Here is a dust separator I put together because I was doing some drywall repairs in the house and I wanted to capture the dust. It probably gets about 99 percent of the drywall dust out. It will get 100 percent sawdust from the tablesaw. I think it would work pretty well in a blast cabinet too.
The most difficult part of this project was cutting off the bottom if the bottles without cracking or breaking the bottle. You tube to the rescue!
• Two five gallon buckets. Cut the top off the bottom half and the bottom off the top bucket so they fit together. With the taper of the buckets it makes a good airtight seal.
• Some 12mm MDF for the different chamber separators
• four PVC elbows and some PVC tubing.
I studied the Pentz plans and google images of cyclone dust separators for my ideas.
I sized the elbows and the tubing to be cumulatively similar to the hose diameter on the vacuum. The thought being to keep the air velocity high enough for the cyclonic action to be effective.
I used regular wine bottles because the shape was closest to a cone. I cut the end off the bottoms and recessed them into the bottom MDF separator disc.
In the photo, you can (barely) see the elbow with some of the side cut off to get the incoming airflow to run against the inside surface of the bottle.
The PVC tube in the middle goes through the bottom and middle MDF separator disc.
The MDF separator discs took some fitting to get a tight fit on the edges inside the bucket. Sealed with clear silicone caulking compound. Let it completely dry before trying (don’t ask).
As this was a prototype I put it together fairly quickly. I might try another with two sets of two bottles in series to see if it is more effective, or possibly a Thien type separator in series with a cyclone separator.
And next time I might try to manage the airflow though the chambers a little more efficiently, with radiused openings ect.