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

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.

@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.

@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.

@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.

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.

 

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.

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!

haha one of those people in the video was me :D

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.

Fixed it.

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.

Worked for me. It was an aside, anyway.

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 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.

Like this. 

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.

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!

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 
http://www.cotdoc.com/catalog/ferno-stretcher-parts/ferno-model-93-es-ex-parts

you know that Dawg just did blueprints for third generation cinva ram over at OSRLiving.org  

I wonder if sandy soils are suitable for compressed bricks.

@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.

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

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.

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.