External websites and user communities
(Work in progress / to be organized)
External websites with Reference materials
Advanced Programming Links
Frequently used acronyms
VRC - VEX Robotics Competition (main site: http://robotevents.com/)
GDC - Game Design Committee
RECF - Robotics Education & Competition Foundation (https://www.roboticseducation.org/about-us/)
VEX - It is not an acronym (VEX Robotics: www.vexrobotics.com)
EDR - It is not an acronym (https://www.vexrobotics.com/vexedr)
VCS - VEX Coding Studio
VC - VEXcode
DRow - Banhammers and Comic Relief
VEX Forum Wiki Rules and Style Guidelines
As was already said in the introduction, the purpose of this topic is not to duplicate vast amounts of knowledge already available on the Vex Forum and external sites, but to make it easy to find that information.
We welcome and value all contributions and currently any forum users with TL1 trust level could edit Wiki posts.
However, to maintain high quality of the Wiki, everybody has to adhere to the Wiki Guidelines, that are detailed below.
Please, DO NOT CREATE NEW POSTS in this topic, unless you have a prior approval from the Wiki maintainers team (TBD).
Current open discussion about this wiki could be found in this thread: VEX Forum Wiki
This Style and contribution Guidelines are work in progress and we are going to define and put them here in the near future…
In general, the preference is to stay brief and, whenever possible, use a link to an existing topic, instead of copying its content into the Wiki.
We could start by listing things “we wish we knew at the beginning” and then sort them into beginner / intermediate / advanced categories.
Beginner category is something that needs to be communicated right away.
Intermediate is something that could wait until later in the season or second season.
And advanced is something (like odometry/tracking) that would be great to get to, but is not required by most of the teams.
If we use pyramid diagram, then we could start from the top with the most basic and most important knowledge, then expand it into intermediate level, with more information that relies on more prior experience, and so forth …
Building the robot - what constitutes the robot - basics
VRC Legal definition of the robot (according to the Game Manual <R1>)
Brain, Battery, VexNet, and most importantly license plates: 7580A 2015 Robot Reveal.
Overview of common chassis types
How could we help a new team to choose a chassis for the robot?
It is very important to select the proper drivetrain for your robot. You need to consider specifics of the game. Your driving style and experience, as well as requirements for lateral movement, power, and speed among other factors are integral to selection of a drivetrain.
Tank drive is most common type of drive seen, as well as the simplest. A Tank drive consists of two rows of wheels parallel to each other on either side of the robot. There are many different subsets, including 4-wheel, 6-wheel, and whether the use of traction wheels included as any of the sets of the wheels.
H-Drives are built as Tank drives are, except there are wheel(s) mounted perpendicular to the drive which allow for lateral movement. All wheels must be omni wheels for the drive to be able to function.
Holonomic drive, also called an X-Drive, consists of wheels mounted at angles from each other. It is good for lateral movement, and increases speed and power of turns. However, linear drive speed and power are decreased due to the nature of how wheels run toward each other to move linearly. All wheels must be omni wheels in order for this drive to function.
Mecanum drive uses 4 mechanum wheels to move linearly forward, backward, left, and right. Mechanum drives are much harder for another robot to push around, however are usually slower than a H-drive.
|1. All omni tank drive||- easy to build||- can be easily pushed to the side|
|- 2 or 4 motors|
|- can be chained front-back|
|2. H-Drive||- all advantages of tank drive||- needs extra motor|
|- tricky to distribute weight|
|3. X-Drive||- resists pushing||- harder to build|
|4. Mecanum||TBD||- requires 4 motors|
Overview of frequently used Lift Types
- 4-bar, 6-bar (n-bar)
Overview of frequently used intakes
- Side rollers
- Top roller
- Passive (pneumatics)
Best Building practices (general)
Types of nuts
- Nylocks are heavier, but have much greater grip. They likely will not significantly loosen even after extensive use. Additionally, not tightening them (and allowing the screw to spin freely) is perfect for rotating joints.
- Keps are lighter and are the quickest to use. Their teeth help maintain its position when tightened, but not as much as nylocks and cannot be rotated once tightened. Perfect for prototyping or securing less vital structure.
- Plain nuts are the lightest and are used mostly on parts with places for the nuts designed onto them, such as the clamping shaft collar or V2 rack gears.
basic gear ratios
- Builders can trade motor speed for motor torque (and vice versa) by using a system of gears to change the speed of the output shaft.
- gears have a set number of teeth, and when gears mesh, the output gear rotates however many teeth the input rotated, not the number of rotations the shaft went through. Builders can use this to their advantage so that the output gear rotates faster, but with less torque (larger gear -> smaller gear), or slower but with increased torque (smaller gear -> larger gear).
- If gear sizes become too extreme, more advanced builders may use compound gearing to exponentially modify their gear ratios. This is done by having the output shaft from previous gearing become the input shaft for more gearing with different gear sizes.
no cantilevered drive wheels
- As a general rule, for anything on a shaft other than shaft collars and washers, the shaft should be secured to structure on both sides of whatever it is supporting.
- Not doing this results in the shaft having a lot of wiggle room, as typically seen when wheels are exposed on the outside of a robot.
spacers, standoffs mounting
use all omni drive base with 4 motors
VEX Build Quality Tutorial/Instruction video:
Other important build topics and examples
Wallbots (not TT specific):
Tower Takeover Season Specific
Programming environments, links to help and tutorials
- Robot Mesh Studio: https://www.robotmesh.com/studio/
- PROS: https://pros.cs.purdue.edu/
- RobotC: https://www.vexrobotics.com/robotc-vexedr-vexiq.html
- EasyC: https://shop.intelitek.com/easyC-V6-for-IQEDR--Perpetual_p_122.html
TBD: Supported languages, platforms, blocks vs text, which one to choose…
For pre-V5 (Cortex) hardware:
Programming: Getting Started with VEXcode
- Motor config
- Sensor config
- Competition template
Programming: Common Beginner Mistakes and FAQs
make process closed with exit code : 2 means ‘code could not compile, your code probably has errors’. When creating a thread for help, please attach the whole log with your code.
V5 Architecture and Troubleshooting
V5 architecture diagram (may need to move to advanced topics): The PROS of PROS
Invalid Asset Table/Battery Medic: V5 Brain “Invalid Asset Table Version”
Red Controller Screen: V5 Controller shows red screen and computer/brain icon
Controller Vibrating: V5 Controller keeps vibrating
- V5 mini USB Port / use magnetic cable
- V5 Motor inserts / be careful
- V5 ports and static
Make sure you have installed the latest VexOS firmware which could be found here:
Make sure that radio type is to VEXnet and not Bluetooth:
run your program. press the button on the V5 brain to toggle between the user program screen and the vexos screen.
Engineering Design Process
Engineering Notebook Resources
(Screen for redundant / duplicate topics)
Design Award Tips?
Starting the Engineering Notebook
2915A Engineering Notebook 2016
Engineering Notebook Tips Selection and Strategy
How should I start off my notebook? (Summer without teammates)
what are Some Tips to add to the Notebook?
Engineering Notebook Expectations At Worlds
Example of an award winning notebook?
What is the best piece of advice you could give for an engineering notebook to be successful?
engineering notebook 1575A 2015-2016.pdf (45.0 MB)
CAD software: links, tutorials, tips
Preparing for the competition day
Tips on how competition works
To be expanded:
- Alliance selection
- Who qualifies
Beyond the competition
What else is there in VRC beyond going to competitions?