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Acme Yo-yo Company. Omar Hernandez, Alex Slocum, Jr. – Yo-Yo Base. Dayan Paez – Clear Cover and Snap-fit retaining ring. Kimberlee Collins & Rosa Rodriguez - Wiley Cover. Assembly. Base Optimization. Optimization Order Shot size Cool Time Hold Size –Sprue-break Results: SS: 3.25 in
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Acme Yo-yo Company Omar Hernandez, Alex Slocum, Jr. – Yo-Yo Base Dayan Paez – Clear Cover and Snap-fit retaining ring Kimberlee Collins & Rosa Rodriguez - Wiley Cover
Base Optimization Optimization Order • Shot size • Cool Time • Hold Size –Sprue-break Results: • SS: 3.25 in • HT: 60 sec • CT: 90 sec Cycle time • 100 sec
Base Process Details • Process capacity • Cp = .298 • Higher since actual tolerances spec range is greater than 0.005 in. • Cycle Time • 100 seconds, steady state • Production • 125 bases producted • Some got stuck on mold • Several short shots.
Conclusion • Rate: very difficult to increase. • Problems: • Cooling Time. • 1st generation mold was too big. • Flexibility • Geometry: limited • Cooling time • Color: whatever was in the hopper. • Cost: relatively high due to low rate/large part size. • Ways quality can be increased: • Draft angles • MoldFlow™ • Address uneven cooling
Wiley Centerpiece Injection Molding Piece by Rosa Rodriguez and Kimberlee Collins
Inspiration Can you find him???
Optimization Order • Shot size • Hold time • Cool time Results • SS: 0.62 in • HT: 5 sec • CT: 9 sec “Cycle time” • 15 sec on automatic
Production • Process capacity • Cp = 8.33 • Cycle Time • 8 seconds, steady state • Number produced • 133 parts, of 3 distinct colors
Conclusion • Rate: hard to increase without another machine (2 at a time) • Flexibility • Geometry: limited • Cool time • Color: great • Cost: low due to small volume • Quality: using a ball end mill, the core finish could be improved; avoid clear plastic
Retaining Ring Injection Molding by Dayán Páez
Optimization Order • Shot size • Hold time • Cool time Results • SS: 0.70 in • HT: 3 sec • CT: 3 sec “Cycle time” • 8 sec on automatic
Process Details • Process capacity • Cp = .307 • Higher since actual tolerances spec range is greater than 0.005 in. • Cycle Time • 8 seconds, steady state • Number produced • 200 parts, of 5 distinct colors
Conclusion • Rate: hard to increase without a bigger machine (2 at a time) • Flexibility • Geometry: limited • Cool time • Color: great • Cost: low due to small volume • Quality: can be increased through use of proper equipment (e.g. CNC Lathe)
Clear Cover Thermoform by Dayán Páez
Optimization Criteria: visual quality Order • Form time • Varied between temperature and heat time. Results • Heat time: 30 sec • Form time: 15 sec • Temperature: 575 °F “Cycle time” • ~60 sec in steady state
Process Details • Process capacity • Cp = 4.71 (!) • High due to flexibility in spec range. • Cycle Time • 60 seconds, steady state • Number produced • 100 parts at 1% error
Conclusion • Rate: can best be increased by doing more at a time. • Flexibility • Plastic thickness: limited to ≤ 0.030 in • Cost: low due to small error rate • Quality: heavily dependent on operator
Overall • Integration of parts • Tight snap fit • Assembly: 50 yoyos • Functionality • Stable