Not Directly Related to Building.... My Latest Flashlight Mod

Started by MountainDon, November 29, 2017, 05:09:30 PM

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A light that can be used camping or for any emergency, power grid down, situation.

It began life a a cheap Chinese knockoff of a light known as an SRK, a Sky Ray King. The body holds 4 x 18650 lithium ion cells, the cylindrical cells that used to power all laptops. I chopped the head down and rebuilt the front/top end. Light is from a Cree LEDusing a remote phosphor dome for the 3000 K output. It is not super bright on maximum, but has great run time. On highest output it seems to be much like a clear globe 40 watt incandescent. It is kinda hard to make meaningful photos, but here's one in the workshop, on high, right after final assembly. The maximum head O.D. is about 2-1/8"; 55 mm.

With the 4 - 3000 mAh cells it will run about 18 hours continuous on high.

Another view

Not visible is the micro-usb port which powers the built in charger and allows up to 2 amp rate recharging of the cells while in the light.

I have lots more construction photos if anyone is interested.

One more photo.

This is the head, removed from the body with the circuit boards hanging loose from each end. The firmware allows stepless ramping from lowest, moonlight like setting to the highest which I intentionally limited to use 700 mA maximum.

Just because something has been done and has not failed, doesn't mean it is good design.


Cool project! I'd like to make an attachment to go on my Milwaukee M18 flashlight that would redirect and diffuse the light. The light stands up right, uses rechargeable 5.0 A/H batteries, and runs a long time with the LED bulb I got for it.

I'm not poor- I'm financially underpowered.


Those are nice utility lights. A number of people have adapted various plastic jars or bottles to assorted lights. My experience, and that of a couple of other guys on the flashlight forum is that the LED is best facing down like in the light I showed above. There is less glare in your eyes. But placing the led there is more complicated.
Just because something has been done and has not failed, doesn't mean it is good design.


I don't want to modify the flashlight- it's too handy! I was thinking of a reflective cone hanging down, and a lampshade to diffuse the light. It would just sit on top of it.

I'm not poor- I'm financially underpowered.


Go for it. I had a Ryobi 18volt I was going to mod but then I got into  changing the electronics, and changing led's.
Just because something has been done and has not failed, doesn't mean it is good design.


Seems like a good time to add to this old topic. Another light I am almost finished building. This one has a fair amount of woodworking. I will include a few photos here.  I am posting a more detailed build description over on the BLF (budget light forum) website...for any of the more curious that can be found here

The idea for this light was inspired by the bookshelving I built for our son's home recently. 

Here's the current project, a japanese shoji style light. This may be used on a table or may be hung once it is completed. All the woodworking is completed now. The electronics that control the LED output have to be installed. Included is a lithium polymer battery and a charger.

The wood used is pine. The stain is Minwax ebony. The screen material is a plastic laminated paper 0.2 mm thick. 

The screen frames number four in total, one for each side and are removable. They began life as a piece of 1/2" thick pine. Grooves were routed and then the board was cut apart into "sticks" called kumiko.

One of the frames being glued up...

Four frames completed...

Two of the corner posts, or stiles, test fitted with a frame...

Test fitted, rubber bands holding everything together...

The shoji paper is affixed to the backside of each frame with double sided tape...

If interested, more photos of the process are at BLF.   I'll also post a completed set of photos here when it is completed.
Just because something has been done and has not failed, doesn't mean it is good design.


Beautiful and some pretty high level joinery  [cool]
I'm reminded each time we have an outage and have to drag out the smelly old kerosene lamps that I should make some nice long runtime battery lights.


A completed project.  The copper discs have a direct thermal path to the LED to offer the needed cooling for the LED.  In my excited rush to photograph the completed light, I neglected to dust off a few areas.

The second shot os with the LED powered on mid power. The LED is 3000 K, plus the copper plates probably add a little warmth as / if light reflects off them.

The underside, showing the battery cavity plus most of the electronics (charger board, usb port, voltmeter...)  The on-off switch is located in the leg or corner post at lower left where the black and red wires enter through a drilled hole set.

Two hatch covers on the underside; one is installed, the other is still off illustrating the LiPo battery fitment.  The extended copper strip is for cooling the charger.

There is an onboard voltmeter that only operates when the momentary contact switch is held down. The red LED indicates a charge is underway and when the LED switches to green, the charge is complete.

Just because something has been done and has not failed, doesn't mean it is good design.


Bruce & Robbie
MVPA 23824