Click on the following link for the Detailed Design Directory: Detailed Design Documents
Team Vision for Detailed Design PhaseThe 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.
|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 RequirementsFor the latest updated version of the Customer needs, click on the following link for a PDF of the Customer Requirements
Engineering RequirementsFor the latest updated version of the Engineering Requirements, click on the following link for a PDF of the Engineering Requirements
House of QualityClick on the following link for a PDF of the latest updated version of the House of Quality
Operator Survey ResultsA 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.
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 StateAfter 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.
- 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
- 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.
- 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.
- Increase length of fixture and increase spacing between holes.
- Reduce the number of holes on the WIP fixture tile, this will increase the spacing between holes. Retain the 4”x4” tile size.
- Increase the diameter of the countersink to allow for easier part placement.
- Modify WIP Fixture Stand angle and location, allow
- 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
- Create an incremental back support, similar to a beach chair.
- Place the WIP fixture near the part unload area at a height that is equal to or below the chuck/unload area height.
SolidWorks ModelClick 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
Current StatePart 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.
- 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
- 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 StatePlacing a kink in the wire
- Why: Prevents the part from sliding off the end of the wire while transporting. Eliminates the need to balance the part thus reducing the risk of smudging by coming into contact with operator
- How:Tooling/device that quickly and easily bends multiple wires at one time. Should be repeatable, placing a uniform kink at the same location every time.
SolidWorks ModelClick 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.
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 StateAir 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 ProblemsWrist and Shoulder Pain / Exhaustion.
Future StateSolenoid Air Valve (Button)
- Why: Gets rid of twisting motion, and reduces the distance the arm / wrist needs to travel in order to open or close the chuck.
- How:Reduces opening / closing the chuck down to just pressing a button.
Click on the following link for more information about the Solenoid Air Valve
Current StateThere 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.
- The current location of the keypad requires the operator to rotate slightly to press the keys.
- Not all keys on the smaller keyboard are frequently used.
- 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.
- 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
- 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
Current StateOperators 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.
- Operators have a good view of the part
- Operators can adjust zoom and microscope placement to their preference
- Operators are viewing the part from a natural angle; touchup is easy to perform
- Cons:Data from operator surveys show that the leading source of pain comes from the neck. This neck strain is a result of operators flexing their neck and back to look through the microscope
Current ProblemsErgonomic 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 StateMicroscope with a Screen
- Why: A microscope with a screen would allow the operator to sit back and do the process in a more ergonomically safe position. In addition, it would reduce the amount of motion that the operator has to perform throughout the course of the touch-up procedure.
- How:The entire subsystem will consist of a viewing
device, monitor and stand.
- Viewing device or camera
- Monitor or Screen
- Monitor Stands
- Placement: The screen would be placed right in
front of the operator, and would be large enough that
they would not have to lean forward to view it.
Screen Placement Must satisfy all Engineering
- Camera is placed on front of tool fixture for optimal view
- Camera is placed in front of station to replicate operator perspective
Click on the following link for a PDF of all on going research pertaining to the Viewing Apparatus
Current StateAfter 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 ProblemsThe 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 StateObjective: 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.
- Modify the handle of the tooling to be larger and
- 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.
- 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
- Develop a mechanical system to assist with the
- 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.
- 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.
Optimum DesignClick 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.
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.
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 StateAfter 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.
- 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.
- The static load on the forearm and elbow causes stress in the operator’s shoulder.
- The orientation of the operator when leaning on the platform to perform the touch-up procedure is not ergonomic for the operator.
- 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.
- 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 StateThroughout 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 ProblemThe 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 StateSaddle Chair
- Why: Saddle chairs are used in various dental / medical applications which often have many ergonomic issues presented to them daily. They force the operator to sit in an ergonomically “correct” position.
- How: Obtain top seating options for trial evaluation to gathering employee feedback. The old chairs would simply be replaced by the new saddle chair. Saddle Chairs are known to have a little breathing period of about a week where the user must break it in, but once the operators get past that, it is a comfortable and ergonomically friendly position.
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 StateThe operators perform stretches at their discretion.
- The operators muscles are repeatedly placed in static positions throughout the day.
- The operators are in a sitting position for the majority of the day.
- Provide stretch sheets that demonstrate a variety of
- 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.
- 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 PlansClick on the following link for a PDF of the current Test Plans
Design and Flowcharts
Click on the following link for a PDF of the Functional Decomposition
Click on the following link for a PDF of the Structural Decomposition
Test Phase and Component Relationship
Click on the following link for a PDF of the Test Phase Relationship Diagram and Component Relationship Diagram
Risk AssessmentFor the latest updated version of the Risk Assessment, click on the following link for a PDF of the Risk Assessment
Plans for next phase
- Develop operator tooling prototypes
- Purchase materials for final design through Micropen
- Begin testing subsystems
- Begin writing paper for final design and improvements
- Finalize Test Plan
- Complete Section 4 within Test Plan
- Continue to collect Operator Survey & Analyze results
- Develop ideas for Material Handling Tooling (Placing a Kink in the wire)
Weeks 6 - 10
- Finalize testing of all components
- Ensure subsystems are working together as expected
- Finalize system components based on testing
- Encorporate system components to workstation
Weeks 11 - 13
- Perform required training for new workstation
- Tweek workstation based on initial feedback
- Collect Operator Survey & Analyze results
- Finalize deliverables
Weeks 14 - 15
- Ensure system is working as expected
- Present finalized system and improvements