Cosmos in the Stacks earthquake demo

An Earthquake Demonstration Table or “Shake Table” is a piece of equipment used to showcase the impacts of earthquakes on small or large scales. These “tables” simulate the shaking motion of earthquakes to be able to study and learn from the vibrations and how they affect structures. Our team; (BiblioTech), wishes to solve a problem presented by our client, in order to produce a streamlined and engaging shake table to prompt and encourage interactiveness and learning within our community.

The background of the project is one of academic origin: the instructors of Engineering 205 Intro to Design have connected with the Cal Poly Humboldt Library Dean, Cyril Oberlander in order to give real-world engineering experience to the students of the Intro to Engineering Spring 2025 semester; and to serve the campus by improving the interactive learning experiences in the Cal Poly Humboldt Library. Our team, BiblioTech, consisting of team members Jack Barker, Gio Giacomini, and Micah Matias, seek to add on to the interactive learning experience by designing and fabricating a durable, functional “Earthquake Shake Table”.

The client, Dean Cyril Oberlander of the Cal Poly Humboldt Library, wishes to enrich the learning environment potential of the library with an interactive learning experience related to earthquakes and seismology. Tasked with this problem, team BiblioTech set on the path towards creating an interactive and representative device to educate and intrigue more students and tour-goers within the Cal Poly Humboldt library about the study of Earthquakes and Engineering alike.

Criterion	Constraint	Weight (0-10 high)
Cost	Less than $420	8
Noise	Less than 70 decibels	6
Maintenance	Essentially no maintenance required for at least 10 years	7
Ease of Use	Simple to understand and operate	5
Performance	Has to be able to run consistently	5
Safety	Minimal injuries in the process of making the product and using it	6
Aesthetics	Looks like a streamlined, aesthetically pleasing product	3
Interactiveness	Very interactive, allows enough space to build on top of using materials from drawer under table	5
Durability	Structural integrity lasts for at least 10 years	6
Realism	Must be able to be produced within given boundaries of budget and time	9

Prototyping allows the team to be able to test the concepts that were formulated in the many brainstorming sessions the team held. If portions of these prototypes are satisfactory in their test results, they are considered for the final design of the project. This also allows the team to have a model that can be scaled up in case those parts of the prototype are what both the team and the client are satisfied with.

Prototyping both desire, and functionality proved to be extremely beneficial towards the progress of our final design.

A few different ideas were implemented from the initial brainstorming sessions, such as the use of a lip design to stop the toys from falling in the spaces in between the walls and the shaking platform of the earthquake demo table.

The final product of the Earthquake Shake Table is currently undergoing construction. We are expecting the final product to be completed within the next two weeks, the final design of which will showcase the most balanced aspects and features of the prototypes while also showing the vast improvements and changes that will be necessary to create a safe, intractable, and durable Shake Table.

Description of costs for materials and parts of final design of Earthquake Shake Table. for materials and parts:

Materials/Components	Costs
Black Compression Springs	$17.99 x2
Sienson 24V DC Vibration Motor, 3800RPM	$36.99 x2
Wood (info will change later)	$0.00 (provided by the Forestry Woodshop and Engineering Makerspace)
Epoxy & Sealant	$54.99

Design cost is best quantified in terms of total hours spent working as well as total human hours calculated by multiplying workers by the amount of time they worked. The results are depicted in the following pie chart.

To operate the Earthquake Shake Table you must follow these instructions accordingly:

While Table is OFF: Placing toys and creating structures on shake plate is allowed Use the “Toys” cabinet to locate any desired toy or material to build structures with. Structures cannot exceed 2 feet in height or 1 foot in length or width, and must be less than 15 pounds in weight. To turn the Shake Table on: Plug the cord into the wall socket Press “I” on “X” controller to turn on horizontal shake axis Press “I” on “Y” controller to turn on vertical shake axis While Table is ON: Both shake axis controllers can be operated independently or together. No touching of parts, table or toys Table cannot be operated for longer than 60 seconds at a time To turn the Shake Table off: Clean up all toys and put them back into their respective bins. Press “O” on both controllers, and unplug cord from the wall socket.

Safety Considerations and Limitations:

1. Ages 8 and below must be supervised by an adult.
2. Placement of any other object besides toys from the toy bin is unacceptable.
3. No food or drinks near or on the Earthquake Shake Table.
4. No touching of parts, mechanisms, or shake table while the machine is in operation.
5. Placement and removal of toys during operation is strictly prohibited.
6. Each test on the Shake Table is limited to 60 seconds.
7. Structures are limited to 2 feet in height, 1 foot in width/length, and 15 lbs in weight.
8. Any damages to the machine must be reported to the front office of the Cal Poly Humboldt Library.

Short maintenance checks will be conducted by a member of BiblioTech, or by staff from the Cal Poly Humboldt Library when needed.

1. When the device is not being operated; the toys should be put away, the cords should be unplugged, and the remotes should be off. When the device is being operated, all safety considerations and limitations should be up to par.
   1. If not; complete actions that should be taken.
2. Cords, motors, and springs should be free of damage or wear.
   1. If not; contact a member from BiblioTech to resolve the problem.
3. Shake table should function as intended, (ie. no excessive rattling, the X and Y axis should act independently of one another, remotes and motors function properly, springs are stiff but allow for displacement of the shake plate, etc.)
   1. If not; contact a member from BiblioTech to resolve the problem.

Time Cost	Financial Cost (Only in Case of Critical Failure or Compromise)
Cleaning/Gathering Toys: <5 min	Industrial Compression Springs: $36.99 x2
Reviewing Function: <5 min	Vibration Motors: $17.99 x2
Potentially Contacting Engineering Instructors/Department in Case of Critical Failure or Compromise for Advisory or Repair: about 1 hour or less of communication/repair (variable and not including waiting/transport times)	Epoxy or other sealant: around $43.72
Total Minutes: <10 min	Total Dollars: $153.68
Total Minutes in Case of Critical Failure or Compromise): <70 min (variable and excluding wait/transport)	Total Dollars in Case of Critical Failure or Compromise: $68.73 or less depending on component

The results that were obtained show that the past prototypes were successful in showcasing both the functionality and intended design specified by the client and as defined by the criteria. Each prototype gave insight into certain criteria, such as how low costs usually resulted in lack of durability, or how aesthetics do not directly correlate with performance. These results aided in the progression of the project, and explained many of the ways in which the final product could improve.

Table 5-3 Testing Results from Prototypes

#	Prototype	Criteria Met	Criteria Not Met		Final Score	Figure
1	Testing function (rubber bands)	Cost Interactiveness Ease of Use Realism	Noise Aesthetics Durability Performance Safety Maintenance		4/10	5-2
2	Testing Desire (cardboard)	Cost Interactiveness Ease of Use Realism Safety Durability Aesthetics	Performance Maintenance Noise		7/10	5-4
3	Testing function (springs)	Cost Interactiveness Ease of Use Realism Performance Durability	Noise Aesthetics Safety Maintenance		6/10	N/A

A few results from the prototypes show that noise and maintenance were prominent criteria that were not met. This is most likely due to the cheap materials, and the lack of soundproofing within the structure. In comparison, many of the criteria met such as cost, and realism; also stem from the cheapness of the materials and the lack of safety precautions and aesthetics. Using this information, some improvements that could be made to the final product include; using cheap but durable materials to reduce maintenance, adding soundproofing to reduce noise production, and increasing performance with motors.

Introduce team and semester in the following format:

• GioGiacomini
• JackBarker
• MicahMatias