put antother penny on top of the bb's the push those down until you can see through both the holes, then put the dowel through both holes.
this is the instructions to build a cheap airsoft tripmine. to build this you will need
1 3/4" diameter pvc pipe approximately 2.75" long.
1 metal spring approximately 2.65" long
1 endcap for pipe
6-8 airsoft bb's
metal or wooden dowel approximately 4mm in diameter
Step 1: step one
drill two holes in the pvc pipe about one inch from one end.