This instructable was created in fulfillment of the project requirement of the Makecourse at the University of South Florida (www.makecourse.com). This is a baseball trainer that was made using a 3D printer and an arduino. The baseball that was made with the purpose to teach the use how to throw different pitches by lighting up LED's located at precise locations on the ball. It also has the ability to rotate 90 degree's back and forth with the push of a different button. This is a useful device for anyone who wants to learn how to throw a two seam fastball, knuckle ball, curve ball, and change up. These pitches are great to learn if you ever want to be a dominate pitcher in the sport of baseball. The rotating aspect is a design feature to show the ball from different perspectives.
Step 1: Creating the 3D Printed Baseball and Stand
The files for the baseball and the stand are attached below and ready to be printed on a 3D printer. You will need both to create this project yourself. The baseball needs to be printed with a diameter of 3 inches (which is the diameter of a real baseball) and the stand has to be the same.These can be printed out of any color material you would like. After the ball and stand have been created in the printer make sure to take sandpaper and remove all of the supports. This is a slow processes because you don't and to break off any of the laces but it will give you a very nice looking product. The box located under the ball was provided by the make course at the University of South Florida and can be replaced with any box size big enough to hold and arduino and and a breadboard for the circuit.If you go to makecourse.com you can find the exact box dimensions and a file to use with the 3D printer.
Step 2: Circuit Design
For this circuit you will need an arduino (arduino uno was used in this project), breadboard, hookup wire, 5 LED's, 5 resistors (220 ohm - 1k ohm preferably) and 1 servo motor. The breadboard layout is shown in the picture above. While wiring this circuit you will want to use the LED's on the baseball and use the hookup wire in 2 foot pieces to connect the LED's on the ball to the breadboard. The reason that i say 2 feet of wire i so that you are able to pick the baseball off the stand and have plenty of slack to use the baseball trainer. The pin numbers that the LED's are connected are shown on the picture of the baseball trainer. The push button on the left of the circuit diagram is to make the LED's light up and the one to the right is to make the servo motor rotate back and forth.
Step 3: Arduino Code
Upload the code listed below into your arduino and it will run the circuit built in the last step. All of the code is commented so you will know the purpose of all the steps of the code. This code will take the input of the push buttons and either drive the servo motor back and forth 90 degrees (1 time per push), or light the LED's located on the baseball to show you the different pitches. This code uses switch statements that are triggered depending on how many times the button is pushed.
Step 4: Final Assembly
Once you have the circuit built for the baseball trainer, the code loaded into the arduino, and the baseball and baseball stand printed you can begin the assembly of the baseball trainer. First you will want to take the box you are going to use to contain all the components of the circuit and drill a hole in the center of the lid. The hole has to be big enough for the servo motor so that you can keep it hidden inside the box but still mount the baseball stand to the motor. Once the servo is secured to the lid and then the baseball stand secured to the servo motor. Drill holes in the lid to place the push buttons and wire the push buttons like the circuit diagram but without a breadboard (solder might be need for this). Drill a hole in the back of the box and run the hookup wire out of the hole and glue the LED's to the baseball in the indicated spots in the picture above. The first set of LED's is the fastball and knuckle ball, the second set of lit LED's is the curve ball and the last set of lit LED's is the change up. Now you have completed the baseball trainer have fun adding the new pitches to your arsenal and becoming an elite pitcher.