Skip to main content

Micro Automata



Materials:
• Wide clean plastic cup or clear solo cup.
• A straw
• Skewers
• Bottle caps
• Foam core
• Tape


Tools:
• Scissors
• Hot glue gun
• A wood screw
• Phillips screw driver or pencil

Automata meaning self operating machine typically consisted of a clockwork statue or scene and were first created centuries ago in Europe and Asia.  They were in many ways the direct ancestor of what became electro mechanical robots.  For our purposes automata are a good way to explore machine's function of converting one form of energy and motion into another.  They are also a way to teach simple mechanical problem solving skills.


Micro automata were the first in our series of attempts to simplify cardboard automata. The basic idea was to avoid building the box by putting the mechanism inside a clear plastic container.  Mechanically they are very simple. They have a input shaft with a crank coming out the side and an output shaft coming out the top with a mechanism in the middle to convert the motion. Here is a good basic model to start from to which more features can be added.


 First you use a wood screw to poke a hole in the side your cup about half way down and big enough for your skewer.


Insert the skewer and mark the position of the second hole so the skewer is parallel to the top of the cup.  When inserted this skewer is the input shaft.


Make a hole in the center of the bottom of the cup using a wood screw.


Use a phillips screw drive or pencil to widen the hole until a straw will fit tightly in the hole. Note that the straw has to be big enough for your output skewer, so size your straw and hole accordingly. With the straw sticking about 1/2'' into the cup hot glue it in place being careful not to melt it.


Prepare the output shaft, by glueing about a half skewer into a bottle cap (a round piece of foam core or card board works too)


At this point you have to decide what you want your output and whatever you build on it to do. You can either poke a hole in the center or off center in the bottle cap for the input shaft. Making the hole centered will result in a friction gear which will spin the output skewer when the crank is turned. If you put the hole off center you will get a cam and follower, the output skewer will go up and down when the crank is turned.


In this case we went for a friction gear resulting in a spinning output.


Here are the two parts assembled into the cup. Note that you have to put the output skewer in first and then add the input shaft below it.  


The final mechanical step is to add a crank and some spacers to keep the input from sliding around, a bottle cap or a foam core square can be used to make the crank. You can use tape flags or cardboard/ foam core washers to keep the crank shaft from sliding in and out too much.


The final and most important step is to use the mechanism to drive a puppet or scene, below are some examples we built:





This version used a simple friction gear to turn a horizontal rotation into a vertical rotation. 



This version uses a cam which has been placed of the edge of the follower making the bee go up and down and circle the flower slowly. If the cam were placed in the center of the follower it would just go up and down.


This version uses two offset cams to get the birds to go up and down and back and forth around the tree.

Comments

Post a Comment

Popular posts from this blog

Tissue Paper Hot Air Balloon

Perhaps you've seen hot air balloons for sale as science demonstrations/experiments that you fill up with hot air from a hair dryer and let float to the top of the room.  This product can be easily recreated on a smaller scale with tissue paper.  This project is a great way to demonstrate and learn about gases and density. You'll need: 5-6 sheets of tissue paper, a strip of paper, a glue stick, a marker, scissors, and  a hair dryer. The first step is to layer 5-6 sheets of tissue paper and fold them in half lengthwise. Use a marker to draw a half tear drop shape. Cut along the line and unfold the layers.  Each one will be a panel for the hot air balloon. Using a glue stick, or wet glue thinly applied with a paintbrush, glue one edge (marked in the picture above) and layer another panel on top. Pres down firmly to seal the edge. Once the glue has dried, unfold the two panels to inspect for any holes.  Make sure to seal up any gaps.

Cardboard Opaque Projector

Opaque projectors are the ancestor of the more modern overhead projector and essentially a camera obscura used backwards. The basic idea is instead of having a dark chamber where an image from outside can be projected, have a very bright chamber in a dimly lit room so the light reflected off of whatever is under the projector can be directed through a mirror and lens to be projected into the room. As opaque projectors use reflected light off a piece of paper verses light transmitted through a film as in overhead projectors they are inherently less efficient at the paper absorbs some of the light. They are however optically simpler and able to project the image of any flat surface they are set on.  So you can draw something or just pick it up place it under the projector and it will work, no transparencies necessary. We've come up with this bare bones cardboard box model so you can experiment with what is now a somewhat rare and fairly specialized piece of equipment. Mater