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Alternate CEB press designs: mutual improvements

  • As pointed out by Nagpada, the Auroville Earth Institute has a manual CEB press which seems capable of producing various block shapes.

    What should we copy from them? How to best collaborate with them, so that all of us can end up with an improved machine?
  • 76 Comments sorted by
  • I had a good look at their web site. Their machine is quite different than ours. It is people powered for one. Another significant difference is that it is built to accept different molds. Their machine can press out many different kinds of brick. I'm not sure whether we need this feature or not. Interlocking bricks make constriction easier but not necessarily better.

    To summarize, their brick shapes are much more sophisticated than ours but speedy they are not.

    The Dawg
  • I read up a bit on brick shape, without going into detail, changing from the tried and true rectangular prism shape has some benefits and some drawbacks, it balances out on a playing field where you are just considering shape, with the speed difference, the traditional shape wins.
  • their brick manufacturing may be slower, but constructing a build using their bricks will be much faster and cheaper, mainly because they require less mortar. Interlocking bricks could even be dry stacked, and used with a mortar fill or surface bonded technique. Laying the bricks consumes more resources than manufacturing the bricks themselves.
  • @ VelaCreations - This may be the case, but there is a price to pay for complexity of design. I wonder if it would be worth it in the end? At some point, I was going to suggest a secondary procedure as an accessory to drill 2 holes through the bricks. This would help in anchoring.

    Either way, I think a "Category 1" version that is cheap, easy to build, small and relatively light would be beneficial.

    The Dawg
  • @Dawg - I do think it is worth it, because they generally make all of their bricks this way. It greatly improves the earthquake performance of CEBs as well.

    I've built several buildings with plain CEBs, and it is by no means a fast process. If mortar could be removed, it would greatly increase the speed of construction.

    I've given up on CEBs, though. I am not building a village, so investment in an automated machine is not worth it for me. Instead, I am using earthbags. It's faster, more thermal mass, and a bit more flexible, without the need for infrastructure investment. Earthbags also don't depend on soil quality as much as CEBs, and as I only have clay here (not suitable for CEBs), I've switched over.
  • Worth noting that dirt has an R value of something like 1/foot (not sure on the exact value but it is low).
  • @ARGHaynes - Research by Joe McCabe Uni. Arizona states that R1 for every 1 inch of wood, R 0.2 for every brick inch, R3 for every inch fibreglass batt.  Very roughly Australian R0.7 equates to a US R4 so a US R60 would be Australian R9 or R10.
    The metric system (watts per square meter of wall per second) produces approx. 1/6 th of Imperial ones. Example: R-20 - Rmetric 3.5 and R-40 = Rmetric 7. The average batt of Rm2.5 would be R 15. 
    The world should use one clear easy system.
    The 'stick + brick' building systems should be reversed for the mass to be indoors and much energy would be saved on the planet.
    @VelaCreations: yep I do Superadobe and Earthbags. Way to go is there is space for the floor print, especially in suburbs.
    Every method has its use and purpose.

  • Vote Up0Vote Down
    October 2011
    The cinva ram press they use down in Brazil uses a thin bead of epoxy glue to bond their 10% cement stabilized blocks with a lego design. 

    I just got blueprints for a cinva ram a couple weeks ago.  after my shop is fully running the cinva ram CEB press is the first complicated machine I will make for the local Philippine market. 


  • @VelaCreations: I tend to agree with you regarding the interlocking blocks, I'm sure I made that same realisation somewhere (but now I can't find it). I'd also like to be able to press wedge shaped blocks to enable the creation of arches for doors and windows. I'd like to build a dwelling at some stage from CEB, and if I was able to make interlocking blocks I could enlist the help of unskilled labour e.g. my wife :) who'd be happy to help if it was quick and easy.
  • I was thinking that maybe the side walls of the block mold cavity could be tilted in when you wanted to make a wedge-shaped block. I'm not sure how strong the corners of the the mold have to be, but I assume the walls of the mold could always be reinforced if they're bending or dirt is squeezing through a gap. The tilting of the side walls might even be accomplished with come clever linkages rather than additional hydraulic cylinders.

  • Hey Matt, You always seem to be thinking down the same lines as me :)

    Yeah, I've been staring at the Liberator animation that shows how it works, trying to work out how it could be changed to incorporate different moulds, not only wedge shapes but more complicated ones for use in interlocking bricks. I didn't get very far. The most difficult part of the interlocking block is the irregular shaped bottom and top. Say the top of the brick had two square rises, and the underside had two matching depressions. Ok so you could mould the rises by having a depression in the top press plate (a relatively easy change). But what about the bottom press plate? It would need rises to create the depressions in the brick, what would happen when (after the brick was pressed) the brick was pushed up onto the feed draw, the rises in the press plate would cause the feed draw to foul when it tries to move the brick sideways.

    I found this machine on youtube : SAFIDO Interlocking Brick Machine Doesn't look quite as fast as the liberator, but it's a hell of a lot more compact. I'd be looking for an interlocking brick design that doesn't involve caveties like theirs does, but I like their machine. Looks like it would be very simple to change out brick moulds.


  • That's a pretty cool looking machine! I'm going to add that video as a reference link on the wiki. 

    The catching on the press plate would be a problem for sure which is why the removal is done manually on this one. You could possibly get a way with a mechanism that tips the brick over with the one in the video as the part that sticks out is chamferred. 

    On a horizontally oriented press (vs the current vertical one) you could do it too but it would require both ends of the chamber to move (and then another mechanism perpendicular to push it out.

  • Yeah, I'd thought of that too :)  I'd originally discounted it because I thought the act of dropping it on it's side might be a bad thing, but I think one of the strength tests for CEB is to drop it from a height anyway, so yeah as you say you could probably get away with it and it would be the simplest solution. If it was problematic you could probably implement something additional to soften the fall.

    The only other way I was thinking was having a two part bottom press plate, whereby the non extruded part of the press plate would raise the brick to the feed tray level.
    But this is a lot more complicated and would also make making the press plates pretty time consuming.

    Automating the machine is important to me as it would mean I could feed the hopper whilst the machine continues to run.

    I'd really like to build a replica of this machine and I don't think that it looks any more complicated than the Liberator. It gives you the option of playing around with brick designs, tiles etc. I was even thinking of a brick like what's in the video but with larger holes that could take glass bottle for making uniform internal bottle walls.

  • Vote Up0Vote Down
    January 2012
    The Safido machine from that video looks quite neat. It should be simple enough to put a set of rollers where the man is standing and modifying the machine to push the block onto them when it moves forward to fill the mold. I like how compact the design is.
  • Ya they have another version of the machine that does exactly that, there is just a section of the lower pressfoot that raises up and then the brick can be pushed off with another cylinder without worry about it catching on the internal feature!

    One thing that requires careful consideration in replicating this design is the portability/transportability of it. It's one of the issues currently being looked at on the Liberator as having it easily movable is pretty useful. The easiest thing to do is have it mounted on a trailer. The downside of the vertical press designs is that because of required ground clearances during transportation your CEB hopper can end up being very high up. You'll want to consider a removable/foldable hopper for transportation or a mechanism that allows you to raise and lower the entire structure for when you're traveling with it or not.

  • All good points Mike. I watched the video on how to put together the Liberator together, from the effort those guys needed to exert on some of those parts, the thing must weigh a tonne. I don't see how it's "easily transportable" that's for sure (asside from the use of a forklife and a flat bed trailer), and taking it apart for transport looks like it would take hours.

    Yeah, the hopper does get very high, I was thinking that too. So, just to recap, our ultimate machine is a horizontal press, that allows for customised interlocking brick moulds, with a hopper at a height that can be filled by hand and where the bricks are output in a weigh that doesn't prevent continual operation of the machine. The entire machine should be on wheels for easy transport.

    hmmm. Let me think on that.
  • haha one of those people in the video was me :D
    And to think that video was edited to make it look easy haha

    Your list of specs sounds good to me. I'm literally working right now on a wiki reorganization format that I'll be posting on the forum soon for input to try and allow parallel development for different designs that end up with the same function (i.e. different CEB press methods) but still an easy way to capture all the data and stuff.

    I spent a bit of time with the CEB in Missouri and and have a list of improvements for the next generation one too. If you'd like, pm me your email I'll send you some pictures of a commercial horizontal press that Floyd (construction manager) brought and used to help us press bricks.

    One of the main issues going horizontal is that you now have gravity working on the sliding parts so you have a  lot more abrasion with the metal on metal sliding which then requires better abrasion resistant steel (higher cost) or some sort of delrin insert. I don't have a lot of design experience with dynamic movement like this so if you have any thoughts on that let me know!

  • Too funny! Who ever did the voice over must have gotten pretty sick of saying "coupler"! Reminded me of my fav movie Team America, but instead of "dirka dirka" it was "coupler coupler" LOL.

    Wiki reorganisation sounds great, and in great need!

    Would love to see the pics of the commercial one, there's a company that makes them here in Australia too, their smallest machine is horizontal, the larger ones you can't tell from the pics. I've been thrashing ideas around in my head (not getting much work done at work at the moment!) and I basically keep coming back to a very basic design whereby the hopper sits on top of and feeds into the pre-compression chamber via retractable slide, the main piston moves the dirt horizontally into the compression chamber, the bottom press plate is spring loaded and will push the finished brick as the main piston retracts, the brick now sits in the pre-compression chamber, a slide retracts and the brick drops onto the feed tray. With the next compression, an additonal arm will push the finished brick along the feed tray ready for the next brick to drop in it's place. The only issue is it involves one or two additionaly pistons to move the retractable slides, and therefore potentially complicates the electronics.

  • If the proportions in the CEB press animation are at all accurate then the reason that vertical cylinder is there is you need a long column of dirt to compress into a brick and the easiest way to fill that column is to let the dirt fall into it.

    This page quotes a 1.6 to 1.8 compression ratio. Ironically, for all the stuff OSE published on the CEB press I can't find its compression ratio anywhere. Maybe that's just me?

    That doesn't seem like a large enough compression ratio that it requires a vertical chamber. This design proposed earlier looks superior in several ways, not the least of which is it could just be put on the ground so the hopper opening is at waist height.

    While we're on the subject of non-rectilinear shapes...there are plenty of space filling polyhedron that would REALLY mess with the brick layer's head :D
  • Hey Matt, that link to the other design doesn't work for me, could you recheck it?
  • Fixed it.
  • Hey Mat the polyhedron link resolves to which is a nasty site.
  • Ok fellow collaborators, I think I’ve got it.
    I’m thinking of a design that is basically horizontal tube, has an opening for the hopper at the top on one end, and the press box up the other. But here’s the clincher, on the end of the press box is a swing away door. I’d originally discounted this because of the huge stresses on the door, but there are many manual machines that use this method, just search for interlocking brick on youtube. So it’s definitely possible.
    So basically the main press cylinder is all the way back, the opening for the hopper is open, the dirt falls into the pre-compression chamber. The main cylinder moves forward, closing the hopper opening and moving the dirt into the compression chamber, at this point the rear door on the compression chamber is closed. The brick is pressed. The main cylinder contracts slightly to remove pressure off the rear door on the compression chamber, the rear door is then opened. The main cylinder continues to push the brick out of the compression chamber onto the delivery line. The main cylinder then contracts all the way to the beginning, opening the hopper door as it goes.
    The beauty of this design is that it starts simple, and if the compression chamber rear door is operated manually, it only involves one main hydraulic cylinder, and one control valve. It will accept interlocking moulds because the two end press plates can move away from the brick. To fully automate the machine it would require one more hydraulic ram to drive the rear door of the compression chamber. I guess the downsides are that because the entire cycle involves the main cylinder the maximum bricks per minute would suffer. But I don’t see that as a huge issue.
  • The only thing that needs to be ironed out is getting an accurate amount of material into the pre-compression chamber. From watching the youtube vids of guys making interlocking bricks, they are pretty accurate with the amount of material that goes into the press box
  • Worked for me. It was an aside, anyway.

    Okay, so, in all designs the bricks get pushed out of some sort of cavity. What if you put two blades on either side of the cavity such that they could be rotated into the path of the brick. When you push the brick out you also push it against the blades, slicing an angle off of each end. The angles would be calculated to allow the brick to perfectly fit into an arch of a particular size. If you want normal bricks, just keep the blades out of the way. If you want arch bricks, rotate the blades into the path and the bricks will be automatically shapped when they are ejected.
  • @Matt - Cutting the CEB bricks is not an easy thing to do. At FeF they were having to use a circular saw. Imagine it as a very solid hard material rather than dirt. I don't see it being possible to push it out against static blades and get a clean cut.

    @mrsquish - Yes I think the concept would work. Start working on the design details and figuring out requisite tolerances and such though, that's where the design may start getting tricky (but that's every design haha)
  • Okay. Obviously I don't have any personal experience with  compressed earth :-) how well does it flow into the mold? Can you push it in, kind of like injection molding, or do you have to manually fill the mold with loose dirt then compress it? For example, lets say you take the long straight mold you'd used to make a rectilinear brick, but instead replace it with a rectangular crossection tube that curves a bit in one dimension. If the dirt could be pushed into the curved mold it would take on a shape appropriate to arches. If it could be pushed out in the same direction by the fresh dirt entering the mold, then the curved mold could just be an accessorty to the normal press.
  • The press foot (part that compresses the dirt) would need to travel through the curved section, as it would be a linear motion though this wouldn't really be feasible. The entire geometry of everything would get crazy to do what you're saying. Why would you need curved pieces for arches though? You could do just fine with rectangular ones and some mortar. Or you could much more easily make a wedge shape that added together approximates a curve. Afterwards you can go over the surface with a plaster to smooth it out and make it look like a perfect curve.
  • The foot would just travel in a straight section. As long as there's enough dirt in the curved+straight path to fill up the curved path when it's compressed, the foot would stop at the end of the straight path.

    Seems like curved pieces wouldn't require any mortar or bricklaying expertise, which is more in keeping with the method of laying the rectangular bricks.


  • Yeah Mat, I'm with Mike on this, look it might be feasible what you are describing but you'd basically have to build the entire machine around that idea, which would be overkill given the amount of archways a common dwelling would have compared to normal walls. I think the best option is to design a machine whereby you can change the mould the brick gets pressed into so that you can get an interlocking wedge shape. The same machine could then be used to make interlocking bricks, floor tiles, wedge shapes. I'm also looking at the feasibilty of making interlocking roof tiles that could be baked in a solar kiln.

    Mike, Yeah that's the next step. I'm a computer programmer so using Blender should be pretty easy to pick up, but I've got no idea how to calculate tollerances, and for that matter how much force is required\exerted by the main hydraulic ram. What I'm saying is I might need some help in that department, but I'm assuming that tolerances wouldn't fault the basic design idea but just the materials used to implement it?



  • So I've pretty much given up on a horizontal machine. I just can't work out a simple way to provide an accurate amount of material per brick. It's been going around in my head for days, and I've given up.

    I've found another vertical machine that I like the look of, it has a very simple action : It can be partially hand operated too, and has the potential for full automation.

    I think I'll put together a design based on this one.
  • I think the thing with the horizontal machine is that you tweak the opening size based on how far back the drawer goes. So you would end up getting a bit of dirt pyramiding in the chamber but it accounts for that as being consistent so then you could actually get a pretty accurate amount of material per brick. That's how the machine I sent you pictures of worked.

    I like the one in the video too though, it's a nice setup!


  • Cool, thanks for the guidance Mike. There are some other issues with the moulds and which make the horizontal machine a bit crappy too, e.g like some of the mould sides would have to be the entire length of the tunnel so as to get the dirt into the press chamber accurately.

    I guess where I'm at now is, I've now found two manufacturers that make a similar machine, so the basic design is tried and true. I think it could be made so that it sat a little lower than in the videos ( I don't see why the pressbox could not be a little over two brick heights off the frame) so that the hopper wasn't so high, but to be honest, if I need it lower, I'll just bloody dig the thing into the ground, I'll have an excavator so it's not a biggy.

    I just need to design a way to feed the brick onto a delivery line. But I'll start the drawings of the main machine first, because the delivery line thing isn't critical.
  • Ah yes if you're planning on side molded bricks then yep it would get rather cumbersome! Ok and just don't forget the importance transportability. In your design, try and work out a way for integration onto a trailer, it definitely makes life a lot easier!
  • Sure, how about wheels attached to a subframe that can be lowered or retracted by the main cylinder? Need it on a trailer? Put the wheels down, wheel it on, retract the wheels.

    Although, it would probably be a lot easier to have the wheels attached to the main frame and have a push down stand on one end, I think that would provide enough stability during operation. The stand would be easy to engineer and operate. The downside is the wheels would add to the height. I'll think on it as I'm designing it. 

  • You could design the legs so that they fold up/down automatically when you load and unload it. Like those stretchers ambulances use. Here's the Ferno 93
  • Vote Up0Vote Down
    January 2012
    Oilseed pressing [not as off-topic as you think]. While you are working on a CEB redesign with interchangeable molds, see if you can't make it also serve as an oilseed press.
  • Vote Up0Vote Down
    January 2012
    you know that Dawg just did blueprints for third generation cinva ram over at  
  • Headed on over, but can't find the details of what the third gen is all about.

    From what I saw of the earlier versions I couldn't use them as they weren't easy to automate. As far as I was aware Dawg's goal was only perfecting a manual machine whereas mine is to aim for fully automatic, whilst also providing semi manual options.
  • I wonder if sandy soils are suitable for compressed bricks.
  • Vote Up0Vote Down
    January 2012
    @rich3800: Check this page: - some first-hand experience and some good reference links, too.
  • @Rich3800, sandy soils are ideal! The huge clay content that is at FeF is actually not the best for CEB making because of the high moisture content.

    Between some of the links ChuckH pointed out and other resources on the wiki and the net, you could probably pull together a more accurate ratio, but these are also variable form source to source haha...if you do figure out the exact amount that works great then post it up on the wiki :D

  • Vote Up0Vote Down February 2012
    Hey Guys,

    Still haven't started the blender files for the press, think I've been procrastinating by researching electric tractors (but that's another story)

    I had a novel idea, if anyone wanted to build a fully electric (no hydraulics) CEB Press. If you take a look at those machines I posted links to, but instead of those guide rods you have threaded rod, then the main press beam would have an electric motor, which would turn two gears with internal threads on the threaded rods, this would wind the press beam down to press the brick. Sort of like how your average bench clamp works but instead of clamping your pressing a brick, and instead of you winding it, it's driven be an electric motor.

    Tonight I decided to sit down and try and calculate the pressing force from the torque exerted on the two gears, but haven't gotten very far (I'm no engineer), it would seem that the coeffcient of friction is so hard to determine it would only be an educated guess.

    Mike do you know the pressing force generally required for CEB?

  • You'd probably want to use some kind of roller bearing; otherwise the friction will stop you dead.

    Maybe a scissor-jack arrangement would work better. Wikipedia has an entry on house jacks so as long as you're willing to work really (really) slowly you should be able to press a brick with a lead screw. 
  • Vote Up0Vote Down February 2012

    Yeah you're right Mat. Just don't know what a bearing whereby all of the force exerted on it is basically a side load is called.

    To be honest, I think hydraulics would be easier. Just I've been doing a lot of research into electrics lately, electric cars, linear actuators (including diy) with the potential to build an all electric tractor\loader.
  • Vote Up0Vote Down February 2012

    Ok, so I've started the blender design.

    Some initial thoughts, I now know why the machine is so tall. It basically starts from desired brick height. Say you want your bricks to be 150mm. From what I've read, the standard compression of soil into brick are around the 1.8 mark, so for ease of calculation, lets just say it's double the brick height.

    That means your compression chamber must be 300mm tall. To push the brick out from the bottom we need something at least as tall as the chamber, so we add another 300mm (600mm total). There must be enough space above the press chamber to eject the brick, we'll add another 50mm for safety, so that's 200mm (150+50 = we're now at 800mm).

    The press plate and the pressing structure above it must be almost the depth of the press chamber (to cator for shallow pressed bricks such as tiles), The press chamber is 300mm, the thinest brick we'll estimate to press we'll say is 40mm, (300-40=260). Ok so now we're at 1060mm.

    So now we need a Hydraulic linear actuator (ram) to tavel the length of the press, so that's our 260mm + brick ejection area of 200mm = 460.

    Total = 1520mm. Not too bad I guess. But this figure doesn't take into account the frame underneith to support the structure, and fudge factors for extra support, couplings etc.

  • The math always gets you.

    I was working on a design for a 3D printer head that would have multiple nozzles all lined up next to each other. Then I started to do the math on it. I realized the massive volume of plastic you'd need to feed into it, and the massive amount of heat you'd need to melt that plastic, and the massive amount of pressure that plastic would create, just ruined the whole idea. I couldn't think of a realistic application for it.

    Maybe you can combine two things that require height; the hopper and the chamber/actuator. Maybe the actuator (in a baggie or something) can be inside the hopper. The actuator would pull up through the dirt, exposing the compression chamber. Dirt would vibrate in to fill it, then the actuator would push down through the dirt compressing the trapped dirt into the compression chamber just below the hopper. That way the tall hopper isn't stacked on top of the tall actuator.
  • Vote Up0Vote Down February 2012
    Oh, it's not too bad. Actually I made a mistake, the space above the press chamber needs to be taller than the press chamber, because the soil delivery box has to be at least the size of the compression chamber.

    The compression chamber sits at height 600mm, (less than waist level). The hopper would start at 900mm at a minimum, still not that bad. If the hopper was 1m tall that would be 1.9 or head height.

    I've already decided not to stuff with the basic design, it made my head hurt for over a week. If I need to hand load it, I'll either dig it in, or I'll build a platform to stand on. But I've already pretty much decided I'll build a soil mixer and a conveyor to load the hopper.

  • Vote Up0Vote Down
    February 2012
    Interlocking bricks ("Lego blocks") with the OSE CEB Press. -- Those interlocking blocks made with a Cinva ram look pretty useful, but it's not obvious how to make them in the OSE press design. Sure, you can put mold plates in the press foot and sliding drawer, but how do you eject the finished block? I sketched up a technique that may work at . It relies on 1-inch-wide rails to support the 6-inch edges of the brick while the press foot retracts far enough to clear the mold. The rails are supported by pushrods from lower in the press frame, where a mechanical latch holds them in place until the main cylinder going down eventually releases the latch (after the brick has been fully ejected by the drawer slide).

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