MakeShift 04: Bobby Joe Snyder’s “Hans Christian Andersen” Honorable Mention
by William Lidwell
March 16, 2006
Nice images, unique presentation, and a few key references to famous “Kamenisms” won this honorable mention. The DEKA team comments: “A second honorable mention goes to Bobby Joe Snyder, a.k.a. “Trurl the Constructor,” for his entertaining story and his mention of the South Pointing Chariot and “frog kissing.” Congratulations Bobby Joe!
Before explaining the design of my “water pump” I want to explain some of the design difficulties. It is easy enough to design a pump. There are pumps in every day items. The challenge is to make one in the field. There is no machine shop to turn out custom parts. Springs, valves, and gears that don’t break the seal of the pump are all design challenges. I chose a design that could be made in about 3 hours once the materials were collected. It isn’t the most efficient pump. Also I have only tested it in theory. I tried to rely on my own knowledge for this MakeShift 04 solution because that is how it is in the field. You don’t have the library or Internet. But although my design may need some tweaking, I feel it is a good solution to pumping the water into the oil tank.
The design is simple but required some thought. You find a hose or plastic pipe and place another slightly smaller hose in it. The smaller hose can be cut into quarters and then clamped together with a metal ring so that it is adaptable to many different sizes of pipe. (In the drawing a smaller hose of 1″ radius is used to get general proportions).
Simply stated, an overall description of the pump is the following. It is a piston-like device with a valve to release the water. It is similar to a small gas engine piston, a subject that I have recently studied. Here is how it works. The smaller hose is inserted into the larger hose. Small metal cylinders are inserted into holes in the small hose and held in place by two bolts along the inside of the hose. The very top bar is the place in which the improvised valve rotates. This top bar is not in holes in the hose, instead it has a bent piece of metal connecting it to the main bar below it. The valve is connected to the top bar by wire wound around the bar. If holes are necessary to put in the valve sealant can be used to make it watertight.
Continued: the valve is opened and closed by a bar connected to a gear system that moves the smaller hose back and forth. The valve will open on the inward stroke and close to form a vacuum seal on the down stroke. This inward/outward motion is tricky to create, but is possible to improvise. (That will be discussed latter.) This seal is how the pump works similar to how a syringe would. But it also has the valve opening to complete its motion. The same bar that pulls the small hose back and forth is the same part that opens and closes the valve. There are measured slits in the small hose to let the bar move without moving the hose and at the same time opening the valve.
Some notes on the valve are that there are seals on the top and on the bottom. The seals are opposite the way the valve rotates. They are split halfway in the picture. This only allows for the valve to open a small amount. To improve this the valve could be slanted or the valve could be in the shape of a “Z”. The easiest solution would be to make the top seal less than half of the bottom. This would give the valve more room to rotate.
A key part to the piston is the rubber seals that keep the piston watertight. To improvise this rubber from hoses, cut pieces from a plunger, or the most preferred method of windshield wipers. Malleable metal may also be shaped. (I originally thought of a soda can, but other than the bottom the metal is too thin.) This contraption is held together with a long piece of thin metal clamping together all the parts together.
In the drawing the small hose (piston) is inside the large hose that connects to the water source. This is only one combination. If pipe joints are available, a joint with 2 outlets could be used — one hole containing the piston and the other an outlet for the water. An improvised valve could be made to cover the outlet to improve the pumps power. I should also mention that a screen and funnel-shaped piece such as a cut soda bottle could be placed in the inlet hose or pipe.
The back and forth motion must be addressed. There are several ways to improvise this: electric motor that turns both ways, gear cut in half, turning gear teeth, a chain that alternates gears like a bike, or a transmission similar to a car. Each of these could be explored in depth, but are a MakeShift solution themselves.
Note on Back and Forth Motion
The modified gear drawing is just to show that producing an equal back and forth motion is possible. Cutting the teeth of a gear in an arc length less that 180 degrees is a simple, quick, improvised solution. The only problem is that it takes a large size gear. This gear could be found on a car or possibly a tractor. But in this drawing to move the piston 14 inches a gear of a minimum 10.7-inch diameter would be needed.
Of course there are other methods. I just want to show that the back and forth motion is possible. It is a topic to tinker with and research what designs are already available. It would take me quite some time to draw out the best solution. Designs often lead to more designs especially when a problem occurs. I have mentioned other ways to produce this back and forth motion earlier in the write up.
Hopefully my description is clear. The pictures should explain everything after studying them a while. The piston drawing can be viewed in 3D Studio Max. Its proportions are correct. It helped me to visualize the design better drawing in 3D.
Oh, and …. may the Creative Force be with you, the reader!