This is a machine for smart kitties. Put a piece of candy in the hole on it's back, push the big button and watch as this CandyCat poops out your kitty's snack and waves it away with it's tail! A challenging treat that also looks neat!
One Arduino Uno
A (big) pushbutton
Plates of wood
Straight piece of PVC
Bend piece of PVC
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Step 1: Set Up Your Breadboard
To make CandyCat work properly, you need two servo's and a pushbutton. This can be a regular small pushbutton that comes with a standard Arduino Uno Kit, or you can buy a bigger one (like I did). Set up your breadboard like the image above, and choose a proper electricity supply. I used a 9V battery.
Step 2: Soldering
This step is optional, you could resort to keeping your project on your breadboard. If you decide to solder and need to make 3 wires connect, you could make a triangle. However, make sure you don't connect wires to each other without a resistor (if needed) in between.
Step 3: Coding
It's commented for your convenience. You can change the angle in which the servo turns, now that's 180° for the first servo and 140° for the second. This is important for later.
Step 4: Woodwork
I've enclosed the patterns to make your own CandyCat. However, thickness of the wood isn't included so you have to edit the sides, considering the thickness of the wood you're using, to make it all fit properly. You can draw the patterns on wood and saw it or you can convert them to dxf files and have them lasercut. I chose the latter.
Once you have all the forms it's pretty self-explanatory. You keep the two circles apart for later. You can use woodglue depending on what type of wood you're using. I used 4mm MDF and found Bison Tix glue the most helpful.
Once you've done this, you take the circle with the hole in the middle and take one of your cat's candies to measure a hole that's big enough to let it through. Cut the hole out of the circle and screw the circle (with the screw in the middle) to the first servo.
Step 5: Building the Innards
The first servo should be connected upside down next to the small hole on it's back. Take a piece of PVC pipe and make it the same height as the servo (minus the circle). Connect it to the small hole, creating a portal or lid. Take a second piece of bend pipe, that should fit between the lid and the small hole on the cat's ass. If the servo is placed properly and it's 'on', a candy should be able to directly pass from it's back out of his butt.
Now you can place your big button through the second hole.Put the servo through the rectangular hole above his butt and use a piece of wood that came out of the slids for ears to install the servo at a slight angle.
Take a piece of electrical cord and tie or strap it to the 'wing' of the servo.
Place your soldering, Arduino and battery in the cat. At this point it will get kind of messy due to all the wiring.
Step 6: Finishing Touch
Cut your pillowcase so it becomes one straight rectangular piece of fabric. Cut off one long strip at the side and use it to cover the electrical cord. Now you have your tail.
Drape the rest over the body, cut out the holes and make sure no fabric ends up in the servo. Glue it to the inside of your cat, put the ears in the slids on top and your CandyCat is ready for business!
The only thing left to do is teaching your cat to use it. Practice makes perfect!