Bought some 8×24” hvac duct from home depot. 2 feet of 2” pvc. Some sheet metal screws and I hit the shop.
Problem 1: How do you take a rectangle of sheet metal and turn it into a cone?
Answer: 71º angle, and 2pir. I wanted an 8 inch top for the cyclone, so an 8 inch circle has about a circumference of 25 inches. I took a 26” long piece of scrap plywood and drilled a hole at both ends. I pivot at one end and draw an arc with a radius of 26”. I dont know if this is the right way to form a cone, but it made sense in my head. To be sure i did everything on paper first. Once i was satisfied i then transferred to the metal and cut it out.
With that complete, i formed the cone. I do not have pictures because this was the most difficult part for me. I drilled pilot holes in the overlapping piece and pulled the cone tight together with the sheet metal screws. Once that was complete, i cut out the intake hole with my dremel.
Now on to the bucket lid. I decided to use a plywood sandwich technique where i would pull the lid tight between two pieces. It was fast and worked quite well. It added some strength to the bucket lid too.
The last piece was the cone top, which i made from some 1/2” plywood.
I dry fit everything and did a test run. This was with no sealing or epoxy, just painters tape and suction… i was amazed at the results. It works extremely well … i cant wait to see what happens when i seal everything up.
I shot a video to show it in action:
Finished product with epoxy and sealant.
EDIT #2 (03/2014):
Make one of these. Even if you’re not going to use it for a wood shop, you really should make one of these for everything else. I use this to clean my couch, clean my cars, radiators, chunky plaster pieces, etc… If you have kids and they spill giant bowls of snacks/crackers/etc… and you wonder if that dyson or hoover can pick it all up without clogging … Just be a man, grab your shop vac, attach this thing to it … and suck it all up without skipping a beat.
I’m thinking I might actually hang this in the basement and buy a cheap shop vac with a switch. Use an existing hole in the kitchen area as an intake and I’ll have a built-in central vac for probably < $100.