P16718: Micropen workstation design
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Detailed Design

Table of Contents

Click on the following link for the Detailed Design Directory: Detailed Design Documents

Team Vision for Detailed Design Phase

The group made a significant amount of progress towards determining final designs for our major subsystem level components. The operator assist tooling for the touch up procedure has been refined to a few concepts which we will be building prototypes of for testing during MSD II. Much of the information that made this progress possible was customer feedback from various meetings which lead to a consensus on the direction which the group in going to take for the design of this subsystem. Another major contribution to our progress for this phase was the completion of the team’s test plan for MSD II. This systematic breakdown of steps which we need to take in order to further refine our design will be used as a guide for a large portion of the actions which will be taken during MSD II. Outside of these two major steps forward the group also made many significant strides towards determining subsystem specifics for things such as the airflow control system, the part viewing camera system, the material handling system, and improvement of the ergonomic safety of the operator throughout the production process. All of this was done with reducing scrap rates and maintaining process throughout as guiding principles of the team's design while making decisions.

Customer Interview

Date Location Subject Notes
November 24th, 2015 RIT Gary Fino Review Notes
December 1st, 2015 Micropen Medical Gary Fino Site Visit Notes
December 8th, 2015 Micropen Medical William Grande and Gary Fino Confidential
December 10th, 2015 RIT William Grande and Gary Fino Confidential

Customer Requirements

For the latest updated version of the Customer needs, click on the following link for a PDF of the Customer Requirements

List of Updated Customer Requirements

Engineering Requirements

For the latest updated version of the Engineering Requirements, click on the following link for a PDF of the Engineering Requirements

House of Quality

Click on the following link for a PDF of the latest updated version of the House of Quality Updated House of Quality

Operator Survey Results

A survey was sent out to the station operators to be filled out over the course of a work day, for multiple successive days at a station. The survey allowed the operators to record when they felt discomfort during the day and label that discomfort with area, intensity, and type of feeling. It also allowed operators to give specific feedback on the current station and help suggest solutions to some of the problems. The discomfort part of the survey was analyzed to find which areas caused the most ergonomic issues as well as to discover any trends within the data. The more personal feedback was helpful for prioritizing areas with known ergonomic issues.
Discomfort Frequency shows the neck as the highest contributor to operator discomfort. This makes targeting the source of neck discomfort a priority. Operators noted in their surveys that their neck strain stems from microscope use.

Discomfort Frequency shows the neck as the highest contributor to operator discomfort. This makes targeting the source of neck discomfort a priority. Operators noted in their surveys that their neck strain stems from microscope use.

Findings Through Feedback:

Operators added useful feedback and suggestions, and often located the subsystem of the process that caused discomfort directly. In particular, they cited the microscope causing back and neck discomfort, and suggested the addition of an armrest and footrest to take the tension off those particular areas. One operator noted that a lot of the discomfort can be reduced with stretches, but only goes away completely by walking around and doing non-work movements.

Click on the following link for the Operator Survey Results

Prototyping, Engineering Analysis, Simulation

WIP Fixture for Printed Parts

Current State

After the printing process is complete, the finished part is removed from the chuck and transported to the WIP fixture. The part is held perpendicular to the fixture by placing the end of the wire into one of the 64 holes located on the 4”x4” ceramic tile.

Current Problems

  1. Difficulties securing the part into the WIP fixture due to the close spacing of the holes Part placement becomes increasingly difficult as more parts are placed into the WIP fixture. Increase risk of smudging the gold ink of a part already secured in the fixture
  2. Difficulties orienting the part for placement into the WIP fixture. Part placement requires the operator to rotate their hand and wrist significantly due to the location and orientation of the WIP fixture.

Future State

  1. Redesign WIP fixture
    • Why: Improve ease of part placement by increasing spacing between the holes on the tile. Static stresses of muscles is reduced by simplifying process, decreasing the time that the operator’s arm is held out for part placement. Decreases risk of smudging the ink on neighboring parts due to accidental contact.
    • How
      1. Increase length of fixture and increase spacing between holes.
      2. Reduce the number of holes on the WIP fixture tile, this will increase the spacing between holes. Retain the 4”x4” tile size.
      3. Increase the diameter of the countersink to allow for easier part placement.
  2. Modify WIP Fixture Stand angle and location, allow for adjustability.
    • Why: The current location of the WIP fixture requires the operator to rotate away from the work and extend their arm to reach the WIP fixture. This may be a factor in the left hand and wrist discomfort. Allow for the operator to adjust the fixture orientation based on preference. Will help to reduce bending and awkward elbow and shoulder postures
    • How:
      1. Create an incremental back support, similar to a beach chair.
      2. Place the WIP fixture near the part unload area at a height that is equal to or below the chuck/unload area height.

SolidWorks Model

Click on the following link for a PDF of all WIP Fixture Drawings Completed in SolidWorks: WIP Fixture Simulation
Preliminary testing was completed using prototypes manufactured from scrap pieces of ABS plastic. It was concluded that having a WIP fixture that holds 25 parts improve ease of part placement

Preliminary testing was completed using prototypes manufactured from scrap pieces of ABS plastic. It was concluded that having a WIP fixture that holds 25 parts improve ease of part placement

Material Handling

Current State

Part is placed on stiff wire which allows the operator to handle and transport the part during the process. By accessing/grabbing/holding one end of the stiff wire the part is loaded into the chuck. After the printing process is complete, the operator removes the finished part from the chuck by accessing the wire. The operator then transports the painted part on the wire to the WIP fixture.

Current Problems

  1. Workstation allows little room to load and unload part: The operator has to maneuver their hand in and out of the workstation while balancing the part on the stiff wire. The tip of the micropen is occasionally bumped into due to the minimal allotted space for the operator’s hand. After repeated contact, the printing tip is no longer calibrated affecting the accuracy and repeatability of the automated printing process. The calibration process is time consuming and can only be accomplished by one or two employees, resulting in a slowed process
  2. Difficult to balance the printed part on the stiff wire while the part is transported from the chuck to the WIP Fixture. As stated above, the operator has to unload the part from the chuck and maneuver it out of the workstation, without hitting the tip of the micropen. Next, the operator rotates their body while simultaneously adjusting their grip/hand/arm to a position where they are able to place part into the WIP fixture.

The part will be scraped if dropped by sliding off the other end of the wire or the paint is smudged by contact with the operator or fixture

Future State

Placing a kink in the wire

SolidWorks Model

Click on the following link for a PDF of all Drawings Completed in SolidWorks for the Wire Crimping Device
Machine shown above is comprised of a base, hinge, and lever which control the movement of the crimping forms for the wires.

Machine shown above is comprised of a base, hinge, and lever which control the movement of the crimping forms for the wires.

Above the Base and Lever assembly of the machine we see an enlarged version of what the positive (lower) and negative (upper) crimping forms would be expected to look like. The Positive crimping for would be attached to the lever, and the negative crimping form would be fixed to the base;allowing the lever motion to complete the crimping action of large quantities of wire in a single iteration of the process.

Actuating the Opener

Current State

Air valve with ball joint lever, placed in a position which makes the operator reach up to press it. This causes shoulder and wrist pain for the operators.

Current Problems

Wrist and Shoulder Pain / Exhaustion.

Future State

Solenoid Air Valve (Button)

Click on the following link for more information about the Solenoid Air Valve

Operator Keypad

Current State

There are two keyboards set up with the workstation. One keyboard is a computer keyboard that is sometimes used for setup but is not used in the manufacturing process. The other keyboard is a smaller custom programmed keypad that is used for the manufacturing process to verify alignment of the part in the chuck using the “flip” key and to perform the painting process using the “go” key. There are other keys that are used to modify the location of the part, these views are sometimes used to verify painting and touch-up procedures.

Current Problems

  1. The current location of the keypad requires the operator to rotate slightly to press the keys.
  2. Not all keys on the smaller keyboard are frequently used.
  3. There is a plastic cover over the keypad to protect the keys from acetone cleaner. The plastic cover is quite opaque, making it hard for operators to identify the keys.

Future State

  1. Modify the location of the Keypad.
    • Why: To reduce the turning motions required by the operator.
    • How:Relocate the keypad in a location that is very close to the actuator or the WIP Fixture
  2. Replace keypad cover with a colored cover to help with identifying the different actions.
    • Why: To simplify the identification of keys for the operator, and also cheap solution.
    • How:Colored and labeled keypad cover outsourced from current keypad

Click on the following link for a PDF of all on going research pertaining to the Keypad

Viewing Apparatus

Current State

Operators currently view the part during touch up with an adjustable microscope located at the front of the station. Due to height constraints from the chair and micropen machine, the microscope will always be high enough compared to the operator that they are required to flex their neck and back to reach the eyepieces.
Current microscope setup to view that part during the touch up process

Current microscope setup to view that part during the touch up process

Current Problems

Ergonomic issues presented by the operator having to “lean” forward to look through the microscope. Ergonomic issues include neck, lower back, and shoulder pain from using the microscope.

Future State

Microscope with a Screen

Click on the following link for a PDF of all on going research pertaining to the Viewing Apparatus

Operator Tooling

Current State

After the printing process is complete part of the gold ink is not connected and the operator is required to “touch-up” this portion of the part. The tool used has a toothpick or needle like point and a handle similar to a pencil. The distance between the painted part and the location of the operator's hand requires the tool to be long, or requires the operator to hold the far upper end of the tool so that the point can reach the part.

Current Problems

The tool is not comfortable to hold and use repeatedly all day. The necessary positioning of the hand and arm to perform the touch-up is uncomfortable. The risk factors for the Micropen operators are repetitive hand and arm motions in unsupported, awkward postures. The exposure is in combination with contact stress from grasping tools while applying force, and applied contact stress from the sharp bench edges. The touch up process require operators to lean forward and assume static postures of the arm, neck and torso for extended periods.

Future State

Objective: To avoid awkward postures of the hand and arm as well as to prevent the operator from experiencing excessive exertion and strain while performing the touch up process. Steady movements and high accuracy instrument manipulation are also required.

Suggested Process Improvement (Solution): Utilizing a mechanical fixture to hold/support the tool during the touch up process provides more control than moving the tool by hand. The Mechanical fixture gives the operator a stable performance while simultaneously providing flexibility and maneuverability, enabling the operator to manipulate tooling with precision.

  1. Modify the handle of the tooling to be larger and more ergonomic.
    • Why: To improve ergonomics related to the operator's right hand and wrist.
    • How:Create a lightweight slip resistant foam handle to adhere to the tooling handle to improve the ergonomics of the tool.
  2. Redesign plastic shield used to cover exposed/rotating components of the chuck.
    • Why: The height of the shield is unnecessarily high, placing it directly in the way of the path of the operator during the touch-up. The dimensions and shape of the part aren’t standardized or consistent, they vary between work stations.
    • How: Change size of set screw used. Decrease the distance the shield protrudes out
  3. Develop a mechanical system to assist with the touch-up procedure.
    • Why: To perform the process, the operator places their hand, wrist, and arm in a non-ergonomic position, this position should be eliminated. Precision work demands focus and requires constant efforts and stability. Utilizing a mechanical fixture to hold/support the tool during the touch up process provides more control than moving the tool by hand. The Mechanical fixture gives the operator a stable performance while simultaneously providing flexibility and maneuverability, enabling the operator to manipulate tooling with precision.
      • Keeps wrist in a neutral position (straight wrist).
      • Reduce awkward elbow and shoulder postures.
      • Less effort or rotational movement to use
      • Reduce Touch up time and time spent holding tool.
    • How: Develop a mechanical system that places the tooling in the “view” of the screen so the operator is not required to “find” the part within the chuck. A common issue when testing a microscope with a screen was finding the field of view at the start of the touch up. Small, flexible joints for precise positioning and help to match the operator’s hand movements. Lateral tooling movements are inverted by the pivoting point and can be scaled depending on the tool insertion depth.

SolidWorks Model

Optimum Design
Click on the following link for a Video of the Optimum Design
 Optimum Design: Developed by benchmarking surgical guided robotic systems (MazorRobotics, MAKOplasty, Transbuccal system, Da-Vinc Robotic Arm and Tilo Wüsthoff DLR MIRO). Using a fixture to help support and stabilize the tooling dramatically increases the precision and accuracy of the operator. The seven degrees of freedom of the open kinematic chain allow the systems to inherent motion resembling the actions performed by the operator.

Optimum Design: Developed by benchmarking surgical guided robotic systems (MazorRobotics, MAKOplasty, Transbuccal system, Da-Vinc Robotic Arm and Tilo Wüsthoff DLR MIRO). Using a fixture to help support and stabilize the tooling dramatically increases the precision and accuracy of the operator. The seven degrees of freedom of the open kinematic chain allow the systems to inherent motion resembling the actions performed by the operator.

Simplified Design
 Simplified Design: The fewest number of movable parts (Components and Joints) without constraining the operator.Rails are used to facilitate the linear translation of the tooling fixture sub assembly. Two rails permit precise positioning of the subassembly along the selected axis without allowing rotation. Rails allow the subassembly to translate the selected axis moving the tip of the touch up tool close to the cliff of the probe. By guiding the tooling fixture sub assembly, the system becomes a slave device that is exactly constrained to preferred path of the touch up tool.A ball joint possesses three rotational degrees of freedom. This Allows for smooth motion to maintain precision alignment and handling of the touch up tool. The ball joint can be heat treated, have lubricated fittings and coated with Teflon, to enhance endurance and increase component life. Range of motion is constrained to the desire dimensions required to perform the touch up. Purchasing a Ball Joint Spherical Bearing is a simple way to limited rotation angles and range of motion.

Simplified Design: The fewest number of movable parts (Components and Joints) without constraining the operator.Rails are used to facilitate the linear translation of the tooling fixture sub assembly. Two rails permit precise positioning of the subassembly along the selected axis without allowing rotation. Rails allow the subassembly to translate the selected axis moving the tip of the touch up tool close to the cliff of the probe. By guiding the tooling fixture sub assembly, the system becomes a slave device that is exactly constrained to preferred path of the touch up tool.A ball joint possesses three rotational degrees of freedom. This Allows for smooth motion to maintain precision alignment and handling of the touch up tool. The ball joint can be heat treated, have lubricated fittings and coated with Teflon, to enhance endurance and increase component life. Range of motion is constrained to the desire dimensions required to perform the touch up. Purchasing a Ball Joint Spherical Bearing is a simple way to limited rotation angles and range of motion.

Workstation
Soildworks Model of a Micropen Workstation: During the site visit on the 12/8/2015, measurements were collected to determine mounting options for the operator tooling concepts. Most of the design details are worked out away from the actual Micropen workstation. Not having the ability to take home a workstation to explore possible design models it became necessary to create one. The workstation dimensions were used to generate a Soildworks model. This model will be utilized to figure out the action items listed in the link above.

Soildworks Model of a Micropen Workstation: During the site visit on the 12/8/2015, measurements were collected to determine mounting options for the operator tooling concepts. Most of the design details are worked out away from the actual Micropen workstation. Not having the ability to take home a workstation to explore possible design models it became necessary to create one. The workstation dimensions were used to generate a Soildworks model. This model will be utilized to figure out the action items listed in the link above.

Click on the following link for a summary of the Operator Tooling and future action items: Operator Tooling

Arm & Elbow Support

Current State

After the printing process the operator is required to perform a touch-up step where currently they rest their arm and elbow on a platform to keep it even with the top of the Micropen instrument. This is a forced motion since there is no implemented support currently for the operator when performing the touch up procedure.

Current Problem

  1. The operator has no choice as to where they can place their arm – there is no adjustability. It forces them into an un-ergonomic position.
  2. The static load on the forearm and elbow causes stress in the operator’s shoulder.
  3. The orientation of the operator when leaning on the platform to perform the touch-up procedure is not ergonomic for the operator.

Future State

  1. Adjustable Elbow Support
    • Why: Static shoulder tension would be released.
    • How: The support could be adjusted to the operator’s preference, until they feel they have put their arm in a non-painful position.
  2. Adjustable Forearm Support
    • Why: When the operator currently performs the touch - up procedure, they have to place their arm on a hard, flat surface. An adjustable forearm support would allow the operator to place a “cushion” down at an angle to their own personal preference.
    • How: The support would be placed at the location of the touch up.

Click on the following link for a PDF of all on going research pertaining to the Adjustable Elbow Support

Modification for Proper Seating Position

Current State

Throughout the process the operator is required to perform procedures in non-ergonomic positions. Many of the steps in their process are repeated numerous times throughout the day. The operators are required to sit in a somewhat sideways position to reach the microscope when performing the touchup step. For the process the operators also need to place the ceramic part on a small metal wire and use this small wire to transport the part after the process to the WIP fixture.

Current Problem

The current workstations, prevents the operator from working in a neutral posture. Due to the lack of legroom at the workstation the operators are forced to sit sideways adapting an awkward posture to complete the process. The operator is in a constant state of leaning forward and leaning backward, through the use of the microscope. The current chairs implemented by Micropen do not provide back support in both of these positions.

Future State

Saddle Chair

Click on the following link for a PDF of all on going research pertaining to the Modification for Proper Seating Position

Stretching and Exercises

Current State

The operators perform stretches at their discretion.

Current Problem

  1. The operators muscles are repeatedly placed in static positions throughout the day.
  2. The operators are in a sitting position for the majority of the day.

Future State

  1. Provide stretch sheets that demonstrate a variety of stretches.
    • Why: To encourage the operators to move from their static position more often.
    • How: Provide print off sheets or poster size documents to have in the work area that provide both a visual and written description of the stretches.
  2. Decrease WIP to increase flow.
    • Why: To reduce the muscles repeated static load for long durations.
    • How: Decrease the number of holes in the WIP fixture tile to 25 holes in a 5x5 pattern. When 25 parts are completed the operator moves the tile to the next step. This forces the operator to get up from their seating position and use other muscles in their body.

Click on the following link for a PDF of all on going research pertaining to the Stretching and Exercises

Final Detailed Designs

Click on the following link for a PDF of all Final Detailed Designs the Final Detailed Designs

Bill of Material (BOM)

Click on the following link for a PDF of the currentBill Of Materials and Budget

Test Plans

Click on the following link for a PDF of the current Test Plans

Design and Flowcharts

Functional Decomposition

Functional Decomposition: The functional decomposition shows the process steps related to manufacturing the parts. The process of manufacturing the parts has not been modified.

Functional Decomposition: The functional decomposition shows the process steps related to manufacturing the parts. The process of manufacturing the parts has not been modified.

Click on the following link for a PDF of the Functional Decomposition

Systems Architecture

The structural decomposition identifies the physical components, at a high level, that are required in the system. The structure of the system has been modified from the current system based on the proposed changes which provide ergonomic benefits for the operator.

The structural decomposition identifies the physical components, at a high level, that are required in the system. The structure of the system has been modified from the current system based on the proposed changes which provide ergonomic benefits for the operator.

Click on the following link for a PDF of the Structural Decomposition

Test Phase and Component Relationship

Test Phase Relationship Diagram: A three phase plan will be used for testing the subsystems. The format shown illustrates the test phases and the subsystems that will be tested. The phase approach is used due to prerequisite requirements and resource requirements.

Test Phase Relationship Diagram: A three phase plan will be used for testing the subsystems. The format shown illustrates the test phases and the subsystems that will be tested. The phase approach is used due to prerequisite requirements and resource requirements.

Component Relationship Diagram: Each of the subsystems are related, some are more related than others. The figure shows, at a high level, the relationships between the subsystems.

Component Relationship Diagram: Each of the subsystems are related, some are more related than others. The figure shows, at a high level, the relationships between the subsystems.

Click on the following link for a PDF of the Test Phase Relationship Diagram and Component Relationship Diagram

Risk Assessment

For the latest updated version of the Risk Assessment, click on the following link for a PDF of the Risk Assessment
Updated Risks

Updated Risks

Plans for next phase

Weeks 1-5

Weeks 6 - 10

Weeks 11 - 13

Weeks 14 - 15


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