edge lit acrylic panels

[Rodney Pierce]

Alright my fellow engravers, I have done some research on here, and there is a TON of information on edge lit panels, with just a design cut into them so that the light catches it and lights it up. I have a different deal im trying to get to work here. Im trying to get a 12 x 12 panel to light up, evenly all the way across the panel. With a LED light strip at the top and the bottom. Basically, just like these here:
http://www.luminousfilm.com/led.htm#edge

Now, if you look down the page, you can see that they cut a grid into the plex to help move the light. I have done this with numerous different patterns, and still cant get it to light all the way across the panel. Its very brite at the bottom, and fades drastically as you go towards the top (mind you, this is with LED's only on one side).

So, I didnt know if you guys had experience trying something like this or not. Have maybe a specific pattern you use?? I have flexisign, enroute and engravelab here to work with as far as software. And the downfall, I only have a rotary engraver, not a laser. Anyhow, anyone with some experience or insight would be helpful!! Thanks so much guys, Rodney Pierce

[Dan Hintz]

Rodney,

Increase the depth of your cut lines as you get farther away from the LEDs... you'll have to experiment, but this will help even out the brightness.

[Robert Walters]

Rodney,

Just for clarification....

Are you trying to distribute light evenly across the plain (unengraved)12x12 panel, much like a laptop screen?

If so, what I have seen is that they are backed with thin layers of materials to diffuse and distribute the light across the whole panel.

You might take apart the LCD display on a broken camera or cellphone to see what they've done.

[Joe Kace]

Dan,
I'm a newbie here, but what are cut lines and how does it help with distribution?
Thanks
Joe

[Dan Hintz]

Joe,

Lines are scribed into the surface of the panel, which act as informal reflectors to the light entering the edge of the panel. By increasing the depth of the scribed line the further they get from the light source, the light blocked by the prior line will not affect the light hitting the next line.

[Rodney Pierce]

Rodney,

Just for clarification....

Are you trying to distribute light evenly across the plain (unengraved)12x12 panel, much like a laptop screen?

If so, what I have seen is that they are backed with thin layers of materials to diffuse and distribute the light across the whole panel.

You might take apart the LCD display on a broken camera or cellphone to see what they've done.

Actually, the panel is engraved. I have a grid of lines across and up and down on the panel. I will try and see if I can get deeper the further away from the LED's I get. And also,we have one of the panels, and it is backed with some sort of thicker, white material to diffuse/scatter the light. i have yet to figure out exactly what it is that they are using though. We have tryed light enhancing vinyl, white blockout vinyl, chrome, reflective; all to pretty much the same effect.

[Dan Hintz]

Why not get acrylic designed specifically for backlighting panels? Evonik Cyro sells some called EndLighten... it's not cheap, but there's no processing required to make it work.

[Rodney Pierce]

Why not get acrylic designed specifically for backlighting panels? Evonik Cyro sells some called EndLighten... it's not cheap, but there's no processing required to make it work.

Dan, do you know by chance the cost of that per sheet???

[Rodne Gold]

If you are only lit from one side , here are a few strategies to get "even" lighting all over the panel
The first thing to try is clad the edges of the panel with reflective silver vinyl , even on the glue side , the reflective will stop light escaping from the edges and send it back
The second strategy is to engrave in a photo or black and white mode where the engraving is dots and not solid , the reason you want to do this is that you apply a fade , lightest at where the light is and darker further away from the light source , you convert the engraving to raster. There are less dots nearer the light and more further.
I have used both strategies when doing edge lit stuff that needs to be consistently bright across a large panel and can only be lit one side.
If these don't work , you might have to accept the physical limitation of what you are doing and light from both sides or all 4

[Robert Walters]

Dan, do you know by chance the cost of that per sheet???

$1200 USD per sheet

[Bruce Hoffman]

How big were those sheets?

I found it at $10-30 per sq ft at a place called "acrylite-shop" depending on thickness. That would be 400 sq ft or 20'x20' at max thickness.

[Rodney Pierce]

If you are only lit from one side , here are a few strategies to get "even" lighting all over the panel
The first thing to try is clad the edges of the panel with reflective silver vinyl , even on the glue side , the reflective will stop light escaping from the edges and send it back
The second strategy is to engrave in a photo or black and white mode where the engraving is dots and not solid , the reason you want to do this is that you apply a fade , lightest at where the light is and darker further away from the light source , you convert the engraving to raster. There are less dots nearer the light and more further.
I have used both strategies when doing edge lit stuff that needs to be consistently bright across a large panel and can only be lit one side.
If these don't work , you might have to accept the physical limitation of what you are doing and light from both sides or all 4

Rodney, we have tried the vinyl on all edges and back, except the side lit. It does make a difference. Just not as much as we need. Now, i was trying to get the engraver to do what you have listed above, but im not sure how exactly to do that in my software. I have engravelab 8, and cannot find how to make that sort of pattern. For the lines, I manually set them up in flexisign and then exported it to engravelab. Also, im worried that might take forever on a rotary engraver. If i had a laser, it would be done in no time.

[Dan Hintz]

Prices start at $11/sq ft for the thinner stuff and goes up to about $30 for the mar-resistant thick stuff. If you buy in 4'x8' sheets, the price drops...

[Rodne Gold]

Didnt know you didnt have a laser - you coulod probably do it with a rotary if you convert the engraving to a one bit file and trace the "dots" with some raster to vector program , you need to fill em too and compensate for tip width - a huge mission.