47a8b40fdb
TREE(74): training modules, entity profiles, 2890 references, keyword indices SPROUT(42): knowledge pages, project docs, curated source material SEED(164): daily notes, raw session logs, unprocessed material Updated AUDIT_MANIFEST.json with growth classifications.
247 lines
7.9 KiB
Markdown
247 lines
7.9 KiB
Markdown
---
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type: training-material
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source: hawkcollective Google Drive
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date: 2026-05-03
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growth: tree
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---
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# Mechanical Level 3
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Mechanical Level 3
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Gearboxes, Wheels, Chassis, Motors
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2890: The Hawk Collective
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Motors
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NEO Brushless motor
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Medium Torque motor.
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The most common we use.
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Be careful, they can burn out easily if too much torque is applied to them.
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External motor controller ( spark max)
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Specs :
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stall torque =
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Free Speed =
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Optimum RPM =
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Shaft options ?
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Spark Max Trouble Lights
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Spark to neo connections
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Medium Torque motor.
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The most common we use.
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Be careful, they can burn out easily if too much torque is applied to them.
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External motor controller ( spark max)
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Specs :
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stall torque =
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Free Speed =
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Optimum RPM =
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Shaft options ?
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Spark Max Trouble Lights
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Falcon 500
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High Torque motor.
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Rarely used.
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We mostly use them for tasks that require extra torque and are too limited in space to add a larger gearbox, or the speed is too low when the torque is high enough.
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Internal motor controller Talon SRX
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Specs :
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stall torque =
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Free Speed =
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Optimum RPM =
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Shaft options ?
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pg 39 Trouble Lights
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Redline / 775 / NeverRest
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High speed
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Rarely used.
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Often used for shooters
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Use Victor or Talon SRX motor controllers
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NEO Vortex
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Pass through shaft
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New / preorder
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Integrated removable Motor controller
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Swappable shaft options
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Performance Curve / Data
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Performance Curve / Data
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Performance Curve / Data
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Motor
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No load speed
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Efficient speed
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Max rpm
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Stall torque
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Neo 1.1
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5676
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3000
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5820
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3.28
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Falcon
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6380
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3200
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6380
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4.69
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775
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18730
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9370
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18730
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0.71
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Neo Vortex
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Side by Side
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Gearboxes and Torque Multiplication
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Torque Multiplication
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In gearboxes, when you decrease the speed of an axle, you increase the torque of the axle. That means that while it may spin slower, it can spin with much more weight/force, the same way having a long lever allows you to lift heavy objects, but you have to move the lever farther. If the gear on the motor is larger than the gear it is connected to, the speed is increased and the torque is decreased and vice versa.
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Gearboxes
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Gearboxes are one way to multiply torque. By interconnecting several gears, the speed of a motor is multiplied by several times. You attach a motor or two to one side, and a hex shaft comes out the other side with a higher rotation. Most of our motors need to be plugged into a gearbox in order to function, but many of those can change their ratios
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Chain and Sprockets
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An alternative or addition to gearboxes, chain and sprockets can also be used to change the speed or torque of a motor. They are usually mounted on hex shafts. They take up more space than gearboxes, but are simpler to adjust without prior experience.
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How to Calculate Surface Feet Per Minute
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This allows you to calculate how fast a wheel will roll a bot forward given the rotations per minute and the diameter of the wheel.
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Diameter*RPM*0.262=Surface feet per minute
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Ex. A wheel with a 12” diameter spinning at 40 RPM would move a bot by 125.663599… feet per minute.
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12*40*0.262=125.663599…
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How to Calculate Surface Feet Per Minute
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You will be given a SF/M speed.
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Start with the wheel and motor, since they are limited in your choice
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Neo and a 8 inch wheel
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How to Calculate Surface Feet Per Minute
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Start with the wheel and motor, since they are limited in your choice
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Neo and a 8 inch wheel
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Calculate the circumference of the wheel:
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2 x π x Radius = circumference.
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2 x 3.1415 x 4 = 25.132 inches per rotation
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25.132/12=2.094 feet per rotation.
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How to Calculate Surface Feet Per Minute
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Neo and a 8 inch wheel
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Neo optimum speed ≈3000RPM
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If we were to connect the wheel directly to the Neo we would move at 3000RPM x 2 = 6000 SF/M
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Nearly 70 Miles per hour at a very low torque.
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How to Calculate Surface Feet Per Minute
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Neo and a 8 inch wheel
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Neo optimum speed ≈3000RPM
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Wheel ≈ 2 feet Circumference
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Direct motor speed 6000 SF/M
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Target motor speed =
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FRC typical 10-20 SF/S
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or 60-120 SF/M
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How to Calculate Surface Feet Per Minute
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Neo and a 8 inch wheel
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Neo optimum speed ≈3000RPM
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Wheel ≈ 2 feet Circumference
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Direct motor speed 6000 SF/M
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Target motor speed =
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FRC typical 10-20 SF/S
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or 60-120 SF/M
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We divide the direct motor speed by the desired to determine the overall ratio.
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6000/60 =100:1 ratio
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With this you can find a gearbox / sprocket set that will achieve this.
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All these numbers are freespeed ( no load )
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A note about torque
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Neo and a 8 inch wheel
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Neo Stall torque ≈ 1.5Nm
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Or ≈ 1.1Ft/Lbs
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Or ≈ 13.2in/Lbs
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Motor can lift 1.1lbs at the end of a 1 foot arm
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A note about torque
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Neo and a 8 inch wheel
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Neo optimum torque ≈ 1.5Nm
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Or ≈ 1.1Ft/Lbs
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Or ≈ 13.2in/Lbs
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If we were to connect the wheel directly to the Neo we have:
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52.8 in/Lbs or 4.33 ft/Lbs or 5.87n/m
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4”
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A note about torque
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Neo and a 8 inch wheel
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After a 100:1 gearbox we would have 5280 in/Lbs
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Or ≈ 440 Ft/Lbs
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Or ≈ 596 n/m
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Of Stall torque.
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4”
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Motor can lift 440 lbs at the end of a 1 foot arm
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Wheels
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AndyMark Variable Malleability Rubber Wheels
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Rubber wheels that have different hardnesses facilitating different uses. Often used for actuators, especially in tasks involving grabbing and moving elements. The hardest(black) ones can be used as tires on the drivetrain.
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Omni Wheels
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Wheels that push in one axis of motion and are nearly frictionless in the other. Can be arranged to allow motion in multiple axis.
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Mecanum Wheels
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Wheels composed of a bunch of small rollers that can rotate diagonally to the direction normal wheels push in. When paired together, these wheels can move a robot in directs traditional wheels usually cannot.
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Drivetrains
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Overview
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Drive systems are the set of wheels and motors that allow the robot to move. The kind of wheels used, the amount of motors, and the arrangement of these devices allow for different capabilities, pros, and cons.
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Tank
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Drive System consisting of two sets of normal wheels that can rotate in both directions. The wheels are positioned on opposite sides of the bot in order to allow the bot to rotate. Very simple to make and program, but very limited in capabilities and degrees of freedom and causes a lot of sideways friction on the wheels.
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H
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Drive System consisting of 4 omni-wheels pointed forward and 1 omniwheel oriented to the side to allow the robot to move in more degrees of freedom. Can be pushed around more easily than other systems. Takes up a lot of room on the bottom of the bot
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Kiwi
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Drive system that allows for movement in all four direction. Uses Omni Wheels in a triangle shape to allow for the movement. Halfway between H Drive and Mecanum. Only here because this random guy named Jacoby thinks it’s cool
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Mechanum
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Drive system consisting of special wheels that can be used to move a robot in 3 degrees of freedom. By turning combinations of wheels in different directs or different speeds, the robot can move side to side instead of just forward and back.
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Swerve
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Drive system consisting of 4 wheels that can point in any direct. THeir angle is controlled by one motor, and the rotation is controlled by another. The best drive system for most projects, but very complicated to program. We have tried it before, but failed and had to revert to tank drive.
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Comparison
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Sideways Movement
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Traction
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Space used
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Programming complexity
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Tank
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No
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High
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Low
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Low
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H
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Yes
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Low
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High
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Medium
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Kiwi
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Yes
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Low
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Depends
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High
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Mecanum
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Yes
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Medium
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Low
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High
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Swerve
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Yes
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High
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Medium
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Extreme
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To Achieve Mechanical level 3
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Using the items listed on a worksheet, design a chassis that moves at a speed(SFPM) at optimum performance as determined by the evaluator. Show Speed and torque at each system change ( motor to gearbox , gearbox to sprocket, Sprocket to wheels, wheels to floor).
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Describe the construction and kind of wheels necessary to build a Kiwi-Drive chassis.
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Construct any letter out of at least 3 metal bars. You can use any form of connection that doesn’t permanently damage the metal.
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To Achieve Mechanical level 4
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Successfully train another team member to Mechanical level 3.
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