So, to hold off future barbarians, we'd like to show how to build a simple tool set on a very low budget.
Larry Bentley, the man who figured out how to make these tools, said a wise thing: "Without tools, kids don't take stuff apart, and without taking stuff apart, you don't learn how things work."
These tools, Bentley says, could be in the hands of the next William Kamkambwa,who made a working wind power generator from backyard scraps in a village in Malawi.
Here's Larry's quick guide to DIY tools.
The tools in this guide:
- Wooden vice
- Wood drill bit / star drill bit
- Strap hinge vice
Step 1: How to Bend Rebar
Step 2: Saw: Step One
That inspired this rebar saw.
Start by bending the saw and the handle into the shape shown. You can use the pipe bending technique shown in Step One.
Step 3: Saw: Step Two
Pro tip 1:
Make the gap between the prongs that hold the blade about 2cm (1/2-3/4") further apart than the blade's length. When you put the blade in the frame, the extra length makes tension that holds the blade in place and makes it work much better.
Pro tip 2:
If you don't have a hacksaw to cut the grooves that hold the blade, you can always use a hacksaw blade by itself. Wrap one end in cloth to hold it, turn its teeth toward you (the vertical edge facing you) so that it cuts when you pull it. Carefully cut the grooves, then turn the blade around when you insert it into the saw frame. The teeth should cut when you push the saw, not when you pull it, unlike when you hold the blade in your hand.
Step 4: Blacksmithing 101
Simple blacksmithing (Bentley calls it "primitive," which is right), requires only a hammer and any flat, hard surface. It's easy to make useable wood and cold chisels, spade type drill bits for wood, and to shape screwdrivers and make simple twisted end pliers and blacksmithing tongs.
Blacksmithing is a craft where you make the tools to make more tools, a great way to build up a tool set and even sell extras to raise money for the purchase of the hard-to-build tools and materials.
Rebar works as a material for making tools. It has enough carbon so it can harden into drills, chisels, star drills, and other edged tools. You can bend it, hot or cold, to form hacksaw handles and brace-and-bit drills. And you can forge it into tongs or knife blades, and larger diameter sections can become digging bars, axes, hoes, and picks for digging.
For simple blacksmithing, heat iron or steel in a fire (charcoal, coal, natural gas or coke are best) with enough air flow to raise the temperature until the metal glows bright and red. While it's hot, you can shape the metal by hammering, bending, or twisting it. The iron or steel is hot enough to work when a magnet won't stick to it. When it cools to a dull red color, put it back into the fire to heat it again before you continue.
Avoid heating the metal to a bright yellow or white because that heat will destroy the metal's useful properties. If you want the metal as soft as possible, heat it to a bright red and let it cool slowly in the ashes of the firepit. If you want to harden steel (iron won't harden like this, only steel), heat it to bright red and then quench it in water or even used motor oil.
Properly hardened steel will be very hard to cut or even scratch with a file. The problem is the hardened steel is very brittle, it will break off if edged or struck with a tool. To make a useful tough and hard tool, the now hardened steel has to be reheated to a straw color for wood cutting tools, and to a dark blue color for metal working tools. That is called tempering.
The exact temperature and color will vary with each different type of steel, so once you learn what is best for one type of steel you can reproduce the results you want. It's a learning exercise. If it comes out too hard, reheat a little more and check again, this is safe since you won't overheat it and lose the edge holding qualities. If it comes out too soft, you can reheat it to bright red and reharden and try again.
You likely won't get it right the first time, Bentley says, so try again and again. You will get it right eventually, Bentley assures us.
[For more, here's a good guide. And please see Flamesami's comment on the Intro page about different types of metals]
Step 5: Drill: Step One
Using the method shown in Step One, the following photos show how to bend the rebar into the shape you'll need.
Step 6: Drill: Step Two
To make the crank handle, slit a narrow PVC pipe along its length and fit it over the handle part of the bent rebar.
For the top cap, if you file the end of the rebar to smooth it, you can reduce friction when the drill spins.
Now your drill is finished. You just need the bits.
Step 7: Drill Bits
Wood drill bits can be left harder, but metal-cutting tools need to be a less brittle so the working edges won't chip off.
Flat wood drill bits are forged and need to be filed or ground into rough shape before hardening. Once hardened and tempered it takes a grinder wheel to touch them up.
Worn out files, broken leaf springs, knive blades and drill bits are all made made from good tool steel. You can reform them into a number of useful items.
Here's how to attach bits to the drill:
The easiest bit to make is to simply forge one end of the rebar into a fixed bit. You should do this before you bend the rebar into the drill shape.
If you want to drill only a few hole sizes, consider making a small set of fixed-bit drills. The construction is cheap and simple.
Interchangeable bits - coupling
To make your bits interchangeable, weld a pipe coupling or thread a threaded rod coupling onto the end of the rebar.
If you have threading dies, you can thread the rebar after filing off the ridges. Rest the smoothed rebar on a firm surface and turn it as if you were drilling while someone else works the end with a file.
Then cut the same thread size into the top of the bits to make a fully interchangeable set of bits. Even if the threads are a little off, the bits will still turn a usable hole.
[Here's a how-to video on using threading dies.]
A piece of 1/8" pipe can act as a chuck for a 1/4" (6mm) hex extension bit holder. This lets you change bits quickly, but you'd be limited to 6mm (1/4") hex shaft metal twist bits and smaller. Larger wood spade bits are available with the same hex shaft.
Step 8: Pipe Drill
It's a hand-powered drill press made of iron pipe. It can be pretty slow, but it can drill holes even in hard materials with standard twist bits.
Yes, Bentley says, that is a U.S.-made hand file (in other words, very hard), that he drilled with standard tooling and it was not annealed to soften it.
The entire drill, apart from the drill chuck, is made from pipe, washers, bolts and loose ball bearings that you can buy in village trading centers or salvage from worn bicycle parts.
One weld makes it easy to add the hand crank, but it can be turned with a wrench if you don't have access to welding.
Step 9: Pliers: Step One
- Start with a flat metal bar.
- Cut two equal-sized pieces, each to the size you'd like for your pliers.
- Drill a hole in each and bolt them together as a pivot point.
- Heat the short end above the pivot point to red.
Step 10: Pliers: Step Two
- Twist both bars at the same time with an adjustable wrench.
- When the bend is right, quench the metal to freeze the bend where you want it.
Set the wrench to the right width before you begin and you won't have it on the hot metal long enough to damage it.
Step 11: Pliers: Step Three
- Cut the tips of the short end to make them pointy. You can follow the cut lines shown here, or make your own custom pliers.
The jaws could also be reformed around round or square metal stock to form more customized holding tongs for blacksmithing work.
Step 12: Strap-hinge Vice
Just drill a hole through both leaves and run a bolt and nut (wingnut is better) through the matching hole.
- If you don't like the shape of the working tips of the strap hinge, the tips can be sawed into a useful shape.
- If you need additional working depth for the jaws, the leaves of the hinge can be bent into a bow shape as you see in the sideways photo (but this takes a much longer bolt).
- If the jaws are angled outward too much ( \ / ) the work piece will not be clamped and will kick out of the jaws. The jaws need to be parallel or else angled inward ( / \ ) to properly grip the workpiece.
- If you want to mount it to a workbench the original holes for one leaf of the hinge can be used with flat-head screws to mount it in a fixed position.
Step 13: Wood Vice
Sawing a wood block with a compound taper (both across the width and length of the block) gives you the clamping force and the slight undercut ensures the wedging jaw doesn't pop upwards when work is done. The undercut angle can be small and still prevent kickout of the jaw.
Ideally, the rear fixed jaw (where the writing in the model is located) doesn't have to be fixed. It could have headless bolts or screws on the bottom of it and be inserted into a matching hole pattern across the top face of the workbench. This would allow one fixed (front) jaw and wedge piece to clamp widely varying widths.
A similar idea for the workpiece holding dogs has been used for centuries and is still seen on a Black and Decker folding Workmate, where plastic dogs (Black and Decker calls then Swivel Pegs) are moved into holes drilled through the top surface to hold odd-shaped pieces of work.
Step 14: Hammer
"I saw an old Peace Corp document years ago with a simple hammer made from a large discarded bolt and a stick for a handle. It is possible to burn or cut a hole in the wood and enlarge it with the bolt heated in a fire and get the hole through the wood with a decent fit. Some string, glue or wire can help secure the now hammer head even if you don't have a nut to fit the bolt."
Awesome Lego photo by Joriel "Joz" Jimenez / Flickr - Creative Commons license