Understanding the VEX IQ Plastic Construction System

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The VEX plastic construction system is a snap-together toolless system which is designed for speed of assembly and versatility. Utilizing a standard three-dimensional pitch system for all VEX plastic pieces, you can build in any direction and always connect pieces back to the rest of the build.

The VEX plastic construction system consists of the following part categories:

Electronics - Robot Brain, Battery, Motors, and Sensors to bring life and intelligence to your robot.

Structural Components - Beams and Plates are the building blocks of your robot.

Fasteners - Pins, Standoffs, and Corner Connectors are used to connect the structural components.

Motion Components - Wheels, Gears, Pulleys, and other accessories provide motion and additional capabilities to your robot.

Many of these parts come in a variety of colors which allows for a customized and creative robot design.

Helpful aids when using the VEX plastic construction system is the VEX IQ Parts Ruler. This ruler has a 1:1 scale, so parts can be placed directly on the printed version for easy identification. See this article for information about the ruler and links to the printable PDFs. This information is advantageous when assembling a VEX IQ Robot Build, or searching the VEX product line for a replacement part.

Sizing Systems for Parts

There are several sizing systems associated with the VEX plastic construction system. These include the Pitch system for Structural products, sizing for Connector Pins, and the sizing systems for Motion products.


Pitch is the distance between two successive corresponding points. With the VEX plastic construction system, this is one unit in a three-dimensional grid system. All normal mounting holes are 1x pitch apart (12.7 mm / 0.5"). Shafts, Standoffs, Corner Connectors, Beams, and Plates are sized in integer multiples of Pitch.

This allows structural pieces to be referred to as the “number of holes.” Using this method, a 1x12 Beam has a width of one and a length of 12 holes. The 2x Beams and the Plates have a center row of holes running between the grid set of holes. These holes are offset by 1⁄2 a hole which allows for a multitude of additional assembly options. When following a set of VEX build instructions, paying close attention to the count of the holes, is essential for success. When creating custom robot assemblies counting the number of holes can assure structures are parallel and have square corners.

Counting Holes Parallel and Square


1x2, 1x4, and 1x6 Beams

The 1x2, 1x4, and 1x6 Beams have an additional center hole within their length giving them a line of 3 holes, 5 holes, and 7 holes. This additional hole allows for a shaft to be inserted through the center of the part, or for additional parts to be connected in the middle of the beam.

Example of using 1x2 Connector Pin

Connector Pins are typically used to connect beams, plates, and corner connectors in a parallel orientation. Pins are identified based upon how many beams can be connected together (ex; 1x1 or 1x2), with the "x" in the name denoting the location of the flange. In the case of naming connector pins, the term “pitch” refers to the thickness of a beam (6.35 mm / 0.25" thick). For example, a 1x2 Connector Pin means one side of the pin can be inserted through a single beam and the other side of the pin can be inserted through two thicknesses of beams.

Example of using 1x2 Corner Connector

Corner Connectors are typically used to connect beams and plates in a perpendicular orientation. Corner Connectors come in a variety of orientations, allowing for a nearly endless number of options to create three-dimensional designs. Similar to beams and plates, corner connectors are identified based on the height and number of holes.

12 Tooth Gear 10mm Pulley 200mm Tire
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Motion Products fall into three categories, each with a corresponding sizing identification.

Sizing for gears and sprockets uses the number of teeth on the component. For example, a 12 Tooth Gear will have 12 teeth around the circumference of the gear, and an 8 Tooth Sprocket will have 8 teeth around its circumference. Gear teeth are smaller in size than sprocket teeth.

Pulley sizing uses the pulley’s diameter in millimeters, so a 10mm pulley has a diameter of 10 millimeters.

Tires and Omni-Directional Wheels are classified by the circumference of the tire, which is equal to the distance in millimeters the tire will roll after one revolution. For example, a 200mm Tire will roll a distance of 200 millimeters after it has rolled for one revolution.

Tips for Assembling and Disassembling the VEX Plastic Construction System 

Assembling and disassembling the VEX plastic construction system should be a snap. After completing several builds numerous techniques will be developed. Here are a few examples.

Assembling Tips

Use a 1X Beam for extra leverage when mounting small elements on shafts. Insert the shaft into a hole in the beam above the small element then push down on the beam.

Capped Pins can be started into a hole and then placed on a solid surface. The pin can be seated by applying a downward force on the component.

Rubber Shaft Collars become softer and easier to install if they are warmed by holding them in your hand for a few seconds.

Disassembling Tips

VEX Pin Tool

Pin tool


The VEX Pin Tool has several features that can be used to make disassembling easy. The Puller, can be used just by placing the tool over the unwanted pin, squeezing the handles, and pulling out the pin.


Each handle is also designed to be used for disassembly. One side is constructed to push out pins (such as a 0x2 capped connector) that the tool would normally not be able to grab.


The other side incorporates the Lever, which can be used to pry two beams apart.

Connector Pins can be smoothly removed from Smart Motors, Sensors, or Robot Brains using a 1X Beam. Put the 1X Beam onto the pin then twist the Beam while pulling outward.

Remove Connector Pins by pressing a Beam against the back of the Pin then pull the Pin out the other side.

Standoffs and Standoff Connectors can be separated by pushing a shaft through the Standoff Connector.

Remove Corner Connectors by inserting a metal shaft through one of the holes then pull upward.

With proper care and good building techniques, the VEX plastic construction system should last for many seasons of creating multiple robot iterations. However, small parts such as Connector Pins can become bent or broken. When this happens the parts should be discarded/recycled and replaced with new parts.


For more information, help, and tips, check out the many resources at VEX Professional Development Plus

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