Rocket Powered Tardis

While we wait for a new season of Doctor Who, why not build a Tardis??
This isn't just any Tardis, this one is rocket powered!

A rocket motor housing for model rocket engines such as A-D series Estes.
This includes transparent detachable fins for flight stability.
A parachute which ejects out of the roof of the Tardis.

Step 1: The Police Box

Parts

- Thick blue card (2mm thick). - Mine was only blue on one side, from Hobbycraft (UK)
- A cardboard tube from a cling-film or foil roll (diameter 24).
- Something for a light on top. I used a tall clear plastic push pin
- White grease proof paper - for the windows
- CD cases - for plastic fins
- Model rocket engine and parachute (optional)

Tools

- Ruler
- Craft knife
- General purpose glue
- Dark blue permanent marker

The box

1. The first step is to create the box. This is done by cutting out a rectangle 340 mm by 150 mm. This rectangle is then folded to create a rectangular tube. See picture.
2. On the white side of the card, along the 340mm edge, starting from one end draw a line every 82mm across the card. Each of these marks is where you are going to fold. After 4 marks there should be a little left for a tab to link the card into a tube.
3. This cardboard is thick so difficult to fold. At each mark, use a knife to score through half the thickness of the card on the blue side to aid folding.
4. Where the tab section is located peal away material from the blue side of the card to reduce the thickness of the tab.
5. Use a ruler to aid folding and create a rectangular tube, gluing the tab on the inside

The roof

1. Cut out 4 roof pieces. See image.
2. Score along the tab lines
3. Glue these to the top 4 sides of the rectangular tube adjusting so that they line up and the tube is square.

The roof cap

1. Cut 2 squares of the card, 24x24 and 30x30mm and glue to a 35mm long section of the cardboard tube as shown. Make sure the blue side of the card is on the opposite side to the tube.
2. Create a cone (I used a very small piece of card) and glue to the push pin. I also used a blue permanent marker to put 4 vertical lines on the push pin. Fix this to the top of the 30x30 piece of card.
3. The roof cap should neatly slide into the top of the Tardis roof.
4. Cut a slit in the tube of the roof cap and use to shrink the tube slightly. This should allow the end to slide inside an uncut section of tube.

Step 2: The Rocket

The rocket housing

Inside the Tardis a tube is needed to hold the rocket engine and parachute.

1. Cut a 150mm long section of the card tube.
2. At the end cut slits spaces 6mm apart in 4 places, about 10mm deep. Fold these inwards. These help support the rocket motor.
3. Try sliding a rocket motor half way in to check that they grip
4. 60mm down from this end cut similar slits in a U shape and fold these in. Again these should help grip the motor.
5. Stick a clothes pin through the middle of the tube a little further along (65mm from the slitted end). This stops the motor being pushed in too far. (Motors are typically 70mm long)

Supports

The rocket tube is supported using rectangular sections of the blue card. These are split and the ends to strongly attached to the tardis and the tube.

1. Cut 8 rectangular sections of card 15 x 70 mm.
2. Use a craft knife to split the card through the thickness of the card so that the ends are Y shaped. 10mm at one end and 20mm at the other.
3. Stick inside of the 10mm long Y shaped card end to the rocket tube, so that 4 of the supports stick out at 90 degrees. Repeat at the opposite end about 15mm from each end of the tube.
4. Fold the opposite ends of the split card back on themselves using the end of the tardis to judge where to fold.
5. Carefully slide the tube assembly into the bottom of the Tardis box as show in the picture.
6. Adjust to make sure the tube is straight and well centred. The tardis roof cap should also fit into the end of the rocket tube. Fold each split section back and apply glue.

Step 3: Decals

Final Steps

In order to get the box looking more like a Tardis some additional parts were added.

Door Frames

1. Four strips of card 150x16mm need cutting for the edges of the box. The 150x16mm sections of card need a 4mm wide section thinned out from the white side of the card. See picture. This allow them to be easily folded whilst leaving a good finish on the outside. Also a 35 mm long cut is needed at one end of this fold line for the fins.
2. 4 strips 82 x 8 mm are needed for the bottom of the doors
3. 4 strips 68 x 15 mm are needed for the tops of the doors
4. First the bottom door frames are fitted which line up with the bottom edge of the tardis box.
5. The edges/sides of the box are fitted and overlap the top of the box slightly. This hides the untidy corners of the roof.
6. The top sections of door frame are trimmed to length and line up with the top of the door frame sides.

Logos and Windows

1. Police box logos can be printed and stuck to the box.
2. The windows are made from translucent paper, a bit like grease proof paper but white. Stick these on with a very small bit of glue (I used a glue stick)
3. A marker pen and ruler can be used to add door and window panelling.
4. Small door handles can be carefully cut from card and stuck in place.
5. Any white edges or gaps can be filled in with blue marker

Step 4: Flight Preparation

Fins

Fins are needed to stabilise the Tardis in flight. I've made them removable and transparent as this isn't a normal feature of a Tardis!

1. Take some clear plastic and cut into a triangle. I used a CD case cover cut diagonally to create two triangles for fins. The dimensions I used are shown in the picture.
2. Shape the fins so that they slot tightly into the corners of the Tardis. The extra thickness of the door frames helps keep them sticking out at 45 degree.

Flight preparation

1. Insert fireproof wadding to protect the parachute
2. Tie the roof cap to the internal support struts with some cotton and tie the parachute to this.
3. Fold up the parachute and insert into the tube.
4. Place the roof cap onto the tardis making sure it holds the roof in place.
5. Add a small section of plastic tube to one of the fins and something near the roof of the tardis so that it can be slotted onto a rocket launch pole.
6. insert a rocket motor and you're ready to go!