Midterm II TEAM 25: OIL PALM HARVESTER 11/12/13 Ricardo Aleman, ME Yuze (Liam) Liu, ME David Boswell, ECE Bolivar Lobo, IE.

Midterm II TEAM 25: OIL PALM HARVESTER

11/12/13

Ricardo Aleman , MEYuze (Liam) Liu, MEDavid Boswell , ECE

Bolivar Lobo, IE

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Review:Oil Palm Harvester

• Goals • Develop an effective, efficient, and economical

oil palm harvester

• Tasks• Study existing harvesting techniques• Develop conceptual design• Carry out machine design• Create a product prototype• Report findings

• Midterm I presentation• Studied existing harvesting techniques• Presented 3 concepts• Selected cart

• Midterm II presentation• Develop conceptual design • Demonstrate mini prototype

RicardoRicardo

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Review: Cart with Telescoping Pole and Cutting ToolCOMPONENTS

• Cutting Tool (A)

• Telescoping Pole (B)

• Cart (C)

• Power/ Auxiliary System (D)

Ricardo

A

B

C & D

Oil Palm

Palm Harvester

R ≤ 5ft

H ≤ 40ft

h = 4ftDrawing to scale

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Motorized Methods of Harvesting• What motorized tools are used?• Sickle• Chisel• Pole Saw

• How are they powered?• Gas• DC power (battery)• AC power (cord)

• What can we use• Pole Saw• Any power solution

Sickle with chisel attachment below

Pole Saw

Not available in USA

Ricardo

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Motorized Methods of Harvesting• Example cutting (video)

http://www.youtube.com/watch?v=qh9TP0Vzc1k

Ricardo

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Example Pole Saw• Black and Decker 20V Max Lithium Ion Pole Pruning Saw

• $133.09 on Amazon.com• Up to 100 cuts • Cuts up to 6” thick branches• 8” long cutting bar• Pole can extend 6.5 – 10ft• Includes battery & charger• http://amzn.com/B00AZW9Y8C

Ricardo

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Using a Pole Saw in Design• Assuming Pole Saw

• Power TBD

• Supported at pivot joint

• Potential DOF• 1 – Vertical rotation• 2 – Horizontal rotation• 3 – Horizontal Translation

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2

3

Liam

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DOF 1 – Vertical Rotation• Torque requirement• Up to 4lbs required at tip• 20ft-lbs of torque required w/o balance mass

• How to rotate the bar• Connect chain on two sides of pivot• Connect chain to DC motor on support• As DC motor rotates, it rotates the arm

• Use geared DC motor

•DC motor • Traxxas Titan 550 Size Motor (12T)• http://tinyurl.com/ocdo6ab • $21.99

• Gear set to make gearbox◦ Tamiya Spur Gear Set TT-01 #53665◦ http://tinyurl.com/o2efvwe ◦ $15.23

Liam

Up to 5ft

~4lbs

20ft-lbs

Need up to20ft-lbs torque

Support

DC Motor

Chain

Cutting Arm

Pivot joint

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Potential DC Motors • 2 – Horizontal rotation

• Overcome friction to rotate

• Use Lazy Susan below support

• http://amzn.com/B0006LBVDI

• $5.71

• How to rotate

• Use Geared DC motor

• Fourbar-crank slider mechanism

• Produces about 90° rotation

2

Liam

Range of motion ~90 degrees

Rotating platform

(lazy susan)

DC motor + Linkage

Lazy susan

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Potential DC Motors •3 – Horizontal Translation

• Overcome friction to translate

• Use low-friction sliding joint

• Also use a linear actuator

• (still being worked out)

3

Liam

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Would it work?

2 – DOF PROTOTYPE

• 1:8 scale prototype

• Vertical and horizontal rotation

• Still needs translation

• Spent under $100 for materials

• http://youtu.be/4uAnkyqshMU

• It works!

Liam

1

2

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Cart Design• More cost-effective to modify a pre-made cart than make it from scratch

•Large, soft wheels will be mounted to extension arms for increased cart stability

•Pole may fold down (still being worked out)

•Display and controls will be elevated for ergonomics

•Power supply sits on bottom shelf of cart

Liam

Monitor & cutting tool controls

Telescoping Pole

Modified Cart

Extended wheels

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Example Tires for the Cart Low Speed Industrial Tires

Diameter: 10.6”

Sidewall: 3.5”

Width: 4.10”

Rim: 4”

Cost: $33.70 x 4 ~ $134.80

Load Capacity : 250lb

http://www.gemplers.com/product/10916/410-350x4-2-ply-Stud-Tire-Wheel-Assembly

Liam

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How Telescoping Works• Telescoping is performed with pulley system

• Electric winch raises entire mast in under 1 minute

• Poles are made of PVC, with steel supports in critical regions

• Tracks will be used to keep poles radially aligned

• Electric winch: $80• 2000 lb capacity, used for ATVs• Corrosion resistant• Pulls at 13.3 ft/min unloaded

http://youtu.be/7qwizZdSHg0

Liam

Electric Winch

SteelCable

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Camera• Needs to be waterproof

• Needs to be durable

• Needs to have a simple connection

• Good option is car camera for monitoring accidents

• http://amzn.com/B005CTKYB4• $13.64• Simple RCA cable• Waterproof• 12VDC 60mA (.72W)

Liam

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Camera Connects to Monitor• Monitor also needs to be waterproof

• Needs to be durable

• Needs to connect to camera

• Good option is monitor used to record traffic accidents

• http://amzn.com/B007SLDF7O • $30.40• Will require waterproof case• 12VDC• 8W

Liam

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Waterproofing• Simple to have wires hang outside of pole

• Want to prevent tangle

• Also want waterproofing

• Solution is to use coiled hose that can attach from top to bottom

• One example is http://amzn.com/B000NIYT6K

• $30.00

• 50ft long

• About 0.3” diameter

• Fit all power cables inside*

Liam

*May need to be cut into sections to help push wire through all 50ft

18Liam

Drawing not to scale

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2 Power Configurations

David

Power Draw Options

Option 1 (~1300W)

Pole Saw (~800W)

DC Motors (~500W)

TV + camera (~10W)

Option 2 (~500W)

DC Motors (~500W)

TV + Camera (~10W)

*Pole Saw uses its own power supply (e.g. battery)

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Selected Power Configuration

David

• Select Option 2• Camera and monitor • DC motors• Add up to ~500W

• Pole Saw will be powered independently

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Generator as Power Supply• Sunpentown TG-1000CA

• $133.99

• Supplies 1000W of power

•PROS• Lasts up to 6hrs• Gas is everywhere• Outputs AC/ DC

•CONS• Actual output no more than 900W• Heavier• Noisier • Produces emissions

David

Battery as Power Supply• 12VDC car battery

•$75.99

•35 Amp Hour (420W-hr)

•http://www.harborfreight.com/12-volt-35-amp-hour-sealed-lead-acid-battery-68680.html

•PROS• Easy to replace• No max. power output• Instant power on• Outputs to DC components directly• Quiet

•CONS• Has to be recharged• Runs out quicker than generator

20David

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Select Generator• We own a generator already

• Palm harvester needs to be used for 6 – 8 hours nonstop

• Generator supplies 6 hours before requiring more gas

• 1 battery would supply about 50 minutes

David

Screen DesignWhen designing our computer display monitor, there were two main factors that we took into account in order to have a safer process.

•Flicker: 75 Hertz or higher.

•Resolution: character size range of .116” to 0.128” for a reading distance of 20”.

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Screen Selection•Contrast between the character and background should be at least 3:1.

•Refresh rates should be greater than 75 Hz.

•Resolution should be pixel ratio 0.28mm or better.

•Dark letters on a white background is preferred.

Bolivar

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Screen Location•Optimal viewing distance, from the eyes to the screen: 18 to 30” for operators without vision correction.

•Screen tilt or inclination from the horizontal: -15” to 15”.

•Top of the screen should be at eye level.

Bolivar

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Control Design•For two out of the three motions of our design, we are going to be using spinning knobs.

•Range of adjustment is one full turn or more.

•For the cutting motion, it is better to use a hand push button with no more than 2 lb of force.

•It is recommended to use elastic resistance (spring-loading) plus slight sliding friction.

Bolivar

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Consequences of Poor Control Design, Selection, Location•If motion stereotypes are not observed, injury potential increases.

•If controls are not coded and labeled properly, the operator may use the wrong control at the wrong time resulting in an error or injury.

•If controls are not arranged properly, search time and number of errors may increase.

•The worker’s safety might be put at risk.

Bolivar

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Human-Cart Interface •Shoulder height

•Design the cart and the wheels such that the force applied by the worker does not surpass 48lb for the initial push and 31lb for the sustained force.

•The worker will operate the machine at a position with no potential danger.

Bolivar

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31Bolivar

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Next Steps• Finish scaled cutting tool prototype (A)

• Create scaled telescoping pole prototype (B)

• Create scaled cart prototype (C)

• Assemble scaled prototype (A + B + C)

• Carry out Machine Design

• Finalized part/budget list

Ricardo

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Remaining Fall Schedule

Ricardo

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Questions