Welcome to Socolofsky Farms
Colorado-raised all natural Pork and Lamb
from the foothills of the Rocky Mountains
In-Vessel Composter
» Page 3: Design Details
Page 5: Parts and Materials List
Design Details
The door for the drum is a simple rectangular cut-out, reinforced with angle iron. A hinged door could also work, but this door design provides the capability to rotate the drum while emptying it, and a hinged door would get in the way. This design proved to be simple to build and has worked well. The door opening was cut using a metal abrasive blade on a circular saw. It measures about 38" wide by 16" high. The door is reinforced with a piece of angle iron about 4" longer than the door welded to each long edge. The angle iron keeps the door from falling into the drum. The long edges of the opening in the drum are also reinforced with pieces of angle iron about 4" longer than the long dimension of the cut-out. Four pieces of angle irong were used for this: two on the outside of the opening and two on the inside. The pieces on the inside of the drum provide somewhat of an agitating mechanism during rotation. The door is kept closed with spring clips inserted through holes drilled through the legs of the angle iron on the door and the door opening.
The drum rests on steel casters. Ours are large fixed casters that can each support 1000 lbs. Since the composter when full could weigh as much as 3000 lbs, the casters had to be pretty substantial.
The casters are welded to a frame welded from 3" x 5" x 1/8" box beam. The beam was selected with these dimensions to allow our skid loader's pallet forks to easily slip inside the ends of the beams. We had to buy our steel new, but this could be an opportunity to save money by using second-hand materials. The short frame members are 4' long and the long members are 6' long. They are attached together by fillet welds at on both sides of each joint. The casters are placed side to side on the frame to run about an inch inside of the ends of the drum, i.e. the spacing from outside to outside of the casters is about two inches less than the length of the drum. The strongest part of the sidewall of the drum is right near the heads (ends), so placing the casters as near to the ends of the drum as possible takes advantage of this strength. The casters are placed across the diameter of the drum at a spacing of about 23 inches. The goal here was to have the casters placed so as to allow the drum to run on the drive wheel. Place the casters close together and the drum rides higher. Place them farther apart and the drum rides lowere. This was a game of inches, and I first had to come up with a drive mechanism before deciding how far apart to place the casters and therefore the long beams.
The last parts added to the frame were a pair of outriggers, one on each end of of the drum, to preven the drum from listing to one side or the other. The outriggers are 1 1/2" x 3" box beam sections welded vertically to each end of one long frame member. The outriggers have small rubber casters that roll on the drum ends to keep it centered on the frame. When perfectly centered, there is about 5/8" of gap between each outrigger caster and the drum end.
And now on to Page 4: The Drive Mechanism