Cube30xx Log
April 16-17
When I wasn`t helping prepare for the Microhouse (MH2) workshop, I spent the first couple of days watching Sketchup videos, learning how to use the program.
April 18
Did a bit of yardwork preparing for the MH2 workshop. We removed the concrete form for the MH2 location and set up the assembly belt for the Compressed Earth Brick Press (CEBP). Measured around the MH2 foundation, The north, west, and south (plan views, not directional) sides measured 14". The east side measured 14'-3/4". The SW to NE corners diagonal measured 23' and 6-7/8". The NW to SE corners diagonal measured 23' and 8-1/4". This was acceptable at foundation height, but by the time the last course is laid the diagonals need to match within 1/8".
Two ideas were proposed by Chris. The first was to place the CEB's flush with the outer edge of the concrete form, with equal dimensions. The second option was to increase the size of the bottom course so the bricks would be flush with both the inner and outer perimeters of the concrete form. The second brick course would be slightly thinner than the first, and the third slightly thinner than the second. The fourth course will match the standard brick size all the way up to the top of the main floor.
Meet and greets were had when everyone arrived. A lot of cool people with different backgrounds have come together.
April 19
This is the first full day of the workshop. Meeting started at 8:45. Everyone was divided into two groups. The first group worked on Main Floor Carpentry, which included a door frame, a window frame, and structural beams. The plans for this are on Dozuki. The second group went to set up the CEBP. I went with them to start dumping in soil and clay to produce bricks. James gave a brief tutorial on measuring the integrity of the bricks:
-Know your local land, its proportions of clay, silt, soil, sand. -Mixing concrete with silt and sand works great, you get a robust brick. -Clay and concrete work against each other. Lime should be used. In particular, use Hydraulic Lime; it comes in a fine powder. You will get a solid brick.
The clay on site has hardened to the point where it would be difficult to work with, so in Marcin and Catarina's new place they are using pure soil, so I'm sure that even without any recipes using mixes these bricks are going to work just fine. The HabLab was built with the same, and it is a sound building.
Difficulties began with the CEBP, James had to tinker with it to correct the automated sequence, so I started checking out the other modules. Later I helped James with re-assigning the pins for each of the hydraulic circuits. One pin wasn`t needed and one was incidentally missing, so we had to make the pins match between the female and male connectors.
The CEBP still wasn`t doing its sequence properly, so James started looking at the C code (saved in .h format) to adjust the delays between automated tasks. After an hour of adjusting the delay it started to work.
The controls were simple but effective. There was an auto-manual switch where "Auto" runs the machine code. "Manual" provides access to the three manual controls. These were: Pan the brick chamber (left-right), Shaker motor to help push soil in, Compression cylinder and plate to compress the bricks (the soil is compressed at 3000 psi). The controls were encased in a re-used NEMA-3R rated enclosure, with three toggle switches (one 2-point and two 3-points) and a push button routed to the micro-controller's input pins.
The shaker motor was spitting out oil at increasing rates so we had to disconnect the hydraulic line. Getting the soil into the "brick chamber" had to be done manually. The problem was a "bridging effect" started when there was too much soil pushed into the neck of the hopper - the chamber would open but the soil was so dense it wouldn't fall in. Therefore we manually had to maneuver the soil to get it into the chamber.
We were behind schedule, so the keeners went back out to catch up for tomorrow by compressing a bunch of bricks in advance. We were there until 10:30pm.