9/28-10/5

This week we had a meeting with Bengt, the patient holder for the railway and bogie design. We showed him our initial designs, and he gave us really good feedback on improvements and things to consider. One of the suggestions completely changes our direction for design, however, will be better in the long run. He suggested that there only be one actuator for steering of each bogie. If two actuators were used for each bogie, and one of them fails, that could mean that both bogies could be derailed. We are planning on using a timing belt system to actuate the lower steering arm. The next has to do with wind forces on the bogie. Up to this point, I designed the joint between bogie, without considering a moment being created by the cabin from wind forces or lateral forces during cornering. The universal joint will have its width stretched in order to overcome these forces during windy conditions or cornering. The placement of the joint is also important and current is not in plane with the axial of the main hub wheel. The problem will be creating something that still allows the axial to be driven the way that propulsion is suggesting. Bengt also suggested that we redesign the upper steering arm from a four bar mechanism to a simpler rocker. This is one design point, that I am reluctant to change. It is possible to design the driver diad to lock out and resist more force than just the holding torque of the stepper motor. Overall the group needs to meet today, and split the work load, and have create clear guidelines and design requirements after meeting with Bengt.