It has been a while that this blog hasn't been updated. During this period, our sub team has made some progress in the final designing and fabrication state.
Most of the major steering components, including 4 upper control arms and 2 lower control arms, are finished already. We carried out most of the cutting in the Tech Shop San Jose using the water jet cutter. We come across problems with fitting the cut parts onto the main structure since the material is thicker than initially planned. Since we reduce the size of the upper steering arms to 95% of the original size. The rest of the parts stay the same.
We also discover problems with assembling the parts together since the tab on the parts are too shallow to fit properly onto the slot of the other parts, making them every unstable when being assembled. So We use a metal file to make the depth of the slot to 0.25 inches deep. And for the rest of the parts, we change the design so the water jet cutter can make precise tab and slot.
I took both the MIG/TIG welding class in Tech Shop but we reckon that we will use MIG welding in assembling the parts together because 1.) MIG welding is relatively easier and less  time-consuming 2.) MIG can make stronger welding. We actually experiment with both method before we came out with that decision. All the parts can be assembled without major problems except when occasionally the material is too thin and they are burnt through when the 2 pieces have different thickness.
We have chosen to use NEMA 34 stepper motors for our actuator and we are in the process for seeking sponsorship from a stepper motor in Santa Clara. They agree they can donate 2 stepper motors in return for their company name to be mentioned in the project.
Our current schedule is to fit our control arms onto the main structure to inspect the fitment before full welding is carried out on the main structure. On the coming Thursday and Friday we will eb fabricating the linkage system consisting of ball joints, threaded rods and some of the pieces we cut from 1/4 inch thick steel plate. We will also build the mounting bracket for the stepper motor.

In last week we further analyze the our current designs and try to figure out the shortcomings of each of the design. We notice that there is one shortcoming of these designs and that is the bogie may have the chance that the guiding wheels on either side of the bogie are not supported by the rail during rail switching action and this may result in safety issue. So we have decided to come up with designs of steering mechanism that keeps the bogie on the supporting rail constantly. The whole design team, both the fail safe and steering mechanism team, agree that the new design of the track and steering mechanism should not be something totally different from the previous design. We also discuss the 1/4 scale model that we are going to build and we agree that the finished product will be in a loop and there will be some inclination simulating the bogie is approaching the boarding station on ground level. I have further brainstormed for some new design and I was thinking about using tube structure for the rail. However since the new design shouldn't be deviate from the old design too much and hence I reckon the design is not feasible.
Some of the rail design I made:

This is some of the sketches for the steering mechanism of the ATN bogie. In the first design a hook-like mechanism on a rotating shaft is used and the hook-like structure keeps in contact with the side surface of the rail of the direction the bogie is switching to. The shaft is rotated by gears or actuators ( electrical, hydraulic or pneumatic). In the second design the bogie switches direction by using 2 guiding rails and a pair of guiding wheels. The guiding wheel is raised up to keep in contact with the rail according to the direction the bogie switches to. The steel control arm is either raised up or lowered by actuators. The bogie also has an extra guiding wheel to keep the bogie in contact with rail. The third design shares similar design. In both the second and third design plastic guiding wheels are used in order to absorb vibration during direction switching action and provide better gripping force on the guiding rail

In last week, the full scale ATN was demonstrated and operated to us and all of us have a brief idea on how the powertrain and the steering system of the bogie functions. However, from my observation vibration and noise is generated when the bogie is rolling along the guide structure. Hence I think possible solution is to add a active damper consists of coil spring or more refined air suspension on to the powertrain. Also braking system consists of automobile brake pad powered by actuator (electric, hydraulic or pneumatic ) can be installed to individual wheels for safety. Disc brake system  from automobile or motorcycle can installed on the drive shaft of the guiding wheel.

In last week, we are pleased to have our second Spartan SuperWay meeting and at the beginning of the meeting, every member made a one minute speech on reviewing some of reports and papers written by the previous team. Many of us commented how what expectation they have for the upcoming project and some of their advice on the design of the mechanical part or structure of the ATN. Then we move on dividing ourselves into teams that are responsible for different parts of the project, such as the structure of the guide, the full scale model, the mock up model of the ATN system and the cabin design. I have joined the group in which we want to improve the mechanical part of the powertrain of the full scale design. We have decided sub-teams need to be set up for respective areas: steering, active suspension and fail-safe system. I have signed up  to take part in improving the fail-safe system because I am particularly interested in adding a brake system into the design in order to make the design fully functional and realistic. We  needed to do some follow-up by further reading the documents done by the previous team in order to gain better understanding in the design and discovery potential rooms for improvement.

Hi My name is Jeffrey Chau and I am one of the members in the 2015 ME195 SuperWay Team. I am majoring in mechanical engineering in San Jose State University and My focusing discipline is mechanical design. My anticipated graduation is in June 2016. I was an international student from Hong Kong before I transferred to SJSU. I am interested in automobile repair and I am learning to play the piano and other musical instruments. After I am graduated, I would like to pursue my career in mechanical engineering or manufacturing field.