Compost Screener

As shown on another page, I generate about 5 cubic yards of finished compost annually. The process of turning and aerating the compost as it the pile works incorporates some of the rocks from the gravel it sits on, so I need to screen it before use. Initially, I used a piece of expanded metal with 1/4 inch spacing, loaded it with a shovel and shook it by hand to work the material through. Made for nice compost, but it was a LOT of work, especially when you screen a couple of hundred bags a year through it. Obviously, a better method was required.

I looked at various ways of going about it on Youtube. Most of them used some variation of a vibrating screen. Those that looked like they might stand up to more than a couple of hours use were expensive and complex. Those that were inexpensive looked like they'd shake themselves to pieces in short order. This is what I came up with: An oscillating rather than vibrating system.The power pack is the engine and transmission off an MTD snowblower I was given. This gives me both speed reduction and a way to clutch the drive so I can stop it to empty the bucket.

The oscillating action is accomplished via a crankpin and dogbone fabricated from whatever junk I had in my pile

The screener table rides on casters in channels with a travel of about 3 inches. I find about half-throttle provides the best screening action. The front legs on the screener are hinged so the table can be tipped forward and the debris dumped out. Since this was written, I've also added a reducing cone under the screener to better direct the screened material into the bucket. (A 5 gallon bucket nicely fills the sandbags I use to retail the compost in)

Go here for more on composting and a video of the screener in action.

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