Rule Modifications: Robot

<VUR1> Teams may use two (2) Robots in each Match.

1. Both Robots may only be built from the following materials: 
   1. Official VEX Robotics products (see <VUR2> 
   2. Fabricated Parts made by the Team (see <VUR3> through <VUR7>)
   3. Commercially-available springs, fasteners and bearings (see <VUR8>, <VUR9>, and <VUR14>).
   4. A legal electronics system (see <VUR10> and <VUR11>) 
   5. Any legal Additional Electronics (see <VUR12>) 
   6. A legal pneumatics system (see <VUR13>) 
2. One Robot must be smaller than 24” x 24” x 24” at the start of the Match 
3. One Robot must be smaller than 15” x 15” x 15” at the start of the Match 

Note: <SG2> applies as written to both Robots. 

<VUR2> Teams may use any official VEX Robotics products, other than the exceptions listed in the tables below, to construct their Robot. This includes those from the VEXpro, VEX EXP, VEX IQ, VEX GO, VEX 123, VEX CTE and VEX Robotics by HEXBUG* product lines. To determine if a product is “official” or not, refer to www.vexrobotics.com. Rule <R16> applies, and most modifications to non-electrical components are allowed. 

This rule takes precedence over all other rules regarding Raw Stock and/or Fabricated Parts, such as <VUR5>. 

* The HEXBUG brand is a registered trademark belonging to Spin Master Corp

<VUR3> Fabricated Parts may be made by applying the following manufacturing processes to legal Raw Stock:

1. Additive manufacturing processes, such as 3D printing. 
2. Subtractive manufacturing processes, such as cutting, drilling, routing, or machining.
3. Bending, such as sheet metal braking or thermoforming. 
4. Attaching materials to one another, such as welding or chemically bonding (e.g., epoxy).
5. Molding of non-metals, such as injecting polyurethane into a 3D printed mold. 

<VUR4> Fabricated Parts must be made from legal Raw Stock. To be considered Raw Stock, the material must be purchased in one of the following forms before undergoing the fabrication processes listed in <VUR3>: 

<VUR5> The following material types are not considered Raw Stock, and are therefore not permitted: 

Note: <VUR2> takes precedence over this rule. Materials purchased from VEX Robotics that fall under one of these categories (e.g., VersaFrame pre-drilled extrusion) are permitted. 

<VUR6> Fabricated Parts may not be made from Raw Stock which poses a safety or damage risk to the event, other Teams, or Field Elements. Examples of prohibited materials include, but are not limited to: 

1. Any material intended to produce flames or pyrotechnic effects 
2. Any material that is liquid at the time of the Match. Examples include hydraulic fluids, oils, greases, liquid mercury, and tire sealant 
   1. This does not include fabrication processes that involve the use of liquids, such as milling coolant or epoxy 
3. Any matter that shatters or otherwise presents an excessive field/safety hazard upon failure. Examples include fiberglass, acrylic, and carbon fiber sheet/tube stock
   1. This rule refers specifically to material legality itself. Any potentially unsafe mechanisms made from legal Raw Stock may still be addressed by <S1> and <R6>

<VUR7> Fabricated Parts must be made by Team members. Any Fabricated Parts must be accompanied by documentation that demonstrates the Team’s design and construction process for that Fabricated Part.

1. The minimum acceptable form of documentation is an engineering drawing with multiple views for the part in question. These drawings may be included in a Team’s Engineering Notebook or in a standalone appendix to the Engineering Notebook 
2. Any Fabricated Part must have been entirely designed and produced by Team members. For example, parts ordered by the Team and 3D printed by a third party would be prohibited 
3. Teams will be required to provide this documentation as requested by inspectors, Head Referees, or judges at any time at an event. Failure to provide acceptable documentation will result in the part being deemed illegal for use; therefore, <R3>, <R28>, and/or <G1> will apply 

<VUR8> Teams may use commercially available springs on their Robots. For the purposes of this rule, a “spring” is any device used for storing and releasing elastic potential energy. Examples include, but are not limited to: 

1. Compression, tension, torsion, constant force, or conical springs made from spring steel 
2. Springs made from elastic thread or rubber, such as surgical tubing, bungee cords, or stretchable braided rope 
3. Closed-loop (pneumatic) gas shocks 

Note: Gas shocks are not considered pneumatic devices in the context of <VUR13>. Gas shocks may not be modified in any way. 

<VUR9> Teams may use commercially available fastener hardware on their Robot. Examples include (but are not limited to): 

• Screws, nuts, rivets 
• Hinges, pins, rod ends, threaded rods, hose clamps 
• Ancillary fastener accessories, such as washers or spacers 
• Adhesives such as epoxy, glue, or tape (when used to join together two parts) 

If the primary function of the part is not “fastening”, then <VUR5>, <VUR6>, and/or <VUR7> take precedence over this rule. Illegal examples include (but are not limited to): 

• A prefabricated non-VEX wheel, even though it may technically connect tread to a shaft
• 80/20 extrusion; other items get “fastened to it”, it is not the part doing the “fastening”
• Using grip tape to improve wheel traction

<VUR10> Each Robot must utilize exactly one (1) V5 Robot Brain and up to two (2) V5 Robot Radios connected to a V5 Controller.

1. Teams must abide by the power rules noted in <R14> and <VUR12c> 
2. Wireless communication between Robots is permitted if using legal V5 Robot Brains / Robot Radios. No other types of wireless communication protocols (e.g., radio, Bluetooth, Wi-Fi) are permitted 

<VUR11> There is no restriction on the number of V5 Smart Motors (11W) [276-4840] and/or EXP Smart Motors (5.5W) [276-4842] that Robots may use. No other motors, servos, or electronic actuators are permitted, including those sold by VEX (e.g., the 2-Wire 393 Motor).

• Note 1: Rule <R15> still applies in VURC. Teams may not modify Smart Motors, and must use official/unmodified gear cartridges 
• Note 2: Commercially available pneumatic actuators and pneumatic solenoids are permitted within the guidelines of <VUR13> 
• Note 3: Legal Additional Electronics may include their own motor, servo, or actuator, per <VUR12> 

<VUR12> There is no restriction on sensors and other Additional Electronics that Robots may use for sensing and processing, except as follows: 

1. Sensors and Additional Electronics MUST be connected to the V5 Robot Brain via any of the externally accessible ports (i.e., without any modification to the microcontroller). A sensor may be connected to a processing unit which then connects to the V5 Robot Brain 
2. Sensors and Additional Electronics CANNOT directly electrically interface with VEX motors and / or solenoid 
3. The additional sensors and electronics may only receive power from any of the following:
   1. Directly from the V5 Robot Brain via any externally accessible port 
   2. From an additional lithium ion, lithium iron or nickel metal hydride battery pack (only one (1) additional battery can be used for sensor/processing power). This additional battery pack must operate at a maximum of 12 volts nominal 
4. Only the V5 Battery can power the V5 Brain 
5. Additional Electronics which include a low-powered motor as an integral part of their primary sensing/processing function, such as an external processor’s cooling fan or a spinning sensor, are permissible 
   1. Standalone motors which serve no additional sensing or processing functionality (e.g., using a commercially-available brushless motor in a drivetrain) are not considered legal Additional Electronics, and would be considered a Violation of <VUR11>
6. Pneumatic solenoids are the only types of solenoids that are permitted as Additional Electronics. Solenoids used for any purpose other than opening and closing a pneumatic valve are considered an actuator and therefore prohibited, per <VUR11> 

<VUR13> Teams may utilize an unlimited amount of the following commercially available pneumatic components: cylinders, actuators, valves, gauges, storage tanks, regulators, manifolds, tubing, and solenoids.

1. Pneumatic devices may only be charged to a maximum of 100 psi 
2. Compressors or any other forms of “on-Robot” charging are not permitted 
3. All commercial components must be rated for 100 psi or higher. Teams should be prepared to provide documentation that verifies these ratings to inspectors if requested 
4. Components must not be modified from their original state, other than the following exceptions: 
   1. Cutting pneumatic tubing or wiring to length; assembling components using pre-existing threads, brackets, or fittings; or minor cosmetic labels 
5. If commercially available 12V solenoids are used, these are considered Additional Electronics and must therefore satisfy all conditions listed in <VUR12>. 12V solenoids may be either powered by an additional power source (per <VUR12c>), or by a 5V-12V step-up converter from the V5 Robot Brain. If an external power source (or other Additional Electronics device) is used to interface with the solenoid, Teams MUST be able to demonstrate that there is no way for the solenoid to receive power while the Robot is receiving a Disabled state from the field controller 

<VUR14> Teams may use commercially available bearings on their Robot. For the purpose of this rule, a ‘bearing’ is a part that supports external loads, reduces friction, and improves efficiency by facilitating smooth dynamic motion between components. Legal examples include (but are not limited to): 

• Parts supporting rotational motion: radial bearings, roller bearings, thrust bearings, needle bearings, one-way bearings, bushings, etc. 
• Parts supporting linear motion: linear bearings, linear slides, drawer slides, etc.