Introduction:
This a complete redesign (and size increase) of my previous 2019 British K6 phone box. It's a wholly new project, planned as a lamp from the outset, and it uses a 12 volt G4 LED disc "bulb".
Waffle:
Back in 2019, I put in a lot of effort to create a true scale copy of a real phone box near me:
https://www.printables.com/model/594508-traditional-k6-british-phone-box
I worked hard to recreate the various curves and shapes in the mouldings and architraves - even the hinges were there! But it turned out that these fine details just disappear when reduced to this size. So this time around I've simplified those areas down to straight lines and angles, and only used curves in the places they will actually show.
But I HAVE added one missing detail: There's now a representation of the crown emblems that are always found above the roof signs on real phone boxes of the type. I had to simplify them somewhat to be recogniseable as crowns, but at least they're now where they should be.
I was also a little unsatisfied by the size of the 2019 design: When I planned it, a height of around 6 inches/150mm seemed a nice size for placing on a shelf. But, after it was printed, I kept thinking it would be better if it was about half as big again. The new design meets this criterion - and I've included a pic of the old one next to the new to demonstrate the difference.
A major improvement over my 2019 design is the use of an internal frame. The 2019 model worked by incorporating a pseudo-frame into the sides. But it made some parts (like the door panel for example) rather tricky to print. By using a separate frame, all the side panels lie completely flat for printing. It also helps to keep everything lined-up during assembly, and makes for a good solid foundation to the structure.
I also opted for a complete re-think of the roof. I'd copied a lot from the real thing, which uses a one-piece roof cap to link the side panels. So I did the same on my model. But this needed a LOT of support to print, and much of this support was right next to (and around) the weakest parts of the roof. It could be printed, but the model would often break during separation. Not ideal by any means!
This time I incorporated all the weaker parts into the side panels instead. This makes the roof into a simple domed plug that's simplicity itself to print. It also means that the roof now prints nicely at 90 degrees (with a little tree support - see picture). This provides two benefits: There's hardly any waste involved, and it eliminates the horrid stepped-layer lines that result from 3D printing shallow curves on the top surfaces of a part.
Long-term experience with the previous model demonstrated that, as individual LEDs fail, the heat from the G4 disc increases. This affects the plastic, causing it to crumble away and the light to fall out. I've designed the new one to have the G4 disc clip into a replaceable module. If any similar crumbling happens in this new design, the whole module can be removed and re-printed!
I've also designed an optional blank LED module as a starting point for any tinkerers wishing to try alternative light sources such as LED tape or COB units etc etc. To aid this further, I've added a second mounting position in the base. You could even mount your G4 disc down there instead - although I'm not sure how good this would look. But it opens up options for others to experiment with.
Thanks to the size increase, I'm finally able to print legible writing on the roof signs. I'm afraid it's not the correct font (it should really be something similar to Times New Roman), but I needed something that would reproduce well at this scale. So I went with basic Arial to make life easy.
I printed all of my side panels with 100% infill because I wanted the light to ONLY show from the windows and roof signs. It's not necessary for you to do this, and it's just my preference. Anyone wanting the sides to allow light through should print them at 15-20% infill - but, bear in mind that the infill pattern will show through at night time. So pick something you can live with! I used gyroid to good effect on the previous design because it's not as visible as a purely geometric infill.
I chose Hilbert Curves for the facing surface of each side panel. This gets rid of the normal print lines, and provides a nice tactile surface. But it's not essential, and just another personal preference.
In my opinion the one place you REALLY don't want any visible infill is on the glazing and signs. It ruins the effect! So use solid rectilinear infill, and rotate your STLs to ensure the lines on the visible window surfaces will be horizontal when installed on the lamp. Do it right and there will be a subtle horizontal grid pattern that looks quite attractive when illuminated.
One optional addition I created is a white reflector panel to sit in the base. The real boxes were always lit by a dim light tube in the roof dome, and the light would taper off dramatically towards the floor of the box. On the real thing this doesn't matter. But it doesn't look so good on a lamp. So the reflector is there to cover the black base, and to bounce the light back upwards for a more even distribution of the light on the sides.
Finally, another optional extra is a small plug designed to fill the cable entry hole if you don't plan to light the model. It should just pop in place by friction. But a dab of CA glue will make sure it stays put.
________________________________________________________________________________________________________________
Assembly:
Each side panel has a corresponding window panel and roof sign, marked either "A", "B", "C" or "D". The same letters also appear on the base to make sure everything ends up in the right place. All the "A"s go together, as do the "B"s, "C"s, and so on. To help you remember which is which, I considered "B" to mean "back" and "D" to mean "door".
When I used Bambu Studio to slice the parts, I came across an issue on a couple of occasions where using the “autorotate” or “lay on face” options didn't lay some parts absolutely flat. I have no idea why! But manually rotating them flat worked just fine. So it's a glitch somewhere in either the STL file or the slicer. My money's on the STL (as it was created on an ancient free copy of Sketchup that has definite glitches from time to time).
After printing, the first job is to glue the frame together. Keeping it square isn't hard. But you do still need to pay attention, since this is the backbone of the entire structure.
The shorter legs on the frame will go into the base, and should be a nice friction fit. There's no letters on the frame, so look for the cable-tie slots. These go into the back corner between the A and B sides.
Don't glue anything else at this stage. Make sure it all fits first. The glazing panels are a fairly tight fit into the sides. So you'll need to ensure they go all the way into every single window aperture, and check the whole panel sits flat and even on the side panel. If anything doesn't go all the way in with firm pressure, first check that you've matched the letters correctly (ask me how I know!). If that's all correct, you may need to check for print artifacts, or stray filament strings etc. Make the same checks for the sign panels too.
Starting with the "A" assembly, you should be able to push this into the base by starting off at a slight angle. The first insertion (Ooh err missus) will be tight. But if you've printed it accurately it will go in. Make sure the “A” panel assembly seats fully into the base cut-out. Once satisfied with the fit, repeat the check with the other side panel assemblies.
Ensure all the sides are in good contact with the frame over their full length. You may find the tops have a tendency to spread outwards until they're glued in place, but an elastic band will take care of this while we test fit.
For some reason the gaps between the panels come out larger than designed. They're only 0.15mm in the CAD drawing. But, for some mysterious reason, they're much bigger on the final print. Try as I might, I haven't figured out why. And I'm not eager to mess around with the tolerances any further, just in case it messes up something else. Because of this, the one thing I would do differently is to print the frame in the same colour as the sides. You can just catch it grinning through the panel gaps, and it stands out in black filament. Red would disguise it much better.
With all side panels in place, the roof cap should just drop loosely into the top opening, and will stay put under its own weight.
Once everything checks out, you can now take it apart and CA glue the frame into the base. Make sure it's properly located and square. Then glue the window panels and signs into each side panel, and allow them to dry thoroughly before moving on.
Starting again with assembly "A", turn the base and frame onto its side and apply CA glue along the whole rail where the side panel makes contact. Then pop the base/frame assembly back upright, and slide the "A" panel assembly back into the base. Because you already checked it, there should be good contact for the entire length of the frame. If the panel top tries to spring outwards, just hold or clamp it into place until the glue bonds.
We don't want assembly "B" fixed-in yet. So miss that one out, and repeat everything you've just done with assemblies "C" and “D”. Always allow the glue to dry fully before moving onto the next panel.
When it's all secured and dry, make sure that assembly "B" still slides freely into (and out of) the base.
You now add the power socket to the "B" assembly, and solder on the wires to go up to the LED unit. Make them long enough to reach the roof, with around 50mm extra to provide enough slack to allow final assembly. Use light coloured wires if you can. Darker ones may show through the glazing when illuminated. I used pink and white because that's what I had to hand.
I added a fan connector between my G4 LED and the power socket. This isn't essential, but I did it to facilitate the changing of parts in the future. If you don't care about this, just solder the G4 LED disc straight to the wires so that you can feed it up inside the frame from the bottom. Check there's enough slack for you to be able to clip the bulb into the roof holder when the panel “B” is later put into place.
Use small cable-ties through the slots in the frame leg to keep the wires tidy and away from the windows. I only needed to use the lower three slots in the end. The cable ties should be loose enough for the wires to slide up or down for assembly, but not sloppy enough to move around or rattle. Don't forget to clip off the excess from the ties!
By sliding the extra wire all the way down, you can now slide panel "B" into the base before gently feeding the extra wire back up to the top. I used the tiniest dab of CA glue at the top of each frame leg to secure this panel. It should be just enough that I can separate it at a later date if I ever need to gain access to the power socket or its retaining nut.
Clip the bulb into the roof cap (and join the fan connector if you used one). Then dress the wires so that you can pop the roof into place without them fouling or creating a shadow on the glazing. I haven't bothered glueing my top in place, just in case I need to change the G4 disc (or that replaceable holder that I mentioned earlier). But feel free to glue yours if you want to.
Finally, power up the lamp and enjoy the ambience.
The eagle-eyed amongst you may notice that I forgot to shrink the heat shrink on the G4 disc pins. Don't worry, this has been corrected since the pics were taken! :)
Happy printing, and feel free to give me a bell!
The author marked this model as their own original creation.