CHEAP Yellow Beam DIY

[LewDude]

Hi all!
I recently destroyed some of my old Xmas laser projectors to see what was inside. They were Prime Laser Light Projectors - some can be found on clearance (frys = https://www.frys.com/product/8790931?site=sr:SEARCH:MAIN_RSLT_PG) for $20 - however, these have the red and green modules pointed out of the machine in parallel. Adding a dichromatic x cube prism or single dichroic filter could be done... BUT I came across a different G/R laser projector that was almost completely ready to be modded : (Fry's Link) https://www.frys.com/product/8988143?site=sr:SEARCH:MAIN_RSLT_PG.

Compared to the Prime units - they are cheaper, have less parts (1 less diffraction grating filter, no cooling fan, etc.), but I liked the way the modules were nearly already aligned to mix our red and green!

IMAG3081 by Lewie Wilkinson, on Flickr

A quick look inside the projector head:
IMAG2983 by Lewie Wilkinson, on Flickr

Essentially, the Red and Green beams hit in the same "Y-Axis" position, just a couple-few millimeters apart from each other on the "X-Axis" within the dichroic filter. So - I see there being 2 options to make them blend:
1) Reposition the filter
2) Adjust the laser modules

I honestly do not know if option 1 would have been easier -but this needs to be very precise, and I felt option 2 would provide more 'fine tuning' in the end. I might try this again using option 1 at some point...¯\_(ツ)_/¯

I swapped the red module with a LG 24x DVD burner diode/Aixiz module and new driver to brighten up the red output.

Some wooden blocks / shims and glue - and we have a yellow beam for 20 bucks (+ cost of Red module). A few more pics for fun:

IMAG2975 by Lewie Wilkinson, on Flickr

IMAG2988 by Lewie Wilkinson, on Flickr

IMAG3070 by Lewie Wilkinson, on Flickr

IMAG3071 by Lewie Wilkinson, on Flickr

IMAG3078 by Lewie Wilkinson, on Flickr

 

[deadshadow]

very nice and cheap indeed,btw is it normal for that much green light lose to the side of optics?

 

[diachi]

very nice and cheap indeed,btw is it normal for that much green light lose to the side of optics?

Hard to say without actually measuring the loss. Cheap optics will do that though.

 

[LewDude]

very nice and cheap indeed,btw is it normal for that much green light lose to the side of optics?

Great point...and could possibly lend to option 1 (moving the lens as opposed to 'aiming' the modules) being the better option?? As not only did I adjust the direction of the red module, I also adjusted the green - and if its not hitting the lens at 45 degrees - that could create more of that undesired reflection (loss) ? Someone keep me honest here, please

 

[diachi]

Great point...and could possibly lend to option 1 (moving the lens as opposed to 'aiming' the modules) being the better option?? As not only did I adjust the direction of the red module, I also adjusted the green - and if its not hitting the lens at 45 degrees - that could create more of that undesired reflection (loss) ? Someone keep me honest here, please

Dichros are usually designed for 45° angles, at least for our applications. That said, a few degrees either way shouldn't increases losses all that much.