched with double face adhesive film to a 12mm brass strip inside of 12mm ID Al U-shaped guide.

Now when both LDs are working at 3.5A, the LPM shows 6.6W total output.
The spot at 5m is almost round, ca. 6mm in diameter, but this may be not collimated beam spot, but simply the "beam waist", because I have adjusted the lens separation for producing smallest spot exactly on wall 5m away.

Turning this device 3 times on/off with duty cycle 1 min on, 1 min off showed temperature change at 1 min intervals:
28-37
36-44
41-49, then while cooling down each minute:
46
44
42
what means that 1 min on rises T 8-9°C, 1 min off lowers T 2-3°C. From this I would suppose that the duty cycle of the device should be 1 min on, 3 min off at this power without active coolling.