This project turned out even better than expected. It was inspired by the lights used in pinball machine playfields, where coloured inserts are illuminated from behind.
I've attached two scripts at the bottom of this description. If copied and pasted into openscad they can be used to create custom versions with the following adjustable variables:-
Outer diameter of the insert (all measurements in millimetres)
Depth of main disk
thickness of front layer of plastic. Thicker = stronger/diffused and allows sanding flush
diameter of LED
length of the LED support measured from the front
There are two versions:-
Star, which has eight radial lines and is the strongest version.
Concentric, which has a series of fresnel style lenses to spread the light.
I recommend printing these in transparent/natural PLA to allow maximum light transmission. I've not tried coloured transparent PLA yet. They print very fast with a small amount of filament. For example 20mm=1g, 25mm=1.5g, 30mm=2g, 40mm=3g, 50mm=4g, 75mm=7.5g.
You can fit a standard LED with suitable resistor like 150 ohm for powering lots of these in parallel from a standard USB power supply. Self colour changing LEDs look good, as do self flashing ones. You could size the LED holder to take an addressable LED string pixel.
You could also animate the light in the style of a pinball feature effect.
Diffused LEDs are best to get a softer spread of light through the insert.
For drilling the holes, a plunge drill or router will give a clean vertical hole to a repeatable depth.
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The openscad scripts are below. You can copy and paste the selected script into openscad, and adjust the variables at the top to fine tune sizing to your requirements before making into an STL file.
Here's the star script:-
//Pinball style star LED insert
$fn=100;
//You can adjust the variables below
size=25; //diameter of insert in mm
depth=5; //depth of insert
face=1; //thickness of front face
led=5.2; //diameter of LED
stem=15; //length of LED stem
//don't adjust anything below here
difference(){
union(){
difference(){
union(){
//main disk
cylinder(h=depth, d=size);
}
//internal cylinder
translate([0,0,face])
cylinder(h=depth,d=size-2);
}
//star fins
for (i=[0:36:350])rotate([0, 0, i]){
translate([0,-.5,face])
cube([(size/2)-1,1,depth-face]);
}
//LED pillar
cylinder(h=stem,d=led+2);
}
//led hole
translate([0,0,face])
cylinder(h=stem+1,d=led);
}
And here's the concentric circles script:-
//Pinball style fresnel LED insert
$fn=100;
//You can adjust the variables below
size=25; //diameter of insert in mm
depth=5; //depth of insert
face=1; //thickness of front face
led=5.2; //diameter of LED
stem=15; //length of LED stem
difference(){
//main disk
cylinder(h=depth, d=size);
//internal cylinder
translate([0,0,face])
cylinder(h=depth,d=size-2);
}
//concentric rings
for (i=[0:4:size-8]){
difference(){
cylinder(h=face+1, d=size-i-1.5);
cylinder(h=face+1.1, d=size-i-3.5);
}
}
//LED pillar
difference(){
cylinder(h=stem,d=led+2);
//led hole
translate([0,0,face])
cylinder(h=stem+1,d=led);
}

This video is about these little plastic inserts that can be placed into wood after you've drilled a suitable hole. I used a flat bit. It was probably not the best tool for the job, they're, probably better ones, but that's what i used and each of these inserts will hold a diffused. Colored led just pressed into the back of it.

So you drill the hole down to a specific depth and then you drill another hole in the back all the way through, and it means you can actually sit these in. They can be glued in and if desired, they can be buffed flush with the surface and then the whole lot could be lacquered over if you find a lacquer, that's compatible with the plastics involved. This is pla now you've seen what it looks like. Let's bring back the light and we shall take a look at the construction of these and how you can make them yourself.

The light is back and even under sort of full studio type lighting. These aren't too bad. This one is over drilled and that's just uh. I get the feeling that there are better bits than this for doing the job.

Also, i think you'd be better with a plunge either a plunge, router or a plunge drill adapted to be able to play placed over where you wanted the holes in the wooden surface and then plunge down to a very fixed depth. But if you were to drill a load of these and then find that something had slipped and you drilled them a bit deeper than normal, it's no gate problem, because these are these are 3d printed and the script is down below in the description you can just Copy and paste it into openscad and you can make custom versions of these in any size, and for that reason, if you had drilled it too deep, you could either just pack it up or glue it at the correct height or just print another one. That's a slightly deeper because that you can change the parameters in so the point of this. This was inspire inspired by a picture of a bar that had pinball tables laid into the top of the bar, just the play fields from the machines and wired up with lights, not a great thing for vintage pinball machines, but if they were beyond recovery, the play Fields that was all right and uh.

I initially thought the first thought was to actually make sort of a concentric circle sort of a lensing effect like this. But then i decided to go for the star effect like this and uh have the radio lines and, to be honest, i think this is better because, although this well i'll show you afterwards i'll show you the illumination how well they eliminate evenly. But i like this one, a lot more because once it's laid in it's really strong, even this uh large three inch diameter one. The 75 millimeter diameter is super strong to press in the middle uh, which means, if you did lay them into a bar.

Then it's less likely to suffer damage with people pressing down them. Let me think now this one was done with a colored pla. It's not a great thing. Really i'd recommend the only color.

That's used is transparent pla, either in colours or in clear, and i suppose you could put a coloured ovally over the top, but ultimately clear with a coloured led is going to produce the best illumination. I think anything else worth saying about these, or do i just go straight into showing you what they look like i'll go straight into showing you what they look like one moment please. I shall start with the biggest cover i'm going to use a code white led just because it's a good, neutral color under the studio settings of the camera and in this instance the three inch damper or 75 millimeter diameter and open scad. It's uh! Oh look at that picking up the light from all the other lights uh, it's all right, it's better! If you're an angle, it does spread the light and it does spread illumination over the whole surface.
But i get the feeling at this size it's getting a bit too big and it might actually benefit from having other leds under different parts of it. However, it's just scaled up from the typical size that this was designed for at the first one i printed off was 20 millimeters. Damn try, that's probably about um three quarters of an inch ish and it's nice. This is the typical size you'd actually find in a pinball machine.

However, then it went up to one inch 25 millimeter, which is what these are and it looks pretty good you can see. It's got very good, even illumination. Now, if you use the focus led, it looks pretty sharp. It looks a wee bit too hot.

The diffused led actually spreads that light out sideways a lot better, so it improves the appearance. Uh, going upwards from that here is 30 millimeter, which is just over an inch uh, 40 millimeter, which is still looking pretty good and then 50 millimeter, which is probably the upper level for strength and also for uh, even illumination. It still looks pretty good if you had this flash on dolphin as a bar top the other lensing effect. I've got here is the concentric circles quite complex to create, but it creates a genuine lensing effect.

It's looking pretty good. It provides good, even illumination. The downside to this is that i think that the this one is not as strong as others, because, while the other ones have those sort of ribs to strengthen it, this one is quite a thin layer. It's basically the front, and this one is set at one millimeter thick now.

The parameters you can change are diameter in millimeters, thickness in millimeters the thickness of the front surface, which uh, if you want to to be able to actually buff it down flat or have it strong, you could make it more than one millimeter thick, which is the Default and then you can choose the diameter of this stem and the diameter of the led that goes into it, not the damn till of stem, but the diameter led goes into it and then the length of it from the front surface to the back and that In the case of these bigger leds that might actually help with diffusion by actually having the led mounted much further back from the front of the uh, the lens and i'll show. These will come out if you print them with a resin printer because uh it definitely benefits from the fact that it it fills in uh in one direction, then it fills it in the other and it creates a nice sort of mottled pattern on it. Just the way it fills it in the uh, solid color, pialli works, it glows it lights, but it's not that great. It's not an efficient way of doing it.
It's not going to be anything as bright as the others, but that is it. If you look in the description down below you'll find these files, normally i try and say: if you know you don't need a 3d printer for these projects in the case of this one, you do, but the good news is that it really it prints very quickly. So uh because they're hollow and there's not a lot of plastic in them, so it produces very good results. Let me show you just before i finish this video.

Let me show you it with a colored led because colored leds are the way to go for getting colored lights. It makes a huge difference. It really does make it look so much brighter than trying to use. Maybe a colored plastic with a over a white led.

The self-colored led is going to produce produce the brightest result. It's a good result. I like these, i'm going to have to get some other stuff, while i've already ordered it for actually re actually placing on a bench top and then drilling these holes in to the correct depth. But that turned out a lot better than expected.

It was a fairly straightforward design and, as i say, the files the scripts are in the description. You can copy and paste them into openscad, and you can print these off to your heart's desire in any shape and size that you want.

14 thoughts on “DIY pinball-style lights for recessing into wooden surfaces”
  1. Avataaar/Circle Created with python_avatars skweek says:

    Did someone say PINBALL? These are actually kinda nicer than the ones used in some games, even modern ones with the fancy RGB lighting as that's still done in an a bit of an old fashioned way with a tiny lightboard underneath.

  2. Avataaar/Circle Created with python_avatars kasami says:

    I wonder if it's possible to apply more sophisticated light guide techniques to 3D prints, like those used in thin display backlights… It usually involves laser-etched gradient patterns on acrylic sheets, so something similar could probably be done by printing in a certain way.

  3. Avataaar/Circle Created with python_avatars Ragetist says:

    I have no experience on the subject but for the bigger lightspreaders would it be possible to somehow use the same material they use in flatscreen backlighting since it does really miracles at a short distance? ๐Ÿค”
    Maybe print the spreader with a slot to insert the screen or something

  4. Avataaar/Circle Created with python_avatars Guilherme says:

    You should have a go at making more click-baity titles and thumbnails to make more people discover your cool shit, this one could be called something like "How to make glowing Christmas planks" or something like that, also the latest one could be "this device claims to repel all mosquitoes" use your creativity to get more people interested in your cool content

  5. Avataaar/Circle Created with python_avatars Boffin 2002 says:

    I made something similar and used the Forstner bit mentioned by others- it leaves a very flat bottom to the recess. It's the sort of bit used to fit hinges to kitchen and bathroom cabinets. I had great results using white PLA at 10% infill, it diffused the light well enough that it almost eliminated "pin pointing" the LED.

  6. Avataaar/Circle Created with python_avatars Bob Le Clair says:

    If you put a fine blade from your skill saw on a table saw and set the depth,, the copper string LED lights will snugly fit in the groove you just cut, make sure the LEDs are pointing up and out ,,,moulding with lighting, using clear epoxy filler , 5/16 by 3/4 by what ever length the copper lighting allows

  7. Avataaar/Circle Created with python_avatars greenaum says:

    The lack of diffusion in the 75mm one might be addressed by printing it as if it were entirely made of light guides. So no simple back-and-forth pattern for the top plate, instead have it radiating from the centre. Yeah I'll leave the details to somebody else… Just having several thick-ish radial struts might help. Think about the plastic as it's oozing out the nozzle, the light is going to follow that pattern.

    Failing that… cast some out of epoxy? You can see in the 75mm one, the light just bounces off the sides of the printed lines, that's gonna happen to them internally as well with the LED light. So maybe print one, smooth with acetone vapour, sand, polish, then make a mould from that and cast a smooth solid piece. Moulding would also save on filament cost. Would probably only be necessary for the biggest ones, the small ones are fine.

    Nice little invention though, would look nice on an appropriate bit of furniture or even shelves.

  8. Avataaar/Circle Created with python_avatars greenaum says:

    You can get the addressable, WS2812 LEDs in through-hole, ie with pins, conventional LED packages, in 5mm and 8mm. So they'd be good, wire 'em all up in series and stick a little control box somewhere. If you really must, you could use an ESP32 or the like to make it Bluetooth or Wifi. Then you could set whatever patterns you liked. The Arduino libraries for the LEDs are an utter piece of piss to use.

  9. Avataaar/Circle Created with python_avatars James Brown says:

    As others have said, Forstner bits in a drill press would be the way to go. An added advantage is that you can make clean overlapping holes , so you could make more complicated effects like a flower or possibly a nautilus shell.

  10. Avataaar/Circle Created with python_avatars calicantdrive says:

    I wonder what a color change LED would look like on a larger, say 2in or so, radial lensed insert. I'm thinking the slight offset of the red, green, and blue emitters in the LED would create some interesting patterns.

  11. Avataaar/Circle Created with python_avatars jlucasound says:

    Hi, Clive! I am new to 3D printing. I have an Elegoo resin printer. I see that you're using a filament printer. Can I use (or convert and use) the programs for filament printers to work with the resin printer?

  12. Avataaar/Circle Created with python_avatars Jason Kuehl says:

    Either one (rings or spokes) remind me a bit of the industrial indicator lamps. I never had thought of printing something like this, but these could be an interesting addition to my office/workshop.

  13. Avataaar/Circle Created with python_avatars Terry Lawrence says:

    I use my little Ryobi cordless palm router. I often do inlays that are lit. It looks so fancy and opulent! I just didn't put the 3D printer into the formula!! Jeez that's a match made in heaven! I ordered a little CNC to do more like this. It's addictive!

  14. Avataaar/Circle Created with python_avatars Trashnomancer says:

    Interesting idea. Open to some additions? Seeing your bullseye style got me thinking, take those rings, and continue them up to the stem as appropriate angles to land fully around the sides of the led. They should function as lightpipes and carry the light further from the center to reduce the hot spot contrast… Also… They would be MUCH tougher. Could alter this as tilted pillars to get a polka dot effect. Or triangles for arrows…

    What of logos graphics or words on the lense layer?

    And if there was a lip on the edge, you could use a step drill for seating them.

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