Click to enlarge photo.
Here is a list of parts;
35mm black pipe
40mm black pipe (check different makes as some are tighter fit)
35mm lens with a 108mm focal length
1 Fizzie water bottle top.
2 LED Holders
Some pipe glue
The white bit in the photo is what I use to work out the holes, get a sheet of paper wrap it around the 40mm pipe (cut it were the ends meet) work out the size on the computer, then decide were you are going to put the holes, print this and wrap it around the pipe and drill out the holes. This will keep your holes nice and straight. If doing more than one, laminate it first as this will last a lot longer.
Glue the larger part of 35mm pipe in place first, drop in lens, then glue the small section of 35mm pipe in place. Then drill two holes in the top, add the led holders and fit the leds in place with the wires attached.
Slide the top up and down the tube till you get the perfect focus ( Do this just like how you would try and burn a hole in a piece of paper with a magnifying glass )till you get a sharp focus, then fix the screw though the pipe into the bottle top to hold it in place.
Hope this is of some use. Video: How to focus your lens set-up
