My dad needed an efficient light source for the inside of a camping van. The lights needed to be able to run multiple nights without draining the battery while still producing decent quality light. The following is the construction of such lights.

The lights use Cree LEDs with 90 CRI and efficiency of 110lm/W (400mA). A warmer 3000K color temperature was chosen to facilitate falling asleep at night. The light output is continually adjustable from 150lm (0.8W) to 900lm (10W) using LEDdynamics' BuckPuck 1000mA drivers. The lights also have reverse battery protection from P-channel MOSFETs.

The ears on top are for hanging the lights using paracord.

Step 1: Parts and Materials

Materials (pictures show material for two lights)

1/2" aluminum plate
3/4" aluminum rod
Acrylic diffuse 0.118" ACRYLITE Satinice 0D010 DF (left over from another LED lighting project)
LED emitter Cree Xlamp CXB1304, 9v 3000K 90CRI 110lm/w, CXB1304-0000-000C0UB230G
LED driver LEDdynamics BuckPuck 1000mA 7-32v 3021-D-E-1000
220uF 25V electrolytic capacitor
MOSFET P-channel IRF5305PBF
Power jack 2X5.5mm PJ-065A
Cable 2.1X5.5mm 2m 10-00110
Power jack 2.1X5.5mm 50-00025
Cigarette lighter plug with 2.1X5.5mm plug on other end of cable (select desired cable length for light placement)
2X 8-32 1" stainless button head cap screws
2x 6-32 1/4" stainless button head cap screws
6-32 1/8" set screw
2X #6 plastic washers
2X #6 stainless washers
Thermal paste
4.7K ohm B4K7 linear potentiometer with ON/OFF Switch (6mm shaft with flat)
Two part epoxy
Glow-in-the-dark powder (from glonation.com)

Tools

CNC mill and 11/32" end mill (min 1/2" depth of cut)
Metal lathe with normal tooling (for turning the knob, could also purchase one)
Drill press
Drill bits: #29, #36,1/8", 3/16", 5/16", 7/8", 6mm
Hex keys
6-32 and 8-32 taps with handle
Hacksaw blade (for cutting the tabs after milling)
Disk sander, file and 220 grit sandpaper (for smoothing tabs)
Soldering iron, solder and flux
Heat gun or lighter (for heat shrink tubing)
Heat shrink tubing to cover wiring and MOSFET

Step 2: Drawings

SolidWorks (2016) and STL files are provided.

Step 3: CNC Mill Housing

Clamp the 1/2" aluminum plate in the mill vice
Generate the G-code for the two halves of the housing (I used tabs to hold the parts in place)
Let the machine do its thing (11/32, 2 flute HSS end mill was used)
Drill the connecting holes (I only drilled 1/8" for now and finished on drill press)
Mark the LED fastener locations or drill them to size

Step 4: Remove Parts and Smooth Tabs

Free the parts from the plate using a hacksaw blade
Smooth the tabs flat on a sander being careful not to sand too deep
Finish smoothing with a fine file and 220 grit sandpaper

Step 5: CNC Mill Diffuser

Attach the diffuser material to a sacrificial back plate held in the mill vise (drywall screws into plywood)
Generate the G-code for the diffuser
Let the machine do its thing
Remove parts from the sheet using the hacksaw blade
Remove tabs on sander

Step 6: Drill and Tap Assembly Holes

Drill box back holes (#29 bit) and LED mounting holes (#36 bit)
Tap box back holes (8-32) and LED mounting holes (6-32)
Drill box front clearance holes (3/16")

Step 7: Drill Power Jack and Control Knob Holes

Mark the location of the holes for the potentiometer and power jack on the two halves
Notch the marks using a hacksaw blade (only leave a shallow cut for a drill bit to follow)
Assemble the two halves with 8-32 fasteners
Drill a 1/8" pilot hole into the notches
Follow the pilot holes with a 5/16"
Drill the center web by going through the bottom hole

Step 8: Install LED and Diffuser

Apply thermal past on the back side of the LED and place into the holder
Slide stainless washer then plastic washer onto 6-32 fasteners
Install the fasteners so the LEDs are held in place
Slide the diffuser lens into box front

Step 9: Wire the Insides

Using soldering iron attach wires to the potentiometer and power jack (remember to cover the joints with heat-shrink tubing as you go)
Work the potentiometer and power jack into the back half of the box
Attach wires to LED driver and apply heat-shrink tubing
Add the capacitor across the power terminals on the LED driver
Wire in the P-channel MOSFET and cover with heat-shrink tubing
Solder wires to LED
Work all components into place

Optional drop cable for LED light

The cable on the cigarette lighter can be used directly with the light but is detached easily. The drop cable screws into the power jack on the LED light allowing for more permanent attachment while still offering a separation point at the other end if excessive force is applied to the cable.