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NCDA. Dental Products Development Group. Automatic Dental Bur Loader. Final Design Presentation Team 99.06: Jason Dickey, Greg Frantz, Allison Martin, Nancy Meyer Sponsor: Dave Berezowski, Dentsply/Caulk Advisor: Dr. Jim Glancey. 23 April 1999. Mission & Approach. Mission :
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NCDA Dental Products Development Group Automatic Dental Bur Loader Final Design Presentation Team 99.06: Jason Dickey, Greg Frantz, Allison Martin, Nancy Meyer Sponsor: Dave Berezowski, Dentsply/Caulk Advisor: Dr. Jim Glancey 23 April 1999
Mission & Approach Mission: To develop a cost effective dental bur automatic loading and unloading device, while fulfilling as many of the customer and team wants as possible, within the specified time and budget constraints. Approach: Using the SSD process, we determined our customers, their wants and constraints, associated metrics, and benchmarks, which lead us into the conceptual design and prototyping of the automatic dental bur loader.
Presentation Overview • Project Description & Background • Customers -- Constraints & Wants • Wants -- Metrics -- Target Values • Concept Generation & Selection • Prototype Development • Final Design & Budget • Testing & Results • Recommendations for Improvements
Project Description & Background • Automate Unload / Load Cycle of Bur Grinder • Currently 3 Operators Per Shift to Manually Unload / Load 27 Bur Grinders • Looking to Reduce Labor Costs Through Complete Automation of Grinders • Estimate Only One Operator Per Shift Will be Required for the Automated Process • Economical if Firm Budget is Maintained
Dave Berezowski Bur Area Manager Jim Foreman Facility / Production Engineering Manager Brad Hannah Machine Repair III Ray Stachnich Machine Repair III Bill Martin Machinist Cary Daniel Director of Manufacturing Kevin Barkley Grinder Operator Brian Huntington Safety & HAZMAT Officer James Agnew ISO Auditor Brian Melonakis General Manager Customers
Project Constraints • Must Be Under Budget • Must Load 4 Bur Families • Quality of Burs Produced Must Not Decrease • Average Cycle Time Must Not Increase • Must Have Operational Interlock • Must Perform Design & Equipment Validation • Voltage and Air Pressure Requirements • PLC Will Replace Mechanical Counter
Top Ten Wants & Related Metrics • Minimize Per Unit Cost • Prototype Cost • Per Unit Cost • Simplify Operation of Grinder • Number of Steps Needed by Operator • Increase Consistency of Operation • Percentage of Incorrect Loads • Ratio of Interlocks to Positions • Easy to Adjust, Diagnose, and Repair Problems • Number of Status Indicators (Amount of Feedback) • Completeness of Documentation and Drawings
Minimize Unscheduled Down Time • Cycles Between Failure • Completeness of Documentation and Drawings • Ratio of Interlocks to Positions • Comply with Regulations • Noise Level • Completeness of Documentation and Drawings • Reduce Bur Production Cost • Number of Steps Needed by Operator • Complete Documentation • Completeness of Documentation and Drawings • Match Caulk Engineering Philosophy • % of Parts from Standard Vendors or Made in House • Decrease Bur Unloading / Loading Cycle Time • Unload/Load Cycle Time
Metrics & Target Values • Prototype Cost . . . . . . . . . . . . . . . . . . . . . . . . . . < $10,000 • Per Unit Cost. . . . . . . . . . . . . . . . . . . . . . . . . . . . . < $8,000 • Number of Steps Needed by Operator. . . . . . . . . < 7 • Percentage of Incorrect Loads . . . . . . . . . . . . < 0.5% • Ratio of Interlocks to Positions . . . . . . . . . . . . . . = 1/1 • Number of Status Indicators . . . = # of Indicators
Metrics & Target Values, cont . • Completeness of Documentation and Drawings . . . . . . . . . . . . . . . . . . . . . . . . . . = 100% • Cycles Between Failure . . . . . . . . . . . . . . . . > 250,000 • Noise Level . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . < 80 dB • % of Parts from Standard Vendors or Made in House . . . . . . . . . . . . . . . . . . . . . . = 100% • Unload/Load Cycle Time . . . . . . . . . . . . < 13 seconds
System Benchmarks • Yamaha Automatic Loader • Machine Centers • Current Manual Loading Process
Initial Concepts 1st 2nd ConceptIterationIteration • Swing Arm 16 11 • Linear Screw Drive 20 15 • Linear Piston 17 18 • Robotic Arm 29 --- • Four-Bar Mechanism 28 --- • Yamaha --- 29 • Human --- 17
Bur Delivery 2-Stage Release Collet Control Pneumatic Cylinder Steady Rest Control Pneumatic Cylinder Bur Transfer Swing Arm Type of Grippers Pneumatic Grippers Final Bur Storage Basket Control Systems PLC System Functions
Advantages Of Swing Arm • Bur Transfer has One Degree of Freedom • Easier to Diagnose and Repair Problems • Minimal Redesign of Current System • Fewer Parts • Lower Design & Implementation Cost
Modified Collet Extension Closed Collet Modified Extended Collet: Extension ~3/8”
Modifications For Final Prototype • Modified the Collet to Extend Further • Alignment (x,y,z) for the Bur Holding Tray • Shock to Dampen the Swing Arm • Brass Tubing in the Bur Release • Changed Steady Rest & Bur Release Air Cylinders • Strengthened Support Bracket • Plug & Cover for Tray
Final Design Bur Tray & Feed Tube Grippers Head Unit Bur Release Collet Control Piston Swing Arm
Cabinet Modifications Before After Mechanical Counter PLC Relay Power Supply
Base Modifications - Before Original Wiring
Base Modifications - After Pneumatic Solenoids Sensor Wiring
Budget • Parts………………………………………………………... $3,500 • Caulk Shop Time: 100 hours @ 30 $/hour ………….….. $3,000 • Our Shop Time: 100 hours @ 0 $/hour ..………………. $0 • Engineering Hours: 1600 hours @ 0 $/hour ……………… $0 Total Cost ………………………………….. $6,500
Function Testing • PLC Logic • Grippers • Collet Extension & Retraction • Steady Rest Motion • Tray Movement • Swing Arm Range of Motion • Bur Ready Mechanism
Function Integration • Position Bur Release to Deliver Bur to Tray • Tray Alignment with Grippers • Collet Alignment with Grippers • PLC Delays Optimized
System Level Testing • Calculate Cycle Time • Determine Percentage of Incorrect Loads • Number of Steps Required • Verify Consistency of Each Function
Testing Results Metric: Target Value:Actual Value: Prototype Cost . . . . . . . . . . . . . . . . . . . . . . . . . . . < $10,000 . . . . . . . . . . . . . . . $6,500 Per Unit Cost . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . < $8,000 . . . . . . . . . . . . . . $6,500 Number of Steps by Operator . . . . . . . . . . . . . . . . . . . . < 7 . . . . . . . . . . . . . . . . . . . . . 2 Percentage of Incorrect Loads . . . . . . . . . . . . . . < 0.5 % . . . . . . . . . . . . . . . . . TBD Ratio of Interlocks to Positions . . . . . . . . . . . . . . . = 1/1 . . . . . . . . . . . . . . . . . . . 1/1 Number of Status Indicators . . . . . . . # of indicators . . . . . . . . . . . . . . . . . . 1, 47
Testing Results, cont . Metric: Target Value:Actual Value: Completeness of Documentation . . . . . . . . . . . . . = 100% . . . . . . . . . . . . . . 40% Number of Cycles Between Failure . . . . . . . . . > 250,000 . . . . . . . . . . . . . . TBD Noise Level . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . < 80 dB . . . . . . . . . . < 65 dB % of “Standard” or “In House” Parts . . . . . . . . . . . . = 100% . . . . . . . . . . . . . 99% Unload/Load Cycle Time . . . . . . . . . . . . . . . . . .< 13 seconds . . . . .< 6 seconds
Recommendations For Improvement • Replace the Four Magnetic Reed Switches With Hall Effect Switches • Power Indicators & Operator-Level Status Lights • Continuous Spindle Motor Operation • Redesign Bur Ready Tray • Make Easier to Manufacture • Adjustable Rubber Stop to Prevent Bounce