Table of Contents
Team Vision for Detailed Design Phase
The plans of this phase were to answer the questions remaining about part modeling, part production, and prototype construction. The goals of this phase and design review are to have bone designs appropriate for a functional prototype, become better versed in the production methods for the bones (printing and casting primarily) to allow for the final selection of a method, and construct a testable prototype that appropriately meets the expectations and requirements of our customer.
It was planned to complete all models and drawings, begin the printing of bones in a variety of sizes and densities, update all documentation from the preliminary review and progress report, begin the construction of a prototype that could be tested if time allowed, and continue to communicate with necessary SMEs.
Action Item Since Progress Report
- Finish Solidworks models of the bones and joints – 100%
- Print multiple revisions of bones and joints at various scales for updating the models and visualizing any potential issues, ending with the prototype prints from the final models – 100%
- Communicate with the Construct @ RIT for prints & design input – 100%
- Make manual edits to bones and joints – 80%
- Investigate casting materials & options – 80%
- Obtain base for structure stand – 100%
- Update Bill of materials – 100%
- Update Engineering Requirements – 100%
- Update Risk Assessment – 100%
- Update drawings – 100%
- Update Test Plans – 100%
- Address immediate purchasing needs – 100%
- Test ‘muscle’ fit – 50%
- Assembly – 80%
- Print revisions of bones at multiple scales – All
- Consider placement of goniometer and force gauges for data acquisition - All
- Make adjustments to Solidworks bone and joint models – Chris & Amanda
- Communicate with the Construct @ RIT - Maria
- Make manual edits to bones and joints – All
- Investigate casting materials & options – Maria
- Obtain base for structure stand – Amanda
- Update Bill of Materials – Amanda
- Update Engineering Requirements – Shannon
- Update Risk Assessment – Chris
- Update drawings - Chris & Amanda
- Update Test Plans – Shannon
- Test ‘muscle’ fit – All
- Address immediate purchasing needs – Amanda
- Assembly - All
What does the team plan to accomplish by the Detailed Design Review?
- Finish Solidworks models of the bones and joints
- Print multiple revisions of bones and joints at various scales for updating the models and visualizing any potential issues, ending with the prototype prints from the final models
- Communicate with the Construct @ RIT for prints & design input
- Make manual edits to bones and joints
- Investigate casting materials & options
- Obtain base for structure stand
- Update Bill of materials
- Update Engineering Requirements
- Update Risk Assessment
- Update drawings
- Update Test Plans
- Address immediate purchasing needs
- Test ‘muscle’ fit
- Assemble prototype
- Begin testing prototype
What tasks have been accomplished so far?''
- Print revisions of bones at multiple scales
- Consider placement of goniometer and force gauges for data acquisition
- Make adjustments to Solidworks bone and joint models
- Communicate with the Construct @ RIT
What tasks remain, and who is the owner of each?
- Make manual edits to bones and joints - All
- Investigate casting materials & options - Maria
- Obtain base for structure stand - Amanda
- Update Bill of materials - Amanda
- Update Engineering Requirements - Shannon
- Update Risk Assessment - Chris
- Update drawings - Chris & Amanda
- Update Test Plans - Shannon
- Test ‘muscle’ fit - All
- Address immediate purchasing needs - Amanda
- Assembly - All
What decisions have been made so far?
- Take all printing needs to the Construct @ RIT
- Apply goniometer directly to bones
- Locations of attachment points and methods for running ‘muscles’ through the bones for the force gauge
- Joint styles & locations
What questions does the team have for the customer and/or guide in order to continue moving forward?
- What considerations should be made for Static and Dynamic movements? Will dynamic data be part of a lab procedure for students?
Prototyping, Engineering Analysis, Simulation
Casting vs. 3-D Printing
Refer to Bill of Materials for Prices on 3-D Printing and Casting.
Discussion of Density for 3D Printing
- 3D printing at 40% density is strong enough and offers good enough resolution for the purpose of the project.
- Complete 3-D printed model at 40% density will be assessed during first / second week of MSD II and decision will be taken by group and customer on method of manufacturing.
- Feasibility will be assessed with full model.
Engineering Requirements The last revision of the Engineering Requirements can be found_here
Drawings, Schematics, Flow Charts, Simulations
Schematic of the Complete System
Bill of Material (BOM)
To be completed by team members to indicate the validity of a prototype or model and show the satisfaction of the engineering requirements for the project.
Materials required for tests:
- 1 device or device prototype.
- 3 PASCO Loadcells (assembled with 2 screws each)
- 3 PASCO Sensor Adaptors
- 1 Goniometer
- 3 Velcro Arm straps (if model not equipped with Velcro bars)
- 1 PASCO Pasport
- 1 250g weight
- 1 500g weight
- 1 Computer with Capstone software
- 1 ruler
- 1 protractor
- 1 Calipers
- 1 stopwatch/timer
ER1 – Static Force of Muscle A – Attach load cell to break in muscle A string, hang 250g mass from hand hook, wait for arm to lower under the weight and settle, then get read out from Capstone. Validity- Force achieved at rest must match accepted anatomical value.
ER2 – Static Force of Muscle B – Attach load cell to break in muscle A string, hang 250g mass from hand hook, wait for arm to lower under the weight and settle, then get read out from capstone. Validity- Force achieved at rest must match accepted anatomical value.
ER3 – Static Force of Muscle C – Attach load cell to break in muscle A string, hang 250g mass from hand hook, wait for arm to lower under the weight and settle, then get read out from Capstone. Validity- Force achieved at rest must match accepted anatomical value.
ER4 – With each muscle attached and load cells strung, and the goniometer attached and reading out to Capstone, the arm is bent at the elbow and moved through the available range of motion. Validity- readout must show that the arm can move from approximately 0o and 90o.
ER5 – Hang a max load of 500g from the hand hook while holding the lower arm up to the upper arm so that the angle of the elbow is approximately 0¬o. release the lower arm and allow the weight and lower arm to fall. Validity- the arm must be able to fall and stop while still holding the weight, staying upright and stable (no concern of it being easily knocked over), and produce steady force and angel change graphs/tables through capstone. There should be no bending or material failure in a valid case, and the entire base must still be resting on the tabletop.
ER6- With load cells in place, no weights, and the lower arm resting so that the angle of the elbow is approximately 90o, measure the angles of the muscles with the bones and the distance of the muscle attachment to the bones. Validity – Both values must be within ±5%of the average adult.
ER7 & ER8- Set the model in each possible position with the 250g weight. For each position (supinated wrist, pronated wrist, flexed elbow), allow the position to be set and then allow the device to sit, with no contact with a person or extra support from an outside object (excluding tabletop), for 1 minute. Validity – The position set by the user must not deviate by more than ±1cm during the wait period.
ER9- With all loadcells attached to the muscles and the goniometer strapped to track the elbow, use Capstone software to record 30 seconds of data for each sensor by creating 4 graphical readouts of force (N) by time (s) for the loadcell sensor and angle (degrees) by time (s) for the goniometer, and then a table with a column of force readouts (N) or angle (degree) for each sensor and a column of time (s). Record the data results as a 250g weight is hung from the hook hand of the device and the elbow extends. Validity – each graph or table column can be produced, clearly shows the impact of the weight on the device, and can be saved and exported as a .txt, .m, or .xls file.
ER11- Measure the dimensions of the final model, upright, holding no weight and the elbow in such a way that the elbow is flexed and the lower arm does not extend past the base of the model. Strings may be loosened or untied to best minimize size of model. No loadcells or goniometer should be attached. Validity – The base of the device must be within 2ft by 2 ft.
Design and Flowcharts
- The Running risk assessment can be found in this document_Updated Risk Assessment Document P17082
Design Review Materials
Plans for next phase
The full schedule can be found here Full Project Plan Schedule
Project Plan Highlights Printing bones using a higher density. Assemble model. Apply test plans on prototype.
Amanda Cook's Three Week Plan can be found_here
Chris Harley's Three Week Plan can be found_here
Shannon Keenan's Three Week Plan can be found_here
Maria Romero-Creel's Three Week Plan can be found _here