i dig it. but have a question. if you're gonna use the stock red lens, why not use white LED's? wouldn't they be brighter? also, is possible to "dish" the lexan so the brakelight will be more easily viewable from an angle? like say from one lane over on the highway? from what i understand, LED's emit light in a relatively straight beam so if you're looking directly at it, it's very bright, but if you're looking at it from an angle, they're not nearly as effective. if you dish the lexan a bit, that could help them be more effective?
i was considering attempting to dish the surface of the plexiglass. that probably would give a little bit better visibility. it makes it very challenging to drill once its dished, and there's probably a big risk of cracking the lexan with all the holes drilled into it if you wait until after drilling. do you have any suggestions on how to attempt this?
why not white LED's? well, originally i was thinking of putting this behind a clear tail lense. i changed my mind about the clear lense along the way, because i am not sure i like the look of that. as white is not a color, but rather a comination of colors, the stock lense would filter out all the colors besides red, meaning that alot of the light would be absorbed. since the LED's i used only emit red light to begin with, there is actually very little brightness difference between the LED's with and without the lense in front of it. the inside surface of the stock lense does have the effect of diffusing the light in different directions, and there is pretty good visibility at least withing 30 degrees either way of the lense...
GKL Electronics in Germany have been selling those led-inserts for awhile now. They cost 65 Eur without licence plate light.They have also a led insert with licence plate light to. I have ordered both the led rear light insert and led inserts for my turn signals too.
Lexan can be bent, easy or hard. Officially, you should bake the sheet on the form you intend to shape it over. Preheat it to 200+ degrees F for some time to drive out the water. Otherwise the vapor forms bubbles. Then increase the heat, long enough to reach the interior, and bend over your form. You should also use a layer of flannel over the form to prevent scratches.
Unofficially, bubbles and scratches help disperse light and prevent the directionality problem. Just heat and bend.
And feuss2 is correct- there is no such thing as a white LED, really. LEDs are about as monochromatic as a laser, which is to say pretty f'kn monochomatic. "White" is synthesized by mixing two or three colors, and even then it's a pretty cheesy white. Since the plastic lens cover will filter out anthing but broadband red, there's no point. Incandescent bulbs produce white by emitting the whole spectrum, which is why a red lens is needed. If your LEDs are weatherproof, you could just rig this thing with red LEDs and ditch the plastic lens cover entirely. Notice that lots of modern sportbikes use LEDs with no "lenses," or at least just a clear windscreen.
So feuss2, how much are the LEDs themselves? Can you do a bulk purchase if enough people sign up?
This string has inspired me. Do you need to buy a special LED? Where do you get them? I have been making circuit boards for years. There is not reason I cannot do this if I know where to get the parts. I think I will try using some generic circuit board material I have here already. The stuff is old and pretty thick. And its got the holes already in it. I think it would be a cool winter project.