Multiple beams

[RedCowboy]

Just messing around testing some different beam expander lens combos, yes I know there's a mathematical formula, however I am trying out some scavenged optics I have saved and purchased over time, the results are impressive with just 3 x ndb7a75's knife edged......would be even better if they were corrected then knife edged.

 

[kecked]

How about a series of beams in a line with colinear reds that March across the beams rbb brb bbr

 

[RedCowboy]

I had thought about knife edging in 3 rows, 3 columns ( 3 x 3 ) ...so 9 Red, Green and Blue beams with similar dimensions/divergence laid out as RGB, BRG, GBR.

Single mode beams would be best to make a white beam.

 

[biddy79uk]

Sheltering in place and being somewhat bored I bought a used projector for cheap with 2300 hours and harvested 24 x M-140 diodes that work very well, I am driving 4 laser diodes in series @ 1.6a using a LM338 as a current regulator using 0.8 ohms across the adj. and output pins and 8 x 18650 in series,.....my expideted mounts are angle brackets giving me X and Y adjustment so I can converge the beams where ever I want to.........thinking about what else I can do with all of these diodes.......maybe knife edge a bunch ? Anyway just goofing around and thought I would post a couple of pics.

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Do we have a list of projectors to look out for

 

[RedCowboy]

You want 24 of the 5.6 size 1.5-2W laser diodes for cheap .....search for xj-m and get one with low hours, 2500 hours or less are good, you need basic mechanical skills to harvest, de-solder.

Tested Casio XJ-M140 DLP XGA Conference Room Projector 2500 Lumens 1182 Lamp HRS | eBay

Total Lamp Hours: 1182 HRS. Aspect Ratio: 4:3 (XGA). Display Type: 0.55" DLP x 1. I was able to run the projector for 15 minutes without the projector overheating or shutting down. Upon inspection of the projector, I noticed the type of scuffs and scratches that happen with normal use.

www.ebay.com

Casio Xj-M-140 for sale | eBay

Get the best deals for Casio Xj-M-140 at eBay.com. We have a great online selection at the lowest prices with Fast & Free shipping on many items!

www.ebay.com

 

[RedCowboy]

I bought one of the N-brand arrays and tested it, as expected it can't compare to knife edging similar single beams but it's pretty well aligned for what it is, I managed to get about a 1/2 inch cluster/spot at 15 feet with an expedient beam expander which is about what it does at 1 foot without the beam expander, I can probably get it a little tighter with a bigger long FL front lens......it's a shame these aren't just 1 big laser diode......maybe in time ??? Note: This array is one of the 14 beam type only this model comes with the center 10, apparently they were made for slightly lower lumen projectors. I'm running it @ 3.5A using a single LM338 and 12 x 18650's in series.

With the addition of a single convex lens these make great home CNC cutters for wood and other relatively thin 450nm absorbent materials......Also punches holes in soup cans and melts rock up close when focused to a small point.








There's a lot of lens flare from the factory gang lens, some shrouding/masking is in order.


At 15 feet with the beam expander.


And at 1 foot without the beam expander.

 

[Light superglue]

Biddy79, if you want these old M140 diodes I have a block from M140 wih 24 diodes and a block from H1650 with 40 diodes. Both I can give away for free. I do not think it would be so difficult to send them to UK from Spain even after all this Brexit story...