This is an off road light I designed and built in 123D Design. I'll show you step by step how I made it.
Step 1: Step 1
You can download the program or use the online app at 123dapp.com/design. When you first open the program it will start with a blank screen.
Step 2: Step 2
After opening the program start by inserting a 6"x1.5" cylinder. Draw a 5" circle sketch on the top of the cylinder. Next, press the circle into the cylinder .25". After that, delete the first sketch and make a second circle 4.8" on the new lower surface and press it down .5".
Step 3: Step 3
Now Sketch a vertical line 2.75" from the center of the cylinder. Next, sketch a 1/8" circle at the end of the line. Press the circle down .75". Next use the Circular pattern tool to pattern the new cut cylinder 10 times around the housing. Do the same thing again on the lower level on a 4" circle.
Step 4: Step 4
Next make a sketch around the perimeter of the light for an o-ring path and a perpendicular sketch for the profile of the o-ring. Use the sweep tool to cut the groove.
Step 5: Step 5
Sketch consecutively smaller circles on the back side to extrude to form the heat sink. Use the trim tool to remove the excess sketch. After trimming the sketch, extrude then mirror the heat sink.
After you have finished modeling all your parts. Create a new part to assemble it in. Use the move tool to position all the parts. Using outline mode can help when you are aligning parts inside of other parts. After assembling a small group use the group tool to move them all together.
After you have assembled every thing use the materials to color the parts. When you are finished you can sketch a square and cut the model in half letting you see inside.