Doctor Who has had many companions over the years, and when fans get asked "Who is your favourite Dr Who companion?", you will usually hear answers like Rose Tyler, Sarah-Jane Smith, Captain jack Harkness, Leela and Jamie McCrimmon among a few others. But whenever I get asked, I have one simple answer, K-9. Although he was not in many Doctor Who episodes, only the ones with Tom Baker and 1 episode with David Tennant, I just couldn't get enough of the little guy. He was witty, loyal, very clever, and of-course, he looked really cool. I mean, come on, he was a robot dog. How cool is that. Not to mention he had a bite worse than his bark in the form of a laser weapon (very cool if your 8 or 80).

So after building Dalek BOB, there was only one logical conclusion, to build my own K-9. But before I get any virtual "rotten tomato's" thrown at me and saying "Yours looks different to the original" I'll be the first to put my hands up and agree. Allow me to explain. The idea was to build a proper full size replica using MDF wood that I hopefully will start to build later in the year (2014), so I started to make a rough scale size(about half size) frame and side panels using cardboard to see if I could get the body shape right. I did make a bit of a boo boo and got the measurements and overall design a bit wrong, but not wanting to waste the cardboard I had cut out, using a radio controlled tank I had laying around, and raiding the recycle bin again for any useful boxes and items waiting to be thrown out, it ended up becoming a full build, having a little fun with the body design and adding some different features. (phew, I think I got away with that one)

Just before I list the materials I used, I would like to tell you about the main inspiration behind this build. Apart from wanting my own K-9 because I love dogs and love robots, and the superb K-9 Instructable made by Podpadstudios, the main reason was that I came across an artificial intelligence research website which offered an iPhone / Android / PC app in the form of a "chatbot" with a voice synthesizer, and I thought to myself "I want to use that in a robot", and what better way to use it, than in a homemade K-9. If your not familiar chatbots, they are computer program's designed to simulate an intelligent conversation via text and/or speech recognition, meaning  you can have a real time conversation and see or hear what the chatbot responds with. The app offers a pre-programmed bot you can teach, add, and change responses to, or a bot you can train yourself from scratch. The voice has a great robotic sound which is very clear to understand (I'll try to make and add a video to the end of this Instructable). Not quite the high pitched, nasally, pedantic tone superbly voiced by John Leeson in the show and spin off's and briefly by David Brieley , but it sounded good enough for me. Anyway, more on the voice later.

Most of the materials I used were from our recycling bin and other items I had laying around the house. The only items I purchased will be at the end of the list. So, what did I use to make this little guy?

Corrugated cardboard from packing boxes
Thin cardboard from a couple of cereal boxes
Long cardboard tubes from Christmas wrapping paper and aluminium foil rolls
Polystyrene packaging
PVC foam carpet underlay cut off's
1 length of bamboo
A length of disused plastic curtain rail
Vacuum cleaner hose
6 red LED bulbs
5 orange LED bulbs
A black plastic ring (not sure what it came from)
2 telescopic aerials from a broken indoor TV antenna
A translucent pink drinking straw
Battery powered WiFi camera
Bluetooth speaker
An old MP4 player
2 translucent DVD cases, 1 red, 1 green
Electrical wire
A length of foam tube (water pipe insulator)
A battery powered sound activated flashing light circuit
Various screws, nuts and bolts
And of-course 1 radio controlled tank which had been sitting in a box for a few years. Slightly worse for wear but fully functional.

The few parts I purchased were

A length of 20, battery powered, blue LED's (around £3.50 / $5.70)
2 cans of 500ml grey primer spray (£7.00 / $11.50 for both)
1 can of 500ml clear lacquer (£6.50 / $10.60)
and a small T.A.R.D.I.S keyring (£4.50 / $7.30)

The tools and adhesives I used were,

Phillips screwdriver
Set of electrical/jewellery screwdrivers
Wire cutters
Pair of scissors
Craft knife
Pen or pencil
A straight length of scrap wood
Black permanent marker
Drill with various drill bits
Electrical/insulating tape
Super glue
1 tube of grab adhesive (No More Nails of similar)
Duct tape
And a small peace of Velcro.

So before we start, I just want to reiterate that the actual dimensions and measurements I used for this build, are not correct  specifications to make a true scale size replica of the original, but measurements I used to make the little guy you see in the photos. Example's of this is the head I made should of ideally been slightly longer and thinner, and the body taller and angled towards the top of the body, but as I mentioned before, I now wasn't going for exact, I going for my own interpretation and to have a little fun with it. I will however, use the correct specs for my wooden full size replica which I will feature later in the year. I also used some artistic license for things like the eyes, ears, and control panel, just so I could add some features and make it a more fun and personal custom build.

I hope that this Instructable will give you some ideas and inspiration, and that you find it entertaining and informative. I have tried to keep it as simple as I can, yet detailed enough for any novice and seasoned builders alike and including photos you can refer to. So, lets begin

Step 1: Body and Body frame

The radio controlled tank I had measured 40 centimeters long, 20cm wide, and 5cm from top of the base to the ground. The base of the tank was completely flat which would make for easy fixing later on. Although it was working it was also over 10 years old so it couldn't take a lot of weight, so I had to keep the total build weight down as much as possible. So with them measurements in mind, it's time to make the main body. Note: There are probably easier, stronger, neater, overall better ways to make the frame, but as I mentioned on the introduction this didn't start out to be a full build, only a scrap cardboard dummy to see if I could get a nice all-round shape. Anyway, lets crack on.

The materials and tools I used were,

Sheets of corrugated cardboard (from boxes ect)
Couple of sheets of scrap A4 paper
A length of bamboo (about 2ft long)
Craft knife
Short length of wood
Super glue
Grab adhesive
Roll of duct tape
And some clothes pegs.

1.)  For the frame use some corrugated cardboard, cut out some strips using a craft knife and ruler (or a straight length of wood) making them about 5cm wide, and cutting along the length of the corrugate. You will need,

2x 55cm strips (base sides)
2x 25cm strips (top sides)
2x 28cm strips (base front and back)
2x 18cm strips (top front and back)
and for body height,
4x 24cm strips (front and back vertical supports)

Then cut out some more smaller cardboard strips, 2cm by 4cm, and bend in half to make 2cm by 2cm "L" shape bracket fixing tabs.

2.) Super glue some fixing tabs to each end of the 55cm strips, then glue the two 28cm strips to the tabs to make the lower base frame which will now stand 5cm's tall (see photos for references). Now do the same with the 2x 25cm and 2x 18cm strips. Cut a length of bamboo in to 2x45cm and 2x 28cm lengths. Apply some grab adhesive to the inside of the base strips and attach the bamboo lengths. Use some duct tape for added support (optional). This should just now fit over the tank base with a little room for movement.

3.) Using the 4x24cm strips and glue, attach the front corners and about 10cm's in from the back corners to the larger frame (the base) at a slight angle, then attach all 4 corners of the smaller frame (the top)  to create a sort of shallow pyramid shape with 10cm's of the base side strips protruding from the rear lower base frame. Cut two more strips to make a cross section (as seen in the main photo). Cut both strips half way down in the center, slot both center cuts together and glue. Use a few more fixing tabs and fix the cross section to the top of the frame so it sits flush on top.

4.) To help create the angled sweeping back, cut out 4 more strips about 9cm long, glue 2 of the peaces together at a slight angle. Then glue 1 end to both rear base corners and glue the 2 other ends to the diagonal strips so they sit about 3/4 of the way up (as seen in the photos). Then cut 2 more strips and fix across the frame joining the middle where you joined the 2 9cm strips, and where they join 3/4 of the way up. Insure these extra strips are facing outwards so you can attach the rear body panel later.

5.) To finish this section off for now, use a couple more sheets of corrugated cardboard to cut out 2 front panels and 1 rear body panel. Lay the front of the frame onto one sheet of card, draw around the edges then use a knife and ruler to cut around the markings. Pipe some grab adhesive all around the front of the frame and attach the front panel. Leave to set using clothes pegs to clamp in place. Put the second cut front panel aside for now as this will be used a little later on in the build

6.) Now you want to cut out the rear panel. This is a little more difficult because of the angled back of the frame. Measure all the rear frame strips across and down, then measure and mark on to a scrap peace of paper or card. Marry it up to the frame and trim to a nice fit, marking where the bends in the body panel will be. Use this as a template and mark on to another sheet of corrugated card, also marking where the bends will be, and cut out. Use a length of wood and place on to the cut out panel, lining it up to the bend marks, then carefully bend the card. Do the same with the second set of bend marks, bending the card in the opposite direction. Pipe some more grab adhesive to all of the rear frame and attach the rear panel, again using clothes pegs to clamp in place where possible.

In the photos, you will see I used duct tape in a lot of areas especially in the corners. I used it just as a little extra reinforcement for any joins I glued.

7.) At this stage you can now cut out the two side panels. For the side panels I used a box my digital video recorder came in, as the to large sides of the box were a good fit. I cut the box to give me the 2 flat large sides, then doing one side at a time, I laid the frame on to the the cardboard, stenciled around them, cut them out, labeled the left and right hand panels. I labeled the panels left and right because I wanted to laminated sides to face outwards for a smooth finish when painting. These were put  to one side as these will be attached a little later on in to the build.

Next we will be making the head and neck sections.
<p>He is beautiful! Loved it, great job!</p>
Many thanks for your comment @CarmellaR. It's very nice of you to say. He was a great prototype for my K-9 2.0 build, and he's still around too.
Can you try to make a sonic screwdriver?
K9! So cool!
<p>this is really awesome work , </p><p>and thanks for the A.I program idea this will come in very handy for other project to ,</p><p>just a idea you could try painting epoxy / resin to make the cardboard tougher / more water proof , :-) </p>
<p>Yeah, that's right, I made it with my Kage Hat some years ago and it survived a rainy day at the con.</p>

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