Introduction: Weather Resistant Outdoor LED Lights

By
About: Mechanical engineer working on industrial equipment.

These outdoor lights feature a stainless steel body, aluminum cap, polycarbonate lens, and o-ring gaskets for weather and corrosion protection. I used high power LEDs, which can be a little costly, but they are energy efficient, last forever, and are easily dim-able. The LEDs could be replaced by a different bulb if needed. The LEDs could also easily be powered by batteries or a cool PV system.

This instructable does not describe the LED wiring process, just the components. It also does not show detail in the machining processes involved, just the overall process and outcome.

The lights consist mostly of custom parts, so they are time consuming to make, but make a great reading feature for an outdoor hammock.

Step 1: Tools

Tools I used:

-Jig saw (can also use a band saw for this step)
-Metal working lathe with three jaw chuck (3"+)
-Soldering iron
-Horizontal Band Saw
-De-burring tools (file, etc..) or belt sander
-Drill
-Step-bit
-6-32 tap and corresponding drill
-3D printer

-Mill


optional bonus:
(for decals and surface finishing)
-Sandblaster
-Laser cutter

Step 2: Materials and Costs

I made the light fixtures from extra things around the shop, but everything can be purchased from McMastercarr online (keep in mind my prices don't include shipping). The LEDs and drivers were ordered from Luxeon Star LEDs. The cables and thru-wall fittings were ordered from automation direct. The power supply and power box were from the local hardware store.

*This was my first attempt at using high power LEDs and I didn't spend a lot of time sizing the heat sink or choosing LED colors, so the heat sink is probably a little over sized. The LEDs I chose were plenty bright to read by and I like the white color. For this application you can put a filter in the lens to change the color.

**I made three lights, so my totals will reflect that amount.

Fixture Materials:
McMasterCarr.com

#8989K651 - 3" stainless steel tubing 12" length : $26.23 ea (one can be cut into 4" sections)
#1610T19 - 3" aluminum short rod 1/2" length: $5.28 ea x 3 = $15.84
#8574K321 - 6"x6"x1/2" polycarbonate sheet: $10.26
OR
#8581K45 - 3" acrylic rod at 2" length: $13.08 (one rod can be cut into 3 x 0.5" lengths)

LED and Drivers
Luxeon Star LEDs (Luxeonstar.com)

3 x 30mm Square x 25mm High Alpha Heat Sink - 9.5 °C/W $18.90 Shipped
1 x 700mA, Externally Dimmable, BuckPuck DC Driver - With Leads $15.99 Shipped
3 x ANSI White (2725K) Rebel LED, Mounted on a 20mm Star CoolBase - 135 lm @ 700mA $21.18 Shipped
1 x Pre-Cut, Thermal Adhesive Tape for 20mm Hex Bases (12 Piece Sheet) $7.49 Shipped
1 x Wiring Harness for 3021 & 4015 'E' or 'I' Drivers, 6 Wire With Adjust Pot $4.99 Shipped

Cables and Connectors
Automationdirect.com

*If you want to do m12 fittings at both the power box and the lights, use the male and female m12 thru-wall fittings with an m12 patch cable. Otherwise, just buy the male thru-wall fittings and m12 cables with a single connection.

**I've listed the longer version of the cables, but you can buy any reasonable length for your application.



7231-13501-9710050 - Male (m12) receptacle thru-wall fitting: $7 ea. x 3 = $21
7231-13541-9710050 - Female (m12) receptacle thru-wall fitting: $7 ea x 3 = $21 (optional- use if you are doing m12 connections on both ends of the cable)

CD12M-0B-070-A1 - 7 meter length (m12) cable with one female connector: $12 ea x 3 = $36.00
CDP12-0B-030-AA - 3 meter length (m12) patch cable (one male and one female connector): $7.75 x 3= $23.25

Step 3: Creating the Body of the Lamp

-Cut the 3" stainless tube into 4" sections

I used a horizontal band saw and belt sanded the ends to get a flat surface and de-burr the sharp edges.

**Tips:
-A band saw will probably give you the best initial resolution on the cut
-A chop saw will also work, but you may want to mill the face flat if you have that available.

Step 4: Creating the Polycarbonate Lens/cap.

1. Trace the outline of the steel cylinder onto the polycarbonate.
2. Try to cut evenly an 1/8" outside the traced line with a jig saw or vertical band saw.
3. Place the somewhat uneven circle in the lathe chuck with a little less than half the circle depth in the jaws.
4. Turn down 1/4" of the polycarbonate until you get a light press fit on the inside of the steel cylinder.
5. Flip the polycarbonate and turn down the other half to be flush with the outside surface of the steel cylinder. On this step I used a slight press fit.

6. Place a large O-ring on the polycarbonate lens where it slides into the stainless tubing.

Bonus:

Laser print a logo onto tape and place the tape on the surface of the polycarbonate. Then sandblast the polycarbonate to get a cool frosted (good for light dispersion) finish with a visible logo in the light.

Step 5: Creating the Aluminum Cap.

1. Follow the same steps with the aluminum cap as the polycarbonate lens. Get a light press fit on the inside dimension and flush with the outside surface.

2. Cut a hole to fit the thru-wall m12 connector fitting through the aluminum cap using a step drill or the lathe.

3. Using the mill and a 3/4" end mill, create a step into the center of the aluminum cap to fit the threads of the m12 thru-wall fitting. If you use a different m12 connector, you may not have this issue.

4. Place an o-ring on the aluminum cap.

Step 6: Assembling the LED and Attaching to the Cap

For this process I created a Solidworks file of a bracket to press the LED against the cap of the aluminum. Using this file we made a small 3D printed part with two holes for screws and a hole for the LED

From the picture you can see the bracket attached to the aluminum cap from the bottom using two 6-32 tapped holes. The hole apparatus sandwiches against the m12 thru-wall fitting.

The bracket leaves plenty of room for soldering the wires of the thru-wall fitting to the LED.

Step 7: Assembling the Fixture

Once you have the wires soldered and the led attached to the cap you can fit the whole unit together. I tapped holes and placed 2 x 6-32 screws on each component. I then used copper wire to wrap the whole light fixture together. In the future I would use something more along the lines of screws to create the light.

Tighten the light in a vise to get a better seal with the o-rings before attaching the copper wire.

Step 8: Powering and Hanging the Light

1. Attach the m-12 cable to the cap of the light and the leads of the m-12 cable to the LED driver.

2. Hang the light by the cable. The threads of the m-12 cable are plenty strong to support the weight.

3. Everything used on the outside of the light is corrosion resistant. I did not test for water immersion, so I do not know how waterproof they are.

Hope you enjoyed this instructable. For more information on how to wire everything up and tips please request.