|Project by dgom||posted 12-20-2013 07:18 PM||1002 views||0 times favorited||2 comments|
This is a project I planned for a long time and this autumn eventually I had the time to finish it.
All the parts needed for fabrication of the 20 identical 1W power-LED spotlights were ordered at Ebay, mostly from China, totalling about $50. While waiting for the items to be delivered (2-3 weeks) I started to manufacture the spotlight armatures which are made from 22 mm MDF. To get an effective production of so many identical parts, I did one processing step at a time on all items, roughly following these steps:
1. Saw circle blanks (band saw) about 70 mm (3’‘) in diameter
2. Drill a centered hole in the middle (approx. 3 mm)
3. Fasten the blank on the lathe with a screw centered on a face plate, shape the outer profile, sand
4. Drill 4 holes to specific depth indicating the corners of the heatsink
5. Drill 2 holes through for fastening purposes and countersink from the face side
6. Drill 2 holes to specific depth to make room for the screws fastening the LED star to the heatsink
7. Drill 2 holes to specifc depth to make room for the cables to the LED star
8. Drill a centered hole (approx. dia. 22 mm) to hold the lens from the face side with a Forstner bit to specific depth
9. Drill a centered hole (approx. dia. 35 mm) to hold the heatsink/LED assembly from the back side with a Forstner bit to specific depth
Then I painted all MDF-parts white before mounting the 45 degree lens (press fit) and LED assembly (LED stars with attached cables, tightened with two M3 screws to the heatsink with a dab of thermal compound in between). The holes in step 4 were placed to get a snug fit of the heatsink corners so no adhesive was needed.
When all the spotlights were finished I “only” had to crawl in the attic for about 8 hours to place a single cable (all the LEDs are serially connected, two separate circuits with 10 LEDs in each) at the roof base and pull it through the holes I drilled from the outside so that the spotlights could be connected and fastened.
I am very pleased with the end result. The 1W LEDs give enough light (about 100 lm each) to light up the white brick facade in a decorative way. The garden also gets some light (especially when there is snow) and hopefully this arrangement also puts of possible burglars.
Next project is to combine a Raspberry Pi with a wireless transmitter which remotely will control a switch in the attic to handle switching on/off the lights automatically depending on calculated sunset/sunrise times as a function of longitude/latitude…