Maverick Engineering Personal Transportation Vehicle. Brian Wolfe Joe Bilinski Tim Ferlin Mike Schiavone

Transcription

1 Maverick Engineering Personal Transportation Vehicle Brian Wolfe Joe Bilinski Tim Ferlin Mike Schiavone

2 Overview Design Goals Design Discussion Performance Testing and Competition Areas for Improvement Design Highlights

3 Customer Specifications Weigh under 40 lbs Case dimensions 36 x18 x24 Complete 1 mile in under 7.5 min Carry rider of approximately 250 lbs Climb grades encountered on handicap ramps Turning radius of under 25 ft. Etc

4 Maverick Engineering Driving Factors Marketable, Unique Design Ease of Assembly Maneuverability and Stability at Any Speed Rider Comfort Design Simplicity and Functionality

5 System Level Overview 4130 Steel 2 X 2 square main member and 1.25 front axle Two-stage 20:1 gear reduction utilizing aluminum pulleys and timing belts Stihl 017 chainsaw engine Dual steering joysticks with throttle, brake, and killswitch Foldable seat Rear drive wheel and brake Extendable footrest with heel cups Steering comprised of four-bar linkage incorporating Ackerman steering geometries

6 System Level Overview

7 Final Design Proposal Chassis Steering Engine and Transmission Controls Assembly and Packaging Safety Governing Cost and Weight

8 Chassis 4130 Steel Tubing Main Beam 2 x 2 x OD x 0.80 Front Axle Based on preliminary hand calculations and ALGOR FEA

9 Steering Four bar linkage utilizing Ackerman steering geometry Mechanical stops eliminate singularity Caster angle Dual steering handles

10 Engine Stihl 017 Chainsaw (1.5 hp) As Delivered: Output Shaft to Clutch Centrifugal Clutch Manufactured Output Shaft

11 Transmission Timing Belts Aluminum Pulleys (anchored via pins) 12 tooth (engine) to 72 tooth (idler shaft) 12 tooth (idler shaft) to 40 tooth (wheel) Overall Gear Ratio of 20:1 ** Note Parts Reduction: Timing belts are same size for both stages as well as 12 tooth pulley for each stage.

12 Controls Throttle and kill switch mounted on right joystick Brake mounted on left joystick ** Placement corresponding to automobile convention

13 Assembly and Packaging Assembly Flip up seat back Rotate joysticks out and lock down with provided Allen key Extend Footrest Packaging Modified duffle bag

14 Safety Rider positioned away from hazardous areas Warning labels near engine and moving belts Belt guards

15 Governing Throttle limited by mechanical stop Modified bicycle drum brake to act as centrifugal brake Easily retrofit on idler shaft Design on paper and may be able to implement before quarter s end Retrofit to idler shaft

16 Cost and Weight SYSTEM ITEM FROM QTY LOT COST WEIGHT FRAME 2" x 2" x 0.065" tube Dillsburg Aero Works 3 $ " x 1" tube Dillsburg Aero Works 2 $ " OD round Dillsburg Aero Works 1.5 $ Rear fork Online Metals 1.27 $ WHEELS Front forks, wheels Weisco Products 2 $ Rear wheel, brake assem. Huffy 1 $ Head tubes Gaerlan 1 $ Headset Bearings Athen's Bike Shop 2 $ SEAT Folding Boat Seat K-Mart 1 $ FOOTREST 3/8" Hitch Pins C&E Hardware 2 $ Foot peddles Concept II 2 $23.80 NA CONTROLS Throttle/Kill Switch Packer & Peddler 1 $3.99 NA Throttle Cable Packer & Peddler 1 $2.99 NA Kill Switch Cable Packer & Peddler 1 $2.99 NA Bike Stems Packer & Peddler 2 $ TRANSMISSION Stihl Chainsaw Model 017 C&E Hardware 1 $ XL - Timing Pulley 12 tooth Stock Drive 2 $ XL - Timing Pulley 40 tooth Stock Drive 1 $ XL - Timing Pulley 72 tooth Stock Drive 1 $ XL Timing Belt teeth Stock Drive 2 $16.40 NA 1/2 Base Mount Bearing 5912K23 McMaster 2 $ /2" Round Stock 6' 90075K15 McMaster 0.75 $ L14 1-7/8"OD stock - 6' 90075K37 McMaster 0.33 $ MISC C-Channel C&E Hardware 1 $1.80 Aluminum Angle Online Metals 1 $ Hardware C&E Hardware $ MACHINING 4 $18.51/hr* $74.04 WELDING 19-3/4 Linear inches of weld 0.5 $8.51 ASSEMBLY General Labor /hr* $27.00 *Average wages as reported by Dept. of Labor for Greater Columbus Area, 2001 $ $

17 Qualifying and Competition Results Completed 1 mile endurance run in 6 min. 10 sec. (9.73 MPH) Completed obstacle course in 3 min. 8 sec. Speed bumps / rumble strips Variety of turns Incline (handicap ramp) Slalom maneuvers No Penalties

18 Areas for Improvement Based On Testing and Competition Engine noise Lower gear ratio Transmission friction Engine noise Slotted engine and idler shaft mounts for tension control Tested V-belt transmission Increase footrest extension thickness to reduce deflection Implemented pin connections for pulleys and shafts

19 Design Specifications (revisited) Met size requirements Cost ($582.11) Weight? (40-41 lbs, depending on scale) Maneuverability requirements Obstacle course Mile endurance run Governing Throttle limited average speed of 9.73 MPH during mile run Modified drum brake retrofit available

20 Design Highlights Unique Design Extremely easy to assemble Comfortable seat and ergonomic riding position

21 Design Highlights (cont ) Very stable and maneuverable within range of vehicle speeds Caster angle creates self aligning torque in the presence of lateral force at tire contact patch (Caster also produces camber gains during turning) Toe out produces quick vehicle response upon steering input Variety of riders with different skill levels capable of operating vehicle (essentially no skill required)

22 Review Design Goals Design Discussion Performance Testing and Competition Areas for Improvement Design Highlights

23 Questions and Comments?

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