The Basic Elements

So, what do we have here? We know the movements we want to generate. The basic elements of a gourd automaton (remember, automaton is singular, automata is plural) are as follows:

a base - something to support the gourd figure
an action rod - something with which to rotate the gears or cams that interact with the figure
links - the connectors going from the gears or cams to the figure
crank - the handle that turns the action rod

Most important element? Have a solid idea of what the figure is supposed to do! If there is no clear idea of what the outcome is supposed to be, then no amount of interaction with the parts will come to fruition. It would be like doing research without asking questions -- no direction, no goal, no use bothering!  So, let's start with gourds that look like chickens, and make the chickens to the spin, the bob, and the jump.

Making the Soda Bottle into a Dome

OK, we have a plan for the improvised display dome to use with the gourd automata (well, the single ones -- not the multiple gourd automata).  First, cut off the threaded top using a PVC pipe cincher. It makes  clean cut and because it ratchets in steps, there is some control and very little leftover cutting debris. Once done, a spinner gourd makes a nice plug. Then, it is a simple matter of using an Xacto blade or scissors to cut the fluted bottom off to make the dome a suitable height for whatever it will be covering. The edge can nestled into a groove cut into a gourd base - awesome!

Now, having done all this, I decided to go with a dancing chicken trio for the first trial of gourd movements. However, there will be other gourdies coming!  Can you be patient for the dancing pig?  The butcher? The handyman?  Oh MY -- the possibilities!

Soda Bottle Shopping Trip

A quick trip to the local stores produced a couple options for the dome concept that could be applied inexpensively. They might actually allow a miniature bottleneck gourd turn and jump. An unexpected issue came to light once the soda was emptied out and the bottles washed -- the expiration date! Did not see that when the purchase was being made, MmMMmmmmm.

Side Trip into Future Display Options

A brief interlude about displaying automata. In the end, I would like to make and display mechanical gourd figures at a gourd festival for visitors to enjoy as a hands on introduction to the world of gourds. Yet, I am apprehensive of over-eager folks who what to investigate how they work and drop them. OR, as is the case at festivals, children are allowed freedom to go their own way and have not learned the careful art of trying something without being too harsh.

What if the automata could be displayed carefully in a protected case with the crank extended through the case? Then, people can maneuver the crank, see the automaton move but it would still be protected from curious fingers and airborne dust. I am intrigued. American Science Surplus sells shadow boxes that could work for flat automata -- if I use really small gourds OR use flat gourd scraps. That is something to consider, but I want gourd dancers and chefs and pigs and chickens to spin and jump, and that takes more circumference space than a shadow box can afford.   

A glass display dome at National Artcraft is a possibility but geez! at $49 a piece, it would outclass the gourd! I like the size and diameter of the dome because it would accommodate a 3-d automata and could be turned around so the viewer can see all aspects of the construction, but then I come back to the price and consider how many ideas I want to pursue. Nice concept; not going to happen.

Recycling soda bottles might give the same effect of a glass dome if the larger, 3 liter, size can be found. Maybe a trip to my nearest Dollar Tree is in order! 

Paul Spooner

A prolific and innovative automaton designer/builder is Paul Spooner. He is the builder of the Poisoned Cat, He believes humor and ease of building are two important factors involved with this particular art. There are many examples of his work online. His sketchbook is inspiring and makes me want to keep my ideas together as well.

In another YouTube, chickens are used to demonstrate four ways of using the same cam design to generate four movements. I found this interesting since I have been scrambling to achieve different movements with different gear options. By exploiting the many ways a cam can be used, many movements can be obtained.

These chickens do not move in flamboyant ways, but as the person opens the doors it is plain to see how the movements happen.

3 Movement Possibilities

Here are three movement possibilities for my gourd chickens. Each one will make a chick do something different. The round one will be the friction wheel for a horizontal disc so the chick spins, the oval/off-center cam will make a chick peck the ground like an oil derrick, and the sawtooth gear will have a chick jumping up and down and its follower (the rod connecting it) slides up and then bumps down the edge of each pointy tooth.  They are all on the same shaft so as it is turned with a crank, the chicks will all move at the same time.

Off-set Cam

A disc with the hole off-set from the center will produce a methodical ebb and flow motion. The follower (the rod connected to the chicken gourd) rises and falls as it stays on the edge of the disc as it circles around the pivot point which is the center of rotation.

The rod moves up and down.

Friction Drive

I now have an amazing book that explains movement so simplistically that even this non-engineer blogger can grasp concepts! To achieve the twirling movement described in an earlier post (see spinning top gif), it will be necessary to use a friction drive. The authors of Cabaret Mechanical Movement explain a friction drive allowing a change in the rotation of an object from vertical to horizontal (or the other way around) by making use of the friction between a vertical and a horizontal disc.

Page 90 showing a friction drive

The two discs have to touch on the outer edge of the horizontal disc.

So simple, yet the twirling chicken will be fascinating to watch -- or so I hope!