The photos below show the knockbox full ready to go with the removable bottom in place. The second photo shows the unit with the bottom piece removed ready for dumping and cleanup. Purchase the outer ring (D-2852, D-3034 4" diameter, $0.79) and the bottom piece (it has louvers inside) $1.79). Also purchase a foot of 5/8" diameter clear tubing, 1ft of 1/2" copper pipe, (2) 1/2" copper end plugs, (2) 5/8" rubber groumets. Go to a hobby store and buy a sheet of brass (0.010 x 4 x 10) to cover the bottom louvered piece with. Pick up at HD, some JB weld, an epoxy 2 part glue that will glue the brass sheet to the bottom piece.
NOTE: the materials for the tube and bottom piece ARE NOT PVC!. The sewer section handles plastic that is made of acrylic, an easily carvable material, not brittle like PVC. I took a 3/4" spade bit to drill the holes for the 1/2"copper pipe. Go slow with the drilling. Acrylic heats up and melts easily. Once drilled take a knife and trim excess material from the holes. Insert the groumets. Lightly lubricate the inside of the groumets with vaseline where the copper tube will be pushed through. Cut copper tube with a hacksaw, insert the tube through the lubricated groumets and press fit the copper end caps on, lightly tapping with a plastic or rubber hammer. Cut the clear 5/8" tubing to length to fit the inside. Take a razor blade and slit the length of the tubing (one side only). This allows you to open the tube up slipping it on the copper pipe. It also allows easy removal for cleaning (although grounds have never worked their way under the tube). It is best to use fine sandpaper and "rough up" the brass sheet and the bottom piece before putting the JB Weld on. That way the brass will adhere to the bottom better. Place the louvered brass sheet on a table and trace the bottom piece around it. Use old scissors to cut the brass sheet. Mix up JB Weld and using a wooden match stick, LIGHTLY place the glue on the bottom outside perimeter and louvers. Press the cutout brass sheet on the bottom, place something heavy on the bottom piece and let dry overnight. JB Weld is waterproof when dry. I put some sticky foam tape on the N and S poles(outside) to give a snugger fit on the bottom piece. When emptying, push with your finger on the bottom piece and it will pop out ready for dumping. I used a saber saw with a thin blade to cut the opening out on the front to accommodate the portafilter handle. When sawing this out, set the speed on the saw at the lowest setting, if not, as you cut the acrylic at high speeds, it melts forming a weld behind the blade. If you are good with a coping saw, that would also work, but I can't figure these saws out. For the cutout, I drew with a compass a 4" circle and taped that on the front of the top piece and traced around it with a permanent marker. Be careful and don't cut below the ring on the outer tube that supports the bottom piece! Acrylic does not coffee stain! I have had mine under the sink for a month (don't tell mamma) with pucks in it and merely ran it under water using my hand to rid it of coffee stains. By the way, I have used this 60 times with no failure. Acrylic seems to "bend" with stress, versus PVC which fractures.
Home Baristas, Feel free to use this for your personal use, HOWEVER commercial vendors be forewarned! This is copyright and patent applied for protected!!!!
well done!!!!!
