Assembling the case
The first thing we have to do is make ourselves the end cap that will have the PCB fastened to it. This cap has a half-inch hole drilled in it for the buzzer. I made the grill from a beer coaster I got from the local dollar store, but any coarse fabric will do.
We will be using a PVC water pipe (with a diameter of three-quarters of an inch) as our case. You should cut yourself one piece about eight inches long. You will also need a piece of pipe about one-quarter of an inch long as a retaining ring. I used a coin as a template to cut a grill with a diameter of three-quarters of an inch. These are shown in the following image:
Parts of the end cap
From left to right, we see the end cap, the retaining ring, and the grill cut from the coaster, which is in the background.
The next step is to fasten the grill in place with a couple of beads of epoxy.
End cap with grill installed
Once the epoxy has set, it's time to insert the small one-quarter of an inch ring that we made...
