At the end of February I wrote that the tumbler shaft had been bored so that I could rig a vacuum to collect dust. Five months later, my helper, Scott, installed the rest of the system. That’s pretty typical of how things work here.
He fabricated a trap which surrounds the shaft. It fits closely but doesn’t interfere with rotation. The exhaust duct attaches at the top and a slide gate is built into the bottom for clearing the heavier debris. About six feet downstream is a Dayton 134 CFM/1500 RPM forge blower which pushes the air outdoors through a dryer vent type opening.
Since the tumbler runs on 220v and the blower is 115v I decided to put the blower on it’s own timer, a Woods 59717 60-Minute Mechanical Wall Switch. It’s not much trouble to turn two dials now instead of one.
The system has been operational for several days. The interior of the tumbler seems very clean, nearly dust free. The real proof will be after the whole work space has been cleaned well to see if it stays significantly cleaner. I’ll probably get around to that in five or six months.