Edge lit

[Xxray]

Haven't made one in quite some time, was wondering if I had lost the touch.

Made with .25 plexi, I prefer 3/8 but didn't have any on hand. Practical purposes the results are about the same, might get a tad more of an illusion of depth with the thicker stuff, but the main reason I like to use 3/8 is because the slot for the LED strip has to be .38 wide, so using .25 plexi leaves a bit of a light leak, not real noticeable unless you are looking straight down on it, but it might take away from the LED intensity, not sure.
Anyhow this one is for a buddy of mine from a local MC club, club name redacted for privacy. I thought it turned out great, but once I lit it up, 2 flaws were apparent.
There is some crazing under the left wingtip, at first I thought and hoped it was residue from the sticky paper but no, it is ingrained. I think what happened is this plexi was out in the garage and exposed to freezing temps so I had to use a heat gun to peal off one side, the other side I peeled off after it had been indoors overnight. So I probably caused that with the heat gun.
Other thing is the lettering has a stepped appearance, as if the pocket had some kind of offset from the profile. Sure didn't look like that in preview so I don't know, think I'll just solve that problem when I do it again by just doing the pocket, really no need to profile them too.

Toughest part for me was the base, that takes more finesse than the plexi. I have to do 2 pockets fore the LED slot, one is about .40 deep and will contain the LED strip, the other is an overcut right on top of it at about .25 ,, So in this case, I first cut the LED slot about 11", then the much thinner workpiece slot at exactly 12" ,, So in effect, its cut air most of the slow and only hogs out .5" at both ends, and this is the friction fit that holds the plexi in place.
So I had to remember and remeasure all those things that used to be etched in my brain, but before that I went out to get my preferred 3/4 mdf for the base, had none on hand. Was shocked that they wanted $28 for just a 2x2 square of mdf, its been a while since I have bought some and was probably like $16 then. So I passed on that and looked high and low in my garage for a chunk but none to be found, I did find a half sheet of .5 mdf ,,, Really too thin to be used as a base so I cut some strips, glued them together so had a 1" base.

Placing the LED strip itself was quite a chore to remember and dig up all my old connectors and things, but it all went down without a hitch, so hopefully I am back on track when I do another.

[martin54]

Good to see a post from you Xxray, I use to enjoy your posts but you don't post that often these days.

Interesting what you say about the acrylic you use & the bases. I always use 8mm acrylic rather than 6mm because I think it looks better although it probably makes little difference to the illumination, might sound a bit silly but I just think the slightly thicker acrylic makes it look better quality if that makes sense
On the base side I cut an 8mm slot in the top for the acrylic, I do my bases double sided because I fit the controller in the base rather than outside so I don't have the problem of cutting a slot in the top wide enough for the LED light strip to fit in

[Xxray]

Hi Martin.
Took a bit of a CNC hiatus, no particular reason, but still looked and browsed posts occasionally. If one gets a couple 1,000 posts at a forum, then their heart has got to be in it.

Anyhow my bases do the trick for me but there are no doubt better designs, have always shied away from devoting the thought and effort to come up with something better. I use the real slim mini controllers so I just hot glue them onto the back where they are not visible. Whole design is simple and nearly idiot proof, just had to double and triple check things that used to be automatic.

Oh sheesh, just now searched some of my posts using "bases" for the search, now I see what I did for .25 plexi, I made a 2 step base which eliminated the gap viewtopic.php?p=120074#p120074

I still think edge lit signs look nearly magical, really amazing that just a scratch in the surface combined with some channeled light can produce such an effect.

[SteveNelson46]

That looks really good, Doug.

[Xxray]

Did the replacement, decided to snazz it up a bit with pocket traces, good theory but didn't work out so great. Would probably been better off using a tapered BN or Vbit for the pockets and in fact will next time, results are very inconsistent and weak in some areas, especially in the wings. Not sure why this is so, could have done a cross hatch ,,, Drag bits just don't seem to work that great doing pockets, you can almost always see where they start and stop. Lettering came out decent, looks great from a distance anyhow.

Have a little more cleaning to do on this as well, had problems getting the backing off and had to resort to goof-off, sheet is probably 3 or 4 years old and has been through multiple freezing/heating cycles, I should probably toss it and get a fresh sheet and save some aggravation, or just use it for non sign use, clear shelves ect

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