Candypult--Computer Controlled Candy Catapult

Let's start with the parts list and schematic.

Parts:
Arduino
(2) Hitec HS-311 servo motors (Amazon.com)
(1) Hitec HS-645MG servo motor (high torque)--Amazon.com
(1) mini Servo YKS SG90 (Amazon.com)
(1) Two channel remote control toy--I got a car for $11.99 at a local pharmacy
(3) 5 volt relays--Jameco.com #139977 (these are polarized so that positive voltage on one coil lead causes it to pick up, but the other polarity doesn't; you can produce the same result with a 5 volt relay and a diode.  Relays "B" and "C" only operate one at a time--based on the polarity provided.)
1/4" x 3 1/4" x .025 spring (available at Lowes)
(6) 12" servo extension cables
Spring from a ballpoint pen
4" lazy susan http://www.amazon.com/Capacity-Bearing-Turntable-Bearings-VXB/dp/B002TIKEQ6/ref=sr_1_2?ie=UTF8&qid=1372692771&sr=8-2&keywords=lazy+susan+4+inch
9 volt, 500 ma DC power supply
6 volt, 1 amp DC power supply
3D printed parts, design and print files at:
http://www.thingiverse.com/thing:110350
Wood, screws,paint, wire, jumpers

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Wireless RF Controlled Fire Effects

The basic parts of creating a fire effect can fill an entire instructable. In fact, someone has already done a good job explaining this process! Check out:

http://www.instructables.com/id/FireHero-Turn-Guitar-Hero-into-an-extreme-sport-b/

For anyone trying to build propane flame effects, there is a critical element which needs controlling: a solenoid valve. Solenoid valves are basically electrically controlled valves. These come in a variety of different versions depending on your voltage / polarity requirements. Fenrir uses 120V AC solenoid valves. In short, connecting 120V to the 2 lead wires of the solenoid valve opens the valve. Disconnecting voltage from the solenoid closes the valve. I got my solenoid valves from ebay seller valves4projects (http://myworld.ebay.com/valves4projects/)

SAFETY NOTE AGAIN:
If you buy solenoid valves from anywhere for use with propane, make sure they are properly rated for use with propane. Water valves will *NOT* work. They will degrade...you will hurt yourself, or something will explode. Valves seals should be viton. Valve bodies should be brass or stainless steel. Valves should be rated at 200psi or greater.

To control the valve, we'd like to use microcontroller to do the RF sensing, and the opening and closing for us. A microcontroller is like a miniature computer that can't do a lot. Actually, I tell people to think of microcontrollers as little gremlins that you can poke with a small electrical current and they will flick a switch on or off for you...its a bit closer to reality. Arduino is a really popular and useful microcontroller if you are familiar with those. For this project, we are going to be using Pololu's Wixel instead (http://www.pololu.com/catalog/product/1336)

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