Open Source Soil Mixer 2016

Intro

To produce stabilized CEBs with our open source brick press, and to begin economically-significant block production - a mixer is needed for uniform mixing of soil and cement (lime or portland) in about a 5% proportion by weight.

Commercial mixers are $100k, such as this one:

Build

• Build was started during the CEB Press/Power Cube workshop with most of parts cut out by Shayna and Eric?
• Finishing with bending steel over a round edge. It turns out that welding on slats perpendicular to the direction of bending allowed the 1/8" steel to be bent into a perfectly round shape using a lever arm and using bolts to do the pulling
• Closing lid was added at end
• Different motors can be interchanged - coupled via a double-chain coupler with modular motors carrying their own sprocket half
• tines are bolt-on, and work up to 10 cu in motors, but bolts got loose on the 45 cu in motor
• See 70 steps of build procedure here:

Dry Run

• Uses fast rotor, 650 RPM, 5 cu in hydraulic motor driven with 14 GPM hydraulics
• Not enough torque once 5 buckets of soil are used
• Switched to 10 cu in and finally to 45 cu in, the latter being 15,000 in lb of torque

Soil Mixing Initial Tests

• Success. Need to tighten down bolt-on auger, see stall in second video.