I need advice for MacGuyvering a backlit etch-a-sketch. I cant seem a way to work around the Aluminum powder?
I have had this idea for a while now, and wanted to make one as a gift. I plan on using LEDs. What I cant figure out is what material to use that would prevent the super fine Aluminum power/pigment from coating and thus blocking any light from the LEDs. I do know about the possible dangers of the powder combusting (grain silo effect). I'ts prolly why the parent company never tried to market one. But I'm sure I can work around that problem. One idea I had involves the use of 2-way mirror tint...the other a sandwich of plexiglas with the leds stuck somewhere so the LEDs/light path are 100% clear of being blocked or coated with the powder. Is there even another type of powder that may work, even if it meant sacrificing the ability to draw with fine detail? Thanks for any advice.
Update:I have bought an xmas light string set for $4.99 at Target. They are RGB leds that cycle through multiple colors. I was hoping to light up the etched line...not sure if the light will be strong enough to make the fine lines shine through. I could also use a cheap 5mw green laser.
Answers & Comments
Verified answer
Don't bother with back lights. Front lights will solve the problem and the little box with relatively thick acrylic front is a perfect candidate. Drill holes in the edges of the plexiglass that just allow LEDs as plugs. I mean drill on the red frame where the plastic is both red plastic AND clear acrylic. Use clear silicone seal (like clear bathtub caulking) as the glue and black silicone seal on the front as glue and insulation for the wires. Suddenly you are the genius with the nicely illuminated etch a sketch.
The clear acrylic will conduct the light like fiber optic. Only here, the light conductor is across the whole screeen.
The powder will reflect any color light and the clear areas will still look black. That is, the etch a sketch will still look like an etch a sketch drawing. With a back lite, the powdered area will look dark and the places it is sctratch off will be bright. A back light will make a negative picture of the regular etch a sketch look.
Just curious. What color or colors are you shooting for? White light? Red? Green? Maybe it is time to market big etch a sketch for advertisements? Christmas displays? Great idea!
Yes, aluminum powder is highly flammable. Be sure to drill outside and have a clear path to get away from the thing should the worst happen. The powder will be most flammable when the powder is fluffed and mixed with air. Let the little booger lie still for a few moments before opening it with the drill bit. Good luck - be careful with power tools and chemical glues.
I would use fiber optics rather than led's this way it keeps the light source away from the aluminum powder, and you can rig it up so you can change the back light color by changing a film color in front of the fiber optic strands at the source.