This activity will guide you through assembling the BOE Shield-Bot, step by step. In each step, you will gather a few of the parts, and then assemble them so that they match the pictures. Each picture has instructions that go with it; make sure to follow them carefully.
All of the tools needed are common and can be found in most households and school shops. They can also be purchased at local hardware stores. The Parallax screwdriver is included in the Robotics Shield Kit, and the other two are optional but handy to have.
(1) screwdriver, Phillips #1
(1) 1/4″ combination wrench (optional but handy)
(1) needle-nose pliers (optional)
(1) robot chassis
(2) 1″ standoffs (removed from BOE Shield)
(2) pan-head screws, 1/4″ 4-40 (removed from BOE Shield)
(1) rubber grommet, 13/32″
(2) Parallax continuous rotation servos, previously centered
STOP! Before taking the next step, you must have completed these activities: Chapter 2, Activity 4: Connect Servo Motors and Batteries [1], and Chapter 2, Activity 5: Centering the Servos [2].
BOE Shield-Bot Chassis, partially assembled.
(2) Parallax continuous rotation servos
(8) pan Head Screws, 3/8″ 4-40
(8) nuts, 4-40 or lock nuts
1/4" combination wrench (optional, needed for locknuts only)
masking tape
pen
Note: You can choose to use either hex nuts or locknuts to mount your servos, both are provided. Locknuts provide a tighter connection, but if your robots need frequent repair or part replacements then hex nuts are the easiest to remove and reattach quickly.
(2) Nylon flat-head slotted screws, 3/8″ 4-40
(2) 1" standoffs (removed from BOE Shield previously)
(1) 5-cell battery pack with 2.1 mm center-positive plug
(1) 1/16″ cotter pin
(1) tail wheel ball
(2) O-ring tires
(2) plastic machined wheels
(2) screws saved when removing the servo horns
The robot’s tail wheel is merely a plastic ball with a hole through the center. A cotter pin holds it to the chassis and functions as an axle for the wheel.
When you are done, your completed chassis will look like one of the pictures below.
Left: "Outside-forward" servos
Right: "Inside-backward" servos
(4) pan-head screws, 1/4″ 4-40
(1) Board of Education Shield mounted to your Arduino module and secured with standoffs [3].
Using Different Pins for the Servos
The Arduino toggles Pin 13 briefly upon startup or reset. If this causes problems for a particular application, you can use Pins 11 and 12 instead of 12 and 13. Be sure to adjust your code accordingly.
If you are building the BOE Shield-Bot to use with ROBOTC instead of for this tutorial, follow these instructions for using different servo ports [4].
Links
[1] https://learn.parallax.com/180
[2] https://learn.parallax.com/185
[3] https://learn.parallax.com/170
[4] http://learn.parallax.com/node/359