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Walt Langhans
02-27-2019, 3:45 PM
Hey guys!

I had a friend request a LED edge lit display sign and hopefully you can help me not reinvent the wheel :)

The sign will be about 9" wide and 12" tall

1/ Can I get away with 1/8" clear acrylic or does it need to be 1/4"?
2/ Does the depth of the engraving matter for how well the engraving shows up?
3/ Dose the edge on the LED need to be polished? And if yes, what's an easy way to do that? This is not something I plan on doing on a regular basis so I don't want to have to get any extra equipment.

Thanks in advance!

Kev Williams
02-27-2019, 5:39 PM
I've never done but 1 batch of edge lit signs back in 1991 and they were hanging signs lit by a 4' florescent tube above them
... anyway, what I DO know:

--thickness shouldn't matter, although I'm thinking thicker may be counterproductive, but don't quote me on that ;)

--just simple scratches will light up nicely-- depth is only important for any 3D effect you may be going for. However, the deeper the engraving, the less light will get thru above it, as the engraving will reflect the light trying to move straight up-

--more light should pass thru a polished edge. Best way I can think of, sand as smooth as possible, then grab a propane torch and flame polish it. Practice first :)

Mike Thornbury
02-27-2019, 8:21 PM
Hey guys!

I had a friend request a LED edge lit display sign and hopefully you can help me not reinvent the wheel :)

The sign will be about 9" wide and 12" tall

1/ Can I get away with 1/8" clear acrylic or does it need to be 1/4"?
2/ Does the depth of the engraving matter for how well the engraving shows up?
3/ Dose the edge on the LED need to be polished? And if yes, what's an easy way to do that? This is not something I plan on doing on a regular basis so I don't want to have to get any extra equipment.

Thanks in advance!

1/ yes
2/ yes - doesn’t need to be deep
3/ the laser-cut edge is great

Most important is your light source. If using LED, butt them in contact with the edge of the sign. Play with the strip until you have placement/number of LEDs right. If not using LEDs your box needs to be light-tight and a firm fit on the sheet or stray light will lessen the effect

Doug Fisher
02-27-2019, 11:31 PM
For #2 - If you are using a Ruida controller, the RDWorks software has an "LGP" function/option set that will allow you to vary the depth of the engraving as laser moves farther up/away from the base.

Jeff Body
02-28-2019, 1:25 AM
Hey guys!

I had a friend request a LED edge lit display sign and hopefully you can help me not reinvent the wheel :)

The sign will be about 9" wide and 12" tall

1/ Can I get away with 1/8" clear acrylic or does it need to be 1/4"?
2/ Does the depth of the engraving matter for how well the engraving shows up?
3/ Dose the edge on the LED need to be polished? And if yes, what's an easy way to do that? This is not something I plan on doing on a regular basis so I don't want to have to get any extra equipment.

Thanks in advance!

1. I would suggest 1/4" because you're making it so tall. 1/4" allows the light to travel farther in the acrylic. I think it's mostly because there's more surface area in contact with the LEDs.
2. Nope. Any type of engraving will show up.
3. If you cut the acrylic with the laser that should be just fine for a polished edge.
Most important thing........... Use CAST acrylic.

Shipping this sign out tomorrow. William's Garage 404651
This buzzard sign is 12" by 12". I use to own LEDLightbases.com (Admin - the website is no longer up) were I sold light bases. So I've made a few. LOL
The camera picks up the fading colors by in person the colors were pretty uniform.
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Trey Tull
02-28-2019, 8:21 AM
Great looking signs Jeff.

Walt Langhans
02-28-2019, 8:23 AM
Great info thanks guys!

Yes I'll be using LED. My biggest concern is having it show up well in a normal lit room so I figure I'm going to use the brightest LED's I can fine. I also had another though. Anyone ever try filling the engravings with paint that glows in black light and then using blacklight LED's?

Keith Outten
02-28-2019, 9:19 AM
Lots of good information in this thread.

I agree with Trey your signs are great work Jeff. Where are the led lights installed on the William's Garage Sign?

My supervisor at CNU purchased an acrylic Guinness Beer sign that was both laser engraved and CNC routed. The sign quality was amazing and I was impressed at the difference between the laser and CNC areas. I can't say that either one was better quality they just looked different which made the sign unique.

My business cards are laser engraved 1/8" thick acrylic. They light up reasonably well with the light from my cell phone when I have the need to explain the technique to a potential customer if I block the excess light from cascading along the face and back of the card.

Mike Null
02-28-2019, 10:51 AM
I have used 1/2" thick acrylic with good success. Sorry, I can't locate the picture.

Keith Downing
02-28-2019, 1:58 PM
Where are the led lights installed on the William's Garage Sign?


Looks like he's using the standoffs that have the LED's built in. I have a set but haven't tried them yet.

Jeff Body
02-28-2019, 10:22 PM
Lots of good information in this thread.

I agree with Trey your signs are great work Jeff. Where are the led lights installed on the William's Garage Sign?

My supervisor at CNU purchased an acrylic Guinness Beer sign that was both laser engraved and CNC routed. The sign quality was amazing and I was impressed at the difference between the laser and CNC areas. I can't say that either one was better quality they just looked different which made the sign unique.

My business cards are laser engraved 1/8" thick acrylic. They light up reasonably well with the light from my cell phone when I have the need to explain the technique to a potential customer if I block the excess light from cascading along the face and back of the card.

The LEDs are in the standoffs that I use to sell. They're pretty cool.
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Kev Williams
02-28-2019, 11:15 PM
As to thickness, again- I recently found one of the hanging signs I mentioned above, kicking around the basment...
I just dug it out, and surprised that it's only 1/8" thick, I was thinking they were 1/4"-

Here's a pic of 2 of them and how the were used, 1991 National Ass'n of Broadcasters trade show--
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I drilled 2 holes at the top, they cut a slot in the header above them, and just put nails in the drilled holes and let them hang.
Each sign was 48" x 16" with a single 40w florescent tube sitting above the top edge.
The 'Vidifont' sign on the right is washed out by floodlights, but the 'betacam' sign lights up pretty good-
there's a bad spot in the photo but oh well... The engraving is quite deep, around 1/32", probably more than most folks will ever get to with a laser,
but the light loses very little brightness towards the bottom even with the deep engraving and relatively thin plex.
The plex edges really lit up! And I did polish the top edge... :)

FWIW to anyone, I also cut out all the header lettering with my first 5000XT engraver...
the header sections were 2' x 8', framed with 2x4's, capped with 1/2" plywood with .025" brushed aluminum glued to it.
The words on just this header spanned 15'. Had to save all the character holes, which were glued to red plex behind the letters
and backlit with more florescents. 3 or 4 headers per 'building', this is 1 of 5 buildings, I was never so glad to see a job finally finished...

And this stuff- Betacams, character generators, this was as high tech as it got back then!
--So how many of you were even around back then? ;)

Anyways, thickness may not be that big a deal? Mike, I'd love to see what you did with 1/2" acrylic, find a pic!

Keith Outten
03-01-2019, 8:04 AM
Thanks Jeff, I don't know why I haven't seen these standoffs before. I must not be getting around like I used to :)

Mike Null
03-01-2019, 11:33 AM
I found the picture of the 1/2" acrylic. Not a good picture but you can see that 1/2" acrylic works for this purpose.

Grey Goose is the acrylic. It was engraved from the back.

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