We have demonstrated a production rate of 4 bricks per minute in our first test production runs.
We ran the CEB machine with 3 people, low-medium throttle on LifeTrac, about 12 gallon per minute hydraulic flow, a hydraulic pressure of 2200 psi, and a force of about 20 tons on the bricks. The hopper cylinder was adjusted with a needle valve to reduce its speed. We pressed 53 bricks in a sample 13.5 minute run.
These are amazing results â€“ bricks coming out of the machine as fast as we could handle them. For soil preparation, we roto-tilled a small part of our earth pile with the LifeTrac rototiller, followed by a small, walk-behind 6 hp rototiller â€“ to break the soil into a flowing powder. Thereafter, I ran the CEB controls, Nick loaded the hopper, and Bob stacked the bricks as fast as he could on a pallet. Nick was shoveling soil into 5 gallon buckets as fast as he could from the prepared soil. He then poured 5 gallon buckets into the hopper.Learnings and challenges: The critical step was pulverizing the soil to about 1/4 inch pieces. We mixed in about 5% sand into the soil, which helped make the soil flow better. If we used soil with particles larger than 1/4â€, distinct grain boundaries were forming â€“ there were fault lines in the bricks. Once we went to 1/4â€ particles â€“ the bricks got larger and stronger. There was less air space in the soil mix.
The limiting step in the sample run was bridging of soil in the hopper. I had to poke the soil by hand in the hopper â€“ for every brick – so it would fill the compression chamber evenly. To address this, we will operate the machine at a slight angle, or possibly change the slide angle within the hopper. We concluded that with this simple improvement, we could get to 6 bricks per minute. We would then be able to produce about 3 thousand bricks in a day â€“ or enough bricks for our 1200 square foot facility in under three 8-hour days of pressing. This means going through our 20 tons of soil per day.
We believe this is achievable with a minimum 4 person team. One person runs the controls, one person loads the hopper, one person stacks bricks, and the fourth person goes through the soil pile continuously, pulverizing the soil to the required size with a walk-behind rototiller. Come down to Factor e Farm â€“ weâ€™ll be pressing in this coming week.
Hereâ€™s the good part. If we achieve the 6 brick per minute rate, that would make The Liberator the highest-performance CEB machine in the world. The highest production rate that we know of is 5 bricks per minute from a machine that is 5 times higher in cost. We are talking of entry-level, manually controlled, one-brick-at-a-time, hydraulically-driven CEB machine types. We actually think we can get to 8 bricks per minute with the same, manual machine. Hmmm.
We think that we are on the way to demonstrating the full promise of open source economicsâ€“ the promise of highest performance, lowest cost, lifetime-design products. Period. If you want to see this machine go into productionâ€“ donate here. Be a part of changing the world. We are operating entirely on volunteer donations.