Kyndle Cardboard (Opaque Projector for E-reader)




Introduction: Kyndle Cardboard (Opaque Projector for E-reader)

Consider this as inspired follow up to the Kinkajou® Microfilm Projector. Simple, low cost projector for education of third world. Also as nice DIY maker project for learning about optic, lens principles.

If you prefer an instant plug and play project, you just need to buy two items.

Ez Tracer Projector

Kindle E-reader

But read on if you want to take more advantageous route.

Step 1: Parts and Tools

Parts Needed

  1. (2) 1/2 gallon Milk Cartons (Please pick them up from your recycling bin, clean them before use)
  2. Fresnel Lens
  3. 4X6 Plastic Mirror

I had savaged the lens body from a Smart Phone Projector


  • Utility Knife
  • Scissor
  • Tape

Step 2: Mirror Mount

  1. Cut the 4x6 Plastic Mirror in half with Scissor.
  2. Remove the protective film on top of the mirror
  3. Find a cardboard same width as the milk carton. Fold it as the mirror mount
  4. Use double side tape to mount the mirror on the mirror mount

Step 3: Projector Body

  1. Cut off the bottom of the milk carton
  2. Cut the lens opening on the milk carton
  3. Cut Light Source opening on the opposite side of milk carton (Size to fit your light source, larger if you want to use light bulb, smaller if you want to use flash light)
  4. Slip in the mirror mount into the milk carton
  5. Adjust the mirror so it is 45 degree
  6. Attach the Fresnel Lens
  7. Cut the milk carton at the 2½” Line (Because the lens is fixed, we have to move projector body up and down to adjust focus)

Step 4: Light Box

  1. Cut a milk carton in half
  2. Remove the Plastic mouth piece.
  3. Insert 100 watt Light bulb (LED only, Anything else is a fire hazard.)


Use a high power LED Flashlight to make it a wireless Projector.

Step 5: Assemble

  1. Use a rubber band to tie cut off milk carton bottom to the projector body. This is your focus slider.
  2. Attach the light box to the projector
  3. You are ready to start your projector

Step 6: Projecting an E-reader Display

The opaque project will project any paper, book you place under the projector to the screen in front. You just need to find a good focus spot. For our design, 3 foot to 5 foot is the optimum range between projector and the screen. Move the projector back and forth to find the good spot. Because the lens will magnify all the minor mis-alignment and wrap in the build, perfect focus is very hard to accomplish.

Step 7: Learn More

Read the attached pdf for more about Opaque Projector. Maybe load it into your E-reader and present it in the class using your DIY projector to complete the cycle.

Summer Fun Contest 2016

Participated in the
Summer Fun Contest 2016

Maker Olympics Contest 2016

Participated in the
Maker Olympics Contest 2016

Cardboard Contest 2016

Participated in the
Cardboard Contest 2016

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    4 years ago