Building and assembling the case
The flasher is designed to fit inside a piece of one-inch PVC plumbing pipe. The LEDs are bent at 90 degrees to the PCB and inserted through holes drilled in a one-inch PVC pipe cap. A #7 drill bit is used to drill the holes for the LEDs. The cap is then turned over and a quarter of an inch drill bit is used to enlarge the rear of the holes so that the LEDs will penetrate further into the cap. You should drill about half way through the cap with the quarter of an inch drill. A drill press with a depth gauge will come in handy here.
One end of the case is sealed shut with another one-inch end cap, which is glued into place. The cap with the holes is not, so that you can change the batteries. Also, I did not include an on-off switch in the design for the sake of simplicity, and to make the case as moisture-proof as I could.
The preceding image shows the completed PCB assembly installed in the end cap. These...