Introduction: Telephone Booth - Indoor Greenhouse With Lights

I've always loved this iconic telephone booth, I like the design and I find its vivid red colour very eye-catching. Since I'm slowly running out of space on my window sills on account of my ever-growing collection of plants, I decided to make a small version of the booth and use it as a greenhouse for some of my smallest succulents. To aid my plants I also installed LED grow lights as sun is in short supply where I live.

Originally, when I decided to make this phone booth I planned on a slightly different design for a completely different purpose. I wanted to use it as an enclosure for a vivarium where I planned on keeping a tiny frog. However, when I went to see the frog I realised I react to amphibians the same way most people react to spiders- absolute terror. But that is something to keep in mind, as this project is flexible and doesn't have to be treated as a greenhouse. It could simply be a small curiosity cabinet to display small collectibles or maybe it could be adapted to hang from a bathroom wall and hold supplies or toiletries.

This telephone booth is entirely 3D printed. I used a 3D printer with a printing volume of 220x220x250mm. All parts are scaled in such way, that you can print them whole, with the exception of the frame, which is 46cm tall, so it has to be cut in half and printed separately.

Finished booth measures approximately 21cm (width) x 20cm (depth) x 58cm (height).

This instructable ended up being sooo long, but don't let that fool you, the project isn't difficult or all that time consuming at all. I just like to be thorough and provide lots of examples and different options, especially since you can't just download STL files and print straight-away, you will have to adjust the design first. Also, all those videos I added are very short (mostly under 1 minute) and they are fast forwarded for quicker viewing.

To sum up this project in one long sentence:

Adjust the model to suit your preferences, print, clean the printouts, assemble everything and decorate, add lights and enjoy.

Step 1: Supplies

If you are planning of sanding and using fillers you will need:

  • spatulas, wooden sticks, toothpicks, filler spreaders
  • facial mask and gloves (nitrile gloves- most fillers melt vinyl and latex)
  • spray-on primer
  • spray-on paint - red and black ( for UK people I recommend Wilko's paint, it has a nice vibrant colour ->
  • clear varnish, spray-on or brush-on (optional, but I used matt varnish because I don't like shiny surfaces)
  • clear, wide packing tape and a printer ( for 'TELEPHONE' labels)
  • glue- super glue, all purpose plastic glue, two-part epoxy glue, hot glue gun (you can really get away with using just two-part epoxy, 1 tube should be enough)
  • small, weak, plastic clamps or large paper clips
  • soldering iron and all that's needed to reconnect the cables
  • also might be needed: small hand saw

Step 2: Filler or No Filler?

Before you start printing and gathering supplies you have to consider how you want to print this model. You have three options and they depend on your printer's quality and your personal preference.

Option 1: (what I did) Print all parts in lower quality (0.2 or 0.3 layer height) and cover the entire project in huge amounts of filler. This option involves a lot more work post-print, but it prints faster and that was important because this model is so very large and I didn't fancy printing all parts round the clock for nearly 14 days (Cura's approximation for 0.1 layer height).

Option 2: Print all parts in the highest quality possible, do minimum sanding (if needed at all), use a little bit of filler to cover the joining points and spray paint everything. If you print in 0.1 (and below 0.1) layer height, your print will already be very nice and adding a few layers of spray paint will only help make it more smooth and give it a nice finish. This of course means that your printing will take days, and days and more days...

Option 3: Find a nice, vivid red filament, print the model in the highest quality possible and use plastic welding to cover up the joining points. You won't need to use any spray paint and the booth will be pretty much good to go with an optional layer or two of clear varnish.
Video above shows plastic welding using a 3D pen and a soldering iron, it's only my second time doing it and it's pretty crude but you will get the idea.

Step 3: Mistakes

I will quickly go over mistakes I made to avid confusion and questions later on.

A) Three holes for hinges - but that was an oversight and only two hinges ended up being used. I fixed this mistake now.

B) Holes at the back- they are there to screw the shelf support onto the back; the shelf can be moved up or down.

C) Painting mistake- this is a reminder to double and triple check all parts and from all angles because door and windows are particularly tricky to spray paint; by the time I realised I forgot to paint this side, it was already too late to fix it.

D) Too many parts- I sliced this model into 8 parts because I couldn't get it to print properly, eventually I realised the fault was with my new filament and not the model itself; since I was more than half-way through printing I just continued instead of reprinting the original 2-part model.

Step 4: Part 1 of STL Files

Decide which door knob to print (or use something else entirely).
Split the body of the booth into two or more pieces (however you want to print it), add holes for metal nuts at joining points. Do the same to the window model.

Step 5: Part 2 of STL Files- Choosing the Roof and the Platform

One of the things you have to decide on is the shape of the top. I made two versions and either one will work. The green booth in the picture has the second top model.

Another thing to choose- base. There are three options: fast and sturdy hollow base, full base (you could add a hole for an on/off switch in this one) and a third base with a drawer.

If you are using LED lights in this project don't forget to create small holes, so you can thread your cables through.

Step 6: Part 3 of STL Files- Choice of 'glass' and Door Design

Another thing to decide is what to use as the 'glass' for the windows. You'll need three transparent panels, each one about 20cmx41 cm.

Three options are available:

1. Leaving windows and door bare and without any plastic 'glass'.

2. Using rigid acrylic sheets 0.5-2mm thick.

3. Using thin plastic film from cheap photo frames.

I went with the third option and bought three A3 photo frames in Poundland, each one £1, big enough to cover each window and door.
Another option would be using frames from IKEA. IKEA frames used to have thicker plastic but recently they started using thinner, more flexible plastic you will be able to cut it with scissors ->

It's important to decide before printing because each of these three options uses different door design.

About my plastic 'glass'- the plastic sheets are quite reflexive, they have this glare, almost like polarisation when exposed to light. It doesn't bother me at all, but do take a look at the video so you get what I mean and keep that in mind when choosing your 'glass' option in case you don't like this end result.

Flexible sheet of plastic has to be glued down to the frame (Step 17), but rigid acrylic sheet slides into the frame (see video above).

Step 7: How to Adjust Your Model in Tinkercad- Labels

Before 3D printing you have to adjust the size of the labels in Tinkercad. To do so you have to print the labels first. Use Word or similar program to create three separated cells with a word 'TELEPHONE' in each cell. I used Bodoni MT and Bell MT fonts, Elephant font is also an option.
Check your models in Tinkercad to get a rough idea of how large the labels have to be. My top had enough space for a label between 140mm and 170mm. I printed 'TELEPHONE' in Bell MT, size 65, once printed, I measured the cell and used those measurements to make an appropriately sized label in Tinkercad. See video.

Step 8: How to Adjust Your Model in Tinkercad - Hardware

Hardware supplies:

  1. 16 nails with heads cut off, I'm using this exact size nails ->
  2. two strong magnets, 4mm x 3mm or 4mm x 4mm ->
  3. strong, thick metal thingy to be used when connecting two parts of the main body, this is what I used -> I had it laying around for ages and it fit this project perfectly, each nut was about 30mm long and 5 or 6 mm in diameter, you can use something different as long as it's sturdy metal
  4. two small hinges, the type for jewellery boxes ->

Since most of your hardware will be different from what I used and you will probably scale your model up or down anyway, you will have to change the dimensions in Tinkercad. You need all those pieces to fit perfectly and to do that you should print small parts of the model to check dimensions and figure out how big the holes for nails, nuts, magnets and hinges should be. You want a tight fit, nothing should be loose, leave only the tiniest space for glue. It's also a good idea to print a part of door and frame to see how the hinge is behaving and if it moves the right way.

Step 9: IRONING in Cura- How to Print Windows and Door Parts

Cura has this fantastic feature- IRONING. When enabled, the nozzle goes over flat surfaces of the print and essentially irons out any visible lines. Check the internet for more info and more examples.

If you use this feature while printing windows and door parts, you will cut the need for sanding and you most likely won't need any filler. I of course forgot about it until I already had most of them printed in regular mode, so I had to sand like crazy...

Don't be a hero- use IRONING!

Step 10: Printing and Testing + Magnets

I printed all parts with thick walls (1.6mm) and 20-30% infill. Since I planned on sanding everything anyway, I didn't bother enabling RETRACTION, so I ended up with some stringing, which was easy to remove, but if you don't plan on using fillers, you have to engage RETRACTION for the main body.

When all parts are printed, assemble them together to check if everything fits right. Check if the top of the booth and the bottom platform align with the main body and if your prints haven't developed elephant's foot.

It's a good time to glue the magnets now, so you don't forget later on.

Step 11: Filler, Filler and More Filler + Sanding

I don't really know what to say here, this step all boils down to applying filler and sanding everything smooth while trying to remain patient. The amount of sanding depends on the quality of your print and your desired final effect. I wanted to make my booth look as smooth and plastic-y as possible, so I spent a lot of time sanding.

One thing I can't recommend enough is using emery boards when sanding all those small spaces on windows and the door. It's a game changer how much easier they are than regular sanding paper.

I also think it's better to do majority of sanding and filling before joining the two frame parts together. It's just easier to manoeuvre this way.

Step 12: Assembling the Frame

Although I used hot glue to join the main frame with metal nuts, I think epoxy would be a better choice. When the glue it dry, you will have to go over the joining point and cover the visible seam with filler.

Step 13: Adjustable Shelf- Design and Hardware

I wanted the shelf height to be adjustable. The front part of the shelf support is fixed to the frame, but the back part is removable. The idea is to screw the shelf support to the booth with short but sturdy screws (see video). However, in my experience, using screws in PLA objects ends up being a massive disaster over time. Plastic wears out, screws can't grip properly and in no time, the whole thing is useless.

To be safe I decided to do something weird- I cut small pieces of wall plugs and pushed them through the holes in the back. Now, I know for a fact that screws will deteriorate the wall plugs slower than they would PLA, so that gives me extra security. Regular wall plugs, size 5.

If you don't want an adjustable shelf, you can always change the design and fix the back shelf support to the wall, so it's printed within the frame.

Step 14: Window Assembly With Metal Pins

To connect window parts, you have to use epoxy and metal pins (nails). Then, you have to use some filler to cover up the joining line.

Step 15: Spray Painting

Spray painting is honestly the most annoying part of this project and that's saying something since I hate sanding with passion.

Before spraying colour, you might want to use a layer of primer, preferably grey.

Use black spray to paint label holders and the platform and gold paint for the emblem. I like to paint small pieces by using Blu Tack to temporarily glue them to a long stick like a chopstick or a thick skewer to avoid touching the pieces when wet.

The main body has to be spray painted from the inside first, you will have to move the model around, angle the booth and do some acrobatics to access all corners. That being done, you can move to painting the outside parts of the body.

Windows also have to be painted on both sides and you have to move the pieces around to spray all those nooks and crannies.

It's not strictly necessary, but you can use a clear sealer or varnish afterwards. I opted for a matt sealer to keep the shine to the minimum since I don't like that look.

Step 16: Labels and Emblem

Use clear, wide packing tape to cover the entire 'TELEPHONE' cell. Add tape to the back too, don't forget the back, otherwise glue will seep through paper and create ugly spots. Use a ruler and a craft knife to cut the label along the cell.

Use epoxy or plastic glue to adhere the label to the 3D printed label holder. Then trim and glue toothpicks to the backs of the labels and to the emblem, and affix them to the top- see the video.

Step 17: Windows and Door Assembly With Glass

Measure how big you need the plastic sheets to be to cover the windows and trim them to size. Use two part epoxy to glue it to the underside of the window and leave it to dry. Apply epoxy to the window cut out and affix the window pane onto the main body.

For the door, if you are using a thin plastic sheet (like me), you have to glue that sheet to the 'glass' frame. The 'glass' frame's parts should of course be glued together and painted red. Once that plastic sheet is in place, you can glue it to the main door part. It's easy to align these two parts, so I just joined them together and used weak clamps and paper clips to keep everything in place while the glue was drying.

If you are using thick acrylic sheet and have 3D printed a 'glass' frame model for acrylics, you have to glue both parts together before sliding the acrylic panel through the slit (see Step 6).

Step 18: Hinges and Door Knob

Just in case, I went with both glue and screws to affix the hinges to the door. Once dry, I carefully added epoxy to the hinge holes located on the frame and then simply installed them and let them dry while keeping the door closed.

I then used toothpicks and glue to affix the door knob to the door.

Step 19: Top Fitting Blocks- Optional

These fitting blocks are just four 15mm x 20mm 3D printed cubes I hot glued to the top. The only reason they are there is because I wanted to have the ability to remove the top, so instead of gluing the top to the frame, I wedged the cubes inside the frame.
You can skip this part and glue the top to the main body, though I recommend using blocks anyway as they will help keep the top in position while the glue dries.

Step 20: Light and Final Assembly

My grow lights came with a flexible metal neck and a clamp, so I had to dismantle it to access the cable. The easiest and fastest way was to cut the flexible neck off at the base of the lamp and pull the cable out. These two light rings had cables that connected to each other, so I still had to cut through them to extract them and then to install them inside the telephone booth.

I used a hand saw and a steel file to carefully cut through the flexible neck, then cut the cable and extracted it. Then, to install it, I glued one light to the top of the booth and the other one to the underside of the shelf. Then it's just a matter of threading the cables through the holes at the back of the booth and using a soldering iron to reconnect the cables.

Once lights are in place and wired, you can finally attach the bottom platform and the top.

Step 21: Finished

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