Download - E BOT Workshop #1

EBOT Workshop #1

Zan HechtOctober 14th, 2004

Basic Mechanical Design

What’s in the Kit?


Bars and Plates


Angle


Nuts and Bolts


Standoff


Shafts and Shaft Collars


Locking Bars


Gussets

Plus Gusset Angle Gusset Pivot Gusset


Motors


Motors

• Motors are fragile• Do not back-drive• Do not side load• Be careful when

mounting

What’s in the Kit?Delrin Bearings

Use with motors or rapid movement

What’s in the Kit?Delrin Bearings

What’s in the Kit?Bearing Bars

Use with slow movement (such a pivot)


Bearing Bars


Sprockets


Chain


Wheels


Robot Controller

http://www.innovationfirst.com/FIRSTRobotics/edu-rc.htm


Wiring the Robot Controller




Building a Robot

Building a Robot

Skid (Tank) Steering

ROBOT

A B

Building a Robot

4 Wheels vs. 2 Wheels

ROBOT

Building a Robot

4 Wheels vs. 2 Wheels

ROBOT

RO

BO

T

Building a Robot

Center of Gravity

Building a Robot

Chain Theory

16 32

Building a Robot

?*

?*

inputoutput

inputoutput

torquetorque

rpmrpm

Chain Theory

Building a Robot

?*

*

inputoutput

output

inputinputoutput

torquetorque

teethteeth

rpmrpm

Chain Theory

Building a Robot

input

outputinputoutput

output

inputinputoutput

teethteeth

torquetorque

teethteeth

rpmrpm

*

*

Chain Theory

Building a Robot

?robotspeed

Robot Speed

Building a Robot

**60 wheelwheel

robot Diameterrpmspeed

Robot Speed

Building a RobotMotor Performance Data

Speed (RPMs) Torque (oz. in.)

Current (Amps)

Power Out (Watts) Efficiency Heat (Watts)

170 0.00 0.1 0.0 0% 1

159 4.68 0.3 0.5 26% 2

147 9.35 0.4 1.0 34% 2

136 14.03 0.5 1.4 36% 2

125 18.71 0.6 1.7 36% 3

113 23.38 0.7 2.0 34% 4

102 28.06 0.8 2.1 32% 4

91 32.73 0.9 2.2 29% 5

79 37.41 1.0 2.2 26% 6

68 42.09 1.1 2.1 23% 7

57 46.76 1.2 2.0 19% 8

Building a Robot

Robot Speed

What size wheel should I use if I want my robot’s maximum speed to be 3 feet per second?

Building a Robot

Robot Speed


3~**60120~3 wheelDiameter

Building a Robot

Robot Speed


5.wheelDiameter (6 inches)

Building a Robot

Robot Speed

If the 6” wheels are the largest in the kit, how would I make my robot’s maximum speed 1.5 feet per second (without damaging the motor

or making custom wheels)?

Building a Robot

Robot Speed



**60 wheelwheel

robot Diameterrpmspeed

Building a Robot

Robot Speed



output

inputinputoutput teeth

teethrpmrpm *

Building a RobotRobot Speed



Put a sprocket on the motor that is half the size of the sprocket on the wheel.

Building a Robot

Chain Wrap

Motor

WheelWheel

Building a Robot

Chain Tension

Building a Robot

Wheelbase

Building a Robot

Chain Alignment

motor

Building a Robot

Supporting Shafts

motor

Building a Robot

Pivots

Nylock

Steel Washer

Nylock

Teflon Washer

Building a Robot