Intro: Pointilist Edge Lit Card With Auto On/Off Switch
Several months back, I wanted to send a thank you card to the folks at instructables HQ for letting me hang out with them during Maker Faire. I knew a store bought card just wouldn't do, so my mind immediately turned to the edge lit cards created by the nice people at evilmadscientist.com.
These cards are simple and fun to make, and I wanted to add my own touch to them--a pointillist drawing of my avatar and a pull switch arranged so the card is off when it's closed and turns on when it opens.
Step 1: Gather Materials
The card is made from:
- Heavy cardstock
- 2 LED's of whatever color you would like
- 3v Button Cell (CR2032 or similar)
- A small sheet of clear acrylic
- Tape (I used electrical tape to go with my black cardstock and some clear tape)
- A tiny bit of tin foil
- Hot glue
- Electrical tape
- A sturdy, very sharp awl
- Hot glue gun
Step 2: The Image
My avatar is an upside down picture of the moon I took by carefully holding my camera up to the lens of my telescope. I thought it would make an appropriate picture for this edge lit card.
I wanted the bright areas of the moon to light up, and I didn't want to get confused while I was working (trying to remember to mark the light spots and ignore the dark would be hard for me), so I did a bit of computer work to alter the image for use as a template. I opened my profile image in photoshop, made it black and white, then used a filter to make it negative. Then I played with a variety of filters until I'd inverted the color and simplified it a bit (it was the charcoal filter that finally did the job).
Depending on what sort of image you would like to etch into the plastic, this technique will probably work well. The final thing to do is print the image at whatever size you like, and cut it out.
Step 3: Etching the Acrylic
Remove the protective covers from the acrylic sheet, and tape the image to the back side.
On a clean, sturdy surface, press the awl into the acrylic, to make a dot. Use heavy pressure and many dots in dark areas, and light pressure with few dots in light areas. When light is shone through the edge, it will create the opposite effect, the areas with lots of heavy dots will be bright, the others, dark.
I started this being very careful where I placed each dot. By the end I was moving very fast and still producing great results. I gripped the shaft of the awl in my left hand and hit the handle with my right. The nice thing about this pointillist approach is that you can afford to make several mistakes, as long as the dots average out to make a recognizable picture!
Finally, scratch a message into the acrylic. I used the tip of the awl for this, but if I had it to do over I believe I would use a fine tipped dremel at very high speed. Scratching with an awl doesn't produce the best results, I suspect a rotary tool would have allowed my handwriting to look more natural.
Step 4: Build the Card
Cut three pieces from cardstock: one large piece to be the card itself, one piece half that size to use as the frame for the acrylic, and one small strip which will act as the switch.
The large piece is simply folded over and set aside for now.
Cut the middle out of the frame so that the picture and message on the acrylic shows through, and leaves room for the electronics at the bottom. Hot glue the acrylic to the frame.
Hot glue the LEDs to the bottom of the frame and then use epoxy to make sure they're attached securely. Make sure the positive and negative leads of the LEDs are on the same side! After that's cured, bend the leads around so that they are very close to each other (see pictures). Wrap both the positive and negative leads in a bit of foil.
Put the coin cell battery between the leads--your card should light up! If everything is in working order, hot glue the coin cell in place.
Wrap about an inch of the tip of the small strip of cardstock in tin foil. Slide it between one set of LED leads and the battery. You should be able to slide it back and forth, turning the lights on with the foil part and off with the paper.
Position the strip so the paper part is between the batteries and the leads, but the foil is just a little way past. I stretched a strip of electrical tape and hot glued it in place to create a bit of tension over the lead/strip/battery sandwich.
Cut a little notch out of the side of the frame for the on/off strip, and hot glued the frame to the card. Bend the strip (see pictures), place a dab of hot glue on the end, and close the card. Once it cools, when you open the card, it should turn on!
Step 5: Final Thoughts
Now that it's all finished, mail that sucker to whoever needs it, and hope it still works when it gets there!
Thanks for taking the time to visit my little project! Please take a moment to rate, subscribe, and comment--I thrive on feedback from readers. If you should make your own edge lit card based on my instruction, post a picture in the comments and I'll send you a DIY patch!