Tactile graphs for a blind math student

The last few weeks, I have been working with a colleague producing raised graphs for a blind student who is taking a math class, but who has never really been taught the details of plotting.  It has been a very interesting experience learning a few details of how to design such graphs.  So far the student has made excellent progress in understanding, since nobody has ever even tried to show this to him  before! The 3D printer makes for an excellent tool, since it allows relatively quick  of graphs tailored for the class, the student, and the situation. After the first few, it has taken 15-20 minutes to prepare a graph for printing, and around one hour to print.

Below the figures of the tactile plots, I have given the workflow and the details of what has worked and what has not. I'd be very interested to hear from anyone who tries this out!

x^2 compared to x^4

ln(x) compared to exp(x)

The top graph is a  polynomial and the bottom is 1/x

x^3 versus x^(1/3) and sin(x) on two different domains

Technical details: In all cases, my general workflow was as follows:

• Step 1. Produce  two JPG figures using Matlab: (1) A grid. I used linewidth 4, with a larger size dot at the origin for reference.  (2) A graph of a function. (Note that you could use any method at all of coming up with a graph and follow the next set of steps still.) 
• Step 2. Convert figures to vector graphics SVG format using the free program Inkscape. 

Step 1 Grid



Step 1 Graph of a function

• Step 3. Open the free program Tinkercad, and add a box approximately 80x80x1 mm.

Step 3 Box in Tinkercad around 80x80x1mm

• Step 4.  Import the SVG file of the grid into Tinkercad. It needs to fit on the box from the previous step. (In my case this involved shrinking to 8%.) It should be 2-3mm high so that it can be distinguished from the background.

Step 4 add the grid to Tinkercad

• Step 5. Import the SVG file of the function into Tinkercad. It needs to be exactly the same size as the grid so it matches up, so if you shrink one to 8%, make sure to shrink the other to 8%. However, for the graph, make it 1-1.5mm taller than the grid. At first I made it too tall, and the graph and the grid couldn't be felt simultaneously. 1mm sound small, but think about the thickness of Braille, and it won't seem so mind boggling.

Step 5 Add the graph to Tinkercad but make it 1-1.5mm taller than the grid. 

• Step 6.  Download for printing, using  file type STL.



Step 6 download for 3D printing

• Step 7. Print on printer, with a raft but without support. It takes around 1 hour to print each.