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160mW Dorcy Metal gear mod

stevetexas

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Here's a simple, cheap and powerful laser I built today.  It puts out a stable 160mW over at least 5 minutes without ANY signs of warming. [highlight](be sure to scroll down the picture to see both lasers)[/highlight]

(the other laser is a mini dorcy mod I did that puts out about 115mW and is VERY stable over at least 5 minutes.  I used a LOT of solder as a heatsink within the head of the mini dorcy and ground down the head of the mini dorcy to allow it to fit within the blue heatsink.)

I hope the instructions are clear and I didn't miss anything...  ::)

notice the open air space within the red heatsink - plenty of airflow around the diode, module and shaft collar

it uses 2 c123 batteries and the power could go up if you use a smaller resistor.  My next one will use a 7.5 ohm resistor or maybe even 5 ohm.  

instructions follow this post and the pictures will help you understand my instructions.

Sorry about the size of the images - they're big so you can see it better.  The total setup cost about $40 and the component list is the following:

metal gear flashlight
diode
aixis module
heatsink
10 ohm 1 Watt resistor
switch
1/8" 4"x4" rubber sheet
1/2" shaft collar
copper washers
wire, solder
 

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stevetexas

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it runs off  2  CR123 batteries.  to do this, completely dissasemble the metal gear light.

remove the switch from the back of the light - it won't be used (but the tailcap will).  

remove the head of the light - it won't be used.

remove the black plastic threaded retaining ring at the front of the battery tube - keep this

remove the black plastic cup at the front of the battery tube and replace the resistor with a 10 ohm 1 watt reisistor.  solder a 3" red (+) wire to the top end of the board at the end of the resistor - this is your + contact.

cut a copper washer (with side cutters) to fit inside the metal gear body between the black plastic cup and the black plastic retaining ring - it MUST make contact with the metal of the body.

drill a small hole through that copper washer and thread a 3" black wire through the hole and wrap the bare wire around the outer edge of the washer and back through the hole at least once and solder it in place, this is your - contact.

drill a 1/2" hole through the front of the heatsink for the module.

use a dremel and cut off the back end (only the last 1/4") of the module, or drill out a larger hole for the wires.

run the wires through the black retaining ring and the back end of the module.

place 1/2" of heat shrink tubing on each lead wire.

solder the + and - wires to the diode and slip the heat shrink tubing in place.  (then apply heat)

seat the diode in the module and thread the 2 module pieces together (leave the optics off for now)

VERY briefly test the diode - 5 seconds or so

apply thermal grease to the module body at the level of the diode and slide on the shaft coupling then tighten the set screw - do NOT epoxy the module to the shaft coupling or the heatsink...

test the setup by placing the module/coupling into the heatsink to verify depth and position of the module relative to the heatsink - it must extend enough so you can screw in the optic
portion of the module and adjust it after you're done.

insert the shaft collar/module into the heatsink and thermal epoxy the shaft collar (not the module) in place inside the heatsink - be sure to leave the set screw facing a hole in the heatsink so you can unscrew it if you need to slip out the module and change the diode.

remove the electronics from the dorcy body and grind off the threads at the "head" - (you will need the threads at the other end for the tailcap)

press the dorcy body into the heatsink after the threads are ground off - this will take some experimenting to get the right amount ground off, but you'll be close when you don't see any of the thread...

remove the body from the heatsink and re-install the electronics portion into the dorcy body then press it into the heatsink.  

the front end is now done.
 

stevetexas

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remove the switch and o-ring from the tailcap.

drill a small hole through the side of the tailcap (where the o-ring will cover it).

run some bare wire through the hole leaving about 1" inside the cap and loop it around the tailcap a few times where the o-ring sits. replace the o-ring.

This must be a sturdy connection and you may want to add some solder to the area where the wire goes through the hole

insert your own switch and connect it to the wire on one pole of the switch. the other pole is for the - battery contact.

the tailcap is now complete.

cut the rubber sheet to fit around 2 CR123's laid end to end. insert the sheet into the battery tube.

insert the batteries and screw on the tailcap.
 

LarryQ

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Very Nice!!!!!!

Really thinking outside the box (did I just say that??) with your use of the heatsinks from a Nitro Powered RC car!!!!!

Good Job!!!!!


LarryQ
 

Daedal

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That looks amazing Steve! I'm jealous of those heatsinks you have there... but I like your batteries ;)

BTW: it seems to me from your explanation that the flashlight didn't have a driver board in it? :-?

Thank you :)

--DDL
 

stevetexas

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it is a VERY simple board with connections for a resistor and the positive connection to the battery - it sits within the plastic cup inside the body of the metal gear light

(see reply #10 above)
 

stevetexas

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I tested the Metal Gear tonight with a pair of fresh batteries.

It peaked at 181 mW, hovered around 175 mW for a minute, and then settled in at 160mW for 35 minutes (then I turned it off because I got bored...)
The mini Dorcy peaked at 112mW and stabilized at 102mW for 35 min.

I guess these are full duty cycle. If they were going to overheat, I would think that they'd have done it in 35 minutes of continuous run time. I'm sure I could have left them on until the batteries died. :)
 







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