Introduction: 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:

Step 1: 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

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

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

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

Assemble the stool by attaching legs and spin pipe into center mount.

Step 6: Set Rotor Mold on Stool

Place outer rotor mold on stool, by sliding the shaft sticking out through the hole in the stool and through the pipe on the other end. The bolts sticking out of the mold should drop into the two big holes on either side of the one for the central shaft.

Step 7: Attach Inner Rotor Mold

Slide inner rotor mold onto shaft.

Step 8: Securing the Rotor Mold With Lock Nut

Spin Lock Nut (nut with welded flat bar) onto shaft thread and hand tighten.

Step 9: Attach Clamp to Shaft

Fit wooden clamp to exposed shaft, keeping inner rotor mold pressed down. Check the Lock Nut for tightness. The clamp is there to keep the mold from floating up on top of the liquid concrete.

Step 10: Pour Concrete Into Rotor Mold and Let Set

USE HARD SAND, SAND BLASTING OR RIVER SAND, AVOID CRUSHED CORAL. MIX SAND AND CEMENT IN A 50/50 MIX. Pour concrete into mold to within about a fingers width of the top of inner rotor mold lip. LET STAND UNTIL A SHARP OBJECT CAN STILL SCRATCH A GROOVE IN THE SURFACE. The concrete will cure faster in warmer climates. Make sure you place this is a level spot . Important Note: Please use a bubble level if available, or just do the best you can to level out the assembly, for this ensures the rotor runs "true" inside the outer piece (stator).

Step 11: Removing Rotor From Mold

Note: These steps should be completed while concrete is still soft enough to brush surface to make it rough- WARNING: IF CONCRETE HAS LEFT TO SET TO LONG IT WILL BE TO HARD TO BRUSH AND THE SURFACE WILL REMAIN SMOOTH. IF THIS HAPPENS BREAK CEMENT OFF SHAFT AND START OVER. Times vary according to cement type, temperatures, and wetness of mixture.

Remove bottom Lockdown nut and lift Rotor Mold off stool.

Step 12: Remove Nuts

Remove 2 nuts from bottom of mold so that the attached threaded rods will release.

Step 13: Remove Wooden Clamp

Step 14: Pry Out Center Hub

Gently pry out Center Hub using bottom and top brackets.

Step 15: Remove Rotor From Mold

Place Rotor in mold on blocks with central shaft between the blocks. Hit side with piece of wood to loosen. Drop the whole assembly gently onto the blocks until the concrete releases.

Step 16: Prepping the Stator Mold

Prior to prepping the mold for use, please check that side expansion joints are free and clear of any residual mortar, or foreign matter of any kind the seal should join cleanly. Also clean the expansion joints of the mold with a knife or similar tool, and bolt the sides together, sealing it closed. Do not over-tighten bolts.

Step 17: Grease Inside of Outer Stator Mold

Wipe inner surface of outer stator mold generously with cooking grease for easy release later.

Step 18: Prep Liner for Inner Stator Mold

Your kit should come with a plastic liner in it. This is used to help release the inner stator mold. However if the liner needs to be replaced this can be done with any heavy plastic liner. Just cut out a piece that fits the inner stator mold.

Step 19: Prepping Plastic Liner

Once you've cut out the part for the plastic liner go ahead and seal the seam with electrical tape. If any liner is left above the mold trim it with scissors. Try to make the liner fit around the mold as smoothly as possible. ANY FOLDS IN THE PLASTIC WILL WEAKEN THE CONCRETE. Once your done simply slide the liner on top of the mold. Your will then be able to reuse the liner in quite a few more machines.

Step 20: Insert Support Bolts

Insert four (4) bent threaded rods into 4 holes in inner stator mold,leaving two opposite holes open as shown. Thse rods are for attaching the carrying handles. Be sure to turn rods so that tips are a finger's width away from surface of mold (see image.) Place one washer and nut above and below the lip, leaving three finger widths above the inner stator mold lip.

Step 21: Place Inner Stator Mold in Outer Stator Mold

Insert inner stator mold into outer stator mold. Center pin will slide into hole in center of inner stator mold, inserting pin in center.

Step 22: Insert Long Threaded Rods

Insert and drop longeest threaded rods into the two remaining holes in the inner stator, these rods pass through the bottom of outer stator mold, and are secured by a washer and nut.

Step 23: Secure Long Threaded Rods

Secure each bolt with a washer and nut to hold the two mold sections together.

Step 24: Pour Stator

MIX HARD SAND AND CEMENT IN A HALF AND HALF MIX, SAND BLASTING SAND OR RIVER SAND NOT CORAL OR FINE SAND. On a level surface, on a level surface pour concrete between molds, using a thin stick to remove air, only if necessary. DO NOT OVERFILL. Fill within one centimeter of the top of molds.LET SET AND HARDEN UNTIL A SHARP OBJECT CAN STILL MAKE A GROOVE IN SURFACE, hardening times vary with temperature and local cement type. Harden until cement has the the consistency of styrafoam. Use a bubble level in a few directions to assure it is level and straight. Note: Monitor the cement as it hardens. When the surface is hard, but can be scratched, remove inner mold and plastic liner for roughing up surface with wire brush.

Step 25: Remove Washers From Stator

After concrete is the consistency of styrafoam remove all six nuts and washers from mold.

Step 26: Remove Inner Stator Mold

Using the top and bottom bracket pry and lift inner stator mold out.

Step 27: Remove Plastic Liner

Pull Plastic Liner out Save Liner for later use. (However if it does rip it is easily replaceable).

Step 28: Brush Inner Stator

Leaving stator in outer mold, brush the inside surface of the stator using a wire brush using vertical brush strokes until the surface is rough. A machine with smooth inner surfaces will work very poorly. IF CONCRETE IS TOO HARD TO BRUSH REMOVE STATOR FROM MOLD, BREAK OUT METAL PIECES AND START AGAIN.

Step 29: Remove Remaining Nuts

After final 12 more hours setting time - Remove remaining 2 nuts.

Step 30: Loosen Expansion Joints

Loosen nuts holding expansion joints closed.

Step 31: Release Mold From Concrete

Pry both joints open 1 cm.

Step 32: Lift Mold Off Stator

Lift mold off stator. Smooth the edges.

Step 33: Attach Center Top Bracket

Set bracket on exposed threaded rods with loose nuts and washers. Center pipe in opening.

Step 34: Secure With Washer and Nut

Step 35: Add Heavy Machine Grease

Pack as much heavy machine grease as possible into top bearing.

Step 36: Turn Stator With Top Bracket Upside Down on Blocks

You will want to set the stator with the attached top bracket on top of concrete blocks (cinder blocks) or something of a similar shape, being careful that the bracket is suspended between the blocks and off the ground.

Step 37: Place Rotor in Stator

Gently insert upside down rotor into upside down stator. The reason for having the stator up on blocks is to allow space for the rotor shaft to go through the bracket tube.

Step 38: Grease Bottom Bracket Tube

Pack bottom bearing tube with heavy machine grease.

Step 39: Identify Bracket Rods

Identify two threaded rods that also connect to top bracket. Identify the other end of the threaded rods that are holding the top bracket on. Place a nut and then a washer on each.

Step 40: Attach Bottom Bracket

Slide bearing tube (with bottom bracket attached) onto shaft.

Step 41: Secure Bottom Bracket

Install nut and washer on bottom mounting bolts, and tighten.

Step 42: Attach Wooden Supports

Cut and drill wooden supports. You can figure out where the holes should go by placing a support on the threaded rods then hitting the top of the wood with the other support, leaving an idention from the threaded rods to show you where the holes should be. Attach to bottom of machine using remaining a washer and nut on each threaded rod.

Step 43: Turn Machine on Side Then Install Washers

You will now carefully, with two people turn the machine on its side, being careful to not let the shaft slide down through the bracket. Grease 4 (four) large washers, and install onto the top threaded end of the shaft.

Step 44: Attach Turning Handle and Lock Nut

While the machine is still on its side spin the handle onto threaded shaft, and install lock nut after, as shown.

Step 45: Attach the Metering Plate

This is the Layout of the Metering Plates for the Sheller. Install the larger half-circle plates first so that that the notches meet. Then install the small plate on top, securing it with a wing-nut. Rotate the smaller plate in either direction to open or close gap. THIS IS SHOWN OUTSIDE THE SHELLER BUT YOU WILL ACTUALLY BE DOING THE STEP WITH THE ROTOR INSIDE THE STATOR.

Step 46: Set on 1/2 Oil Drum and Adjust

Set on box or 1/2 oil drum or other supporting object. To adjust for shelling bigger or smaller nuts raise or lower the rotor. To raise the rotor release the lock nut and spin handle to expose more thread on shaft. To lower the rotor do the opposite.

Setting for Nut Size:

Shell a nut by hand. Drop through gap in metering plates. If the nut falls through the bottom of the machine, raise the rotor by turning the handle clockwise. If the nut fails to drop through, lower the rotor until it does. At that point tighten the lock nut.

Fine Tuning:

Shell 1 liter of nuts. If breakage rate is high lower rotor. If too many nuts are unshelled raise rotor. In the case of any nuts with a wide variety of sizes you may have to set for large nuts and seperate unshelled small nuts and pass through machine again.

Seeting for Volume of Nuts Shelled:

If nuts shell too slowly. Loosen wingnut on metering plate and adjust top plate to open gap.

Setting for Larger Nuts

If you want to set for larger nuts you may have to undo the two small bols on the the top bearing tube with an adjustable wrench and drop the entire assembly as far as necessary.

Step 47: Travel to Developing Country

Proceed to introduce sheller to villages. Any small farms that grow peanuts, pecans, neem nuts, wing beans palm nuts, shea nuts and pine nuts have a use for this machine. You may even discover other nuts that it can shell (and please let us know if you do). The people of these villages will thank you profusley as will their children who typically have to spend hours shelling nuts.

Step 48: Pedal Powered Agricultural Center (Coming Soon to an Instructable Near You)

This is a picture of our Pedal Powered Agricultural Center (PPAC), essentially it adds on to the Universal Nut Sheller (UNS) by making it pedal powered, increasing the amount of peanuts that can be shelled from 50 kg (110lbs) to 90 kg (200 lbs) an hour. The machine rests on a oil drum base, with the top 1/4 of the oil drum being used to make a squirrel fan that acts as a blower to seperate the shells from the nuts after they've come out of the UNS. The rest of the machine is simply made of pipe, a few pulleys, belts, and wooden bearings. Amazingly the peanut breakage rate (which is very important as broken peanuts will go rancid if their papery skins are pulled off) is only 5%. The industry standard is 20%, and electric machines with similar outputs and are much more expensive, and powered by electricity are around 40%. We have tested the machine in the Philippines (thanks to the efforts of Illac Diaz and the Myshelter Foundation) with great success. In addition we also won an MIT IDEAS Award for it, once again thanks to Illac Diaz who coordinated our entry. We will have instructions on how to make it as soon as we can. But if you need more info right away go to our website also check out our blog at