What can i do with a mechanical engineering degree: Pattern As Well As Fabrication Of Ic Engine Powered Radio Command Car

Guest article past times Srihari.B

The Radio command dates dorsum to the nineties when it origin evolved. It is a hobby for almost of the applied scientific discipline as well as automobile enthusiasts. It is proved past times its rigidity, precision as well as ability.
The blueprint of such RC cars has larn a keen marketplace inwards the western nations. The blueprint of such RC auto involves precision, rigidity as well as squad piece of occupation too
This projection involves the blueprint of the chassis as well as steering organization of a 3cc IC engine powered radio command auto as well as to fit its performance alongside that of the originally available components.

The principal objectives of this projection are

• To blueprint a specific chassis organization to accommodate all the components of the RC auto to live mounted on to it.
• The blueprint of the steering organization which should live capable of steering the auto similar the already available machinery as well as also to eliminate the ball joints nowadays inwards the steering mechanism.
• To fabricate the suspension arms to improve strength.
• To fabricate a suitable torso for the RC car.

1. Introduction: 1.1 Radio Control Car:
Influenza A virus subtype H5N1 radio-controlled auto (R/C car) is a powered model car driven from a distance using a radio control system. Inputs from joysticks (or a cycle as well as a trigger) on a transmitter are sent to the car's onboard receiver. The receiver interprets the radio signals as well as sends electrical pulses to the servo as well as electronic speed controller, making the model plow its wheels as well as the motor run.

RC Buggy (Scale 1:8)

Radio-controlled (or R/C) cars are unremarkably categorized every bit either "toy" or "hobby" grade. Remote-controlled vehicles differ from radio-controlled past times the presence of a wire cable connecting the transmitter as well as the car, limiting their movement
Cars are powered past times diverse sources. Electric cars are powered past times modest but powerful electric motors as well as rechargeable nickel-cadmium, nickel metallic hydride, or lithium polymer cells. There are also brushed or brushless electrical motors. Most fuel-powered models utilization glow plug engines, modest internal combustion engines fueled past times a special mixture of nitro methane, methanol, as well as fossil oil (in almost cases a blend of castor oil as well as synthetic oil). These are referred to every bit "nitro" cars.
Further these cars tin live classified every bit Off-road as well as on-road models. Off-road models, which are built alongside fully-functional off-road suspensions, tin live used on diverse types of terrain. In comparison, on-road cars, which mostly have got a limited or non-existent suspension, are strictly limited to smooth, paved surfaces
1.2 IC Engine Powered Car:
An R/C auto tin live powered past times motors or engines. The cars that are powered alongside engines are called every bit Nitro-powered RC car. They utilization methanol every bit a basic fuel alongside a pct of nitro marsh gas every bit booster as well as castor fossil oil for lubrication.
Fuel-powered engines allow model cars to scope moderate speeds unmodified. Maximum mightiness is mostly achieved at medium to high speeds as well as a slightly slower throttle answer than electrically powered vehicles are to live expected. Electric motors effectively create instantaneous torque, where nitro engines, similar full-sized gasoline engines, accept fourth dimension for the engine to spool upwardly as well as for the clutch to engage. Nitro- (and fuel) powered cars may live refueled as well as returned to activeness inwards a few seconds, every bit opposed to electrics needing to take the torso vanquish as well as battery fasteners to supercede a discharged battery. Nitro cars are completely air cooled, as well as may live run continuously alongside no demand to accept breaks for cooling down. Nitro cars tend to live larger than electrical cars on average
1.3 Principle of Operation:
Radio-controlled cars utilization a mutual laid of components for their command as well as operation. All cars require a transmitter, which has the joysticks for control, or inwards pistol traveling pocket form, a trigger for throttle as well as a cycle for turning, as well as a receiver which sits within the car. The receiver changes the radio signal broadcast from the transmitter into suitable electrical command signals for the other components of the command system. Most radio systems utilize amplitude modulation for the radio signal as well as encode the command positions alongside pulse width modulation. Upgraded radio systems are available that utilization the to a greater extent than robust frequency modulation as well as pulse code modulation. The radio is wired upwardly to either electronic speed controls or servomechanisms which perform actions such every bit throttle control, braking, steering, as well as on some cars, engaging either forrard or contrary gears. Electronic speed controls as well as servos are commanded past times the receiver through pulse width modulation; pulse duration sets either the amount of current that an electronic speed command allows to catamenia into the electrical motor or sets the angle of the servo. On the models the servo is attached to at to the lowest degree the steering mechanism; rotation of the servo is mechanically changed into a forcefulness which steers the wheels on the model, mostly through adjustable turnbuckle linkages. Servo savers are integrated into all steering linkages as well as some nitro throttle linkages. Influenza A virus subtype H5N1 servo saver is a flexible link betwixt the servo as well as its linkage that protects the servo's internal gears from impairment during impacts or stress.

Belt Driven On-road Car (Scale 1:10)

Fuel powered models utilize a servo for throttle as well as braking control; rotation of the servo inwards i management volition drive the throttle on the carburetor to open, providing to a greater extent than air as well as fuel mixture to the internal combustion engine. Rotation of the servo inwards the other management causes torque to live applied to a slice which causes friction alongside the braking material. The brake is located on the driveshaft as well as stops exclusively ii wheels on a two-wheel drive auto as well as all 4 wheels on a four-wheel drive car.
The whole machine is divided into iii major categories:
1) Engine
2) Chassis as well as Suspension
3) Control
2. Engine
2.1 Introduction

Engine

Most gas R/C models utilization a 2- or 4-stroke glow engine, sized specifically for that model. Glow engines have got a uncomplicated ignition organization that uses a glow plug rather than a spark plug so there’s no coil, magneto or points. The glow plug is heated past times a battery-operated glow starter. When fuel enters the combustion chamber, it’s ignited past times the heated glow plug as well as alongside that, the engine springs to life, straight off gaining the momentum to maintain running after all the starter accessories are removed. The engine’s carburetor supplies the fuel as well as air needed for combustion. It has several adjustments. Influenza A virus subtype H5N1 rotating throttle arm controls the amount of fuel as well as air that enters the combustion chamber. The high-speed needle valve controls the mix or proportions of fuel vs. air at mid- to high-speeds. The idle mixture screw is similar to the high-speed needle valve, except that it controls the mix of fuel as well as air when the engine is exclusively idling.
2.2 Glow plugs

Glow plugs

A gasoline combustion engine uses a spark plug to ignite the fuel-air mixture within the compression chamber, so a glow or nitro engine uses a modest glow plug. Although the plug needs to live heated upwardly using a glow plug igniter initially, i time the engine is running, the estrus generated within the combustion sleeping room keeps the plug glowing constantly as well as is thus able to ignite the fuel-air mixture on each revolution.
To start a glow plug engine, a modest straight electrical flow (around 1.5 volts) is applied to the glow plug, initially heating the filament. The engine is so spun from the exterior to innovate fuel to the chamber. Once the fuel has ignited as well as the engine is running, the electrical connecter is removed. Each combustion keeps the plug's filament glowing hot, allowing it to ignite the side past times side charge, thus sustaining the mightiness cycle.
Technically a glow plug engine is similar to a diesel engine inwards that it uses internal estrus to ignite the fuel, but since the ignition timing is non controlled past times fuel injection (as inwards an ordinary diesel), or electrically (as inwards a spark ignition engine), it must live adjusted past times changing fuel/air mixture as well as plug/coil design. Influenza A virus subtype H5N1 richer mixture volition tend to cool the filament as well as so retard ignition, slowing the engine. This "configuration" tin also live adjusted past times using varying plug designs for a to a greater extent than exact thermal control.
2.3 Fuel
Glow engines cannot live operated alongside the same gasoline you lot larn at a filling station pump. They require a especial fuel, called “glow fuel”. It contains methanol every bit the base, alongside varying amounts of nitro marsh gas to growth the let on energy that the fuel tin provide. Oil, pre-mixed into the fuel, lubricates as well as protects the tiny engine every bit it pounds out amazing power. The mixture of the fuel is 85% methanol as well as 15% castor oil.
2.4 Carburetor

Carburetor

Sitting at the forepart of the engine on top of the crankshaft is the carburetor, which is the constituent of the engine that introduces the fuel into the crankcase. The fuel / air mixture is ignited past times a glow plug which is screwed into the top of the cylinder head.
3. Chassis & Suspensions:
The chassis should live lite inwards weight, stiff as well as also able to accommodate all the components. It tin live made of aluminum or carbon graphite. The chassis should acquit the whole weight of the car. So it should live stiff as well as also accommodate the other forces acting on it.

The basic components of a auto are

1) a) Rear drive shaft or domestic dog os b) Front domestic dog os

2) Front as well as nurture disk brakes.
3) Center bulkhead.
4) Fuel tank
5) Center differential as well as spur gear.
6) a) Rear chassis brace
b) Front chassis couplet
7) Servo tray
8) Battery as well as receiver box
9) Rear stupor tower. The stupor tower has many different mounting holes for both the stupor as well as camber link.
10) Rear camber link – turnbuckle (adjustable)
11) Rear hub carrier.
12) Rear suspension arm.
13) Rear sway bar.
14) Rear CVD shaft.
15) Rear hub.
16) Rear differential housing, differential as well as nurture volume head.
17) Rear springs.
18) Rear shocks

Rear suspensions

Front steering as well as suspensions

19) Upper as well as lower pivot/pillow balls. They thread into both the upper as well as lower A-arms. This gives you lot the mightiness to alter camber.

20) Front CVD
21) Front lower suspension arm
22) Upper suspension arm - A-arm.
23) Front stupor tower.
24) Front drive shaft or domestic dog bone.
25) Steering knuckle.
26) Front hub.
27) Front sway bar.
28) Front differential, differential housing as well as bulkhead.
3.1 Suspensions
The principal factor of a suspension is its springs. Coil springs are used commonly. These are unremarkably placed about the damper housing to shape a spring-damper unit. Influenza A virus subtype H5N1 bound is an elastic device that resists displace inwards its management of work
The principal task of the suspension organization is the following,

1. Maintain the ride meridian
2. To supply damping
3. To give the best suspension go for a typical auto
4. To foreclose the auto from rolling
5. To protect the auto as well as all its components

3.1.1 Ride Height
This refers to the clearance betwixt the set down as well as the chassis, both at the forepart as well as the dorsum of the vehicle. The bound adjusters on the stupor tin live adjusted (which are at the top of each stupor spring) until the appropriate meridian is achieved after the drib test. If you lot have got an on-road vehicle, you lot should house it on a apartment difficult surface, compress the suspension a few times past times pressing on the chassis as well as allow it render to its normal position

Deflection of different springs

3.1.2 Toe-In/Toe-Out
It is the angle of the forepart tires when viewed from inwards a higher house when the suspension arms are level. If the fronts of the tires angle in, it is called “toe-in” as well as if the fronts of the tires angle out, it is called "toe-out.” This is adjusted past times turning the steering rods - the rods that run betwixt the forepart hub as well as the steering linkage that is mounted on the chassis.
3.1.3 Camber
Camber is the angle of the tops of the tires when viewed from the front. Negative camber is when the tops of the tires are angled towards the pump of the vehicle. Positive camber is where the tops of the tires are angled away from the pump of the vehicle. Positive camber is really rarely used, if ever. Influenza A virus subtype H5N1 modest amount of nurture negative camber is helpful to growth traction inwards the rear. Negative camber at the forepart volition growth stability.
4. CHASSIS FABRICATION

Comparison with Fabricated Chassis (Left - Modified Chassis, Right - Original Chassis)

4.1 Fabricated chassis

The chassis has really minimal flex as well as is really rigid. The chassis is mitt worked inwards a tincture store as well as all the holes as well as the spur clearance as well as starter box provisions are drilled to fit alongside the required dimension to suit the layout of the car.

The next alterations are made on the novel chassis:
Ø Added stuff for extra strength at the corners
Ø Bent sides which volition human activeness every bit a bumper inwards i means as well as also reduces the longitudinal torsion

Specifications	Fabricated Chassis	Readymade Chassis
Material Thickness Mass Length Width Maximum thickness	Aluminum 6061 3mm 750gms 392mm 225mm 12.2mm	Carbon Graphite 2mm 500gms 392mm 190mm 7mm

Table 4.1 Comparison betwixt the fabricated as well as readymade chassis

4.2 Method of Fabrication:

The raw stuff taken was Aluminium 6061 as well as of thickness 3mm.
Then the diverse processes that were done on the canvas were

1. Cutting as well as parting off : The chassis was cutting to the required dimension alongside the aid of the readymade chassis
2. Drilling: The required holes for the mounting of the diverse components were measured as well as so drilled on to the chassis
3. Slot Drilling: The slots for the flywheel for starting as well as stopping the engine are also provided. It was machined using a mitt drill
4. The corner bends were provided inwards guild to foreclose the flexing as well as bending of the fellow member
5. The slots were also given for the mounting of the servo motors inwards position.

The fabricated chassis proved to withstand the diverse forces similar the vertical bending, Longitudinal torsion, lateral bending as well as Horizontal lozenging.
5. STEERING MECHANISMS:

The steering machinery of this on-road vehicle is totally unique where nosotros have got eliminated all the ball as well as socket joints inwards guild to brand the machinery every bit good every bit the fabrication constituent a chip simpler.

Drag links alongside ball as well as socket joints

The challenge hither was to eliminate all the joints alongside ii or to a greater extent than grade of freedoms as well as bound it to i grade of liberty inwards ii directions. The thought was inspired from the universal joint. Usually the joints are made of plastics. The stuff alternative was also a challenging task since it has to have got the strength as well as functionality every bit that of the readymade one.
5.1 Steering Link Design
The objective of the blueprint was to eliminate the ball as well as socket joint. So the unmarried fellow member was split into iii different components. The i was a rod alongside external threads. The other fellow member is to concur the articulation as well as the 3rd fellow member volition have got i rotational grade of freedom.

Steering Components

Stud

The factor inwards Fig 5.1 is fastened alongside the stud as well as on the other goal is a freely rotating fellow member which volition live fastened alongside the hub on i goal as well as to the servo link on the other end. It volition supply the ii DOF as well as also is like shooting fish in a barrel to fabricate.
5.2 Steering Link Assembly
It bears some similarity alongside a universal articulation but how always the application constituent is new!!! The brownish fellow member is a stud on which ii brackets are screwed into. Then the greenish fellow member is a ‘free to oscillate’ sort of fellow member which volition effectively allow both the degrees of liberty that a ball as well as socket articulation would do.

Steering Mechanism Assembly

For representative the fellow member on the left is oscillating along the XX axis so the fellow member on the correct volition oscillate along the YY axis thus satisfying the weather of a steering link.

Steering links

The links shown hither volition live substituted instead of the ball as well as socket joints. The modest fellow member is the fellow member that volition displace both inwards X as well as Y directions as well as the bigger fellow member is the coupling member.

Steering Link inwards the auto

6. ENGINE: O.S. xviii TZ (S)-T

OS ENGINE

6.1 Specifications:
DISPLACEMENT: .183ci (3.008cc)
BHP: 2.27 at 31,761 rpm
TORQUE: 84.58 in.-oz. at 24,000 rpm
BORE: .629 in. (15.97mm)
STROKE: .590 in. (14.986mm)
PORTS: 5-port
Practical rpm: 3,000-34,000
CRANKSHAFT O.D.: .471 in. (11.963mm)
CRANKSHAFT I.D.: 305 in. (7.747mm)
CRANKSHAFT PIN: .175 in. (4.445mm)
PIPE: X12 Turbo
PLUG: O.S. Turbo P3
ENGINE TEMP: 230°F
EGT: 625°F
HEAD SHIMS: (1) .007 in., (1) .0035 in.
HEAD VOLUME: .21cc
POWER STROKE: .370 in. (9.398mm)
COMPRESSION RATIO(S): Trapped 7.89:1 Geometric 11.99:1
INDUCTION DURATION: 208 degrees
EXHAUST DURATION: 164 degrees
TRANSFER DURATION: 124 degrees
BOOST DURATION: 108 degrees
6.2 Port Configurations:

0 degree, ninety degree, 180 degree, 270 grade Port Configurations

The exhaust port is widest at the top to allow to a greater extent than exhaust gases to escape quickly. The port inwards the sleeve really closely matches the shape as well as seat of the exhaust port inwards the engine block, as well as that allows exhaust to catamenia much to a greater extent than smoothly. The Schnuerle ports are ii separate ports on each side of the cylinder, as well as there’s a vane cast into the transfer passage inwards the block that matches the ports. Influenza A virus subtype H5N1 unmarried boost port features moderate port timing.
6.3 Dyno Tests:

Dyno test

Green Line: Peak torque 83.1 oz-in @ 25850 RPM torque—83.1 oz.-in.
Red Line: Peak Bhp 2.28 @ 30500 RPM
6.4 Advantages:

Oversize fins on the instance dissipate estrus to aid maintain engine temperatures lower.
Five ports inwards the liner growth air catamenia for to a greater extent than power.
The nurture bearing is 12 mm inwards diameter, which lessens vibration as well as allows the engine to grip to a greater extent than torque.
Influenza A virus subtype H5N1 super-hot turbo P3 plug is included for ameliorate burn, to a greater extent than mightiness as well as improved fuel economy.
The 18TZ-TX version features a novel compact recoil starter that's smaller as well as lighter, making it easier to install.
7. Basic Components - Specifications:

Basic layout

Length: 431mm
End to goal width: 310mm
Distance betwixt cycle centers: 325mm
Ground clearance: 25mm
Diameter of wheel: 100mm
7.1 MECHANICAL COMPONENTS:

The next components are classified nether the mechanical components,

1. Chassis
2. Engine 3.0 cc (0.18TZ OS)
3. Air Filter
4. Exhaust manifold
5. Muffler
6. Clutch
7. Gear Box
8. Differentials
9. Front & nurture hubs
10. Drive Shafts
11. Steering System
12. Disc Brake
13. Front & Rear – Lower & Upper Arms
14. Shock Absorbers
15. Fuel Tank (150ml)

7.1.1 Exhaust Muffler

Exhaust muffler alongside the engine

The exhaust muffler is an attachment along alongside the engine. It is tuned inwards such a means every bit to trim down the exhaust pressure level as well as thus the noise of the engine to its minimum.
7.1.2 Clutch

Centrifugal clutch

The centrifugal clutch is an automatic clutch. The bound tension determines is engagement as well as disengagement. The clutch engages at 2000- 3000 RPM. The stuff it is made of is an alloy of brass, so that it tin withstand high temperatures as well as also it has a practiced coefficient of friction also. The flywheel is a corporation aluminium block to store let on energy during the non-power strokes.
7.1.3 Gear box:

Gear box assembly

• The gear is made of Nylon stuff
• It is mounted at the pump of the chassis as well as gives mightiness to the ii drives that goes to the forepart as well as the nurture wheels
• It has a gear ratio of 1:2.4 as well as 1:1.5

2 speed No of teeth: 1^st speed: 50, 2^nd speed: 42
Brake: Disc type
Material: Fiber glass
7.1.4 Differential alongside casing

Differential as well as casing

The RC auto is a 4 cycle drive alongside a fundamental drive as well as ii differentials on both the sets of wheels. The stuff of the bevels used inwards the differential is a estrus treated steel. The basic role of the differential is to command the speed of the wheels rotation spell encountering a turn. The differential is lubricated alongside crease as well as it is sealed alongside a plastic casing. The drive shaft is a domestic dog os shaft as well as is connected alongside the differentials using a CV joint. From the differentials the mightiness is transmitted to the wheels using the domestic dog os shafts.

7.1.5 Suspension system:

The suspension organization of the RC auto is a wishing os type of suspensions alongside all the upper as well as lower arms made of plastic. The suspension is i time to a greater extent than an private suspension.

Suspension components

Spring type fossil oil damped
Spring material: carbon steel
Free length: 35mm
Pitch: 5mm
No of turns: 7
Damping is provided using the suspension oil.Damping is needed to absorb the let on energy associated alongside suspension travel. That suspension go tin live induced past times bumps, or lateral or longitudinal acceleration. Without damping, the magnitude of the suspension displace would never halt increasing, leading to a really humorous situation. In damage of energy, damping absorbs almost of the let on energy the auto receives every bit it moves, different springs stores the energy, as well as let on it again
7.2 ELECTRICAL & ELECTRONIC COMPONENTS:

The electrical as well as electronic components basically aids inwards the command of the steering as well as the throttle. The electronic components inwards the RC auto are,

1. Crystal Transmitter
2. Battery pack
3. Servo motors
4. Radio Pistol
7.2.1 Crystal transmitter:
The crystal transmitter transmits AM radio waves which is received past times the receiver as well as controls the servo motors. The frequency of the transmitter is 24.045 MHz

Transmitter

Battery pack for the radio box (4 numbers)
1.5 v AA size batteries
7.2.2 Servos

Servomotors

One for the steering as well as the other for throttle as well as breaks

HS311 Servo Specs:
Speed: 0.19 sec/60 degrees at 4.8V

Speed: 0.15 sec/60 degrees at 6.0V

Torque: 42.00 oz-in at 4.8V

Torque: 51.00 oz-in at 6.0V

Length: 1.60" (41mm)

Width: 0.80" (20mm)

Height: 1.40" (37mm)

Weight: 1.5oz (43g)

Servo motor

7.2.3 Radio:

Pistol radio controller

Pistol traveling pocket radios incorporate the transmitter. The trigger is used for the acceleration as well as braking. The steering is controlled past times the steering cycle sort of control. The pistol traveling pocket radio is a iii means command every bit it controls acceleration, braking as well as steering


Pistol traveling pocket radio
AM Transmitter/Receiver
27.045MHz band
Output power: <0.75 mW
Current Drain (w/servos): around 250mA

BODY
The torso of the RC auto is of import inwards the means of protecting the engine as well as other critical parts from impairment due to accidents. It volition also inwards some means aid inwards the aerodynamics of the auto as well as it gives aesthetics to the car.
The torso of the auto is tinkered from a 3mm thick mild steel canvas as well as is welded to obtain the shape of the sedan.
The shape of the torso was achieved past times canvas metallic working as well as welding of the ends.




9. Work progress inwards phases:

Phase -1 Body fabrication, Welding, Painting

Phase -2 Basic work, Chassis modification, Parts matching, Suspension mounting

Phase -3 Engine mounting, Engine assembly, Engine alignment, Final testing

10. TEST RESULTS

The results obtained inwards the fabrication of the RC auto tin live compared alongside the actual readymade model as well as the diverse deviations as well as accuracies tin live known. The results are tabulated every bit that of the specifications of a existent car.

The next results were obtained during the in conclusion testing,

Price - Rs.16,618
Length: 431mm
End to goal width: 310mm
Distance betwixt cycle centers: 325mm
Ground clearance: 25mm
Diameter of wheel: 100mm
Turning Circle: 400mm
Kerb Weight: v Kgs
Engine: 3cc OS engine
Peak Bhp 2.28 @ 30500 RPM
Peak torque 83.1 oz-in @ 25850 RPM torque—83.1
Steering Type – Bell crank machinery alongside universal joints
Suspensions – Double wishing os suspensions
Brake – transmission disc brake
Top Speed – lx KMPH
Fuel tank capacity – 150 ml
Steering control: High torque Servo motor:
Throttle as well as braking control: Servo motor
1^st Gear engagement: 0-5000 RPM
2^nd Gear engagement: 5000-35000 RPM
Braking: 50-0 KMPH inwards 3 seconds
Acceleration: 0-50 KMPH inwards 3.5 seconds



Courtesy as well as References:

• Mr. Murarie Kumar. Personal as well as professional person back upwardly
  
• OS xviii TZ Engine manual
  
• www.towerhobbies.com
  
• http://www.rc-truckncar-tuning.com/RC-Nitro-Engine-Carburetor.html
  
• http://www.raptortechnique.com/enginetuning_beginner.htm
  
• http://www.rc-airplane-world.com/model-airplane-engines.html
  
• http://www.easyrc.com/index.html
  
• http://www.easyrc.com/cars-trucks/carstrucks4.html
  
• IIT Bombay, Techfest 08, FTGP tutorial.

Tribute

The successful completion of this projection is a glittering hallmark of academic achievement as well as I am greatly indebted to scores of individuals who have got contributed their mite for the jubilant goal of this projection work. I would similar to limited my sincere cheers to the next people, who inwards i means or the other helped or inspired me inwards the success of this project.


Mr.Murarie kumar, Mentor, guide as well as sponsor of this projection
doc P.V.Mohanram, Head of Department of Mechanical Engineering
Mr. B.Giriraj, Faculty, Department of Mechanical Engineering
Sowrirajan K, Team fellow member
Rakesh Narayanan, Team fellow member
Ramani S, Team fellow member
Ragunathaprabhu S, Team member

About The Author

Srihari.B

Founder : Team RHTP

Webpage:- http://rhtp.in

email id:- teamrhtp@rhtp.in

Sumber http://meadinfo.blogspot.com/

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