10/19-10/26

During this week, our team continue working on the new adjustments towards our bogie, steering and failsafe. A meeting via Skype with Bengt was made in order to discuss our adjustments and new possibilities to improve our design. It was decided that the bar connecting both bogies will be lowered below the track. By lowering such bar, the normal forces will be greatly increased thus the amount of torque necessary by the motor to go up the 17 degree incline will decrease considerably. Another advantage of lowering the bar is the spacing within the bogie will increase. The more space we can provide for the other sub-teams the better it will be as they will not be limited to certain parts and design. The steering was decided to be maintained as a gear and pulley system which will provide more safety thanks to the gear ratios in place. Our communication with other teams is and will continue to be essential as we want to make sure all sub-systems can fit as expected. Also, we had another meeting with all the sub-teams where we decided on a date where we will finalize our design and all the parts that will be order. November 16 is the day every sub-team will submit their list and prices of all parts needed to essentially obtain the funding and finally placing the order. By setting the date we will ensure the parts will come before the beginning of next semester.

10/12-10/19

This week we met with Bengt to discuss the design progress we currently are making. Propulsion has made a final decision on the motor that they will be using. The placement of their components are making a huge impact on where we can place the linkages for the steering. We have a final concept for how the steering will be switched with one single actuator located at the top. It will use a driver diad for the top steering arm, and a geared pulley system for the lower control arm. We are also discussing using a solenoid as a failsafe for steering and we have a final concept for the failsafe that prevents the cabin from falling through the rails. This would also lower the stall torque requirements for the driving stepper motor. This weekend we are planning on laser cutting out a plywood prototype to see how it fit on the rails. We will also be preparing our presentation for next weekend, and working on the CAD for the linkages.

10/5-10/12

During this week, all sub-teams composing the half scale project decided to have a team meeting. In this meeting we essentially discussed and set a deadline for different issues. In accordance we shared our future plans and our future design changes. The changes and all design components are dependent of each other, therefore knowing exactly the route everyone is taking will ultimately make our work easier. The team decided in a deadline to acquire all the information and decide in what parts will be order. By doing so, we give ourselves plenty of time to test and prototype our systems. Our communication with one another is crucial as it will define our success in the project. In our specific team, we decided to assign tasks, thus it will be easier to accomplish our final design. We decided to change our steering system from a 2 motor controlled system to a 1 motor controlled in conjunction with a pulley system. By changing our steering design to only one motor, the chances of failure will be decreased and there is more change for two motors to fail in comparison to one motor. Essentially one member of our group will focus on designing the new steering pulley system, while he other person will continue the changes in the CAD design we currently possess. One important and crucial matter we came to accordance with the other sub-teams is to have weekly meetings thus improving our communication.

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.