This is a pretty basic setup that can be made in a couple hours. Ive seen many different types of these made by other people, some are very extensive and complicated designs. What i found is that i made something that works by removing 99% of the material into a bucket before it ends up in the vacuum. Which means a clean filter with nothing in the vac for a long long time. And it was simple in concept. The picture of it set up is before i added another bucket section underneath the blue one. I had an old plastic garbage can which was cool because it was a heavy duty plastic.
The down-side is that it was made out of plastic that repels chemicals. I had to use 80 grit paper to rough it up before the plastic epoxy held, so keep that in mind. It has to be strong, a simple traffic cone some people have used will deform under a strong vacuum. I then used some metal snips and cut the garbage can into something i could fold into a cone. The black electrical tape in the picture is there to hold the seam together as the epoxy dried. It was riveted on the seam from the inside. Ok so i had the cone set up. Next was sticking it through the lid of the bucket. Cut a round hole, and stick it through it. I then epoxied and riveted the lid to the cone sticking through it.
Now the top had to be made, so i used a piece of Luaun and glued it to the inside of the opening at top of vortex setup. The hose at the top sticks through the wood about an inch. Now for the rest of the setup.
NOTE: The (white) vortex setup itself is about 2 feet tall.
Step 1: Buckets
My Ridgid shop Vac is rated at 170 CFM. With that said, one bucket is not enough to keep it from imploding after a couple minutes. I used 4 buckets i had kicking around and made the bottom of the set up, revised of course, so i'm skipping to the final setup which i don't have a picture of, of 2 buckets connected together at the bottoms to make a 10 gallon setup.
A quick note is that you have to use the jigsaw at full speed to make it easy to cut through the super-hard plastic buckets. And you have to use or find USG drywall-type buckets, regular home depot or Lowes buckets are very soft in composition and will fold easily. Drill a hole to start the jigsaw so you can cut the bottoms of the buckets out.
Take two buckets, put one inside the other, and rivet them together from the inside. The picture shows how i cut the two separate buckets before they were riveted together. I didn't plan it this way, it just appeared to me how i could join the two together. So you're looking at what are the bottoms of the two-ply buckets before i joined them together.
They fit together in a sleeve kind of design. Then i epoxied them together, and riveted the seam, again from the inside. Now you have two buckets that are now a 10 gallon container. The bucket lids (lids meaning the lid the cone goes through and the lid on the bottom) will go on either end, and it can be emptied from the bottom if needed. Wherever there was a section i was concerned that air gaps might form, i filled with latex caulking and smoothed it over.
This thing removes 99.9% of EVERYTHING i vacuum up, into the container, meaning super fine powdered dust from sanding, wet sawdust outside, whatever you want to remove. Keeps the filter clean...
There are no measurements, formulas or ratios, just a thing that works properly. The intake is pretty close to the top of the lid.
And bigger than most of its type being sold at ten gallons or however large you want the container to be. And bigger because the Vortex part is 2 feet tall. Can be made any size really.
Step 2: Intake
This was at first a complicated concept, but all it took was A) an end of a hose connector, and B) a dremel.
Of course rivets require drilling, so you need a drill bit that the rivets require depending on the size of the rivet head. The flanges on the rivets i used were 1/4".
The next step takes a bit of carving. The plastic for the hose end is obviously pretty tough so it might take some strength to hold it while shaping it. Use a vice and it'll move and you don't want to deform it (remember a hose has to be connected to it eventually). You can buy a hose end and they're a good 5 or 6 inches long so you'll have a good length to carve from. It has to be the male part of the hose BTW.
Take the hose end and hold it next to the outer edge, envisioning the curve that has to be formed. You can scratch or etch the rough outline of the contour cut you need to do so you can see it. In this picture, I'm going to explain the cutout from the bottom of where the hose end blends/joins into the cone in the picture. So now envision the top of the hose connector going into the cone as viewing from above. Cut the upper part of the contour first, then the bottom part of the curve on the hose end and use the upper contour to help copy to the lower cut-out part of the hose end while viewing it. This will make it a lot easier to carve it to match/join to the side of the cone. Unless you're really good, its not going to mate up at first. I used a wood bit in my dremel. Use a glove on the left hand (if you're right handed) and hold it and carve away at it. Fit it against the side of the cone, take some more off here and there, keep fitting it, and eventually it will conform to the outer contour of the vortex cone.
Hold it in position on the side of the cone and draw an outline. I used one rivet on the side where it connected to hold it in place as the epoxy dried. Make sure you sand all parts to be joined before epoxying. I didn't think of it but fiberglass mesh and epoxy is the strongest. Theres usually a lot of force that can be applied to the joint if the hose is being used all the time, so keep that in mind. This hose setup is supported now by a string to hold the top hose up, and another at the intake, suspended from the ceiling above it. Kind of easy because the top comes off when emptying, and stays there hanging at the right height until i connect the buckets back to it.