Tactile Graphics Team 3


TACTILE GRAPHICS PROJECT



[Alan Barney]
[Daming Zhu][Khoa Tran]
[Mike Stewart]

Abstract

It has been shown that a major difficulty for blind children is making the mental connection between a 2-D map and its 3-D counterpart (e.g. circle and sphere). Drawings present abstract information that may not be easily grasp by a blind or nearly blind child. This set of tactile learning aids were designed to help blind children make the connection between a flat map, and its relationship to a three dimensional globe.

Design Process


There are two designs for our project. The 2D map was designed by taking advantage of Pro/ENGINEER's surface manipulation capabilities. The 'tweak' and 'free form' commands were employed in the creation of the raised relief features of the map. The braille was created by first creating a master braille cell, composed of extruded cylinders rounded at the top. This master cell was then repeatedly copied and modified to create all the labeling required. The final design was acheived by assembling all the separate components together (continents, braille, equator).

Construction of the map was completed through two separate processes. The world map top piece was built using stereolithography technology. This was necessary to achieve the surface contouring of the relief map. The lighted display base was created from half-inch plexiglass cut to size and milled using a CNC milling machine.

The'continent lighting' feature is incorporated mainly as a tool to encourage interaction in the classroom between sighted and blind students. The design for this part of the project consists of a seven-LED circuit powered by a DC source. The LED's are positioned to individually highlight each continent on the map.

Since a 3D globe had been previously manufactured, our task was to modify the existing model. All of the conponents were drawn using Pro/ENGINEER software. First, all the surface manipulations previously on the globe were removed for North America, South America, Asia, Europe and Africa. This was done to resolve regeneration conflicts in Pro/ENGINEER. Next, the actual splines of the continent shapes were modified to be more geographically accurate. Also, the size of the globe was enlargered to better show the spacing between the continents.

Once the continent splines were shaped correctly, the surface cuts of these continents were redone. Next, a hollow sphere was created for the continents to be mounted on. Using the Assembly feature on Pro/ENGINEER, all of the continents were placed on the sphere. Three rings were then added to the globe, each representing the Equator, Tropic of Cancer, and Tropic of Capricorn. Finally, Pro/ENGINEER surface manipulation techniques were used to re-apply mountains to the continents that they were previously removed from.

Because of the complexity to create three dimensional braille labels on a curved surface in Pro/ENGINEER, the braille labels were not drawn onto the globe. To compensate for this, braille labels were manufactured as separate blocks with braille on them. These blocks were then used as the mold to create thermoform braille labels. Once created, these labels were attached to the globe using an adhesive.

All drawing modifications were made using Pro/Engineer software. A 3D-SYSTEMS SLA-250/40 Stereolithography machine was used for the construction of both the 2D relief map and 3D globe. The base of the 2D relief map was constructed using Plexiglas and a Matsuura MC-510V CNC machine.



Final Design


2-D Relief Map



ACTUAL RELIEF MAP


3-D Globe


Links TO More Information


National Federation For The Blind


American Federation For The Blind


American Council For The Blind