The FabNet Invention System
The FabNet Invention System consists of a series of interlocking FabNet Invention Kits that can be recombined in countless ways to allow users to create their own innovations or inventions. The FabNet Invention System sequence currently includes the following elements:
- Magnetic Pole Detector
- Continuity Tester
- Electrical Meter
Motors and Actuators
- Electromechanical Solenoid
- Battery Alternator
- Linear Motor
- Ratchet (linear to rotary conversion)
- Mechanical Linkages
- Linear Generator
- Rotary Motor
- Telegraph Switch
- Cross-over Switch
- Electromechanical Relay
- Telegraph Sounder
- Dynamic Speaker
- Dynamic Microphone
- Amplifier (Op Amp)
- Amplifier (Power Transistor)
- Waveform Generator
- Arduino Microcontroller with HyperDuino H-Bridge Motor Controller
- HyperDuino for Chrome app (Arduino Hypermedia Software)
- Cables and Connectors
- FabNet Assembly System
The FabNet Invention System is released in two forms: (1) in open source format for non-commercial use with attribution and (2) in pre-packaged formats with all the components of FabNet Invention Kit collected in one place for the convenience of families or schools that do not have the time or technical capacity to fabricate their own FabNet Invention Kit elements.
The open-source versions of the FabNet Invention Kits are released on the Make to Learn web site (www.maketolearn.org). Versions of FabNet Invention Kits that are based on reconstruction of historic inventions such as the telephone and the telegraph are also hosted on the Smithsonian X 3D web site (www.si.edu).
Illustrative Example: An Animated Diorama
An example of a mechanism created with the FabNet Invention System is depicted in Figure 1. A linear motor fabricated using the FabNet Linear Motor Invention Kit is connected to a 3D-printed linkage.The linear motor and linkage rock the reindeer forward, causing a LEGO arm to swing around, striking a jingle bell. The reindeer and a tree in the background were designed in Maker Studio and fabricated using a Silhouette Portrait digital die cutter. The components are mounted on a laser-cut base.
A subsequent version of this animated diorama used the HyperDuino hardware & software and an Arduino microcontroller to synchronize the movement of the reindeer with timing marks in a YouTube video (https://youtu.be/SxV_h2MzH3Q). This example illustrates the way in which FabNet Invention Kits can be combined with other elements to create an original application or design.
Combining FabNet Invention Kits
The FabNet Invention System was developed with specific pedagogical goals. One goal is to allow K-12 students gain foundational knowledge through successful reconstruction of 19th century inventions. Once this foundational expertise is acquired, the system supports connections to modern-day applications.
Relays, for example, are often used to allow computers to control physical objects such as solenoid actuators and electrical motors. This topic is the subject of the Midland Motor Controls course.
There is nothing to see in a solid-state relay. It is just a solid block of material. Cutting it half does not reveal anything about its function or mode of operation. Therefore the underlying principles remain opaque and somewhat abstract for many students. Once a mechanical telegraph relay has been reconstructed and understood, it can be used to control the reconstructed linear motor. Because the functions of the electromechanical relays are more visible and can be observed, they allow students to develop an understanding of purpose and applications of modern-day relays.
This is illustrated in Figure 3. The microcontroller in the diagram only has an output of about 40 milliamps. This is insufficient to power the motor. The two relays depicted provide a solution. When the first relay is turned on, it activates a secondary circuit powered by a nine-volt battery that moves the armature of the motor in one direction. The first relay is then turned off, and a second relay is turned on that activates a circuit with a nine-volt battery whose polarity in the circuit is the reverse of the first battery. This moves the armature of the motor in the opposite direction.
Once the students understand the underlying principles of operation, the modern-day solid state equivalent can be introduced. The HyperDuino Motor Control Shield is designed for use with the FabNet Linear Motor Invention Kit and the Rotary Motor Invention Kit. It incorporates two H-bridges. This enables simultaneous control of two linear motors or four rotary motors. (The use of the term “H-bridge” to describe this type of circuit is derived from the shape of its typical graphical representation.) This instructional approach to introduction of this topic proved to be useful both for community college students and for middle- and high school students.
Extending the FabNet Invention System
As students learn about the different functions of reconstructed inventions, they have the opportunity develop an understanding of basic building blocks and the manner in which they can be recombined in many different ways. Our goal goes beyond provision of a basic set of FabNet Invention Kits that connect foundational inventions first developed in the 19th century to their modern-day applications; we also hope that exploration of these building blocks will inspire other teachers and students to develop their own extensions of the FabNet Invention System.
The basic set of FabNet Invention Kits, developed over a period of five years, provides students with a set of foundational tools that allow them to begin developing their own creations. However, there are many other foundational inventions and extensions that could be developed.
The FabNet coalition has a planned list of inventions that we anticipate will take several years to develop and release as FabNet Invention Kits. There are many more that others could develop. We envision that such development will most likely occur in response to specific needs identified by users. The mission of the FabNet coalition will be fulfilled when a robust community exists that supports and shares this type innovation,