October 24, 2024
Description
Description
Slightly naff video here:
WAFFLE:
I designed this as a nightlight for my grandson. It's based around a tiny little microcontroller kit I found online - more on that later. But it can be easily modified to take a flashing LED or even just used as an unlit ornament.
Mine runs off an old 12v “wall wart” I had lying around (I never throw them away as they've come in handy for so many of my projects over the years).
The tower dimensions were loosely based on a ceramic tea-light holder I've had for about 30 years. It looked nothing like the real thing, but it was around the size I wanted, and gave me a good starting point.
I soon had the basics of the tower designed, and began searching for ways to create a rotating beacon. I quickly stumbled across this handy little LED kit from a UK seller:
At 28mm diameter, it's absolutely minscule, and 100% perfect for what I wanted. The kit has everything you need, although I dispensed with the board's power connector, and instead went with directly soldered wires. This makes for easier cable routing - and avoids any risk of the connector coming adrift after everything's glued together.
The owner of the shop, Steve, is very passionate about his kits and, as much as possible, makes sure customers get EXACTLY what they need. He's an absolute medal-winning star!
When I told him what I had planned, he put together a bespoke kit for me, using all white LEDs, and he even spent a lot of extra time programming the microcontroller with several unique “rotating” LED sequences for the project. I can't praise him enough for his efforts, and I'm pleased as punch with the results!
His shop also contains a huge variety of other kits and modules. So take a browse on the site, and see what else he's got that might inspire your next project.
Anyway, back to the lighthouse. After some experimentation with the initial draft prints, I felt that the body of the tower could do with some illumination too. So I added an LED mount in the base, along with a wiring cover/mask thingy that doubles as a reflector. I could have just used a plain white LED for simplicity, but I chose to use my old stand-by of a colour-changing LED (and 600 Ohm resistor). Nothing fancy, but it does the job and looks cool.
After a little more experimentation, I also added an optional clear diffuser tube within the Tower body to provide a more even light distribution inside.
I wasted a lot of time designing the base. Partly because I wanted it to look rocky (which took a while, since I'm nobody's artist), but mostly because I spent forever creating a full masonry-effect sea wall on the front of the boat dock. Completely forgetting, of course, that such a high level of detail is almost invisible at this size. D'oh!
One self-imposed constraint was that I didn't want a hefty base on the model. I felt it would make it look “lumpy” and bottom-heavy. My wall wart was fitted with a 2.1mm barrel jack that I wanted to keep if possible. But if I used a 2.1mm barrel socket on the model, it would have required a lot of extra height to fit the retaining nut, and even more to admit the tool to tighten it. So I chose to put my power socket on a small external flylead instead. This provides the additional advantage that the model needs hardly any space behind it when connected to power, and opens the door to alternative power supply options.
PRINTING:
I've included all of the .3mf files that I used in my print. But, for the most part, printing is really straightforward anyway. I printed both my Tower and Lantern with 100% infill. This was done to avoid seeing the infill's geometric shapes on the outside when lit from within. But if you aren't lighting yours, or if you're willing to live with visible infill geometry, you can take it down to around 15%.
I tried out random seams on my Tower, and this was my first foray into using the feature. Whilst I love the fact there's no visible seam on the outside, it leaves some odd exterior print artifacts that may not be to everybody's liking. So if you'd rather have an old-school seam instead, rotate your STL so that it's at the back, in-line with the cable entry - i.e. diametrically opposite the windows.
The colour bands on my Tower are very roughly placed at 25mm (1 Inch) increments from the bottom face of the tower. I say “very roughly” because I pretty much judged them by what looked right to my eye! Since I was using Bambu Studio, I used its colour painting function to make this easy for me. But if you only have a single colour printer, it CAN still be done easily enough. You'll just need to pause and make manual colour changes during the print - or maybe even have a go at modifying the gcode for automatic pause points.
I added a colour change to my base too. It probably doesn't need to be there, but it's just my attempt to simulate a water line around the Base. I'm in two minds about how it turned out, so I'll leave it to you to judge whether you want to do it.
Because I was using PETG, I had my best results printing the Lantern upside down, at 100% infill, and using tree supports. I did actually manage to print a couple of my PETG prototypes “right way up”. But the supports I used left horrid scars after removal, and I felt that they spoiled the inverted “cone” shape where the base interfaces with the Tower.
There's a number of parts printed in vase mode: The Inner Lens around the PCB (printed in white) and the clear plastic Octagonal Lantern Windows (note that the .stl files incorrectly call this "hexagonal"! But since it has 8 sides...) This makes for a very thin panel, with no visible seams.
I also recommend printing the black Light Baffle in vase mode. This means that you can easily shorten it if it touches the solder joints on your PCB.
Incidentally, the purpose of the Light Baffle is mainly to provide an optical break for when the illumination nips around “the other side” of the lantern. But it also helps make sure that the PCB stays in place after everything is put together.
ASSEMBLY:
Assembly isn't difficult at all. Build and test your LED PCB first, obviously.
After stupidly buying some cheap low-quality hook-up wire that was only fit for the waste bin, I hunted around for an alternative. If you're anything like me, you'll have a load of obsolete network cables sitting in a drawer somewhere. By stripping these down, you'll find that the cable pairs inside use real copper wire, and are perfectly sized for small electronics work. So I grabbed myself about 250mm (10 Inches) of it and used it to make up the PCB's power leads.
After soldering them to the board, I fed them through the mounting Platform, and then secured the PCB in place on the Platform with a tiny dot of CA glue - I built-in some clips for this purpose, but they weren't doing the job properly: The LEDs are very slightly proud of the board circumference, so the clips weren't really gripping the board. It kept popping loose at annoying moments during assembly, but the superglue did the trick nicely. Then the Platform was gently inserted into the Lantern, and was glued into position in turn.
The Octagonal Window piece now slides into the Lantern. It's a lovely tight friction fit. But a dab of glue probably won't hurt in making sure it stays there permanently.
The Door is also a nice friction fit into the Tower. But the three round Windows will definitely need to be glued. I tried very hard to get the visible print lines of my Window discs to sit horizontally in the Tower's openings. But the blasted things kept sticking to my tweezers! So they aren't very straight at all. Annoying as that is, I'm certainly not going to reprint the whole thing over it.
I now I made up a power cable using about 200mm (8 inches) salvaged from an old, dead, wall wart, and soldered on an inline barrel socket. I then inserted the other end into the hole in the base and fitted a cable tie and a dab of CA to provide strain relief. I soldered the black (negative) wire straight to the cathode of the Base LED, and the red went via a 600 Ohm resistor to the anode. I then powered up and tested operation before glueing the LED into its final position.
I then temporarily hooked in the leads from the Lantern PCB to make sure that still worked OK, and I also made my final choice for the light sequence via the button on the PCB. Once satisfied, I unhooked the wires and fed them through the little tube in the Tower. Then the Lantern was finally glued into place atop its Tower.
Things get a bit fiddly now because the length of the leads coming from the PCB limit assembly options. But slipping the Base Lens loosely inside the Tower solves this, and allows room to trim and solder the Lantern PCB's wires to the power feed. I allowed just enough extra wire so that the Tower could be laid beside the Base while making the final connections.
The Wiring Mask was glued over the top of the Base, followed by the Base Lens. This was done with it still inside the Tower body, so you need to be a little dexterous in keeping it out of the way while you fix the Lens into place. Note the little positioning slot, with its corresponding tab on the Base Mask. That's there to make sure the Lens doesn't collide with the cable tube within the tower.
Still holding the Tower just above the base, I used some tweezers to gently guide the excess wire into Base chamber, before finally lowering the Tower onto the Base and glueing it into position.
Moving back up to the Lantern, the PCB Inner Lens was now glued into place, and I then test-fitted the Cupola, with the Light Baffle and the Sloped Reflector. Remember I said to use vase mode on the Baffle? This gives it one solid end that glues into the recess in the Cupola, and one open end that's very easy to trim to length if you need to clear any solder joints on the PCB.
When I was happy with the fit of these last parts, I glued the Light Baffle into the recess in the Cupola, and added the Sloped Reflector over the top of that. I messed up here because the widest part of the Sloped Reflector should glue to the Cupola (so that it's at the top when fitted). But I went cross-eyed for a moment, and stuck it the other way around! It meant I had to print these three parts all over again. Oopsy!
The (replacement!) Cupola was a nice interference fit in the lantern, so I picked the best side to face forwards, and pressed it into place. I'll probably glue it in later, after some longer term testing.
Don't worry if all that sounds complicated. It really isn't! Like anything that's broken down into steps, and then written down, it sounds far more involved than it actually is. Take it from me: if an old duffer like me can do it, you can too. And you might even do a better job of it!
So there you have it: one light house night light. I'm off now for some fish and ships!
Happy printing!
Just for fun, here's a 4 and a half minute timelapse video of every single print made to arrive at the finished design:
License:
Creative Commons - Attribution - Non-Commercial - Share Alike
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