This tactile symbol designer is inspired by the Project Core Universal Core tactile symbols but attempts to go further to provide flexibility, extensibility, and simplicity.

Graphic Alternative

We wondered whether there was a way to provide relevant graphics, make them easy to print, and sturdy at the same time.  It turns out that Project Core focuses primarily on a set of visual graphics that it makes freely available to individuals who would like to use their system.

The visual PCS symbol that Project Core uses to represent “Get” looks like this:

The question we had was whether this image could be turned into a raised graphic that could be tactilely explored and interpreted by someone who’s blind or visually impaired.

Our approach is to covert the graphic into an SVG file and then create 3D version that can be added to a tactile symbol:

We’ve taken the 36 Universal Core graphics and used them as a basis for our symbols.

An added advantage to taking this approach is that it makes it easy to extend the current set of 36 symbols to cover new concepts.  All you need is a representative image in SVG format.  Need a symbol that represents the concept “butterfly”?  You just need to find an SVG image of a butterfly:

If you can’t find the right SVG file but you have a graphic in a different format that you like, there’s a simple way to convert it.

Using the Symbol Designer

First Things, First

You’ll need to do a few things before you can begin using the symbol designer:

• Go to Printables and download the zip.txt file you find there.  Remove the “.txt” part of the file name. 

Note, you may have to change your settings to see the “.txt” part of the file name.  If you download the file and the name looks like “3D_Symbols_Remix.zip”.  Change to the “View” tab and check the box named “File name extensions”:

Now the file name will look like “3D_Symbols_Remix.zip.txt”.  Rename the file to remove the .txt part of the filename.  You’ll be asked if you’re sure you want to change the file name.  Click on “Yes”.   Now you can right click on the file and expand it.

• Expand the contents of the ZIP file in a convenient location.  You’ll see two folders and two files:

• Next, you need to download and install the free program, OpenSCAD.  Instructions can be found here.  [The instructions reference a different designer, “keyguard.scad”.  Instead, you’ll be loading the file “3D Symbols Remix.scad”, that you just downloaded from Printables, into OpenSCAD.]

The Layout of the Symbol Designer

The designer has three sections.  On the left is a display that provides a view of your symbol as it is currently defined.  On the right is the Customizer pane.  You’ll do all your work here.  Below the display region is the Console window.  For the most part you can ignore this window until you’re ready to print your symbol design.

 

The Customizer Pane

The Customizer Pane has two regions.  The upper region is where you access and create presets.  Below that is a set of expanding sections where you specify the values of several options for your symbol:

 

Click on the arrowhead to the left of each section to expand it.  You’ll start at the top section and proceed downward when defining your own symbol.  [Alternatively, you can start with a preset that has already been created for a symbol very much like the the ones defined by Project Core.  More on that below.]

Symbol Shape

The Symbol Shape section provides you with several options to control the size and shape of your symbol:

 

 

Begin by choosing a shape for your symbol:

You can choose any shape you want for your word, but if you’d like to conform to the Project Core standard, that information is included between asterisks for each shape.

Next choose the size of your symbol by setting the width and depth in millimeters.

A chamfer can be added to the top and bottom edges of the symbol to reduce sharpness of the symbol.

Finally, you can choose the color in which your symbol should be displayed:

As you’d expect from the name, the color you choose is for display purposes only.  You still need to choose the color of the filament you load in your printer.  This option will help you better visualize what the symbol will look like.

Edge features

Next you’ll choose the texture and other features of the sides of your symbol:

 

Again, if you want to conform to the Project Core standard, the Project Core word classes are indicated between asterisks – but you’re free to associate any edge texture with any shape (click on the image to zoom in).

Note: if you look closely at the Project Core word class description above, you’ll see that they specify two edge textures that aren’t represented here – “horizontal wavy grooves” for nouns and “single string of pearls” for interjections.  Project Core doesn’t use either of these textures for their core vocabulary, so it’s difficult to imagine what they should look like.  There’s probably no rush in supporting “interjections” but we anticipate that you’ll want to add “nouns” to your vocabulary.  Putting “wavy grooves” on a round shape is difficult to achieve with OpenSCAD so instead we decided to punt and go with vertical grooves instead.

The last three options are described below if you want to create a graphic stamp or graphic cookie cutter.

Braille can only be printed on a “smooth” edge texture.

Symbol Graphic

The Graphic Info section contains options for which graphic should be placed on the face of your symbol, where to find the SVG file, and how it should be sized an moved around.

Choosing a graphic

 

The first thing you need to do is decide whether you’ll be using a graphic derived from the Project Core Universal Core Vocabulary.  If you do, you can then select the graphic, by name from the “Project Core graphic name” pull-down list. 

Alternatively, you can choose your own graphic by typing the name of that graphic (without the .svg part) in the “my graphic filename” box.  You must have already put the associated svg file in the My Graphics folder that was part of the zip file you downloaded from Thingiverse.  The name of the file must match what you type into the “my graphic name” box followed by “.svg”.

Specifying the graphic’s aspect ratio

The designer doesn’t know much about the graphic but it will try to size it to the approximate size of the symbol.  One thing it doesn’t know is the graphic’s aspect ratio.  That’s the relationship between the height and width of the graphic.  Is it wider than it is tall or taller than it is wide?  The designer needs some help from you to get that right.   To determine the aspect ratio of your graphic, hold your mouse pointer over the graphic file.  A tool-tip will appear that shows the pixel size of the graphic:

Above, the “butterfly image.png” file is 310 pixels wide and 179 pixels high. You calculate the aspect ratio for the file by dividing the height by the width.  (Because of limitations in OpenSCAD you need to multiply that number by 100.) 

(179 / 310) * 100 = 57.7

To get the image to look right, enter 58 as the “aspect ratio”.  Unfortunately, Windows doesn’t know much about SVG files so if you hold your mouse cursor over an SVG file you won’t get any useful information about the aspect ratio of the graphic in SVG form.  Instead you’ll need to experiment with different aspect ratio values until the graphic looks right to you.

Graphic placement

Next you’ll work to get the graphic in the best place on your symbol.  Experiment with different values of graphic size, and horizontal and vertical location until the graphic is as large as possible but still fits on the face of the symbol.  Nothing else is going to go on the face of the symbol so you can make the symbol as large as possible.  [One complication may come along if you put a hole through the symbol from front to back.  More on that topic below.]

This might be a good time for you to save your work by creating a new “Preset”.  You can read more about working with presets below.

Graphic Height

You can set the amount that the graphic rises up off the surface of the symbol from 1 mm to 5 mm.  The value you choose will depend on what value you think will be most effective with the symbol users.

Graphic Display Color

As the name implies, the color you choose for the graphic is just for display purposes and to help you visualize your symbol.  The graphic will only be a different color if you can swap colors during the 3D printing process.  We recommend that you use contrasting colors for the symbol body and the graphic (if you can) to aid individuals with visual impairments as much as possible.

The “flip graphic” option is described below in the event that you want to create a graphic stamp or graphic cookie cutter.

Symbol Text

You have control over whether the word associated with the symbol should be engraved on the underside of the symbol and whether the word should be represented in braille on the front, back, or edge of the symbol:

 

Enter the text that should be included in engraved form or as braille in the “symbol text” box.

Engraved Text

When text is first placed on the underside of the symbol, the center of the text is placed in the center of the symbol.  You may be want to slide the text up or down on the symbol and have more room to fit the entire word or make it larger in height.

Finally  you can choose between regular or bold text.  You may find that bold text prints better on your printer than regular text.

The “flip text” option is described below in the event that you want to create a graphic stamp or graphic cookie cutter.

Braille

Braille for the symbol text can be placed on the front, back, or edge of the symbol.  The symbol designer displays a subset of Braille ASCII (or more formally The North American Braille ASCII Code, also known as SimBraille).  The designer only supports lower and uppercase letters entered into the symbol text box.  It converts all uppercase letters to their lowercase equivalent.

Once included in the design, you can move the braille around, horizontally and vertically, on the surface of the symbol.  You can also increase or decrease the size of the braille.  A value of 10 on the “braille size multiplier” slider equates to standard size braille.  You may choose to increase the size of the braille to make it easier for new braille users to read:

You can also place braille on the edge of the symbol, but you must first set the edge texture to “smooth”:

The braille is placed on each side of the symbol.

On occasion, the braille may be affected by a hole inserted from side to side at the top or bottom of the symbol:

You can shift the location of the braille horizontally to see if you can avoid the hole:

Note that braille that is printed on a vertical surface (i.e., an edge) is much more usable than the same braille printed on a horizontal surface (i.e., front or back).  This is just a limitation of the 3D-printing process.

If you place braille on the back of the symbol, you need to take an additional step in creating your symbol.  A 3D printer has difficulty printing raised elements on the underside of a flat object. 

The solution is to print the symbol in two pieces and glue the two pieces together. 

Open the “Special Actions and Settings” section and choose “top half of symbol” from the “generate” pull-down:

The designer will reduce your symbol to just the top half:

You’ll notice a slot cut in the bottom of the symbol half.  More on that in a moment. 

Render and export this object.  You can print it before moving on or you can wait and print the bottom half at the same time.  Repeat the same process with the “bottom half of the symbol”:

There’s a similar slot cut in the bottom of this half.  Render and export this half.

Finally, choose “splint” from the “render” pull-down.  Here’s what you see:

It doesn’t look like much but it fits into the slot on either half of your symbol and helps you to align the two halves when you glue them together.

Because the symbol is split exactly in the middle, if you use a different color to print the graphic, and if you print both halves at the same time,  the braille will also be printed in that alternate color:

Here’s a video that shows how the halves are assembled into a complete symbol:

Keep in mind that Braille will always print best on a vertical surface.  So while it’s “possible” to put Braille on the front or back of the symbol, it will be easier to read and more tactilely “inviting” if printed on the side of the symbol. 

Hole for String

You can string together several 3D symbols to provide easier access to the individual who will be using them to communicate.  The symbol designer gives you several options for placement and size of the string hole – including, no hole at all.

The following images show holes from side to side of the symbol.  The top images show the hole going through the top of the symbol and the bottom images show the hole going through the bottom of the symbol:

You may find that it’s easier for the user to explore and understand the graphic if the hole goes though the bottom of the graphic orients the symbol better.

Finally, you can put a hole through the symbol from front to back – at the top or bottom of the symbol:

You may find that a front-to-back hole lets you put more symbols on the string than a side-to-side orientation.  The problem with a front-to-back orientation is that it might interfere with the graphic and you’ll need to keep the hole small.

Using the Ready-Made Presets and Creating Your Own

At the top of the Customizer pane, there are some controls that allow you to save your settings for a symbol and recall them later.  We’ve done that already for the Project Core Universal Core Vocabulary symbols.

On the left is a pull-down list of saved, presets.  Each preset stores all the option values at the time you save the preset.  A special preset called “design default values” represents the values of all options when you first start the program.   Click on the pull-down arrow and you’ll see the presets that we’ve already created for you:

The “PC” in some names stands for “Project Core”.  We’ve also created an entirely new symbol definition called “my – butterfly” as an example for how to extend the symbol set for your needs.

If you make a change to a saved preset by changing the value of an option, an asterisk will appear to the left of the pull-down list.  You can save the change by clicking the “save preset” button.  To create a new preset altogether, click the “+” button and give the preset a name.  To delete a preset, choose it from the pull-down list and then click the “-” button.

Presets are saved in the “3D Symbols Remix.json” file.  If you do a lot of work to create your own symbol definitions, you might want to back up this file along with the “My Graphics” folder.

Putting the Pieces Together

If video works better for you, this recording demonstrates the way that the various configuration options work together:

Stamps and Cutters

For fun you can use this designer to create a “graphic stamp” or “graphic cookie cutter”.  The key feature of a stamp or cutter is that it uses a “negative” image.  That means that the text and/or graphic on a stamp/cutter, needs to be flipped horizontally compared to the “positive”, tactile image.

As a result, you’ll see an option to “flip graphic” in the Graphic Info section:

flip graphic = no	flip graphic = yes

and you’ll see an option to “flip text” in the Text Info section:

flip text = no	flip text = yes

 

You can raise the edge of any symbol shape by setting “raised edge” to “yes” in the “Edge Info” section:

raised edge = no	raised edge = yes

The raised edge starts at 6 mm tall and 1 mm thick but you have complete control over the height and thickness of the edge.

Some stamps will benefit by adding a raised edge along with the raised text that has been flipped:

Note that you are free to set the edge pattern on any symbol shape to a pattern that will give you a good grip when pressing the stamp/cutter downward.  Horizontal grooves (shown above) or cross-hatches will probably serve you best.   You also have full control over the size and thickness of the stamp/cutter so that it fits best in your hand or the hands of your students.

Now here’s a video showing you how you can use these to pump up the fun!

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Do you have any ideas about how to improve this design?  Provide some information below: