Wiki

Best Building practices (general)

  • bearings

  • screw joints

  • 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

DR4B Tutorial by 333A

VEX Build Quality Tutorial/Instruction video:

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Other important build topics and examples

TBD General

  • Geartrains
  • Chaindrives

Wallbots (not TT specific):




VEX Reference Build instructions for starter kits

Tower Takeover Season Specific

Theory:

Physics of Tilter
How To Fix Intake Compression [Guide]

Showcase Tilters:

448X, 21S, 6671X, and 1437Z RI3D Reveal
1961Z Tower Takeover Teaser: Mk. III
42700N Summer Reveal
25461Z early season reveal: https://youtu.be/Wvz_8Ja-JQw

Showcase DR4Bs:

97963A Early Season Reveal
Robot in 3 Days Reveal: Houdini | 9605A + 9421
VEX Tower Takeover 21000C 66 Point Driver Skills (Robo Bonanza @ Beckman)

Showcase Wallbots:

2019 NorCal RI3D Reveal

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Programming environments, links to help and tutorials

https://www.learncpp.com
https://www.tutorialspoint.com/cprogramming/index.htm

V5:

Cortex:

TBD: Supported languages, platforms, blocks vs text, which one to choose…

API Reference:

Tutorials

LVGL:

For pre-V5 (Cortex) hardware:

https://www.robotc.net/wikiarchive/Tutorials/Getting_Started/Getting_Started_with_the_VEX_CORTEX

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Programming: Getting Started with VEXcode

https://help.vex.com/category/130-getting-started

  • Motor config
  • Sensor config
  • Competition template


VEXcode, motor groups and drivetrain example
VEXcode for experts

vexforum.com/t/autonomous-help-with-vexcode/71698/2

https://help.vex.com/article/110-vex-example-program-with-controller-c-arcade-drive

http://www.cplusplus.com/doc/tutorial/

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Programming: Common Beginner Mistakes and FAQs

TBD

Note:

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.

https://help.vex.com/article/120-how-to-use-blocking-vs-non-blocking-code

Force Compile of Files

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V5 Architecture and Troubleshooting

V5 architecture diagram (may need to move to advanced topics): The PROS of PROS

V5 Troubleshooting:

Tips/warnings for v5?

  • 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.

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Engineering Design Process

https://www.google.com/search?q=engineering+design+process
TBD

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Engineering Notebook Resources

(Screen for redundant / duplicate topics)

Design Award Tips? - #2 by tabor473
Starting the Engineering Notebook
2915A Engineering Notebook 2016
Notebook Tips
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?
Notebook setup/layout

engineering notebook 1575A 2015-2016.pdf (45.0 MB)

With permission from Keilan, Alumni of 590B:
Instance of a World-Winning Engineering Notebook From VEX Worlds 2019

This notebook helped give 590B Design Award at:
2019 VEX Robotics World Championship - VEX Robotics Competition High School Division

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CAD software: links, tutorials, tips

VEX w/ Fusion 360 Tutorials

https://www.autodesk.com/education/competitions-and-events/vex/recommended-software

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Preparing for the competition day

References (redundant?):

https://www.roboticseducation.org/resources-library/
101 Things I Wish I'd Known Before My First VEX Tournament
Advice for first competition?

https://www.vexwiki.org/robotics_competitions/101_things
https://www.roboticseducation.org/documents/2013/06/101-things.pdf/

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Tips on how competition works

To be expanded:

  • Qualifications
  • Scouting:
    At tournaments, there are various ways of scouting that can be done to improve your chances of doing well. They are as follows:

• Match scouting: Before each qualification match, it is extremely important that you go and talk to your alliance partner, to coordinate autonomous programs, match strategies, and any other miscellaneous aspects to the upcoming match. This will also tie in with the second way if scouting.

• General tournament scouting: Throughout s tournament, it is helpful to take notes on each team/robot in attendance. Whether it be a quick robot summary, or detailed notes on the successes and weak points of each mechanism, doing so will allow you to be better prepared for your matches. This ties in to the 1st way of scouting, as you should be taking down notes on your alliance partners and opponents after every match.

When it comes time for alliance selection, having notes and scouting data is extremely helpful when deciding on who to pick for the elimination bracket. They will also help you to find any “hidden gems” that might be a better pick than some of the higher ranked robots. Scouting will also prepare you if a team decides to use the “scorched earth” strategy (go down the line of teams and ask each one until one accepts) to mess up any potential powerhouse alliances.

  • Alliance selection
  • BO1
  • Skills
  • Judging
  • Who qualifies
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Beyond the competition

What else is there in VRC beyond going to competitions?

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School based vs independent team / fundraising

TBD

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Tips for organizing the team

Getting Started in Robotics (Tips and Advice)

https://www.roboticseducation.org/resources_library/how-to-start-and-organize-a-vrc-team/

List of products/items to purchase?
What parts should I not buy?

Should this be here or moved up to post 25?
Help motivating procrastinators to do their job
How to help combat un-involved team members

How many people on a team?

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Tools

Sort tools in order of importance…
Add pictures?

  • wrenches 1/4, 11/32
  • screwdrivers hex (5/64,3/32), star (T?)
  • pliers, needlenose pliers, diagonal cutters, etc…
  • tabletop grinder
  • dremel

Custom Tools:

Tips:

Don’t strip screw heads - sharpen Hex screwdrivers regularly!

Safety considerations:

Wear goggles!!!

Color coding screwdrivres and wrenches:
vex_tool_set1

Special tools

Insert puller:

insert_puller

Drilling template:

drilling_template_1

drilling_template_2

Bearing cutting template:

bearing_template_1

bearing_template_2

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Alternative part sources

https://www.robosource.net

VEX Cost Reductions
Vex Low Cost Identical Legal Parts Compilation
Cheaper Option for Nylon Washers

Cheap Alternative Tiles

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Reserved for all Omni tank drive

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Reserved for X-Drive wiki entry

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Reserved for H-Drive wiki entry

https://en.m.wikipedia.org/wiki/H-drive

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Reserved for Mecanum wheels drivetrain wiki entry

Code examples:

A Holonomic drive is free to move in any direction without having to rotate around its axis.

https://en.wikipedia.org/wiki/Holonomic_(robotics)

One form consists of 3 or 4 omniwheels mounted at angles to each other. It is good for lateral movement, and increases speed and power of turns. However, linear drive speed and power are decreased since some or all of the powered wheels run at angles to the bot’s motion. All wheels must be omni wheels in order for this drive to function. The 4-wheel version is referred to as " X-Drive".

Another omniwheel Holonomic drive is the “H-Drive”, where 1 omniwheel is placed at right angles to the other four conventionally mounted omniwheels.

Mecanum drive is holonomic drive where four mechanum wheels are placed in a tank drive format. The wheels should look like this when looking from top:
image
Like all holonomic drives, mechanum bots can strafe, and does so with a simple rectangular base. However, mechanum wheels have rollers that slip, reducing traction and pushing power.

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