Handcranking as a start?

This seems simple, right? A crank, a drive shaft, an egg cam with a rider that moves a rod up and down that is connected to a horizontal level. How can the be translated using gourds? A bottleneck gourd can be the vertical rod and with loosely jointed legs could appear to be jumping up and down. With wire arms/hands, the gourdhead could be following a lively gourd chicken as it drags him along? Small bottleneck gourds could work...mmMmMMMmmm.

Thank you Automata GIFS on Giphy!

Automata Future

In his book, Making Simple Automata, Robert Race suggests the future of automata may be wrapped around 3D printing. As 3D printing becomes more accessible and more inexpensive to use, parts of an automaton's mechanism could be 'printed' - a fairly easy way to manufacture hard-to-get parts.

CalGraphix makes prototypes using 3d technology.

Backing up to Simple...

I jumped into this project with eager feet, then got overwhelmed with the complexity of engineering. I am not an engineer - I just want to use my gourds to make fun, moving gadgets I can show off and enjoy.

Robert Race, author of Making Simple Automata, lays out a plan for making moving gadgets. His recitation of automaton history is fascinating and will be addressed in a later post, but for now let's review his golden rules: 1) there are no rules, 2) keep it simple, 3) use the properties of the materials, 4) size matters, 5) don't worry about the gaps, and 6) there is always an alternative.


For immediate purposes, Rule #2 - keep in simple, is the mantra to follow. I have been trying to wrap my head around gears, and cogs, and ratchets and rotation formulas when all I need at first in a push handle and a spring. In this example, a handle pushes against a rod which is backed with a spring. The spring is compressed and pushes the rod back against the handle. The center rod is rocked back and forth with repeated pushes of the handle.

The center rod angle and amount of squeeze already in the spring will determine the amount of movement the rod will have. As Mr. Race says, "A good deal of trial and error may be involved in getting a new design to work properly. See that as part of the fun."  And so I shall!

The handle and spring can be hidden inside a box or something,
and a banana gourd painted as a fish on top of the rod would rock back and forth
like it was swimming.

Fun Historical Fact about Gourds

Gourd historian, Scott Nelson, shares a fun fact about gourd history in an article he wrote for Arizona Gourds:

"Here is an unusual use of gourds!  In the Popul Vuh - a pre-Columbian document of the Kiche people of Central America - a BOMB is mentioned: It's a gourd filled with live hornets. I can only imagine, in a feud/war, how nice it would be to have a stash of those around the house. And not much fun to be on the receiving end of the "first ever" hand grenade."

We will not be making any exploding gourds here, but phew! this gives me a whole new point of view regarding war and agricultural products, right?

The Gourd Side of Things

Looking at this project from the gourd side of things:

Gourds, the kind I am considering - hard-shelled gourds - are the inedible part of the squash family. There are the pumpkins and butternut squashes that can be eaten, but hard-shelled gourds dehydrate to a wood-like wall structure and can be used for all kinds of utilitarian purposes: birdhouses, bowls, masks, dollies, etc. Historically, gourds have been powder horns, grain carriers, and water dippers.

Digital Gourds chart © Dan Dunkin 2003
This chart is used courtesy The Gourd Reserve

Automata Resources

The Onslow College Library has compiled a pretty extensive list of resources that relate to my project. Interestingly, the United Kingdom seems to be a central locus for mechanical toys and theatre.

A Simpler Entry into the Automata World

Oh my gosh! By changing keywords and searching 'automata gears', I found a website that is geared (no pun intended, but how cool, right?) to people making mechanical toys, Automata! At this website, the gears are broken down into types of mechanisms: cams, gears, ratchets, pulleys, levers, and cranks. Each one has a specific action associated with it and when combined with each other, a mechanized product can do just about anything.

Gears are divided into input and output gears. An input gear is the one being turned; an output gear is the one being moved by the input gear. The number of teeth per gear will determine the speed. A ratchet is a jerky version of a gear. It is a little more complicated but is effective in slowing the motion down in an automata. Pulleys can connect gears across a distance, or change the direction of the gear action. For example, a rubber band can be wrapped onto two gears that are a distance apart and, in essence, connect them. Because they work with friction, having an incredibly smooth edge would be a disadvantage.

Cams work in a circular motion with a rod (called a follower) rubbing along its edge to move whatever is attached to the rod up and down. This is called a reciprocal movement. Having absolutely smooth edges is critical because the follower has to slide along the edge of the cam in order to produce effortless movements.

Cranks convert circular motion into reciprocal motion (the up and down of the moving parts of the toy). They only move in a circular fashion and only 1 drive action per revolution. They are usually the mechanism used for hand-operated kinetic toys.

Levers work with a fulcrum of balance to achieve varying amounts of movement. Like a see-saw, the longer end produces the most amount of energy so a designer has to look critically at the end where the action is supposed to happen to determine how much length and force is needed.


 

Begin at the Beginning

When starting research, it's best to begin with the basics (lower level of Bloom's, so to speak). What is a gear? What kinds are there? These are the basic questions since I know absolutely nothing about gears.

A quick search in a dictionary finds that a gear (as a noun) is a toothed wheel in a machine -- in fact, a mechanism that performs a specific function in a complete machine. Further down on the page the more complete explanation says

"Machine component consisting of a toothed wheel attached to a rotating shaft. Gears operate in pairs, the teeth of one engaging the teeth of a second, to transmit and modify rotary motion and torque. To transmit motion smoothly, the contacting surfaces of gear teeth must be carefully shaped to a specific profile. The smaller of a gear pair is often known as the pinion. If the pinion is on the driving shaft, the pair acts to reduce speed and to amplify torque; if the pinion is on the driven shaft, the pair acts to increase speed and reduce torque."

This sounds pretty simple: a gear is a toothed wheel that works with another one to speed up or reduce the action. In fact, it sounded so simple I get cocky and visited the Kohara Gear Industry Company's online pdf booklet, Introduction to Gears 1st Edition, and YIKES! found out I am so clueless. There is so much math and terminology. Although this booklet will be helpful eventually I'm sure, it is far more complicated than I am ready for at this point. Is there a more simplistic way to learn about movable toy-making without becoming an engineer?

The Driving Force of Research...

It is well known that the driving force of research, in this case the investigation of making gears out of gourds for automata, is questions. At the beginning of a project, I usually have lots of questions. I know a lot about gourds -- there are many kinds, many thicknesses, many shapes.  A gourd grows on a vine very much like a pumpkin vine, although pumpkins are edible and gourd are not. Fully grown, a gourd is 85-90% water. Once the gourd dehydrates, the wall is pretty tough. Gourd wall structure is similar to a soft wood like balsa or maybe even pine.

My questions are going to center around gears. What are they? What kinds are there? Do I make the gears first and build the gourd automata around whatever gear thing I can make, OR do I design the automata first, then figure out the gears to make so it does what I want it to do?  Which way is better?

Basic question? What is an automata?  It is an movable object or piece of art, usually with a humorous touch. Also called kinetic toys or machines, they can be handcranked items for entertainment. This one from Singapore Polytechnic School of Mechanical and Aeronautical Engineering is advertising their Toy Design Competition 2014. Note how the three different gears produce different movement.

Welcome to The Wheels on the Gourd!

Welcome to another semester of research! This semester I will explore the techniques of making gears and connecting them to make gourd toys that move...gourd automata, also called kinetic art. Usually these types of mechanisms are made with wood and/or metal. Being a believer and follower of gourd culture, I want to expand the body of knowledge into gourds by not only making the movable parts of gourds, but the inner gear workings as well.

Gourds come in many shapes and sizes. That will will fuel my ability to do what may seem improbable, or perhaps impossible. I have tools, I have interest, and I have gourds. Let the wheels on the gourd start turning...