DIY Reuse Flash Projector

 in Eco-Art / Re-Purpose / Reuse / Tutorial

Projections are everywhere these days. With just four elements, build a portable nighttime expression device:

  • 1000+ lumen parabolic (no dome lens) flashlight ~ $25
  • Salvaged Rear Projection TV lens ~ FOUND
  • Sliced aluminum can side wall ~ FOUND (c our 3D can cut tut)
  • PVC plumbing reducer coupling ~ $13

Here is what we used:

The key ingredient – harvested lenses from these monstrous rolling TVs –occasionally found dumped in the wild:

If you can’t locate the unit, let your local e-waste collection point know you are looking. Or check online marketplaces for free offers. These weigh a ‘ton’, so if you locate a sale, you can offer to haul the dinosaur away for free. Alternatively, lenses can be purchased on eBay for $30-$40 each.

One of the three lenses you will find inside an RP TV.

IMPORTANT: When selecting a flashlight, check that the LED source/bulb is clearly visible; any dome over the reflector will not transmit the image to the lens.

STEP ONE:

  • Access the strip of three lenses, found where the screen meets the lower speaker portion. This teardown usually requires Phillips, hex, and nut bits; a screw gun is recommended. If the front screen is soft, you can slice it to access the lens panel.
  • Each lens is housed in a seating bracket that must be removed. There’s usually a little wing nut and seated screw post to remove, then pry the cuff away.

STEP TWO:

  • Measure the outside diameter of your flashlight and the OD of your lens.
  • In our case, this was 2″ and 4″ respectively.
  • We ordered the appropriate soft, PVC, step-down coupling to ‘attach’ the two pieces.
  • The hose clamps allow the PVC to flex and tighten, holding your flashlight and lens.
  • Beware, the whole apparatus is front-heavy, so support the heavy front end with your hand.

STEP THREE:

  • Make your GOBO – ‘goes before optics’ out of the aluminum can sidewall.
  • A metal disc is best because the temperature of the LED source rises in the PVC housing.
  • The light passes through the cut-out art. Text needs to be a solid shape or in stencil form.
  • Our art was set within at least 1/8″ from the edge of a 2″ circle.
  • The GOBO can be cut by hand or with a Cricut or similar machine.
  • The GOBO sits against the flashlight.
  • The projection focus is determined by how far the lens sits from the GOBO in the wider part of the coupling.
  • After finding the desired focal distance, tighten the clamp
An actual GOBO was found dumped in 29 Palms in 2016!

EXTRA CREDIT:

  • Because the PVC clamp is flexible, one could cut a channel to accept different GOBOs.
  • One could create a holder for the discs just like OG theatre lighting design.
  • Because the projected light area is small, it is easy to add a gel to color the art. Swatch books are available from camera shops and Lee and Rosco.
  • An alternate GOBOs, made from thin acrylic discs and cut vinyl for greater detail, though heat exposure can compromise the material over long periods.

EXPRESS YOURSELF! Show us what YOU have to say @deshart.