Edge Lit LED Sign!

Picked up a sheet of acrylic at the hardware store and decided to give my new bits a try. Got an engraving bit. Decided to try and make an edge lit sign for my dad’s birthday! Actually turned out really good! The acrylic I used wasn’t as thick as I would of liked it to be. But the prices at the local store where pretty high. 8"x10"x 0.1" was 9$.

Anyways, I am still working on designing a base. I was originally gonna use this leftover piece of pine I had, but with the acrylic being so thin, I don’t have a bit that can cut through the 3/4" board. So I am hoping I can pick up some 1/4" pieces at the lumber store tomorrow! Thinking of doing a 2 piece design for the bases. Here is a pic I took of the sign held on top of some blue leds I had lying around. I’m hoping once the light is more contained it will give it a better glow. I’ll update the thread when I finish the base.

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Thanks! I’m kind of confused why it left that little triangle part in the spider, since it wasn’t like that in the design, but it actually looks really good, so I’m not even mad.

Nice job, and pretty cool photo to boot.

If you don’t mind me making a suggestion, you want to pay attention to how deep you engrave/carve/etch the various graphic elements.

You want the items closer to the light source shallower because they will block some of the light before it can get to the next element, in your case the spider making it appear dimmer.

I etch crystal and glass for a living (not with a cnc) and I have to watch for this all the time.

Granted you’re working on a fairly thin piece here, but just something to think about as you progress.

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That is a really good suggestion! Thank you very much! I’ll give this a try for my next one! I carved the whole design .01" deep. Maybe next sign Ill make the text .02 and the spider .01". I’m hoping once the leds are in the frame, it will send out a bit more light. (I imagine it will)

I think you will want to reverse those depths, .01 on the text and .02 on the spider. having the spider cut a tad deeper will allow it to pull light from the acrylic, if the text is deeper it will be even darker / less lit on the spider because it will have interrupted the light path within the acrylic.

Ah okay, I had it backwards. Thanks for the info!

For the base you could always use that 3/4" pine and just put a recess in it for the LED’s this should allow for your bit to go lower and then you only need 1 bit of wood allowing for a cleaner finish however you will need to do a manual 2 stage cut so you can cut out the outside.

Example here. http://easel.inventables.com/projects/xNLo6Zrk6bNoaWNFWmfbNw This is what I did for my Nibbler sign(sorry best photo I have at the moment)
https://discuss-assets.s3.amazonaws.com/original/2X/0/02a542cef460628714170faef3fdc87c6618585a.JPG

In the end I just used packaging tape to fix the led’s to the base. You never end up looking at the bottom and the packaging tape is the thinest thing available. Where as you always see the sides.

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Hmm, wouldn’t I still need to be able to cut all the way through the board?

Aaahhhhg. right my imperial to metric was way off.

I used a small engraving v-bit on my signs and set the depth at .004 and got great results… very crisp lines and lots of detail.

Tim.

You should try the diamond bits.
They give really good results.
Just use air for cooling the tip and keep that plastic off of it.
You can also use a paper towel soaked in water and keep it wet.
The speed should be very low too. Friction is your enemy with plastic and bits that it can collect on.
Some use a type of fluid as a lubricant instead of water. Most diamond engravers use water though.
Some experimentation will yield good results.
Oh yea the depth you use with the diamond bits will be .01 or less. Depends on the look.
Your feed should be fast as your not really cutting only abrasive or scratching the surface. Think of it as using a piece of sand paper to abrade the surface.

I have used a diamond bit at slow speeds and did get really good results. (sorry no pics. I forgot to take them and since moving I lost the acrylic sheet I did this on)
Anyway good luck :slight_smile:
I did the spider btw…

What Kind of bit you had used?

It was part of a Dremel set.

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I had a bit set like this. I used the small ball one.

I use this also but a few years ago for carving by hand with my dremel.

I think i want to test it with the X-carve.

What diameter it has? And what diameter you have saied to easel?

Does the acrylic melts with this bit?

What diameter it has? And what diameter you have saied to easel?
the diameter is the ball. You need a caliper to measure it.

Does the acrylic melts with this bit?
if you run this very fast without any cooling the residual dust will pool and melt forming a layer on the bit.
You can cool it using a water mist or paper towel that is soaked in water. ( let it sit for a while and the paper will shread under the bit. It may go flying so wear eye protection. It will not however damage the bit or what your cutting.

Air works well but the most important thing is to keep your speed low
Dewalt 16k is too high. You need to keep it under 3k for acrylic.
you can score the Plexiglas with the bit by hand so it does not take much for the spinning tool to do the job. Also your depth pass should be small. Like .01 or less. it depends on your speed and feed and how deep your going. Use the V-bit for the corners only cause a ball cannot create a corner. (I would set up some values for you but I have just moved and still need some more testing to do.)

Bone you can run it at the dewalt’s higher speeds however you would really need cooling as the bit will get hot at this higher speed.
If the bit gets too hot the diamond bits tear off cause the glue melts.

I did this with 2 bits.

  1. upcut 1/16 bit standard end mil.
  2. V-bit (I think it was a 30° .01 inventibles )
    I did not record the speed and other settings however I do recall using a very low speed and doc was less than .1mm

V-carve was the tool used to generate the g-code.
Easel was used to run the g-code to the X-carve.

This is cast acrylic. This is the type you want to use for your signs
Here is why:
http://www.pmma.dk/Images/Akryl/Cast%20extruded%20laser%20engraved%20acrylic.jpg

The cast will look much better.

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