I, like several (at least) have a Bill Pentz design cyclone. What do you guys use to tell you when the bin is full. I had the bin fill at least 3 times in the past month and blow dust all over the shop. I saw on Bill's site there is a plan to make a sensor from a solar powered motor with a fan blade, He also said that you could use a regular photocell and christmas light bulb in the pipe right above the bin to trigger an alarm or light or whatever. Any thoughts?