Emily Hancock
Jacob Layne
Chris Loftis
Antonio More'
Jacob Stubbs
Abstract
This project is the development of an activity board for multiple children with various disabilities. There are seven children ages ranging from ages 3-13 to accommodate. The main need for these children is vestibular input, which tells the child that something is moving by the noise and the mechanical feel under their hands; vestibular sensation is one of the strongest sensations and is greatly beneficial in learning. The various activities will provide “cause and effect” feedback to the children while they play and help them learn at the same time.
Introduction
The activity board will allow the children to play with various activities that provides them a vestibular input as feedback. One of the seven children that we are designing the activity board for is Jon Alex. Jon Alex has a developmental delay, which means that the feedback between his nerves and brain are interrupted and he lacks centralized vision. Jon Alex has trouble grasping things in his hands, yet his brain still needs to touch and feel things to recieve sensory input. The activities on the board provide audible and visual feedback so that Jon Alex and the other children can learn that a certain action yields a specific result.
Design Specifications
At its core, the design project involves the integration of an activity board (made up of six different stations divided onto two three-station boards) with an external vestibular input (designed by group #2) designed with an estimated system lifespan of eight years. Each side of the board will be approximately 4’ wide by 2’ tall, and will be able to slide up and down along two lockable 5’ tall tracks. Four lockable castor wheels per leg will make up each leg base, allowing the board to be rolled for transport and storage, but safely locked in place during use. A 2’ by 2’ vibration pad (again, designed by Group #2) capable of supporting 200+ lbs will be stored between the two activity boards, and will slide "down and out" for use. A built in trickle charger will be utilized, allowing school staff to charge the board overnight at a low current draw the day before use.
Each side of the activity board will be made up of three different activities each taking up about 16" of space. Side 1 will incorporate three stations: an “ABC” style puzzle with movable (recessed) letters, a simple peg board, and a maze puzzle incorporating an electric sound output as the user moves the peg across each detent. Side 2 consists of an additional three stations: station 1 incorporates a light switch connected to a series of (non-blinking) lights as well as a key switch connected to an audio feedback, and a door handle attached to a ratcheting device for sensory output. Station 2 features a “rope pull” wheel connected to another ratcheting device for a second sensory output, and Station 3 is a driving wheel connected to an audio track of various “driving sounds”.
Side 1
Side 2
Design Concepts
Design Concept 1
- Overall wooden construction.
- Three permanently fixed activities per side (six total).
- Both three-station boards move up and down independently.
- Each three-station board is attached to a simple up/down manually adjustable sliding track to adjust board height.
Overall view of the activity board.
A side view of the board showing independent motion for both individual activity boards.
Design Concept 2
- Overall metal construction (likely aluminum).
- Three removable activities per side (six total).
- Both three-station boards move up and down independently.
- Each three-station board is adjusted up and down using a “elevator-style” single electric motor attached to a spool which winds up and down controlling board height along the track.
Sample sketch of the front of one side of the activity board; each activity is slid on and off the four pegs shown on the board.
Side view of the activity board; note the detachable activity slot.
Sample of a "removable station"; the activity is slid on and off the pegs using the four holes.
Design Concept 3
- Overall wood OR metal construction (TBD).
- Three removable activities per side (six total).
- Both three-station boards move up and down independently.
- Each three-station board is adjusted up and down using a single shaft connected to two identical pulleys. The “right-most” pulley is controlled by a single electric motor whose output controls up and down board position.
Diagram representing the pulley-motor mechanism.
Concept 3 - Front View
Concept 3 - Side View
Concept 3 - Top View
Concept Evaluation
The final board will probably be a metal frame with a wooden board face and incorporate the DC motors and pulley systems. We would like to stay away from manually lifting the board due to its weight; therefore, we will probably avoid the track system with screw-in locks. We will likely avoid the removable puzzles design due to time and money constraints; it is a nice idea, but it would certainly be a secondary goal.
Our current final design:
- Metal frame, metal legs
- Locking casters
- Wooden face
Specifications:
- 4’X2’ board
- 6'6" at its highest point
- Range of vertical motion of the bottom of the board: 2’ to 4’
Final Design Overview
With the design analysis feedback of Dr. Canfield, our overall framework has changed quite dramatically from the original design phase, but all six activity stations remain basically unchanged. Due to the high cost of aluminum, the frame is characterized by a single T-slotted tracked post rather than the original two smaller posts, which were used to support the board framework.
One advantage of using the single tracked post is answering the question of individual board height adjustment without the use of electric motors – instead, each board is connected to the T-slotted aluminum post by a Faztek© “linear motion guide bearing” which allows for independent manual adjustment up or down. Additionally, the newly designed base is an aluminum “H” frame, which displaces weight over a greater area and allows for an improved safety factor in regards to tipping (see engineering analysis #1 below).
The six activity stations remain unchanged from their previously stated designs. Side 1 will incorporate the three following stations: a wooden “ABC” style puzzle with movable letters, a simple peg board, and a “barnyard animal” maze puzzle incorporating an electric sound output as the user moves the peg across each position. Side 2 consists of the additional three stations: station 4 incorporates a light switch connected to a series of LED’s and a door handle for sensory output. Station 5 features a “rope pull” wheel connected to three pulleys for a sensory and visual output, and Station 6 is a driving wheel connected to an audio track of different driving sounds.
Analysis
Engineering analysis 1
Tipping moment analysis, Page 1
Tipping moment analysis, Page 2
Engineering analysis 2
Metal selection analysis
Engineering analysis 3
Analysis #1
With our original design, the overall framework was composed of rectangular metal tubing and angled aluminum. After discussing the inherent plusses and minuses of this approach with Dr. Canfield, the design team chose to select “80/20” as the parts supplier and researched the total price. However, 80/20 not only added several unnecessary components to the framework, but the materials price ballooned to $990, almost double our entire project budget!
After more analysis, the design team focused their efforts on "FAZTEK" as the primary aluminum parts supplier, and analyzed the use of either “light” or “regular” aluminum for the board framework. Again, cost was a driving factor in our analysis, and with the help of the great customer support folks at FAZTEK, our team chose to redesign the entire board totally using FAZTEK “T-slotted” aluminum parts. As such, overall framework price came down, and the issue of interchangeability between the FAZTEK parts with the stock rectangular metal tubing was negated.
Analysis #2
Another area of cost-driven improvement involved the castor wheels. Our original cost estimate put the wheels at $25 a piece (multiplied by four wheels) plus the individual screws and mounting brackets for each wheel. Again, after conferring with Mrs. Lindsay Smith, we opted to use a stock Lowe's wheel mounted on a fabricated mounting plate which interfaces nicely with the FAZTEK framework.
Overall framework cost savings add up to a little over $131, not including the choice to use FAZTEK parts over the 80/20 parts, which essentially saved an additional $500!
Bill of Materials
Materials all ready ordered:
FAZTEK Reciept, Page1
FAZTEK Reciept, Page2
Our group is in the unique spot of having all ready ordered many of the required parts. The receipt shown above includes the aluminum structural framework, which totaled $350. An additional $100 was spent at Lowe's on plywood, pine sheeting, lockable castor wheels, and an acrylic sheet for the ABC puzzle. The final few items required are enumerated below:
Materials remaining to order:
Estimated cost of completed project:
$600.00
Part Drawings
AutoCAD Screenshot - Overall View, Front Shot
AutoCAD Screenshot - Board Interface Detail
AutoCAD Screenshot - Overall View, Side Shot
AutoCAD Screenshot - Top View
Work photos / "Assembly Instructions"
Assembled framework. (11 Nov 2010)
Frame base detail. (11 Nov 2010)
Wheel detail. (11 Nov 2010)
Slider detail. (11 Nov 2010)
Convening to begin work at 6:40 AM on a Saturday! (20 Nov 2010)
Assembling the activity board boxes. (20 Nov 2010)
Testing the stations. (20 Nov 2010)
Polishing side #2. (23 Nov 2010)
Painting station boxes. (04 Dec 2010)
Preparing ABC puzzle letters. (04 Dec 2010)
Varnishing the wood. (04 Dec 2010)
Implemented Design
Finished board. (07 Dec 2010)
Testing side 1. (07 Dec 2010)
Side 2. (07 Dec 2010)
Delivery Photos
Inspection by the masses! (11 Dec 2010)
Dr. Canfield approval #1. (11 Dec 2010)
Dr. Canfield approval #2. (11 Dec 2010)
Final product delivery. (11 Dec 2010))
Summary and Conclusions
After a host of both major and minor design changes throughout the build lifetime of the project, the final product is far different from our preliminary design vision! The final design incorporates advanced safety margins, improved functionality, and interchangeable activity stations which allow for future updates and improvements. In addition, lessons learned throughout the fabrication process allowed the design team to improve the long-term viability of several of the projects critical “wear and tear” components, thus allowing the activity board to be used for many years to come. Several hundred hours of design and assembly later, our finished project is ready for delivery, “on time and on target!”
