CEB Prototype 2 Design Forum and Issues

Finally, the Drupal site is starting to look coherent. Alex spawned it, Jeremy owned it. We are starting discussion on the second CEB prototype there. Log in, join the forum, and we’ll have the second prototype done in a jiffy. Once the second prototype is done, we’ll be taking preorders.

MicroTrac is the power source for The Liberator II CEB press – and we’ve got an 18hp gas engine already taken out from our former ride-on lawn-mower. That will be a good reuse for the engine – as the old lawnmower chassis is ready to join our pile of industrial detritus. Industritus is the new word we coin. We’re collecting piles for meltdown once we get the induction furnace going. We apologize in advance for using a throwaway gas engine, but until we begin producing steam engines, there’s not much we can do about it, since a 20 hp steam engine costs $6500 made in the USA by Mike Brown, and $1700 plus shipping in India by TinyTech Plants. Oh yes, we’ll put the comfy seat from the lawnmower on LifeTrac, so I could sit on ass better.

We will begin building the MicroTrac power unit in the next day or two – a hydraulic Power Cube that will be interchangeable with LifeTrac and life car named UniMOS. Extreme modularity is our game.

There are a few issues left on CEB development, technical and operational. First, let’s adress the operational.

The operational issue is the enigma of the manually-loaded, high performance CEB press. Well, there is AECT and The Green Machine, both of which are manually-loaded, expensive machines retailing at above $25k the last I checked.

The enigma comes from our own brick-pressing experience with The Liberator. We have concluded that a manually-loaded, powered CEB press, does not justify the expense over a simple manually-loaded, manually operated double-block press. This is simply because one can not keep up with the powered CEB machine’s demand for dirt, so one person can make only 1/2 brick per minute on average on a continuous, 8-hour day basis if one has to shovel buckets of dirt manually. That was the bottom line in our field experience. This is absolutely unacceptable for building the world’s first, replicable, open source, off-grid Global Village.

Allow me to explain the ergonomics fully so that you understand the process. First, you have to pulverize soil with a tiller. Then, you shovel the dirt into buckets. Then you carry them to the CEB press. Then you lift the bucket and dump it in the hopper. The machine then eats dirt and spits out bricks.

Now, the fatigue-inducing part of this operation is not tilling. It is not really lifting the bucket to the hopper, because one can either stand on a platform or dig a hole for the CEB press so the hopper is reached easily. The real hard part is shoveling dirt into buckets, one after another. Each bucket got us about 2 bricks. I had no idea that I could shovel only 125 buckets in one 8 hour day – for 250 bricks. That is not an impressive production rate. Read more about our experience in an older post.

One could easily press this amount with a manual, double-block press, that could be made at much lower cost.

So, unless one has a consistent team of at least 10 people, a 5-brick per minute machine is run way under capacity. This is not a practical case for all but the most rare scenarios.

Therefore, why are companies out there still selling expensive, manually-loaded, self-powered CEB machines comparable to The Liberator I? I just don’t get it.

Perhaps if one has a large tiller, one could load a large number of buckets with a front loader? That does not seem to be tooeffective, either. Or a conveyor? That’s a whole major piece of additional edquipment, so why not just increase the hopper size and load with a tractor, which is already part of the equipment base?

We are now going to the tractor-loaded version with a large hopper for the above reasons. I imagine those people who do end up buying expensive, manually loaded machines are either disappointed regarding the difficulty of the work, or they are not aware that manual machines could do a comparable job. I can’t imagine that pressing on the manual lever of a manually-powered machine is all that difficult, having done that a little myself. Are we missing something here?

The practical issue here is, should we be fabricating manually-loaded versions of powered CEB presses? At present, we are not planning on doing that. We will produce just the tractor-loaded version. I would like to hear feedback on this issue. Prospective buyers or fabricators – what makes sense to you? Certainly, some market research on satisfaction levels of buyers of the other manually-loaded, powered CEB presses would be really helpful here.


  1. Lost Chief

    I was researching CEB Machines and thats how i found your group with the CEB videos on Youtube. Check out this company they have the lowest price CEB machines i could find.

    Might help a little.

    P.S. The lowest cost gas model is 10k

  2. Harmon Seaver

    One thing I don’t get about your piece above is the talk about using a tiller to dig up the material. Everything I’ve ever read about making earth blocks says using topsoil is a real no-no, you need to get subsoil clay to have decent blocks. So you need to be digging it with a backhoe, not a tiller.

  3. Marcin

    You scrape the topsoil off first, then till the clay to pulverize it, or till a pile of pre-dug earth.

  4. Scott

    Marcin states:

    We are now going to the tractor-loaded version with a large hopper ….

    You had a tractor loaded concept where you build a tiller on the front of the bucket so it’ll till then the scoop would pick up the dirt. This should be the best solution although I would add a 1″x1″ metal screen angled on top of the hopper to keep rocks, etc. out of the blocks. You shouldn’t have any rocks larger than 1″ in the blocks.

    Keep up the good work, I’m learning a lot.

  5. Jeremy

    Thanks Scott, I’ll be drawing up the design for it soon and posting it for review.

  6. mimarob

    Hmm, looking at your hydraulic cylinder and doing some ruff calculations I came to the conclusion that it would produce about a ton of pressure, about the same as a cheap garage jack?

    I would really like to try just to make a few of these bricks for promotional and educational purposes.

    I read alot about these “simple, cheap, third-world types of CEB presses” everywhere, but where do I actually buy one?

    I was otherwise thinking of a quick-and-dirty $10 garage jack hack and some soil that I dig up in my yard, just to get the feel for this material. Also it would be a great help in testing different kinds of soil, thus learning about what the soil should look like to perform well.

  7. Scott

    For mimarob —

    Here’s some research done on different mixture at Kansas University.

    It might be good to consider asking him for help in designing a CEB energy efficient house/building to use at Factor E Farm.

  8. mimarob

    Thats a cool machine, “protein-operated”, just wonder how it can produce so much force with just a lever?

    The CEB press on openfarmtech had a hydraulic cylinder of 20 tons according to the blogpages…

    The more pressure you apply, the better the result?

  9. Scott

    The more pressure does not guarantee a better block, the range (from what I’ve read) is 900-1200 psi.

  10. Curtis

    If you are near Capitan NM check out Fernco Metals.
    They make the only manual Cinva Ram available I have been able to find. This equipment is first rate and the cost is reasonable. The plans for a Cinva Ram can still be purchased.
    The rate on these machines is 1-2 s minute. While this is not fast enough for a commercial operation in the business of manufacturing bricks, it is pleanty fast enough for someone wanting to build a small number of houses or was using the CEB’s as an addition to an existing business.