One of the most time consuming tasks when moulding with PB is forcing it through a sieve for facing. Over the past 10 days I've been working on a powered sieve to speed up this process. I wanted it lightweight, powered by a cordless screwdriver and fairly quick. Through trial & error and about 10 iterations, here's what I've got to work. The main body is schedule 10, 4" PVC pipe couplings and a couple pieces of pipe. The handle is 3/4" PVC pipe. The agitator is a plexiglass 3 spoke hub with a cut off Allen wrench that fits the cordless driver and turned on the bottom end to fit in the oilite bushing in the screen. A steel washer on the bottom of the hub with the Allen wrench hammered through it is the drive mechanism. Zip tie pieces are used to force the sand through the screen and as the agitators for the sand column. This went through the most changes...short rubber wiper, long rubber, short zip ties, # of ties, at one point a metal plow on one spoke. The plow caused sand backup in that cavity so the outboard ties are bent at an angle so they rub against the wall and clear the sand. The screen rests on another 3 spoke plexiglass piece with the bushing in the hub. It's held in place with the friction fit pipe and is removable for screen replacement if needed. On the top coupling, the pipe protrusion controls the depth of the agitator. A second ring of pipe was added on the inside for thickness. A couple of blocking bars were added to keep the sand column from spinning with the agitators. Occasionally the column does spin a little, if it persists I'll run a long screw into it. Still experimenting with screen mesh size. I'll video later.
