Kit of parts (FTC)

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The Vex Robotics Design System line of parts. Image source: VexLABS [1]

Several weeks before the 2005 FIRST Championships, RadioShack (the official sponsor of Vex) unveiled the Vex kits at their stores. Dubbed Version 0.5, the main kit, which sells for $300 USD, contains everything to make a simple Vex robot. Additional parts, such as spare motors, servos, wheels, and gears were available in Version 0.5. The entire line of parts (Version 1.0), including a programming module and advanced sensors, was released in August 2005.

In addition to standard Vex parts, VexLabs (a subcompany of Innovation First, Inc.) is credited with developing new beta components for possible inclusion into the standard Vex kits. Some of these new mechanical pieces include new/longer 1x1 and 2x2 angle pieces, 1x2x1 and 1x5x1 C-Channel, Linear Bearings, and more. [3]

Line of Parts

• Starter Kit (v0.5)
• Extra Gears Kit (v0.5)
• Sprocket and Chain Set (v1.0)
• Vex Motor (v0.5)
• Vex Servo (v0.5)
• Extra Metal Components (v0.5)
• Extra Wheel Set (v0.5)
• Omni-Directional Wheel Kit (v1.0)
• Tank Tread Kit (v1.0)
• Additional R/C Transmitter/Reciever (v0.5)
• Additional R/C Radio Crystal Packs (v0.5)
• Vex Rechargeable Batteries (v0.5)
• Programming Module (v1.0)
• Limit Switches (v0.5)
• Bumper Switches (v0.5)
• Line-Following Sensor (v1.0)
• Light Sensor (v1.0)
• Ultra-Sonic Sensor (v1.0)

Vex Controller

The Vex Micro-Controller. Image source: VexLABS [2]

The Vex controller uses two PIC18F8520 micro controllers, a Master and User which are uses to execute tasks. Vex robots can be driven by R/C or by an autonomous mode. A stock autonomous mode is available, but users can modify and change their autonomous mode by using the Vex Programming Module and either EasyC or MPLAB. The Vex Controller runs off 7.2 volts, and is compatibly with both Vex rechargeable battery packs and standard 7.2V hobby batteries.

Inputs / Output Ports

The Vex Controller has 16 Analog/Digital Input/Output Ports, one RX and one TX port, 8 Pulse-Width-Modulation Motor Ports, and 8 Interrupt Ports. There are also two (RX1 and RX2) Radio Modem/Tether ports and one Serial Port on the side of the controller.

Analog / Digital Ports

In addition to the official VEX sensors, custom sensors (ex. Potentiometers, Infrared Range Sensors, etc.) may be used with the Vex controller. Devices such as a Spike Relay, a pneumatic solenoid, or a LED may be controlled via the Digital Outputs of the Vex Controller

Interrupt Ports

These ports are used to 'Interrupt' the main user program, in the case that a certain sensor has a much higher frequency than the main program loop. The Vex Ultrasonic and Optical Shaft Encoders both utilize Interrupt Ports.

Motor Ports

The eight Motor Ports on the Vex Controller use Pulse-Width-Modulation to control the Vex Motors and Servos. Standard hobby Servos and the Speed Controllers used on full-size FRC robots may also be controlled via the Vex Motor ports.

VEX Motors and Servos

Motors

The standard Vex motors are continuous-rotation, geared, Futaba servo-motors. They have a maximum speed of 100 RPM. There is no discernible difference in clockwise and counter-clockwise rotation speeds.

Servos

The Standard Vex servos are limited-rotation, geared, Futaba servo-motors. They have a maximum rotation of slightly under 180 degrees. The only discernable difference between a Vex Servo and a standard Futaba servo motor is merely cosmetic differences.

Sensors

In the current line of Vex parts, there are six official Vex sensors. These six sensors, include limit switches, bumper switches, light sensors, line following sensors, ultrasonic range finders, and optical shaft encoders. The Vex limit and bumper switches report a digital signal, while the light sensor and line follower use a analog signal. The Ultrasonic and Optical Shaft Encoders both utilize Interrupt ports when being programmed. The Ultrasonic part also needs a digital output port to create the ping pulse.

Pneumatics

Although not legal in the 2006 FIRST Vex Challenge, VexLabs sells pneumatics kits for the Vex Robotics System. These consist of a accumulator, regulator, solenoids, and single and double acting cylinders. The solenoids can be controlled via the digital output ports on the Vex Controller. The maximum recommended pressure for the accumulator is 120 PSI. The cylinders have a bore diameter of 10 millimeters, and a bore stroke of 200 millimeters. (Source: VexLabs [4])

The Vex pneumatics kits do not contain a onboard compressor, which means that the accumulator has to be recharged by an external source of compressed air (such as a bicycle pump or a FRC compressor). Regulated to the correct pressure, the accumulator can last for up to 45 cycles of the pneumatic cylinders. (If double acting cylinders or a higher pressure are used, the maximum number of cycles drops significantly).

VexLabs Beta Parts

To expand the line of available mechanical parts in the Vex kits, VexLabs (a subcompany of Innovation First, Inc. began to produce alpha and beta stage prototype mechanical pieces for possible inclusion into the standard Vex Robotics System kits. These new pieces include:

• Linear Slide Pack
• 1x1 Left and Right Angle (With Slots)
• 1x1 Angle (Without Slots)
• 2x2 Angle
• 3x3 Angle
• 1x2x1 C-Channel
• 1x5x1 C-Channel
• 2x1 Chassis Rails
• 3x2 Chassis Rails
• New Chassis Kits
• New Threaded Beam Sizes
• Threaded Beam Couplers
• Longer 8/32 Screws