Week 15 Review
Table of Contents
Phase GoalsFor this review team 15741 has fallen slightly short of their task planning predictions. Certain tasks required more time than we initially predicted which led to overall inefficiency. With this being said, our team is still capable of meeting our overall completion goals by the end of the term. With this in mind, we have still provided our promised end state deliverables in their most advanced forms possible, if not already completed. It is our guarantee that the customer will be receiving updates after this final review in order to ensure that we continue to follow our plan.
Our largest priority concerns involve collecting more data to fill out the bill of materials, and selecting the proper bearings to interface our rotational components. All other deliverables are in the projected state as promised at the previous review.
In preparation for phase II, we have produced a schedule as well as a preliminary testing plan and user manual. We have also made plans to invite other departments of the RIT campus to join us for a future review in phase II as per suggestion of our customers.
Technical Questions Answered From Previous Review
Key Subsystems and Technical Questions Associated with Systems
1. Jaw/Table Gripping System
- Can we concentrate loads on the optical breadboard surface with use of bolts? If yes then, we can proceed with our intended design? Otherwise we have to generate another system that is agreeable to both customer and table manufacturer. (Customer wanted bolting used to interface table without clamping)
We have determined that we can use the bolting interface and a minimal amount of clamp force that is equal to the amount of loading the table can support normally under warranty. We have updated our gripping system in the revision history for added support in rotation.
- What are the stresses that the jaw will undergo in both dynamic and static cases? How big does it need to be? This will require a complete structural analysis.
A structural analysis has been completed. We have made modifications such as the reduction of trusses and improved slotted bolt designs. See the revision history below.
- How many bolts do we need to use to hold tables (complete bolt stress analysis)
Bolt stress analysis has been completed. Between both methods of loading and worst-case scenarios, the maximum number of bolts needed is 24. The recommended amount can be found in the analysis.
2. Rotational System
- How are we going to rotate tables? (i.e. human interface system)
We have developed a gear system to support an axle that creates rotational torque. This axle is connected to a plate will have welded jaws on them.
- How are we going to select the bearings needed for the system? Factors include: how to fit, materials to fit into, material of bearing itself, grade, etc.
We will require additional customer feedback to select a proper system as they are considered the recommended subject experts.
3. Vertical Support Columns/Lifting Mechanism
- Do we need to generate Engineering requirements for the structure with strain/deflection criteria or stress criteria? What are those requirements?
See our FEA analysis for our criteria development.
- How big do the vertical columns that support the clamping system need to be? What should they be made of (tubing, boxes etc.)? Structural analysis after determining states of loading will address these topics.
See our FEW analysis for our criteria development.
- How are we interfacing structural beams with the lifting system? How are we going to lock the lifting mechanism in place on the structure so that it does not drop or lower unintentionally?
We have developed slotted channels for lifting. See revision history for the locking system.
- What size ball screws do we need? What grade of material? What size handle will be required to manipulate screws within basic human ease of use criteria? We will also need to undertake bearing selection and interface blocks with base system and vertical supports.
An analysis was performed for the Acme screw selection, however manufacturers can only provide a more conservative size. We have selected a root diameter of 0.75 inches and 5 feet in length. The interface blocks are currently under development.
4. Base of lifting system
- What are appropriate casters?
We have determined that 3 inch casters with a large load rating will be suitable and fulfill the customer's desire.
- Structural analysis of base with vertical columns to determine size and material to make base of system. Interface with ball screw.
Vertical Columns have received FEA analysis. The interface has been determined but will be improved upon in phase II based on cost.
- What sort system will adequately bring our system to a complete stop. How are we going to interface them well?
We have chosen force locks (foot pedal stops) which will sit underneath the center of the frame and will not require the immediate coordination with the opposite unit.
6. System as a Whole
- How is human error going to affect our system and how do we compensate for this?
The largest amount of human error will be attributed to the coordination of both users lifting the table evenly. To compensate for this, we have allowed for slight movement within the slotted channels to prevent seizing. Furthermore, we have determined that the screws will not create large amounts of lift/turn.
- How are we going to keep within initial projected $500 budget? How do we justify larger expenses?
We are selecting parts from an initial company and then comparing these with competitors. Through iteration, we have significantly reduced costs along with minimizing the size of certain components. Larger expenses will be justified to the department with the reasoning that we must make safety considerations over cost considerations for specific components.
- Have we addressed all necessary deliverables for both MSD as a class and for our customers? How are we going to address and finish any that are not in this plan?
We have provided a majority of the components and the overall design with priced materials that have had quotes returned. For any components/deliverables that are not delivered by the end of the academic term, they have been considered in our phase II plan. Our customers will also be receiving updates between our last phase I review and the next one with our progress.
Prototyping, Engineering Analysis, Simulation
The Engineering Analysis page shows the current state of analysis and component selection for various subsystems in the Isolation Table Mover. All documentation contained is under constant review.
Engineering Drawings, Drafting, & Operation Manual Construction
Engineering Drawings and CAD Files This link will lead to our associated CAD files, engineering drawings/schematics, and any information pertaining to the operational manual.
Bill of Materials (BOM)
BOM This section will provide our tentative bill of materials with information pertaining to manufacturers, price quotes, delivery schedules, and other associated financial information.
Risk Assessment This link will provide our updated Risk Assessment as well documentation related to our engineering and customer requirements.
MSD II Phase Planning
Test Plans This link currently contains our developing testing plans for phase II.
Action Items1. Complete detailed BOM (Bill of Materials)
- Select specific screw manufacturer
- Select specific bearings
- Select specific bushings
- Select specific casters
- Select specific brake
- Select specific gear/shaft assemblies
- Select specific handles (If purchased)
- Acquire lead times for all parts
2. Update Risk Analysis
- Part Delivery Delays
3. Revise gear box assembly to reduce risk of twisting
4. Revise MSD II Plan
MSDII Shared Vision
Problem Tracking Sheet
Table of Contents
|MSD I & II||MSD I||MSD II|