Trommel Compost Sifter

Step 5 Build the roller box

This is a pretty simple structure so I won't go into a lot of detail. I used 2x6 lumber because I happened to have several short pieces on hand that were just the right size, but 2x4s should work fine too and would be a little lighter. My side pieces are 34 inches long and the ends are 19 inches long which leaves a gap of 16 inches in the middle. Note that one end needs to be ripped down 2.5 inches lower than the other because the drum needs to overrun the box slightly so that the coarse materials spill out of the drum. Since I used 2x6s (1.5 x 5.5) my spillway end piece was 3 inches wide. If you are using 2x4s (1.5x3.5) Then your end piece would need to be one inch wide.

Note that these dimensions assume that you are using the same diameter rims that I used. If you use different size rims then obviously you will need to modify the dimensions to accommodate your particular arc.

To align your rollers place the finished drum onto the roller box and then mark your roller positions. You may want to attach the rollers first with simple drywall screws (as I did) to test their positioning and then drill and bolt them later once you are happy with the alignment.