Build & Test Prep
Table of Contents
Team VisionIn proceeding with the action items left off from the Gate Review, the following items have been completed.
- CAD model was updated to have a locking yoke for the dynamic eye, ball bearings for linkage joints, as well as other minor details.
- QtGUI has been successfully tested with the motor. PC interfaces with Arduino which interfaces with the motor. Completed two preliminary tests.
- Developed concepts for interfacing the motor shaft to the linkages, and the eye to the linkages.
- Added additional functionality to linkage calculation spreadsheet.
- Updated all of the test plans to follow the exact same format as each other as well as add more details.
- Analyzed the 4-bar linkage (position, resolution profile, velocity profile).
- GUI planning & execution (Steps were taken to add functionality to the GUI).
- Bearings for the 4-bar linkage have been researched.
- The bill of materials has been updated to reflect recent purchases.
- The bill of materials now has sections of how much of the budget is left with the current plan and how much has been purchased.
- Materials and prices are being looked into for an enclosure for the power supply.
- Obtained 3D printed OEMI-7 replica from Dong Wong.
Updated Customer and Engineering RequirementsThe customer and engineering updates have been updated yet again to reflect the realistic goals and scope of this project.
Project TimelineThe overall project timeline for MSD II has been updated since our past gate review and it can be viewed here.
Meetings with Topic Specialists
- Advised against the four bar linkage, stating that with any type of fast, high bandwidth moves, it may deflect.
- He also stated that if we mount the motor (shaft up) where it is offset from the eye, he would advise a belt and pulley setup. It would add some mechanical advantage (1 inch pulley on motor shaft and 2-3 inch pulley on the eye).
- He said we should also make sure that the belt is wide – at least 20 mm and recommended us to look into Gates power grip GT2 belts because they are high performance; accurate with good torque transmission.
- Discussed the belt and sprocket concept mentioned by Abe Amirana
- Advised that there may be a greater chance of success using the belt and sprocket concept over four bar linkage
- Discussed ways to interface the sprocket with the motor
- He mentioned the potential use of heat-treating the sprocket to create a press-fit onto the motor shaft
- Discussed "degree of misalignment" allowances in the bearings which according to Dr. Boedo should be given as a specification from the manufacturer. This was discussed due to concerns of lateral loads potentially causing deflection in the shafts.
Belt and Pulley ConceptAccording to Abe from Teknic Motors, a potential alternative concept to the four bar linkage would be a less complex belt and pulley system, using materials similar to timing belts in vehicles.
A sketch of what the belt and pulley system might look like is shown below.
Another sketch of the concept is shown below, this time from a top-down view.
Below is an up-close visual of how the belt interfaces with the pulleys, using gear-like teeth.
The team compared the four bar linkage concept to the belt and pulley concept, and developed the following list of pros and cons for replacing the four bar linkage with the belt and pulley system altogether:
Test PlansTest plans were created for each of the necessary customer and engineering requirements. Any concepts or features which need to be tested have a test plan. This can be seen in the overall test plan which relates the engineering requirements to the test plans below. In addition to this, preliminary test plans have been successfully performed with the pairing and interface of the motor, power supply, Arduino, and computer.
|Mechanical Test Plans||Electrical Test Plans|
Bill of Materials
Plans for Next PhaseAs a team we have decided that in the next three weeks our goals are:
- to have a functional GUI with similarities to alpha teams GUI and objectives consistent with customer needs
- to have a finalized design
- to have all or at least the majority of necessary parts ordered
- to have started manufacturing the higher priority parts
As an individual on this team, these are our personal objectives to reach the common goals above
Design Review MaterialsInclude links to:
- Action Items