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Dual color custom host 520nm and 635nm rebuild - merge my two lasers into one

djQUAN

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**I also could have put this in the red lasers section but I like the 520nm green a little more. ;)

Having nothing much to do during lockdown, I tore apart my two old lasers which both used cheap flashlights and broken lasers as hosts.

I got tired of carrying several lasers on outdoor trips so combining two into one would reduce the "lasers to bring" count by one less. I would have combined the 520nm green and 450nm blue but the blue used a different style of module and besides, it is already completed into a new version here. The old green laser build was from here and the red build from here.

I started by disassembling both lasers. The green one used a 14500 cell and the red one used a CR123 sized cell. So combining them also reduced the types of battery I needed. It took me about a day and a half to machine the host components from a solid block of T6 alloy aluminum for the heatsink and blocks of acrylic for the battery side.
IMG_20200426_153443.jpg

There will be an integrated USB charger with a micro USB connector included stowed away in its tiny little pocket.IMG_20200426_154625.jpg

First test of the charger circuit. It will be tucked in when in normal use and flipped out to charge the built in 17670 protected AW high drain cell.
IMG_20200426_162549.jpg

First test with the LPM, the 520nm did 91mW and the 635nm red did 182mW. but because of the eye sensitivity curve, they both appear the same brightness.
IMG_20200426_164553.jpg

IMG_20200426_164600.jpg

I could have done a different better looking front aperture but this will do for now. I plan to make a shutter type opening to protect from dust when transporting or storage.
IMG_20200426_165616.jpg

The rectangular form factor feels nice in the hand. I was thinking of machining the main heatsink to add fins but opted to not do it yet and get a feel for the heat dissipation before I do something irreversible. Another reason for tearing apart the two lasers was I did not like tail switch hosts for lasers and preferred side switches so I ended up with this. The momentary rocker switch only allows one laser to be on at a time to prevent heat issues and extend battery life.
IMG_20200426_165630.jpg

Here it is beside the recently completed blue laser. It is still quite handy and fits in the hand and pocket nicely. The battery part of the case would have been fully made from acrylic but some mishaps ended up messing the thin parts so I machined them all out and epoxied aluminum plates which also hides the battery. Ended up better and stronger than thinned out acrylic too. I wished I had some 1mm carbon fiber sheets and I think that would look nice too but this still worked out well.
IMG_20200426_165721.jpg

With the top half open (after 9 tiny screws) gains access to the protected 17670 cell.
IMG_20200426_165921.jpg

positive contact is a gold plated button taken from a scrap battery contact board. The silicone wires easily stick to super glue which allowed me to keep them neatly in place in the machined sides. There is enough slack for the charger wires for the charger module to open up up to 90degrees but I usually limit it to prevent repeatedly flexing the wires even though they are fine strand super flexible ones.
IMG_20200426_170001.jpg

Sorry no beam shots yet as it is still bright where I am while I'm posting this :giggle:
 
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Snecho

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Just like the other one, I really like the rectangular design. The flip out charging port is super cool.

Overall a very unique unit for sure and good job on bringing it to life.
 

djQUAN

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Thanks. Did a little more work on it. Couldn't leave anything done as it is, as usual ;)

I dremeled some tiny channels on each side of the USB module and put in some tiny BB's in it to limit the flip out angle.
IMG_20200426_224909.jpg

You can barely see the BB on this.
IMG_20200426_224922.jpg

Limits the opening angle to only that much to prevent unnecessarily straining the charger output leads too much hopefully extending its life.
IMG_20200426_224935.jpg

Still plenty to access the micro USB port.
IMG_20200426_224956.jpg

There's just enough room for the USB plug.
IMG_20200426_225045.jpg

I also worked on the front aperture shutter mechanism. The front plate is only 1.5mm thick. Milled a pocket for the shutter (0.5mm thick) to slide into.
IMG_20200427_142405.jpg

Here is how they are supposed to fit in.
IMG_20200427_142415.jpg

Sandblasted the back of the shutter and painted a part of it black as a beam dump if (when) the button gets pressed to, hopefully, prevent damage to the diodes from back reflection from the aluminum shutter. The green part is mylar tape so it slides in and out better.
IMG_20200427_151225.jpg

Here it is fully assembled and closed.
IMG_20200427_142549.jpg

And in opened position. This shutter mechanism should keep the lens clean for much longer when I just throw it in my bag and in storage.
IMG_20200427_142555.jpg
 

RedCowboy

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Very nice, thanks for sharing your pics. :)
I have been thinking of making a similar hand held for a Sharp 488 and a 520 and a 450 that way I can show people the 488 along side the green then the 488 along side the blue because our perception of that 488 changes instantly depending on which other beam is next to it.
 

djQUAN

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That would be cool. It has been more than 6 years since I last bought laser diodes and now there are a lot of new different colors and powers. Budget is still tight though so it will have to wait until opportunity comes.

If ever I get to make new color handhelds, it will probably have the same form factor as this with multi color setup too. More colors and less lasers to carry. :) I found that high power burning lasers are cool but it gets old pretty quick. You can't just lase around the house admiring the beam without burning something else, not to mention the eyesight hazard.
 

CDBEAM777

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Very, very nice !! Unique design !! Well executed !! Compact !! Easy to recharge !! Outstanding re purpose !!

But...It is not round....the traditional geometry !! HAHAHAHA....GK !! Thanx for the share !!! Good timing !! ANY diversion is welcome....especially one involving HH Laser units !!!!

CDBeam
 

djQUAN

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Thanks! well, being not round means it doesn't roll away from you when you put it on a non level surface. ;)
 

paul1598419

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Very nice build. I like the shutter and for the same reason you do. It will help keep debris out of the unit and especially the lenses.
 

djQUAN

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While playing about the laser before going to bed, I had an idea.

What if I put tiny holes on the shutter so when it is closed, it restricts the beam and limits output power so I could bring it to countries with laser laws? Just an experiment to see what would happen. I had a "not so perfect fitting" shutter trials I could try it on those first.

for a start, I drilled a 0.66mm hole (26mil). The black pen "ring" was so I could roughly see the middle of the aperture.
IMG_20200428_102132.jpg

Green ended up to be 4mW
IMG_20200428_102541.jpg

Red measured to be 6mW.
IMG_20200428_102545.jpg

This looks promising.... I don't think dust would be an issue because of how tiny the holes are. Dust should not enter unless you rub it in hard I have drills down to 0.3mm so I could reduce the power even more.
 

CDBEAM777

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Hahahaha...Can we say..." Photon Restrictor Plate " ???? Hmmmm Good idea !!! CDBeam
 

djQUAN

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Correction. Drill was 0.46mm or 18mil.

The spot size divergence became much poorer and got rings but it doesn't matter if you just want to keep below the legal limit or dim it to be able to use it in presentations. Opening the shutter makes everything great again :D

These pics were taken at about 5m only. The central spot is a little bit smaller than a dime.
IMG_20200428_200527.jpg

IMG_20200428_200550.jpg
 

RA_pierce

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Pretty cool diffraction patterns from the tiny aperture.
One suggestion:
You can instead glue thin windows into the aperture to reduce the power output. If you have a glass cutter and a couple cheap neutral density filters, you can attenuate the output enough to bring the output to < 5 mW.
Another place to find optics that may work is in a CD / DVD / BluRay disc reader. I used an optic from a BluRay burner to do just that for a 488 nm pointer so I could use it for presentations. I think the optic was a long-pass optic (passes red, reflects blue). For attenuating red, an IR filter may also work.
If you use an optic to attenuate the beam, you get 100% dust protection and preserve the beam quality (i.e. less diffraction).
 

djQUAN

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I have thought of that. But the front plate is 1.5mm thick so I will have to make a new one to accommodate the additional filters. This was done 100% free. Either way, the spot degradation does not matter as I often use it at full power. But still I appreciate the suggestions, I could use it in a future build though ;) maybe on the 450nm pen rebuild! That one does not have a lens shutter yet.
 
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