Presentation: DFM U-Lock Bike Light

Transcript

1. Designing a theft-proof bike light: The U-Light TEAM KLAH KATHERINE O'DELL LUKE WOOLLEY ANURAG VAIDYANATHAN HIRAL GANDHI MCEN 5045 DESIGN FOR MANUFACTURABILITY SPRING 2018, APRIL 24TH PROFESSOR DAN RIFFELL 1
2. Motivation  Lights are an essential accessory of a bicycle  Safety and visibility  Required by law in all 50 states  Bicycle lights are an easy target for thieves  Expensive but small accessory  Often screwed or finger-tightened  Annoying to detach and carry around  But carrying a bunch of different pieces of equipment can be inconvenient 2
3. Design Goals 3  Weather and vibration resistant  Front and rear illumination  Combine multiple features into one product Theft Proof! (as much as anything can be)
4. Product Analysis INPUTS Power: battery Change settings: button Release lock: key Power and settings are internally processed by a PCB 4 OUTPUTS Primary:  Light  Movement (locking mechanism) Secondary:  Heat  Sound
5. Product Breakdown & Subassembly 42 unique components  Front Light  13 unique parts plus…  14 key lock parts  Front Mount  4 unique parts  Rear Light  The U-Light/Lock  6 unique parts  Rear Mount  6 unique parts plus…  5 shared with front light 5 Front Mount Front Light Rear Mount Rear Light
6. Design for Assembly Analysis ASSEMBLY METRICS  DFA Complexity - 82.1/90 (%)  Functional Analysis  Theoretical Effy. 21.4/40 (%)  Practical Effy. 82.1/90.0 (%)  Error Proofing - 1.75/2.00  Handling - 1.00/1.10  Insertion - 1.33/1.44  Secondary Operations - 2.00/2.20 6
7. Design for Manufacturability Analysis  Screening Process  Part Function & Constraints  Geometry  Elimination by constraints 7  Complexities  B2, B6, B7, F1, F6, R1, R5, S5, S6, T3, U4  Process Selection  Mainly casting, stamping and injection molding
8. Material Analysis Example: U-Bar  Functions:  Forms the shackle that bounds the bicycle frame to a secure object  Houses the rear light  Material index: wear rate and hardness  Screen to: withstand vibration, and be glossy  Rank Using Objective: carbon steels and alloys  Weighted Property Index Chart  Final Selection: 304 Stainless Steel 8
9. Market Analysis Competitors  Competitors in Lock: Kryptonite and ABUS ( Price Range: $80-$120)  Competitors in Light: CatEye, Lezyne, NiteRider and Topeak( Price Range: $40 - $100)  Our Target Price Point : $100 ( Less than sum of current prices of a popular light and lock in the market) Production Number Estimation:  17.4 million Bikes sold in 2015  35% of Bike Stores revenue is from accessories  17% of Revenue is estimated to be for bike lights and locks  1% Market Penetration as a conservative estimate (Kryptonite’s is 6-7%)  Sold only in specialty bike stores which is 13% of all stores  Estimate of number of products to be produced 3770 9
10. Cost Analysis  Summation of CM , CL , CT ,CE and COH was more representative than OME  Greatest costs incurred were human: consider outsourcing abroad  Considered fewer machines and hiring more service technicians  Quality materials were needed to fulfill the objectives 10 Category Cost ($ USD) Total Mfg Unit Cost (C ) 51.57 Material (CM ) 5.34 Labor (CL ) 14.07 Tooling (CT ) 2.24 Equipment (CE ) 1.77 Factory Overhead (COH ) 28.17 OME (1:3:9) 48.65
11. Design Iteration #1 Front Light Orientation  Rev A: Front light mounted horizontally  Mounting relied on using the key lock  Handlebars obstruct access to the key hole  Electrical components of front light could not be assembled symmetrically  Rev B: vertical mounting  Ability to attach and latch without locking  Detachment button easily visible 11
12. Design Iterations #2 & #3 Rear Mount Attachment & Enclosure  Rev A: Rear mount attached via fixed hole slid onto the seat post  Tight tolerance  Single seat post size  Complicated electronics housing design  Rev B & C: Apply the same stock material from the front light  Thin bracket clamped with SHCS  Improves on the complexity, cost, market, and user experience 12
13. Summary  DFM  Varied complexity  Majority is metal processing  DFA  Low to medium complexity but combines functions and is compact  Materials  Stainless steel (and other metals) for strong external components  Internal components are ABS  Cost  Largest costs incurred are overhead and labor  OME supports this  Design Iterations  Primary: Make the design more user-centered  Secondary: Reduce complexity 13
14. Acknowledgments Mr. Daniel Riffell – faculty advisor Integrated Teaching and Learning Laboratory – software resources 14