We might have to play around with different blade types before we find something that works best. A thin straight blade should slice cleanly through a brick. But, if not we could try a slanted knife or even a thin wire.

The small cross section would remain the same actually. But you would be able to make the bricks longer if desired.

I think the limiting factor speed wise is the rate at which earth falls from the hopper. But this design eliminates one step so it's quite likely that it will be faster.

As for commercial designs, I'm not sure really. I've watched the odd one running on U-tube and they seem to be comparable the our existing design.

The Dawg

I had some time tonight to model my idea. Here is a series of diagrams showing the concept. This would be way easier to construct and will make the same bricks our current press is making.













The Dawg

You are still thinking too high tech for a level 1 design. A good part of the world's buildings are "rammed earth", which are monolithic walls (instead of blocks) compressed between movable forms. The modern version uses a concrete mixer to blend the ingredients (including cement if you add it), a front end loader to get the dirt to the top of the wall, and engine powered trench rammers, but it can be done entirely manually. A manual ram can be just a metal rod with a small foot plate welded to one end, and some handles. The mass of the rod does the compression by impact load, rather than steady pressure in the CEB machines.

I think the rammed earth becomes too low tech. If you look at our goals, we want to do something comparable to modern.

@Dawg - It's not my great idea *smile* rammed earth has been around for 3000 years and accounts for 30% of the homes on the planet. For curves and corners you just need different shaped forms. The main advantages are you can get by with minimal equipment if you go all manual, and a monolithic wall does not have a million cracks to fill like you do with block. It will be slow of course. Modern rammed earth builders can get the walls up in a few days, but that's using power equipment.

Your initial idea of lower tech solutions is valid though. The full up CEB press can produce 1500 blocks a day in theory. That means it can produce enough blocks for a house and shop in a week or so. So it is vast overkill for a single household, or even a village. It's a town sized machine

@ARGHaynes - both CEB and monolithic are compressed earth, the only difference is the unit size. Both can use cement as a stabilizer if you want higher strength than the basic soil mix gives.

@ Daniel - Well I meant you brought the idea forward....:)

One other thing to consider here is that a brick is something the 1st world understands. What you make it out of is erelevant as long as it has the right characteristics. So if it looks like a duck and quacks like a duck it must be one. This will help in getting building permits and the like. We can't assume we're building in the developing countries. We need to build more economic homes here also.

I must say I totally agree with the overkill aspects of the CEB press as it stands today. This surely isn't meant to put down anything others have done so far. I applaud their efforts if for no other reason than to have the transferable skills when we really do need the automation. But ya, unless someone is going to start a brick making business as their main form of income it's plenty fast just using manual hydraulics. They found it was a challenge just trying to feed the hopper at those speeds. After all, we're not trying to create centralized production here. Quite the opposite, as I understand it.

I would rather see many presses being built close to where they're going to be used rather than one monster press working night and day shipping bricks hundreds of miles. We have that now with all the associated transportation costs in tow. We're trying to shift to local production and in the process shift the power back to the middle class.

Respectfully,

The Dawg

@ARGHaynes - Rammed earth is a wall technology. It has nothing to do with what you put inside the rest of the home. The fact that many old houses were built that way and are still around just shows they last a long time. New homes are being constructed using rammed earth and are fully modern: http://www.earth-auroville.com/maintenance/uploaded_pics/6-Rammed-earth-modern-En.pdf

You cannot transport unstabilized block any significant distance, because the only thing holding it together is the electrostatic charge of the clay particles in the mix. This is why a soil mix with no clay will not work at all. Cement grows a network of crystals as it cures, which does a better job locking the other bits in the mix together. Try driving down the road with unstabilized CEB blocks, and you will find they tend to revert to a pile of soil. So practical CEB unstabilized block production will mean driving the press to the construction site, cranking out a bunch of blocks, and then leaving them for the home builder to assemble into walls on their own schedule. Driving the machine to the construction site is less total mass than transporting the blocks, assuming you have suitable soil on site.

I'm working on a solar furnace concept to make cement out of carbonates (ie limestone). This both will emit less CO2 (cement production account for 7% of global CO2 emission), and lower the cost. Producing cement is a simple process, it just takes a lot of heat, and commercial cement plants use fossil fuels to run their kilns, which drives the cost up. Even CEB walls need a foundation to keep them dry, and that needs to be a building material that doesn't get mushy when wet, and not suck too much water up by capillary action.

@ Ken - the rammed earth projects I have done mixed the cement in dry along with the soil in a concrete mixer, so it is just as dusty and messy as any other concrete work on a small scale. If the soil has enough moisture in it, it will start curing without any added water. If you are not in a very dry climate, moisture from the air will continue the process. Stabilized rammed earth will cure to a reasonable strength in 28 days, but continue to get stronger for years. Traditional concrete gets its initial strength much faster (days to a week). It also continues to gain strength for years, just time shifted to get a higher percentage of strength earlier, because you added enough water to the mix to make the reaction happen faster.

CEB does not *have* be stabilized, but if not you need some combination of roof, foundation, and wall coating to keep the water away.

@dawg check out the new block press by Yanmar (google for "714 Dynablock"). compare this to the Fernco Metals block press that is operated off compressed air. You expressed earlier somewhere on the fef site the idea of a trailer that could back up to a pile of dirt and from the trailer load the dirt into the press. I liked that. Also, by using a screw to lift the dirt up to the dirt hopper, you could also admit at the bottom of the screw a measured amount of stabilizer (lime, portland, fly ash) vis a second screw so that stabilizer and dirt would be mixed while being lifted--avoiding the cost of a mixer .

here is another manual press video  http://youtu.be/LON40kaKFEw

Thanks,

I think it will go well in the Philippines. Although at the present the engineer types don't see the usefulness of using the Brazillian CEB model. The complaint so far is the long cure times.

I am mystified as to the present factor e farm CEB construction method. Using stabilized interlocking bricks that are glued together seems to be a faster, safer method. I grew up in the Midwest, I don't see how unstabilized blocks will survive a wet Midwestern spring very well. I also see them using topsoil instead of subsoil and it has a lot of organic material in it.

I thought that was a no no.

I can see that by the videos.  Im not pulling my financial support.  But the guy needs to get out of the shop and make the transition from being a hands on worker to being a leader.  He cant be both the Sgt and the Commanding officer.  Easier said than done, but he does have a lot of good will, willing volunteers online, and resources that are being squandered.  In short the whole thing needs a good organized project manager. 

A lot of new tech developments have come up the past couple years.  However working in the shop, leaves little time to keep abreast of new developments and one can find themselves making decisions based on old information.

@mjn  I got blueprints and a instructional manual now.  However I contacted the foundation that authored the document and they dont want it reworked and published in a Wiki.  They are not distributing the plans themselves however.  The letter I got back indicated they were looking to somehow put the info online themselves.  I suspect that someone in the organization that took over there thinks they can turn the how to manuals they used to give away for free into money.

I emailed you a copy of the PDF awhile back.  Copyright wont be a issue if we rewrite the information.  Facts and instructions like recipes cant be copyrighted.

The machine was originally designed in the 1950's so there is prior art which means that patents will not be a issue either. 

It prob would take a good long afternoon to combine the sahara press instructions with the other plans I sent to make a good functional wiki.  We would need someone to draft a new blueprint to keep the copyright issue at bay.

Sure count me in.