10/26/16

This week was spent more on cad than anything else, with the motor already selected, it was relatively easy to model the motor as well as a mounting bracket to attach it to attach it to the bogie as seen in the images below. In addition, a bevel gear, which was taken from a part supplier site, was mounted to the drive shaft of the motor and bogie, rotating the motion by 90 degrees. As fair as the brakes are concerned, we would have to go with something more compact than a disk brake to fit it onto the main axel. Even the smallest disk brake, which can be seen in the images below cannot fit into the tight space where the gears and motor are located. For this reason, we are looking at using a belt brake, which are typically used on pocket bikes due to their small form factor

Week 8

This week we worked on completing our 2^nd presentation, highlighting most of the CAD work and propulsion design work we have complete. Currently we are in the process of redesigning the braking system to possibly using a band brake on the driving shaft. Additionally, we plan on creating a list of the products we plan to purchase (materials, motors, brake, etc.) and have it complete soon. We also plan on beginning our team report that will be due at the end of the semester.

10/19/16

A great step has been made this weekend in terms of finding the right motors for our system, it is a 24 volt, 4 amp motor, that will output 45Nm of force which is necessary for movement. Although the speed of the pod-car will be slow with these motor, it is the best that we could come up with given the power constraints that we were given. Cad models are already underway and should be ready over the weekend for use in the main assembly.

Week 6

For week 5 not much was done. Refinements on motor sizing calculations and communication among the other sub-teams were conducted and as a result we began to notice issues. One of the main issues was in realizing the amount of current needed to power the motors to provide the torque calculated was too large.

This week (week 6), the entire half scale bogie team had a team meeting after the final presentations in order to clarify a number of issues. One of the issues was regarding the prototype and what was expected of the team as a whole. We wanted to avoid spending too much time on production and manufacturing of prototype along with the other sub teams and we decided that the prototype due at the end of the semester will serve more as testing the integration of other teams. Additionally, we decided as a whole team that the budget requests for the parts needed will be due mid November in order to have parts to work with for early Spring. 

Furthermore, after further reviewing the bogie CAD, we realized that the space for the motors and brakes we had in mind were very limited, and we decided to put on hold our fail-safe braking system we created previously. The motor will remain offset from the bogie as previously discussed. The motor CAD was added to the bogie assembly via GrabCAD (See image). An idea we are currently discussing is the use of a worm gear for our gearbox, as it can provide good gear reduction and "fail-safe" as the wheels can lock if the motor isn't moving. Discussion among the braking/propulsion team, steering, wayside, and solar will be conducted as we all need information from one another to move along. (Power/current requirements, space along the bogie are major topics we plan on covering Wednesday)

Placement of motor on left bogie is circled in red.