Badger Gate
INTEREGR 160
Team Amit
Professor John Murphy
S.A. Amit Nimunkar
Client Mark Novak
1
About AgrAbility
 Mark Novak, a BSE
professor at UWMadison is an outreach
specialist for AgrAbility
 AgrAbility is a federally
funded program with
the goal of aiding
disabled farmers so
they can continue
production.
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Problem Statement
 Our goal is to design a prototype of
an automated livestock gate. The
gate must be remotely operated to
allow a disabled farmer to stay in the
vehicle while the gate opens and
closes. It must securely latch in order
to serve the primary purpose of
keeping all livestock inside the pen. It
must also be safe, inexpensive, and
reliable
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Brainstorming
 Two-way Winch
System
 Powered by a
motorized spool to
wind cables
attached to the
gate.
 Electronic Actuator
 An electronic arm
extends and
retracts to push
and pull the gate.
4
Brainstorming
 Motorized Wheel
 A remote
operated wheel
drives the gate
open.
 Motor and Chain
 A motor rotates a
gear which opens
a gate by
spinning a chain.
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Evaluation Criteria
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Safety
Cost
Efficiency
Reliability
Ease of use
Installation
Maintenance
Opens Manually
Space/size
Power Required
Locks securely
Remote compatible
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Evaluation
 Motor and Chain requires a new
mounting and difficult installation.
 The motorized wheel would be too
unreliable.
 A decision matrix and a group vote
was used to pick a final design.
 The winch system was chosen as the
final design.
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Final Design
8
Model Construction
The basic model was a plywood base, with square,
2x2 fence posts, wire fencing, and a ¾ inch diameter
PVC pipe, 2’ by 1’ gate. Eye hooks constituted the
hinges, and a plastic wheel can mounted to the end of
the gate.
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Pulley System
 We had several
different ideas for
use as the pulley
system.
 Tensioners were
needed to pick up
slack in excess
cable as the motor
rotated.
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Pulley System Solution
 Utilizes a spring loaded
tube to keep pressure
on the cable and take
up the slack produced
when the gate is
opened.
 Uses 2 tubes of
different diameters
that can slide over one
another with a spring
on the inside.
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Motor and Pulleys
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16-Foot Gate Scaled Calculations
 Amount of power required to open the gate
is approximately 20 watts.
 Voltage varies depending on the motor
rating
 Only 11 watts should have been needed
 Motor efficiency was calculated into the formula
as error.
 Wire: Steel cable, rated 480-500 lbs
 Pulley arms: Wood or steel
 Other materials can be found on our parts
list.
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Servo-Operated Latch
 Powered by
servo motor
 When power is
applied, latch
opens
 1.25 V DC
 Operated via
joystick: pushing
up opens latch
Closed
Open
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Latch Construction
 Constructed of
Grade 304
Stainless Steel
 Servo contained in
waterproof housing
 Impervious to
water
 Able to withstand
large forces
 Will not rust or
freeze
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Latch
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Strengths and Weaknesses
+ The system can be
universally
mounted on
preexisting gates.
+ The gate is able to
swing both into
and out of the pen.
+ Opens gate quickly.
+ Can be opened
manually if system
should fail.
- Requires more
installation.
- Length of pulley
arms and cables
take up more
space.
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Cost Report

Estimated Price List for 1/8 Scale Prototype Gate
Sail winch servo motor
$53.95
50 lb. test fishing line
$(4.00)
Two-Channel remote with reciever and
servo
$39.99
PVC
$8.25
Miscellaneous (clamps, bungees, springs,
pulleys)
$12.00
Total
$118.19
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Cost Report

Estimated Price List for Full Scale Gate
½ H.P. Motor
$60.00
25ft. 3/32” Nylon coated steel cable
$21.15
Two-Channel remote with reciever and
servo
$39.99
Steel Bar
$60.00
Miscellaneous (clamps, bungees, springs,
pulleys)
$60.00
Total
$241.14
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Video Demo
Gate Video Demo
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Questions
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Calculations Summary
 Torque data:
 Torque= Force*Distance= abs(F)*abs(d)*sin(θ)
 “Theta”= the angle between the moment arm and the
direction of the force.
 T=F*d*cos(α)
 “Alpha”=the complementary angle to the gate
 Torque conversion: 1.27 Newton meter≈ 180 ounce
inches
 The motor will exert 183 ounce inches of torque on
the prototype gate.
 Derived formula used for initial torque:
T=0.10667(tension) Newton meters
 Wire should be able to withstand above 20
Newtons/4.5 lbs of instantaneous tension
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Calculations Summary
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Gate speed data:
Angular velocity= ω= 2π/1.4 radians per second: Motor
speed
Diameter of spool= 1.5 inch
Tangential Velocity of spool= (1.5)(π/1.4) inches per second
D= v*t= (.75)(2π/1.4)(time)
D/(π(1.5))= # of turns of spool
D= ((7.5)^2+(6)^2)^(1/2)
Minimum Time= D/V≈2 to 2.50 seconds for the gate to
open
Closing the gate should take approximately the same time
The calculations for the gate speed are accurate within less
than a second. The scaled up gate will have to move
somewhat slower.
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Calculations Summary
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Gate Power:
Kinetic Rotational Energy formula: K= (1/2)Iω^2
Derived formula for rotational inertia of gate (model and
scaled up): I= (1/3)mL^2
L= length of moment arm and m= mass of gate
K= (1/6)mV^2
V= L*ω= velocity of gate≈ 4π/2.25 inches per second
Mass of scaled down gate≈ 1.00 Kg
K= (1/6)(1.00kg)(((π/2)/2.00)^2)((2ft)(1/3.25))= 0.0389
joules of kinetic energy for the prototype gate
Power= Work/Time
Work= Δ Kinetic Energy= K(f)- K(i)= 0.0389 joules- 0
Theoretical Power after assumption of 50% error: 0.039
Watts as a maximum.
Rating of servo motor (from catalogue): 0.0384 to 0.048
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