Picture of Universal Nut Sheller
This machine was invented by Jock Brandis to shell peanuts at the request of a women's coop in Mali, later he would co-found an non-profit international development organization called the Full Belly Project that for developing countries. There are around 1/2 billion people in the world that rely on peanuts as a primary source of protein. Most people can only hand shell 2 lbs (1 kg) of peanuts an hour, but this machine can do 110lbs (50 kg) an hour. In addition the machine is actually capable of shelling a variety of nuts, including neem , shea nuts (for shea butter)and Jatropha The machine uses two sets of fiberglass molds ($550), some common metal parts, some cement and sand.The cost (not including shipping) of one set of molds and enough parts to make 3 machines is $700.  The molds and metal parts can be ordered from the Full Belly Project. We only ask that when distributing our devices that your provide us with feedback and credit our organization for the invention of the machine.  Take a look at our video introducing the machine to Uganda in 2005:
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Step 1: Greasing the Outer Rotor Mold

Picture of Greasing the Outer Rotor Mold
After locating the outer rotor mold, Wipe inner face of the outer rotor mold with cooking grease or heavy oil. This ensures an easy release of the concrete from the mold.

Step 2: Grease Inner Rotor Mold

Picture of Grease Inner Rotor Mold
Locate inner rotor mold and prep for greasing. Wipe smooth exterior surface of the inner rotor mold with cooking grease or heavy oil.

Step 3: Mount Shortest Threaded Rods

Picture of Mount Shortest Threaded Rods
Install shortest threaded rods with nut and washer on both sides of outer rotor mold, exposing just enough threads to get a washer and nut on tightly.

Step 4: Insert Rotor Shaft

Picture of Insert Rotor Shaft
Insert biggest shaft with two attached flat pieces into center hole THREADED END GOING IN FIRST. The threaded end must be facing down otherwise you will be unable to assemble your machine.

Step 5: Assemble the Stool

Picture of Assemble the Stool
Assemble the stool by attaching legs and spin pipe into center mount.
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sushinoms4 years ago
Trying to get the nuts out of certain shells can be really annoying. So hearing about something like this that can crack any shell makes me really curious. Why are these not commercialized yet? I mean in a compact home-friendly sense. If they had them like that I would buy one today. .
The Full Belly Project looks like a really great idea. I heard about the LDS (Mormon) church creating some sort of highly nutricious grain based substance that they are shipping over there to feed people who have literally nothing to eat.
it's morphing to an open source like project being worked on 24 seven so cool see what allowing your design out does all sortsw of help abouve and beyond they will go to feed the people of the world whats next affordable housing cast an idea that fixes that they need houses in hati
stay with what works and get it into the field. then prototyp other designs. i suspect different designs may be required for different nuts. Also the idea of mass produced styrofoam forms to construct the concrete casting in the field or once in country great idea to uses cad cam to design after the prototype is tested molds could be made cheaply.
SinAmos4 years ago
Love it.
wenui4 years ago
Is incredible,
with a few simple things, how much good can be done.

Wonderful Work
Wonderful Work! Congratulations!
sacem6 years ago
I have a request from "Ashanincas" amazon jungle tribes to provide them with some way of shelling their peanut crops, these people were a common target of the Shinning Path terrorist group in the 90's and still are being hit by narcoterrorist bands that use them a forced labor for their "work", some tribes are reinstalling thmselves at their traditional fields and they have the usual hard work of shelling their local grown peanut crop (peanuts are original from here, Peru). I have seen your sheller design and it seems perfect for their needs, I have already downloaded the metal parts drawings and need a simple cross section of the sheller with basic starting dimensions in order to avoid the redesign of the machine. I am going to build the molds from steel plate and make a about 20 or 30 shellers to send them as donations from my company (we deal in heavy minning equipment) and afterwards try to reach most tribal settlements through some aid organization and furnish them with several molds. I wonder if installing a reinforcing wire wound inside the outside shell will not give the equipment a higher shock and effort resistance with very little added cost. Thanks for your feedback Marcelo Cabello SACEM
I've started looking into harvesting local acorns here in Southern California as an alternative food source. This would make the shelling process worlds easier, if they're amenable. I'll be looking into finding plastic children's buckets or flower pots for stator/rotor mold forms (to be modified as needed, of course). The CAD diagram above is IMMENSELY helpful for those of us trying to come up with ways to make a form for less than $500. Now I only wish I had a better idea of the hardware. I was disappointed the CAD drawings weren't available at the Full Belly website as indicated by the clip on But thanks so much for the idea - it's a fabulous design!
Hi stacy, Im looking to use this for acorns here in southern oregon, im just about to start building a makeshift model. Let me know how your machine works with acorn! Good luck!
d_r_e8 years ago
Very interesting project that I just happened to come across in the search for DIY lightweight concrete. Anyway, have you considered making the molds from vacuum formed styrene? You can make the positive from ren wood, which would allow for a few hundred molds. Styrene properties may just fit your requirements as it is fairly inexpensive, lightweight, smooth surface texture, and water proof.
The Full Belly Project (author)  d_r_e8 years ago
Can you provide a link to somewhere to get styrene? and some more information about its composition
Hi Roey This is from Peshawar Pakistan, do you intend to test your product in Pakistan?
Here is a sample site. I have never used them before but just to give you an example. I do suggest getting the 0.06" or even the 0.08" thick sheets as they can be reused several times over and easily repaired. As you can see the prices are fairly inexpensive. You may even get a discount if you order in bulk and mention what you will be using it for as large companies can use this as tax deduction.

Also call around. Here is a link to the Thomas Registry, which has the contact information for many companies.

here is some info on styrene

If you need help, look for industrial designers who are familiar with styrene’s properties as many are idealist (mostly students) and would love to help for a good cause. As for me, I haven't worked with styrene for quite sometime, nor do I have the facilities to work with it. But I have seen very simple vacuum form setups that use halogen lights, peg board, and a shop vacuum.
The Full Belly Project (author) 8 years ago
Hello everyone, thanks for your comments. Actually we already are working with the D-Lab folks. They helped us distribute some of these machines in Zambia, Ghana and the Philippines ( We also just one 2nd place at the MIT IDEAS for a pedal powered version (we would have taken first but a pedal broke in shipment) Jock is going to be teaching a class at MIT in October with D-Lab. Right now what we're looking for is folks that would be interested in collaborting on designing and/or distributing some OSAT technology. Or working with us to improve this design. For instance the fibreglass molds cost $200 to make. But its the only material we can think of that will work with concrete, won't break easily, and is light to ship. If anyone has any ideas for a better material for the molds let us know.
out of curiosity, would two flat pieces of concrete (two slabs) slanted at an angle and moving back and forth, work?
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The stator is just direct drive, right? Hi I'm wondering at what rpm is it hand-cranked for optimum performance?
I will draw out something tomorrow but based on your comments, a revised suggestion.. bottom slab is flat, sloped at 45 degrees, has light vertical grooving Top slab is slightly curved or angled at 47-50 degress, light vertical grooving Slabs move back and forth horizontally Your design is more efficient, no question. There's a reason its used for everything from coffee grinders to rock breakers. But slabs can be produced with wooden molds solving the biggest drawback with the cylinder design. I think I described that fairly clearly but let me know if you want a drawing or if its just a non starter - pauric
You might find that the principles of pressure and friction are not nearly as important as the forces of torsion that occur between the two curved surfaces of the design. When I say torsion, I don't mean mere rolling, as would occur between flat concrete "plates", I mean the curved surfaces are able to put a differential rotational stress on each side of the nut shell, and that tears it off. For the proper idea of this, consider the way fingers move to open a peanut with your hands. Theres the gripping friction, but also there is some crushing, but the main force is to tear one side of the shell one way, and the other the other way. This is what I see the current design doing. On the other hand, flat rotating or sliding angled plates of concrete may have the friction and pressure, but none of the torsion. It would be like opening a nut by pressing a nut between your hands and rubbing them together. You just wouldn't do it that way, it would just roll. I could be wrong, the grooving in your design may help, but the grooving of the concrete may also complicate the design too much, and may limit the other uses of the device - currently they use it to open nuts of many different shapes and sizes. I also see another problem with application of pressure. With the circular design, the pressure from the nuts on one side cancel the pressure from those on the other side. So long as the structure can handle the application of all that pressure, the force to open the nuts are provided by one-another. I wonder how you would solve the problems of applying sufficient force while allowing the structure to move effectively. With industrial-size machinery this would not be a problem, but with something the same size and portability as the current machine, you would need some pretty sturdy and possibly complicated construction in the design. With engineering there are always trade offs, and I do think the current design is excellent. I do see your reasons for wanting this other way to work. I have the same reasons for wanting it to be easier and cheaper for these people to live/survive. Do try your ideas out, you may come up with something better.
put it another way, thing of my suggestion as the cylinders flattened out
I saw the nut sheller a year+ ago at the Olin Expo. My comment then, which I still think is valid, is that you can dispense with the fibreglass molds. Use a hole in the ground as your mold. The outer shape doesn't matter much--what matters is the inner shape. Dig a hole in the ground the approximate shape of the sheller housing. Line with plastic if soil conditions require. Fill hole with cement. Press the "innards", wrapped in plastic if necessary, into the wet cement. Remove innards while cement is soft. Dig cement housing out of the ground when cement is fully hard.
I have been reading about your project and decided to give this a try as my family has several pecan trees. After looking at your fiberglass forms I took a trip to the local Walmart and picked up a couple of recycled plastic flower pots. I don't recall the exact size, big. Both the same shape but one smaller allowing for a 1" to 1 1/2" of concrete. I poured it last night and all worked well. I am looking for the perfect size for the rotor now. These are very light but only available where you can find them. Also they released from the concrete very easily. If possible please post a link to allow for donations. I did use your idea as an example. Awesome project by the way. Jural
Hey Jural consider this - since the rotor and stator are tapered, you need only get close with the rotor size, and slide it up and down to get the perfect gap dimensions... Make sure the rotor is quite a bit shorter, and put shims (washers) under the bottom until it's at the perfect height.
Umm okay I do have an idea for very cheap molds that you could ship to anywhere - Nursery plant pots.

They come in a range of sizes in similar sizes and tapers, you can nail one down inside another larger one to form the stator, and use the next size down as the rotor form, the existing drainage holes can serve as guides for placing the bolts and centreing the axle, and you don't care afterwards if you cut the forms and throw them away as they are only a few cents apiece. And if you coat them with an oil or release agent first then you can even re-use them.

(A roll of plastic tape covers the drainage holes so you don't lose cement or get odd protuberances.)

Want more ideas? Please check and contact me there am happy to discuss.
hmmm, I'm sure you could make an inflatable rubber mold. That fibreglass wont last long after a couple of whacks from a hammer the first time it sticks to the concrete. Interesting, I'll have a think about this...
or plastic if you were to secure funding for a larger production run. I'm sure there will be times when people forget, or dont have to hand, any grease. Once fibreglass cracks its done, very hard to fix. Concrete will have a much harder time sticking to plastic... I would imagine?? This is an awesome project and I'd like to help out in any way I can.
seems like the molds are simple enough to with minor modifications be built using a vacuum forming process if so hobbyists could put the molds together on a distributed small scale basis out of thermal plastic.
Anothe reason that we have for using fiberglass is that is can be manufactured locally in Wilmington NC by a boat builder who makes the molds for us at cost. This can be replicated easily wherever people work with fiberglass, which is usually every port city in the world. If we had a factory that could pump out plastic molds that would be great but we don't. An inflatable mold....I would think that the weight of the concrete would be such that you would need a lot of air pressure to keep the mold in the shape that you wanted it. Also you are left with the problem of making plastic molds...unless you have a factory it would be difficult.
very true, I assumed you might have trouble finding fibreglass in some places away from the coast. Not sure where peanuts like to grow. I do a little work with fibreglass and its not a simple tech. I mentioned the inflatable mold in passing, I know they can be pumped hard, they can make surfboards out of it. And most averyone has a bicycle pump. But again, these are mass production molds, fibreglass is your best bang for buck as they say.
see my shapelock post below. It's a hard, very easy to mold plastic, can mold it by hand after putting in 160 degree Farenheit water, solidifies at room temperature.
The Full Belly Project (author)  leevonk8 years ago
Wow...this stuff is neat. I wonder how much you would need to make our molds. Got any rough estimates?
it's hard for me to estimate cause I don't know how thick the mold would have to be to hold cement. As far as I remember, the 500g containers of shapelock come in cylindrical cases of ~4" diameter and ~4" tall (filled with plastic pellets). You might be able to get a big discount for large quantity purchases (cause they mostly sell small quantities to hobbiests). If you could get away with making scaled down versions of the grinder that might be more cost effective if using this product. The nice thing is if the mold breaks or is cut away to free the cement, you can just melt it and remake or patch it very easily. If you ship the molds back from countries after their used, you could melt it down into an easy to ship brick too.
leevonk leevonk8 years ago
just measured a 250 gram shapelock container I have (turns out I didn't have a 500g container). The 250g container is:

radius = 4.25 cm
height = 8 cm
volume = h*pi*r2 = 453.7 cm3
I think that's a great suggestion, provided that we could set up a plastic mold factory, for the meantime our fiberglass is made at cost by a Wilmington boat builder.
You may want to consider injection molding the molds from polypropylene. Based on what I have seen of the project, you could probably make the molds for $10 per set or less. For comparison, think of plastic 5 gallon buckets. If you would like some help, please feel free to contact me. Regards, Dwayne Esterline
dschutt8 years ago
Hi, do you have plans available for this machine yet? I'd like to build some for here in the Negev and to pay to have some built for friends in Uganda. Great idea! Thanks for doing the work! Have Fun, dschutt
dschutt dschutt8 years ago
I wrote the above on pic #48 page. What I'm asking for is: how do I buy a set of molds and pedal powered sheller/seperater plans? Thanks! dschutt
ewilhelm8 years ago
How about using cardboard forms? Many concrete posts are poured into cardboard tubes. After the concrete hardens, the cardboard is cut away. I can imagine a flat sheet of appropriately thick cardboard with cutting lines (or already laser scribed cutting lines) that field workers could assembly into molds. Once assembled, the molds could be strengthened by wrapping them in rope or evening putting them in a hole in the ground and filling the space around them with dirt.

Robert Lang has been using the Squid Labs laser cutter to score paper, which he folds into some pretty amazing shapes. The laser cutter allows him to do beautiful curved folds that are nearly impossible by hand. The newer stuff isn't on his website yet, but he can fold a Klein bottle, so I'm sure he could fold your molds!

canida ewilhelm8 years ago
Check out the New Yorker article on Lang!

They talk about using the laser cutter scoring technique; Forum post here.
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