question about cyclones

[Bret Champoux]

Hi. I was wondering if the collector (garbage can) under the cyclone needs to be sealed to whatever lid you are using. The reason I'm asking is that if I turn on my cyclone with nothing underneath, there is a suction upwards, enough that it will hold a piece of plywood up across the bottom of the cycolne. I'm worried if the can isn't sealed, that this will prevent most of the dust/chips from falling. I'm also concerned that this isn't normal operation (the upwards suction I mean).

Bret.

[Jay Knoll]

Bret

Yes, you need to seal the can lid, otherwise the air flow from the can up into the cyclone will cause the dust/chips to "float" and not settle but get sucked up into the rest of the cyclone.

I just built the Wood magazine version and though I was being real smart using some round weather sealant on the can lid. Well, in spite of adhering the sealant to the lid with clear caulk, I wasn't getting a good seal and I could see the particles floating above the can (I've got a bit of transparent flex hose connecting the cyclone and the garbage can). I replaced the weather seal with some flat self stick stuff and now I can't lift the can top when the cyclone is running. This is what you want, a closed system with air moving from your machine, sprialing in the cyclone and up the outlet pipe to your blower and then on to the final filter. (at least that's the way it works in my unit).

Any leaks inside the cyclone or can will rob the system of its efficiency.

Good luck

Jay

[David Blangger]

We have another member that can answer your questions about a cyclone. This is his site http://www.terryhatfield.com/ If the info isn't there you can always email him.

[EliotMason]

Yes - it does that. When I have the little can connected and its empty the suction at startup actually lifts the 20g metal garbage can off the floor but doesn't crush it!

I noticed the new cyclones sold at Woodcraft just have a very large and heavy flat sheet of steel as a lid - no clamps or seals. The weight must be sufficient to keep the can sealed.