Turning scrap and left-overs into something useful ...

wquiles

Flashaholic
Joined
Jan 10, 2005
Messages
8,459
Location
Texas, USA, Earth
I have this Dewalt 18V incandescent "lamp" what plugs into the Dewalt battery pack this model, in case anyone wants to buy one for a similar project. I trade it/barter for it many years ago, and it has been sitting in a shelf in my home office - just sitting there, as I hoped to eventually do something with it. I like it since with the heavy battery base, it can stand on its own, and have the head pivot at either horizontal or vertical, which might come handy.

I wanted to take it camping with my son's scout pack on March, but I ran into some trouble, and I could not finish on time. This weekend I finished it :)

I measured the threads on the head as best as I could - something like 18TPI:
20140317_183407.jpg



I started with a scrap piece of Aluminum - gummy, does not machine well (certainly not 6061), but it was "free", so I used it as a base for this project:
20140317_180020.jpg


20140317_184418.jpg



To give the new head/heatsink a non-slip surface, I gave it a swirl knurling finish:
20140322_153252.jpg



Then face, and bore for the thread side:
20140322_153705.jpg


20140322_154511.jpg



Then cut the threads, and test fit:
20140322_160733.jpg


20140322_162307.jpg



Cut the "excess" in my revamped bandsaw:
20140322_162845.jpg



After machining the oposite side for the LED and the lens pocket, the head was finished. Here it is compared to the original plastic retainer ring:
20140504_143458.jpg


20140504_143514.jpg



For the LED head/heatsink, I decided on color quality over quantity, so I used several LED's with a high CRI value, which I had in my storage for 3-4 years:
20140322_151928.jpg



and in the middle, I used on the McGizmo high CRI LED's he sold years ago:
20140322_151957.jpg


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Not pretty, but this is how I decided to plug the head/headsink to the swiveling base:
20140322_212813.jpg



Now, since these packs charge to higher than 18V (actually in the 21V range), I decided to use one of my own PWM LED controllers, connected in direct drive (for high efficiency), and to make it adapt to the temperature in the head - so as it warms up (new/fresh batter), the PWM duty cycle gets smaller (which lowers the temperature), and once the temperature lowers, it can go back to the initial, higher duty cycle. Of course I have a 5C histeresys in the software, so that this is all very gradual, and automatic (Tiny85 gets calibrated at programming time). Of course, I can't connect a 3V PWM signal without some sort of switch, so again, I am using one of my own small MOSFET boards as the switching element. Here is the setup in my bench - I have a "sticky" thermal pad between the boards and the metal head, and epoxy to keep them in place (that schematic is the one for the "white" PWM controller board I designed):
20140504_134719.jpg



Bench testing. The back of the my controller board has the Tiny AVE programming pins, so that I can re-program/fine-tune as part of the development of the firmware settings - right now I am letting the head get to about 48-50C before picking a lower PWM duty cycle:
20140504_135741.jpg



Here is the initial duty cycle setting - about about 68-69% (yes, I am under-driving everything, for cooler temps, and longer runtimes):
20140504_140223.jpg



Once the temperature level is "hit" the PWM adjustment takes place, lowering the RMS current, thus starting the "cooling" process for the LED's - here the duty cycle is 50% lower than initial, at about 34%:
20140504_140033.jpg


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Finished product:
20140504_143227.jpg


20140504_143249.jpg




I just simply used the original plastic lens, and glued it down in place using epoxy:
20140504_143341.jpg



Up and running (pun intended!):
20140504_141742.jpg



Not too bad for stuff/pieces I have laying around, right?
 
Last edited:

wquiles

Flashaholic
Joined
Jan 10, 2005
Messages
8,459
Location
Texas, USA, Earth
I reprogrammed the controller to offer 3x output levels, and low battery detection/shutdown. Two short videos here:




Will
 

bnemmie

Enlightened
Joined
Jan 13, 2010
Messages
226
Location
The UP
Great work! I use the exact same plastic organizer for my spools of small wire. Guess I'm not the only one who had that idea lol
 

wquiles

Flashaholic
Joined
Jan 10, 2005
Messages
8,459
Location
Texas, USA, Earth
Thank guys :eek:


I also have this very heavy duty 26650 host I bought 2-3 years ago, which I had dissembled to change its driver (did not like the modes, levels, etc. - typically low cost AMC7135-based driver). The light itself is great, with outstanding thermal path, etc., but it sat there in parts in my "shop" for several years:
26650_Host.jpg


20140510_134539.jpg


20140510_134612.jpg



Well, this LED PWM controller and FET switch worked so well in the DeWalt, that I decided to try to retrofit the same solution in this host. I started by flattening both sides of the brass heatsink/driver cavity:
20140510_140949.jpg


20140510_141523.jpg



Instead of some random XM-L, I found these I bought 3-4 years ago for some other project:
20140510_143048.jpg



I had to reflow SMT parts to make two more FET switches:
20140510_153349.jpg




I then epoxied together the the LED PWM controller board and FET board (same boards I used in the DeWalt - just changed the SMW resistors to adjust the battery range in the analog input of the Tiny85):
20140510_160857.jpg


20140510_163621.jpg



Then used Kapton tape to isolate the botton board (FET switch) from the heatsink to prevent a short circuit:
20140510_173057.jpg


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Then epoxied the two boards into the brass heatsink:
20140510_174457.jpg



Finished product:
20140510_183549.jpg



The exposed pins allow re-programming:
20140510_184803.jpg



Unfortunately the phone camera auto-adjusts, but you can sorta-see the 3 levels (always starts in low level):
20140510_185142.jpg


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20140510_185154.jpg




Of course, this has a deep reflector, so it has very good throw, so now I have a floody and throwy LED work light combo - all with parts I had for several years just laying around the shop :)

Will
 

blackbalsam

Flashlight Enthusiast
Joined
May 18, 2009
Messages
1,583
Location
WNC
Very nice work as always. Guess that dewalt is a little big for edc (HeHe) Thanks for sharing this Will......Robert
 
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