Senior Design - Capstone Project Presentation

April 25, 2016Mr. MP SpiererCaterpillar CMDCEast 1167 NC-42Clayton, NC 27527

Design Performance Report (Team 4)

Dear Mr. Spierer,Team 4 is pleased to present the attached report detailing the performance of the final design that has been created in order to solve the problem of the stick-slip phenomenon observed in the current decel pedal used in Caterpillar’s small bulldozers. To date the team has put in 487 hours towards this project altogether and was expecting to be at 560 hours at this point. Team member Junjie Zhang has contributed 94 hours, Brandon Felts has contributed 103 hours, Michael Mastrianni has contributed 85 hours, Philip Bell has contributed 97 hours, and Dan Fiset has contributed 108 hours. We look forward to presenting the information in this report and some of our other findings to you.

Sincerely,

Brandon Felts Dan Fiset Michael Mastrianni Philip Bell Junjie Zhang

K2 Series Small Dozer Decelerator Pedal Design - Performance Review

Team 4 Junjie Zhang

Michael MastrianniBrandon Felts

Philip BellDan Fiset

Presentation Overview1. The Problem2. The Goals3. The Approach4. Final Design Overview5. Goal 1: Slow Speed Force Variation6. Goal 2: High Speed Force Variation7. Goal 3: Range of Pedal Motion8. Goal 4: Natural Frequency9. Goal 5: Less than 2’’ of Deflection for 800lb Loading 10. Goal 6: Pedal Position with Respect to Bulldozer11. Pedal Cost12. Possible Improvements13. Questions and Comments

The Problem

• Unwanted stick-slip behavior of K2 series bulldozer deceleration pedal

• Prevents precise minor adjustments

The Goals1. Slow Speed Force Variation - 20%

2. High Speed Force Variation - 17%

3. Range of Pedal Motion - 18.7%

4. Natural Frequency 15 Hz - 18.9%

5. Less than 2’’ (50.8 mm) of Deflection for 800lb Pedal Loading - 12.5%

6. Pedal Position with Respect to Bulldozer - 12.9%

The Approach

Design 1: Spring Only• Pro: Good Slow Speed Force Modeling• Con: No Damping

Design 2: Spring and Damper• Pro: Good Slow Speed Force Modeling• Con: Heavy-duty Spring (too strong)

The Approach

Design 3: Spring and Gears• Pro: Thinner Gauge Material Pedal• Con: Complex Gear System

Selection:Design 1 - Low-Profile, Flange-Mount Ball BearingsDesign 2 - Spring and Damper SystemDesign 3 - Thinner Gauge Material Pedal

Final Design Overview• Low-Profile, Flange-Mount Ball Bearings

• ¼ Inch-Thick Sheet Steel Pedal Arm

• Bent Support Under Foot Plate

• Two 31 lb/in Extension Springs

• Damper (c=2460 Ns/m)

• Slotted Link to Control Motion

Final Design Overview (Cont.)

Goal 1: Slow Speed Force Variation

Force to Start Motion ~ 110N (82N)Force to Complete Motion ~ 145N (110N)

Goal 2: High Speed Force Variation

Goal 3: Range of Pedal MotionMax Displacement (from Potentiometer)

• ~12.49°

Actual Linear Travel (due to 190 mm arm)• 41.4 mm (about 10 mm more than expected)

Goal 4: Natural Frequency

● Frequency of Dozer Cabin○ ~15 Hz

● Natural Frequency from Slam Test

○ ~20.94 Hz

Goal 5: Pedal Deflection

• 3mm of deflection for 30lb

• 80mm deflection for 800lb

• 3.15in deflection for 800lb

Goal 6: Pedal Position

190mm from shaft to center of footplate (181.5mm)50deg from vertical (57.7deg)

156mm from edge of bracket to footplate edge (156mm)

Cost

Possible Improvements

Lower initial spring deflection Secure Spring Link Bolt

Questions/Comments