In this Instructable you will learn how to build a swivel mount using DC (direct current) motors and a potentiometer. This Instructable is meant for beginners and is mostly an introduction to DC (direct current) motors and controlling their speed with a potentiometer.
- A Hot Glue Gun,
- Hot Glue Sticks,
- Two Popsicle Sticks,
- a Clothespin,
- a DC Motor,
- a Battery Holder,
- Batteries (AA, 3V),
- Wire cutters,
- Wire strippers,
- a Rubber Band,
- A pen,
- Three Screws,
- A Potentiometer,
- A Soldering Gun and Soldering iron (optional),
Step 1: Cutting the Cardboard Platform
Cut a 10 inch by 10 inch cardboard square and a small cardboard circle around one inch in diameter. Attach wire to the motor. You can either solder the wire, or just tape it. If you are taping the wire, make sure the wire touches the electric part of the motor, not just the tape.
Step 2: Preparing the Swivel Mount
Cut 1 ½ inches of hot glue stick. Hot glue one end of the hot glue stick to the cardboard circle, and push the axle into the other end. Since you can't really attach anything to the DC motor axle, the hot glue stick will allow you to attach stuff to the axle.
Step 3: Securing the Motor
Find the center and place your motor there. Hot glue the screws around the motor, facing down. Wrap tape around the motor and make sure that the wire is accessible from the outside.
Step 4: Wiring
Place the battery in the battery holder and attach the positive end of the battery holder to the rightmost input of the potentiometer. Take the positive wire of the motor and attach that to the center input of the potentiometer. Attach the remaining two wires together and turn your potentiometer off by twisting the center axle. Tape all the wires and the battery box onto the cardboard and hot glue the potentiometer to the cardboard.
Original Image from: http://www.wikihow.com/Wire-a-Potentiometer
Step 5: Creating the Crossbow Frame
Pull apart your pen by separating the ink dispenser with the frame. Cut the pen about 1 ½ inches from the top. The dispenser will be your arrow and the top part of the pen will be your arrow holder.
Hot glue two popsicle sticks into a cross shape. Hot glue the arrow holder over the intersection of the two popsicle sticks.
Step 6: Creating the Shooting Mechanism
Tape a clothespin to the end of the crossbow frame. Tape both ends of a rubber band to the horizontal Popsicle stick. Tape the centers of the rubber band together.
Step 7: Mounting the Crossbow
Hot glue the crossbow onto the cardboard circle. Make sure you balance it properly. To load your crossbow, pull back the rubber band and lock it with the clothespin. Load your arrow through your arrow holder. To fire, just release the clothespin. To turn your crossbow, just turn the potentiometer on slowly.