Nuts and Volts - September 2014

office buildings to diffuse fluorescent lights. They’re readily available at stores like Home Depot in 2’ x 4’ panels (which is why my display is 2’ x 3’).

If you want a larger display, you’ll need to use either more than one diffuser or a frosted piece of plastic. Craft stores sell spray paints that will frost most anything. Files for the eye and mouth segments are available at the article link to use as a reference pattern.

Drawing the Face

Referring to Figure 5, start the face by drawing an ellipse on the MDF backing. How do you do this on a large surface area? Math! In order to draw a circle, you’d need a pencil, a piece of string, and an anchor. Put the anchor where you want the center or focus of the circle, tie the string between the anchor and the pencil, then trace the circle by stretching the string as far as it will go. When the pencil goes around a full 360 degrees, you’ll have a perfect circle. So, how do you do this with an ellipse?

If you remember your math (if you don’t, check Wikipedia), an ellipse has two focal points where a circle only has one. You’ll need two anchors to draw an ellipse; food cans work fine. Use the string to tie a loop and place it loosely around both anchors. If you stretch the string with the pencil and go around 360 degrees, you’ll have a perfect ellipse. Move the anchors to change the shape of the ellipse, and increase the length of the string to increase the size.

If you want a more natural face, sketch the opening for the eyes at about the center of your display. Make the opening of the eyes large so you have enough room to incorporate all of the segments for the eye animations. The mouth will be centered between the eyes and edge of your display. Again, make the mouth large enough to be open with an “ah” shape. You can also download a template that I used to make the face from the article link or pumpkinfx.com. Print it out, then trace the design onto the MDF using carbon tracing paper.

Building the Face Front

Use a drill to make pilot holes in the eyes and mouth on the MDF panel, then use a jigsaw to cut out the shape of your face. Use sandpaper to smooth out any rough spots. Cut out the shape for the diffuser next. The outline of the diffuser should match the MDF panel you just cut, and you can use this panel as a template. Clamp the diffuser and MDF panel together while you make the cuts. Go slowly in order to prevent chipping on the diffuser. Finish the diffuser by painting on the smooth side with opaque glass paint which is available at a craft store. You may need more than one coat as painting smooth surfaces is a bit of a challenge.

Building the Light Box

For my light box, I’m using a Sterilite 67 quart underbed box (UPC 073149189585). This works well for a small display because all of the electronics are contained in one box. For a bigger display, you can split the light box into three separate units. I removed the wheels on my plastic box and painted the outside with black spray paint.

The segments for the animated display need to be distinct from each other. This means that the light from one segment shouldn’t bleed into another segment. In order to separate the lights, we’ll need to use two of the most magical items used for crafting.

The first is cardboard. It’s cheap, sturdy, lightweight, readily available, easy to cut, forgiving if you make a mistake, and accepts paint extremely well. The only