12/7/2004 AME470 Ltd. - Team Pratham 1Open-Aid TEAM PRATHAM Team Leader: Matt Ryan Chief Engineer: Nick Martin Fabrication: Reed Langton CADCAM: Fraterno Vila Electronics/Control Engineer: Gabriel Letona

12/7/2004 2AME470 Ltd. - Team Pratham Outline Problem Definition Problem Definition Product Requirements Product Requirements Operation Operation Prototype Prototype Design Issues Design Issues Strengths and Weaknesses Strengths and Weaknesses Budget Summary Budget Summary

12/7/2004 3AME470 Ltd. - Team Pratham Problem Definition Break the seal on jars and bottles without requiring the user to apply the torque necessary to open them Break the seal on jars and bottles without requiring the user to apply the torque necessary to open them

12/7/2004 4AME470 Ltd. - Team Pratham Product Requirements Container Specifications Twist off cap/lid Total Height in. Body Diameter in. Lid Height in. Lid Diameter1 - 5 in.

12/7/2004 5AME470 Ltd. - Team Pratham Open-Aid Ability to open a glass or plastic container Ability to open a glass or plastic container Uses a microprocessor with feedback from sensors to control the driving motors Uses a microprocessor with feedback from sensors to control the driving motors

12/7/2004 6AME470 Ltd. - Team Pratham Prototype vs. Concept Housing - Box vs. Cylinder Height Adjustment Fabricated bottom half

12/7/2004 7AME470 Ltd. - Team Pratham Operation

12/7/2004 8AME470 Ltd. - Team Pratham Programming (Opening Container) Yes No Stop bottom assembly motor Does Hall effect sensor 1 still sense magnet? Hall effect sensor 2 senses magnet Count to 1 second Stop turning top assembly motor Start turning bottom assembly motor Sense top assembly contact switch Has bottom assembly contact switch been pressed? No Turn top assembly motor on Plug in applianc e Press ‘start’ button Yes Stop bottom assembly motor and go to release operation

12/7/2004 9AME470 Ltd. - Team Pratham Programming (Releasing Container) Reverse top assembly motor Sense top assembly hall effect sensor Stop top assembly motor Reverse bottom assembly motor Hall effect sensor 1 senses magnet Stop bottom assembly motor

12/7/ AME470 Ltd. - Team Pratham The Prototype

12/7/ AME470 Ltd. - Team Pratham The Prototype Sensors - Contact switches moved to breadboard Prototype Concept

12/7/ AME470 Ltd. - Team Pratham Design Issues Torque Requirements Torque Requirements Motor Selection Motor Selection Plate Design Plate Design Gripping Components Gripping Components Electronics Electronics

12/7/ AME470 Ltd. - Team Pratham Torque Requirements REQUIRED TORQUE EXPERIMENTAL DATA ContainerWeightForceLever ArmTorque (kg)(N)(m)(N-m)(oz-in) Glass Applesauce Jar** Glass Salsa Jar Plastic Powerade Bottle Glass Snapple Bottle **For this first experiment, the jar was laid horizontal. The equivalent mass of the lever arm is factored into the weight shown here

12/7/ AME470 Ltd. - Team Pratham Motor Selection Buehler 12V DC Gearmotor w/ 6:1 Gear Train Output Power0.015 hp Torque1944 oz-in Angular Velocity6.25 rpm Weight1.5 lbs Diameter1.2 inches Length3.3 inches Shaft Length0.4 inches Motor Selection:

12/7/ AME470 Ltd. - Team Pratham Gear Train 6:1 gear ratio required to transmit operating torque with the Buehler DC motor 6:1 gear ratio required to transmit operating torque with the Buehler DC motor Stainless steel clamp hub gears from Berg Stainless steel clamp hub gears from Berg Clamps secure gear and pinion Clamps secure gear and pinion

12/7/ AME470 Ltd. - Team Pratham Plate Design Resulting Force on Grips from Spiral Groove Grip rests at intersection of linear and spiral grooves Motor output results in the spinning of the Plate w/ Spiral Grooves, causing the Grip to move towards the center of the plates along the linear groove Grip Plate w/ Linear Grooves Plate w/ Spiral Grooves Linear Groove Spiral Groove Convergence Angle

12/7/ AME470 Ltd. - Team Pratham Plate Design Torque Key Motor Gears Torque Key is fastened to the central shaft with a spring pin Torque Key interlocks with Plate w/ Spiral Grooves

12/7/ AME470 Ltd. - Team Pratham Gripping Components Concept – three gripping components consisting of a gripping arm riding in a slotted bracket, with a spring and contact switch Concept – three gripping components consisting of a gripping arm riding in a slotted bracket, with a spring and contact switch Inserts into spiral and radial plates Inserts into spiral and radial plates Spiral Radial

12/7/ AME470 Ltd. - Team Pratham Gripping Components Prototype – single unit with high-friction synthetic polymer pads Prototype – single unit with high-friction synthetic polymer pads Problem – prototype slips on glass containers Problem – prototype slips on glass containers Radial Plate Spiral Plate

12/7/ AME470 Ltd. - Team Pratham Electronic Schematic

12/7/ AME470 Ltd. - Team Pratham Microcontroller System and Power Source Minimax Microcontroller Minimax Microcontroller Microprocessor PIC16F877A Microprocessor PIC16F877A Demands 6 to 12V DC Demands 6 to 12V DC 100mA minimum current 100mA minimum current Provides 5V Provides 5V External Power Source External Power Source 120V AC from outlet 120V AC from outlet Use of an AC-DC adapter power source converter Use of an AC-DC adapter power source converter

12/7/ AME470 Ltd. - Team Pratham Sensors Magnetic Hall Effect sensors are used to control the rotation of the plates during the opening of the container Magnetic Hall Effect sensors are used to control the rotation of the plates during the opening of the container Magnet 1 Housing Hall Effect Sensor Container to Open Lower Plate Assembly

12/7/ AME470 Ltd. - Team Pratham Sensors Contact Switches Hall Effect Sensor & Magnet

12/7/ AME470 Ltd. - Team Pratham H-Bridge 2 NMIH-0030 H-bridges DC motor applications from 6 to 18 V up to 5 A current DC motor applications from 6 to 18 V up to 5 A current Provides forward, reverse, and brake modes of operation.

12/7/ AME470 Ltd. - Team Pratham Strengths and Weaknesses ComponentStrengthWeaknessImportance Spiral Plate unlimited number of potential grippers; one motor per plate assembly Carefully selected geometry high - the basis of design for the entire product Magnet Sensors only sensors require power, magnet does not Requires close proximity to moving plates medium - sense position of container; there are no wires to tangle Grippers spring loaded for more uniform grasping increases part count, only a fixed force reaches contact switch medium - ensures that all grippers grip with even force Contact SwitchesSmall wires can get twisted if not controlled medium - wires twist, which must be accounted for in the design Gears positive contact/force transmission may be loud, small pitch requires precision high - gears transmit the torque to the container applied by the motors Height adjustment automatically moves up with lid displacement requires user to initially adjust it manually low – automated system not necessary; user able to lift top assembly manually

12/7/ AME470 Ltd. - Team Pratham Budget Summary Most expensive components: Most expensive components: - Large Gear $ H-Bridge $ H-Bridge $30.00 Budget Available:$ Budget Available:$ Total Budget used: $ Total Budget used: $ Budget Left: $62.00 Budget Left: $62.00