The Liberator Beta v1.0 Specifications

(see corresponding blog post)

=Introduction=

Download Open Document Format (ODF)specifications for The Liberator Beta v1.0 here.

Before you continue, here's a brief description of our offer.

We are offering a high-performance, open source, Compressed Earth Block (CEB) Press - The Liberator. This is a CEB machine shown here. It does not include the tractor or power source - just the machine with manual, hydraulic controls. The machine includes a large hopper and a shaker grate for sifting soil into the hopper. The power source is external. This is part of our strategy to obtain a high-power, low-cost machine.

A CEB machine like this is not a toy. It is not designed to be loaded by hand - as it would take about 32 people to load it by hand to keep up with its proven demand for soil. Soil handling is a major requirement at this scale, and requires a tractor loader plus some way to pulverize the soil. If you are interested in a machine that you can load by hand, just get a hand-operated (non-powered) Cinva Ram or similar for $200-$500. You will save yourself the cost of purchasing a machine that you will not be able to use effectively without a tractor and soil pulverizer. We learned this the hard way with our first prototype. Read about our experience in this blog post.

Doesn't it make sense to have a dedicated engine on the machine? We don't think so. Any construction site at the scale of building intended for this machine will have a tractor or skid loader on site. Auxiliary hydraulic power can be used from these machines to operate the CEB press. We favor the Power Cube for a power source. You can get a PTO-driven hydrauilic power source for about $800.

=Equipment Ecology=

The external power source strategy of FeF is designed such that a large number of machines, including tractors, have interchangeable power sources. This allows an entire mechanical infrastructure of a 10-100 person village to thrive with the assist of a total of 40-80 hp in engine power. For us, we're exploring modularizing this to 20 hp Power Cubes. This way, a machine can utilize 20 hp as needed, or several PowerCubes can be attached to another machine, such s 4 Power Cubes for a bulldozer. We're going further on this to develop steam power, with locally grown, pelletized biomass as the fuel source.

For more information, scan all of our experiences with this CEB press under the CEB category - http://openfarmtech.org/weblog/?cat=13. You can find out about the mechanical infrastructure, agriculture, construction, and fabrication aspects of FeF at Linz Slides.

=Specification of The Liberator Beta v1.0 Product Release=

Note: the following is a table of specifications exported from Open Office on Ubuntu 8.04. The formatting is poor. If anyone can help format this better, you can download the source file here, and email us at opensourceecology at gmail dot com.

The Liberator Beta v1.0

Open Source, High Performance CEB Press

Beta Release Product Information

Factor e Farm, November 3, 2009

Brick thickness detail including standard deviation

=Brick Thickness Data=

Brick thickness data with error bar showing the standard deviation:



The data was obtained using raw soil from near the machine. Topsoil was scraped off, and the Soil Pulverizer was used to prepare the soil. Brick thickness is determined in The Liberator II prototype by timing the compression stroke until full compression occurs with 2300 psi.

An alternative route to perfecting thickness uniformity relies on a limit switch, which stops compression at a preselected thickness. As of 12.15.09, this is currently being implemented.

=Bill of Materials=

See the complete Bill of materials for The Liberator II, and the Calculated Bill of Materials for The Liberator Beta v1.0. The latter shows the optimizations in cost and weight resulting from a number of minor modifications.