Subsystem Build & Test
Table of Contents
Team Vision for Subsystem Level Build & Test Phase
What we planned to do during this phase
- Determine appropriate power adaptor
- Preliminary design of motor housing
- Testing of rolling tray
- Modify rolling tray design and test
- Complete initial prototypes of motor coupling
- Complete neckband dispenser legs
- Determine production increase from implemented improvements
What we accomplished during this phase
- Finished initial design of motor housing and incorporated modifications
- Determined and purchased appropriate power adaptor
- Tested rolling tray and identified problems
- Modified rolling tray and performed limited testing
- Complete final prototype of neckband dispenser legs
- Complete initial prototype for motor coupling
- Determine appropriate adhesive for attaching coupling to roller
- Determined production increase from implemented improvements
Industrial Engineering Improvements
Production IncreaseThe following graph, displays the production increase throughout the project. When the project first began the average daily number of cases being produced was 231. From the start until the end of the spring semester, production increased 9% to 252 cases. After process changes were implemented over the summer, the production increased to 17% since the beginning of the project.
Standard Work SurveyPlease fill out the distributed Questionnaire, attached is a copy of the document:
Employee Survey ResultsWe conducted employee surveys last month and have summarized what we heard in the following PDF:
Mechanical Engineering Improvements
AC to DC Wall AdapterFrom the build and test phase of MSD II, we took the comment to explore hard-wiring the power source. This requires an AC to DC power converter. U.S. wall outlets supply 120 volts (V) at 60 hertz (Hz). The motor we purchased runs on 12 V of DC power. The following table details the options we explored for AC to DC converters.
We chose the Jameco 252824 AC to DC power converter. Due to the reliability associated with Jameco products and the expediency of delivery. The final cost was $17.43.
Modified Wiring DiagramThe wiring diagram has been modified to show the new power source. From our last review, we switched from battery power to hard-wiring the motor. For review, this means we needed to purchase an AC to DC power converter because the motor we purchased is a DC motor.
Also for review, the diode allows current to flow in one direction while preventing flow in the reverse direction. This is to prevent kickback flow from releasing the push button.
The motor box has been the main challenge since the last review. We have spent a significant amount of time designing the motor box for ease of removability. There is a top and a bottom portion that will slide over one another. Similarly to the top and bottom covers of a board game box. The following figures show the current design of the motor box.
After completing our first printing of the motor box, the group reviewed the print and chose ways to improve the design. Listed below are the improvements made:
- Reduced height by 1/4 inches.
- Changed the hole for the wiring down to 1/8 inches.
- Increased the diameter for the motor exit to 0.47 inches.
- Moved the hole for the motor by 0.26 inches to the right of its outward-looking face, as well as setting its height to 1.5 inches from the top.
The top for the motor box has also been a work in progress. The following photos show the initial design for the lid.
Motor CouplingThe motor coupling has been printed multiple times in order to ensure the best fit possible. The larger end attaches to the top roller of the glue well and the smaller end attaches to the motor. It is our intention to permanently attach the coupling to the roller and have the motor end removable. The plastic piece can be washed with the roller and it removes the possibility of getting any electronic components wet. The coupling could still be used as a knob if so desired. The couplings cost $0.28 to print.
Coupler Adhesive OptionsTo permanently attach the coupling to the roller we explored a few different adhesive options. They have been complied in the following table:
Our recommendation is JB Weld because of the lifespan of the glue and the high durability. Some epoxies can become brittle over time and JB Weld does not. Additionally, it has a strength of 3,900 psi. Basically, there is no chance of the glue seal breaking due to torque concerns.
Gate HookWe took a look at multiple options for the attaching the motor box to the glue well. The simplest and cheapest mean is a gate hook. The hook will be attached to the motor box and the other end will be welded to the glue well. All of the options in the following table are corrosion resistant.
We chose the National Hardware Gate Hook and Eye for the following reasons:
- Length of the Hook
- Corrosion Resistance
Two hooks will be required for either side of the motor box. So the total cost will be approximately $12.
Modified Neckband Dispenser Legs
The neckband dispenser legs are on their last modifications, with the final product being completed in the 3D printing lab. The improvements made over the last phase are listed below:
- Increased the density to 100%.
- Reduced the size of the hole for the suction cup.
- Reduced the overall height of the neckband dispenser leg by 0.226 inches.
Rolling TrayThe rolling tray was tested at Arcworks where several issues were identified. Some of these issues include the label being too low on the bottle, the label sliding out of place during rolling, and the label not initially sticking to the bottle at the start of rolling.
The changes made to the rolling tray include shortening the distance between the rolling edge and the side of the tray and adding a groove to help keep labels in place.
The new location of the rolling edge is a clear improvement as the labels are now fully visible. Unfortunately, there was some confusion with the RIT machine shop and the groove was not placed in the correct location. Steps are currently being taken to fix this issue and the tray should be ready for further testing in the near future.
Angles for Glue WellSince MSD I, we have been exploring the option of adding angles to the glue well to simulate the employees propping up their glue well's with a rag. We ran a test last semester to determine that approximately 5 degrees was the minimum angle for glue to roll down toward the rollers. We also determined that 10 degrees was the optimal angle to prop the glue well up at.
Since then we have conducted tested to see how well the glue well works at 10 degrees. The glue well was filled till the glue touched the bottom roller.
We determined that it experiences the following problems:
- Too much glue is placed on the rollers
- Glue was flowing over the top of opening
- Excess glue was being collected at the back of the opening
We also decided to test the glue well at approximately 5 degrees. We experienced the same problems listed above. Additionally, we also tested a different glue well at ArcWorks. It was determined that permanently affixing the angles to the glue well was not the best solution. Rather, a solution that allows the glue well to be propped up or flat is optimal. When glue runs low the well could be propped up and when full it could be laid flat. The improvements from this modification will be minimal so the focus remains of the rolling tray and the motor assembly.
Costs of 3D Printing
Bill of Materials
The previous BOM totaled $102.06, but this accounted for quite a few items no longer being used. It also left out a few items that are needed.
Test PlansME Test Plan
Risk and Problem Tracking
Functional Demo MaterialsThe agenda for this presentation can be found at the following link: Agenda
Plans for next phaseThe plan for the next phase, the Integrated System Build & Test Phase, is as follows:
Emily Hebert's Integrated System Build & Test Phase Plan: Emily's Plan
Troy Bailey's Integrated System Build & Test Phase Plan: Troy's Plan
Justin Cook's Integrated System Build & Test Phase Plan: Justin's Plan
Cassie Kaczmarek's Integrated System Build & Test Phase Plan: Cassie's Plan
Lachlan Newcomb's Integrated System Build & Test Phase Plan: Lachlan's Plan
- As an individual on the team, what are you doing to help your team achieve these goals? (Use the individual 3-week plan template for this)