This costume only took me 2 days to make and another day to paint.
I started this costume by first figuring out some proportions. This involved me looking for every picture of a Tardis from the show I could find on the internet. I came up some percentages on the width of the Tardis, and from there made up my own numbers to build it to the size I wanted. The main body of the Tardis should be about 75% or your planned width with each corner panel being about 12.5% of the width. See my diagram for details.
Step 1: Materials Needed / Getting Started
You will also need:
-Carpenters glue (white glue doesn’t dry fast enough or is strong enough)
-Four 1x1 strips of wood
-Four 1x1/2 strips of wood
I made a box with the 1/2 inch strips and then used the 1x1's to create the 'legs'. I made this simple frame so that I would have something to attach all the cardboard to.
Sorry about switching units of measure, but to calculate my sizes and proportions quickly I switched to metric.
I based the size of the Tardis on my son. In my case the top square was 64 cm by 64 cm and I made it 103.5 cm tall.
Step 2: Building the Sides
Once I had my sheet I had to work out the dimensions of the door details (panels and windows). I measured out the height (103.5cm) and width (64cm) and then worked out dimensions to make the eight panels all the same size. The windows count as panels as their dimensions are the same as a panel.
See the image for the dimensions of my Tardis.
With the amount of cutting that will be needed I recommend getting yourself a pack of new blades. Changing the blades often makes the cutting go smoother and your hands will thank you by the time you are done. I used a metal straight edge and a cutting mat so as to save my floor.
I used the first panel I cut as a template to cut three more sides. In the diagram picture I only have the dimensions for one side of the sheet of cardboard, but both half’s are the same dimensions. Do not cut the sheet you've selected to be the entrance door in half yet. You need to keep this as a solid sheet for the time being.
Step 3: Attaching the Sides, Filling in the Panels
At this point you only want to attach three sides of the Tardis; the fourth side will be for the doors which will be dealt with in another step.
To create depth I glued another piece of cardboard to the inside of each panel. Carpenters glue doesn't take long to start to set so I only needed to weigh each board down for a short while. I used anything I could find (or would stay long enough) as weight.
Step 4: The Base and Add Extra Height
At this point I realized I needed a little extra height for my Tardis. You could incorporate this extra height in your original panels, but the door section must not have this extra height. All these seams will be hidden later by more cardboard.
I cut these panels 8 cm high and the width of each side. Remember that you'll end up with two sets of widths for these panels. One set will be slightly wider as they will overlap the other two in the corners.
Step 5: Fixing an Oopsy...
I fixed this issue by clamping my meter stick and setting a cut line between the adjoining cardboard. This is where a really sharp knife comes in handy. I sliced along the ruler to make sure It was a perfect line.
Step 6: Corner Trim
Attach the corner strips on three sides of the Tardis.
Next take the front door panel and place it on the Tardis. Do not attach it. Hold a corner strip on the door panel and mark the overhang on the door panel.
Step 7: The Doors
Once you have marked the Corner overhang, draw a cut line 1.5cm away from the overhang line towards the outer edge of the panel. Do this on both sides of the sheet. The reason for this is that the corner trim on the outside will hide the hinges for the doors.
Now cut the door sheet in half.
Next cut the outside strip off each door. I went to my local hardware store and bought a cheap set of door hinges for a couple dollars a set. You need to re-attach the outside strips with the hinges. I used a hot glue gun to attach the hinges with. Make sure you line up the two pieces to be re-attached perfectly or once you attach the doors to the Tardis they won’t open and close properly.
Once the hinges were dry I covered the panel’s 18 cm by 21 cm openings. If you cover them before this step it will just make it difficult to cut the doors in half and cut the sides.
Step 8: Attach the Doors and the Rest of the Door Trim
Run some glue down one of the wooden legs and place one door panel on. I stapled it in the top corner only to start so that I could adjust the doors so they were perfectly level with the base. If you don't do this and your doors are off at an angle a little, they will always fall open or closed depending on which way the angle is. I didn't want my doors falling open.
Once you have them level, staple the rest of the side of the door on. When you go to attach the other door, leave a slight crack between the two openings. This way the doors won't bind when you close them.
Step 9: Starting the Roof
I wanted to make sure that the roof glued evenly all around when stuck it on. So I used canned goods as they had enough weight and were small enough to balance on the top of the Tardis.
Step 10: Continuing the Roof
Step 11: Finishing the Roof
Draw an X though the sheet. The Tardis roof does not come to a full peak; it has a flat spot on top. At the center of the roof draw a 10 cm by 10 cm square. This box will be your fold lines.
In the picture with the ruler, you can see I made a mark at the corners 1 cm on each side of the line drawn to the corner. From these new marks you need to draw a line connecting the edge of the cardboard to the corner of the 10 x 10 box that was drawn in the middle. As you can see in the pictures I cut up these lines from the outside corner to the center box. Now fold all four flaps of the roof down until they touch. I used Gaff tape, but Duct or Gorilla tape as well (you just want a strong tape that won’t let go), to hold the flaps of the roof together for the time being.
Place the roof on the Tardis. To hold it in place and stop the glue from pouring through onto my floor I taped around on the inside of the roof where it connects to the Tardis. I then poured glue into all the seams and used my fingers to smooth it all out. you don't want lumpy bits here, they will show too easily. I actually did two rounds of glue as I found the cardboard liked to suck it up into the spaces between the cardboard paper. I let the first round set so first so then when I did the second round, the glue stayed at the edges where I wanted it.
The last step of the roof was to cut out another 10 cm by 10 cm piece of cardboard and glue it to the roof. The Tardis light sits up slightly so i found one piece was all i needed to make it look right.
Step 12: Making the 'Police Box' Panels
Next take a full 53 cm strip and center it on the Tardis. Glue it at the same level from the top as the previous piece. This will be the board you will place the ‘Police Box’ sign. Do this on all four sides of the Tardis.
Step 13: Finishing Details
For the light on the roof I used a Mason jar. I hot glue gunned the lid to the roof and then just screwed the jar on. I ended up using a mag light with the top off as the light, so before a glued the lid down a punched a hole in the lid and the cardboard to fit the light through.
Step 14: Painting
I used CIL Rich Navy and applied it with an air sprayer. I did this all outside on my driveway to avoid the fumes. If you spray it make sure its not too windy or nothing is close that you don't want any over spray to hit. In the bright sun it looks very blue, but under normal lighting it looks like the perfect Tardis blue.
Once the outside was done I painted the inside gloss black to hide all the TV advertising and it served to give some depth.
To paint the windows I taped around the windows leaving a 1/2 cm around the edge as a border. This will also line the windows up with the rest of the door panels when done. Make sure you put paper on the inside too or the white overspray will show on all the black inside the Tardis.
Step 15: Adding the Signage
I lucked out and they were able to print the "Pull to Open" sign as a sticker which made my life a lot easier when it came to attaching it. I printed that sign at 20cm by 17cm.
The St' John's emblem I just printed myself. My wife is into scrap booking and has a Xyron sticker making machine so I ran it through that. You’ll want to print the emblem at 6 cm across.
I ended up screwing up one of my Police Box sign and the perfectionist in me made me re-do the one. I printed it off in three sheets (I've posted them here in case you wanted to go that route) and glued them together. Spraying the gloss coat on after helped hide the seams. Any sheets I glued on I used the carpenters glue again. Use your finger to spread it around thin and evenly for best results.
Step 16: Mounting Brackets
I would still install this piece in your Tardis as the handles did come in handy when walking around.
The next method I tried, which worked quite well, was to build a bracket to mount a backpack to. I installed two cross beams at the back of the Tardis. You'll need to make sure they are not flush with the back. I then put two vertical beams in. I found that once I put the backpack on the center of gravity for the Tardis was too far forward, so I removed the backpack and added some spacers and another two vertical bars. This put my son more in the middle of the Tardis and the balance was much better when he put it on.
To mount a backpack I just put the backpack against the bars and ran a heavy tape around all the bars and the backpack to secure it in place. I found that one vertical strip and two horizontal strips worked great. Using a backpack that has both a chest clip and a waist strap will work best.
Step 17: Have Fun!
The costume was a huge hit at the show. My son couldn't walk 5 feet without someone wanting a picture with him. He even made the newspaper the next day.