Step 1: Get it before you hack it
I purchased my first Butterscotch off of Craigslist for $20. I have since picked up a second one for $25 from a peddlers mall. I commonly see them listed for ~$100, but with a little negotiation and/or patience you should be able to pick one up for dirt cheap.
Step 2: What you will need.
Hardware you will need:
- FurReal Butterscotch or S'More Pony
- Arduino Mega
- Wire 18g
- Electrical tape
- Wii nun-chuck
- Wii Nunchuck breakout adapter
- 0.1" 16-pin strip male header
- 1/8th OD ptfe tube (trade name Teflon)
- Bowden cable (brake cable for the back wheel of a bike)
- Scrap PVC tube around 3" at about 1' long
- Scrap plexi glass
Tools you need
- Wire Strippers
- Razor blade
- Phillips head screwdriver
- Flat head screwdriver
- Soldering Iron
- Computer to program the Micro Processor (Any OS)
Step 3: Removing the skin: Head first
Step 4: Removing Skin: ENT
The ears break off easy (one was already missing when I got to this point). The other broke off when I was trying to get the skin off. This is not a problem as you can glue them back on easily. If you wish to keep the ears attached, you can cut the cloth around the ear holes with a razor. If you are OK with taking them off, a hard tug should pop them right off. Once the ears are removed, pull on the fabric where it tucks into the head. This will rip the seams, freeing it up.
Roll the skin further down, and you will get to the eyes. The fabric is sewn into the top and bottom of the eyes. Simply cut the stitches here to detach the fabric. Try to not look your pony in the eyes when you do this, as you may start feeling bad about what you are doing.
Moving down to the ponies nose, there are 2 pegs holding the rubbery snout on. One in each nostril. These slide out without much trouble, away from the body in a parallel fashion. The rubber on the snout is thin, so try to get a grip on the hard plastic with your tool as not to tear it.
Step 5: Remove Skin: Straight from the horses mouth
To removed skin from the upper jaw you just need to fold the face down until you see a horse shoe shaped piece of plastic around the mouth. It will have 4 pegs pushed up into holes with 3 legs that close around them. You will just need to bend 2 of the legs on each peg back and they will pop right out.
The bottom jaw will most likely have popped off by this point. We need to remove the jaw plastic from the rubber. It for the most part will pill off but it will take some time. I also had to cut some spots with a razor that where to fused.
After you get the lower jaw removed slide it back into the slot under the chin and glue it into place.
Step 6: Remove Skin: The body
On the underside pull the velcro open. In the back side where the Velcro ends you will find a zipper leading up to the tail. There will be stitches at each end holding it together but no slider. cut the stitches and it will come unzipped. There will only be a small area holding the zipper area to the Velcro area. Cut this small bit of fabric and we will move to the front.
The frond end of the Velcro has a small stitch leading to a T intersection. Unstitch this area then unstitch along both sides of the T till you get to the legs.
Step 7: Removing the skin: The legs
At the top of each leg you will need to remove some stitching leading around the intersection of the inner leg and the lower side of the body. When you get close to the stitches running along the bottom of the pony that you have already cut, snip away the fabric in between. You should not be able to lift the skin up all the way around the head.
Step 8: Removing the skin: the Neck
Step 9: Removing the face
Under the face you will find that the circuit board is held in place by 4 screws. Remove these screws, as we will do most of our work from the lower side.
Step 10: Getting access to the Circuit board in the lower body.
Step 11: Cutting the power to the Microcontroler
To do this, cut the trace going to the 4th and 5th pin on the larger of the two boards sticking out at a right angle. The traces will be on the back side of the board. The 4th pin should have a white wire soldered to it. Using a razor you should be able to cut the trace without a problem.
Step 12: Tapping power for the Arduino
Step 13: Tapping the lines into the motor control circuit.
On the board in the pony's head you will need to solder your wires into R14 ,R15, R27, and R28
R14 and R15 move the head up and down plus open and close the mouth.
R27 and R28 move the head move left or right as well as move the eyes and ears.
On the board in the body, you will want to solder you wires onto R10,R42 and R11,R41
R10/42 move the head left and right
R11 Moves the tail (only one way)
R41 bobs the head up and down at the neck (moves one way around in a circle like the tail)
Step 14: Taping into the encoders.
Solder a ~2' long wire to each of these encoders. I used 18g wire.
For the encoders in the body, I was unable to find an easy way to get to them, so I cut the end off of the wire. We will solder the wires from this cable right into the bread board so strip them and you are finished with them for now. Try to leave these wires as long as you can.
Step 15: Getting the morors and sensors connected to the arduino.
Resistor label --- Pin on the Arduino
R14 Pin 23
R15 Pin 25
R27 Pin 27
R28 Pin 29
R10 Pin 37
R11 Pin 35
R41 Pin 31
R42 Pin 33
To get the pins connected I soldered them to the end of .1 male header.
Step 16: Connecting a wii nunchuck into the system.
On your mega, connect it as such
You will want to check the arduino wiring documentation if you are using something other then a mega
Step 17: The Arduino Code.
The sketch has to bitbang the PWM sent to the motor controls as there are to many pins to do it on PWM pins. I think it runs too slow for the Arduino to do it with hardware anyways.
Current controls work like this:
Push the joystick one way and the head will start moving that way from a dead stop.
Move it the opposite direction from the way it is currently moving and it will stop moving.
Move it up or down and it will move that way from a dead stop.
Move the opposite direction then the head is moving and it will stop moving.
C moves the Tail
Z shakes the head
The mouth moves when the head is moving up and down.
The ears and eyes move when the head is shaking.
Step 18: Getting the fuel to the head
To attach the fuel source, we will connect one spray caps from the starter fluid to a teflon tube that runs from the hole in the belly up along the neck and then out just over the nose where we will place our igniter. The tube will not be the right size to fit into the cap so use a drill bit that is the same diameter as the tube to bore it out until it fits.
Be prepared for some frustration as Teflon is very hard to push into things do to its extremely low Coefficient of friction. Once you get it in, put some hot glue around the joint to hold them together.
Step 19: Building an ignition system.
The fuel has nothing to burn so if the ignitor is not running it will blow out in a small breeze. When modifying the ignitor you will want to connect one 6 foot wire to each lead. Ours had 4 leads, if you have the same type you can put electrical tape over the other two so that they do not spark inside of the body. You will also need to insulate the leads that you extended with tape, shrink tube, or hot glue to keep it from sparking at the ignitor rather than at your extension leads.
Step 20: Remote fuel trigger
Step 21: Follow up
Just remember to keep it safe and have fun.