The Worm Sifting Screen on the Brockwood Worm Shi*fter was designed with these attributes in mind:
- Grid Size and Selection
- Strength and Durability
- Fast Efficient Sifting
- Weight and Balance
- Availability of Material
- Quality of Material
We selected the 1/8″ and 3/32″ hole grid for casting separation and a 1/4″ and 1/8″ hole grid for cocoon separation. We make two specialized screens, for night crawlers 1/8″ & 1/4″ perforated aluminum panels and for red worms 3/32 and 1/8″ perforated aluminum panels. Night crawler eggs are larger than red worm eggs so two different screens are necessary.
Perforated aluminum panels are not prone to clogging like the wire screens because they are flat and smooth, easy to keep clean. The Aluminum panels are also not prone to rusting and developing jagged broken wires that will cause worms to hang up and get injured or cut your fingers when you clean them. Aluminum screen panels are lighter and stronger than hardware cloth.
The combination of the angular pitch and velocity of the worm sifting screen assembly causes the worms, castings and cocoons to move from input to output efficiently in about 20 seconds. There are three chutes to direct the three products of harvest into their respective bins and or buckets. It is typical to sift two 3.5 gallon buckets per minute or 120 buckets per hour.
The weight and balance of the worm sifting screen are very important to the longevity of the wear parts and the noise level of the operation. This is why the screen frame is built with wood instead of steel and the output chutes are made with Naugahyde instead of sheet metal. Metal chutes are noisy and prone to stress fractures. They are also more time consuming and costly to replace if needed.
The availability of this combination of wood, perforated Aluminum and Naugahyde is good. Perforated Aluminum is not as cheap as wire mesh but much more desirable in all aspects. Each worm sifting screen is carefully built from the highest quality parts we can find. After being assembled they are tested “dry” for a sufficiently long enough time to assure it meets our high standards. They are then disassembled and packed for shipping. We know when we ship that all the parts fit together and work properly.