Wiki

technik3k · October 2, 2019, 8:53am

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?

technik3k · October 2, 2019, 9:07am

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!

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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

technik3k · October 2, 2019, 9:16am

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

technik3k · November 30, 2019, 2:30am

Reserved for all Omni tank drive

technik3k · November 30, 2019, 2:31am

Reserved for X-Drive wiki entry

technik3k · November 30, 2019, 2:34am

Reserved for H-Drive wiki entry

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

technik3k · November 30, 2019, 2:36am

Reserved for Mecanum wheels drivetrain wiki entry

Code examples:

Vexcode Mecanum Wheel Program

Tank control

int left = Controller.Axis3.position(vex::percent);
int right = Controller.Axis2.position(vex::percent);
int sideways = Controller.Axis4.position(vex::percent);

//you can also calculate this...
int turn =    (right - left) * 0.5;
int forward = (right + left) * 0.5;

frontRight.spin(vex::forward, right - sideways, vex::percent);
frontLeft.spin(vex::forward,  left  + sideways, vex::percent);
backRight.spin(vex::forward,  right + sideways, vex::percent);
backLeft.spin(vex::forward,   left  - sideways, vex::percent);

Arcade Drive

int forward = Controller.Axis3.position(vex::percent);
int sideways = Controller.Axis4.position(vex::percent);
int turn = Controller.Axis1.position(vex::percent);

frontRight.spin(vex::forward, forward - sideways + turn, vex::percent);
frontLeft.spin(vex::forward,  forward + sideways - turn, vex::percent);
backRight.spin(vex::forward,  forward + sideways + turn, vex::percent);
backLeft.spin(vex::forward,   forward - sideways - turn, vex::percent);

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:

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.

technik3k · November 30, 2019, 2:42am

Reserved for additional drivetrain discussion entry

Kiwi:

Lynfield:

Swerve:

…

technik3k · November 30, 2019, 2:46am

Reserved for additional drivetrain discussion entry

Are tracked vehicles viable in Vex?

technik3k · November 30, 2019, 2:48am

Reserved for additional drivetrain discussion entry 1

technik3k · November 30, 2019, 2:49am

Reserved for additional drivetrain discussion entry 2

technik3k · November 30, 2019, 2:49am

Reserved for additional drivetrain discussion entry 3

technik3k · November 30, 2019, 2:50am

Reserved for comparison of the VEX wheel types

Conversion of the robot weight into tractive force:

https://sites.google.com/site/dkellytest1/drive-systems/comparison-of-wheels

technik3k · November 30, 2019, 3:00am

Reserved for discussion of the Claw (intake)

technik3k · November 30, 2019, 3:09am

Reserved for Side Rollers wiki entry

technik3k · November 30, 2019, 3:22am

Reserved for Passive Intakes wiki entry

technik3k · November 30, 2019, 3:27am

Reserved for Top Roller intake wiki entry

technik3k · November 30, 2019, 4:15am

Reserved for the (ball) indexer discussion

Mini Reveal- Single Motor Feeder and Indexer

Indexer vs Extra Flywheel Motor

https://youtu.be/MqD8EmWweB8

technik3k · November 30, 2019, 5:40am

Reserved for Flywheel discussion wiki entry

Single flywheel:

Dual flywheel:

7842F 2018-19 Robot Showcase - Flywheel Control, Odometry, Engineering Journals & More

PID Theory Question

Additional links: Physics of the Flywheel Launcher

Advanced topic: adjustable hood…

technik3k · November 30, 2019, 5:55am

Reserved for (ball) Puncher wiki entry

See also: slip gears
Advanced topic: adjustable angle punchers