Adhithyan Vaiyapuri's Spartan Superway Blog

This week was spent working on some CAD designs based on the XOFO SOFN motor. We have decided that to make sure the motor fits our needs better, the motor should only be supported on one end, and the main housing of the motor should be converted to be the wheel, as it's an outrunner hub motor, and it makes more sense to make it our wheel and fit a tire onto it rather than attach it to a wheel, and face losses. I did two basic CADs: one shaft and one housing, to show the idea of a single shaft and a wheel, and to convert the dimensions of the XOFO CAD to standard measurements. XOFO, sent me some CAD of the actual shaft sometime after, and David and I got the shaft designed. My next task is to design the wheel, and to look at some back up motor companies incase XOFO doesn't work out.   

This week we got a little more information from Mac Motors. Unfortunately, they didn't seem to understand our questions, so we weren't able to get all the information we felt we needed. However, they did tell us that the motors we're looking at don't have a planetary gear set. We aren't sure if they could implement a gearbox for us or give us a gearbox for the motor if we asked which led to concerns. We need the planetary gearbox to give us the torque the system requires while keeping the RPM values within the values the motor is rated for. Because of this, I am looking at ways to fit a planetary gearbox to the motor, should we buy these motors from MacMotors. I was not able to think of a good enough way to do this with just a gearbox we can buy, as there aren't any with the specifications we want. There is the option of designing and manufacturing custom planetary gears, but that may take too long, because we want to get the motors as soon as possible. We ma...

This week I was searching for ways to modify the motor housing for the motor we picked out the week previously. It's pretty much confirmed that we're going to move forward with the M12500-3 motor from MacMotor, and through our communications the company has been very accommodating, and are willing to guide us through the process and even build us custom shafts and housings. However, we're going to double check with the other full scale teams before putting in the order, to make sure everyone is all on the same page. My responsibilities going forward are to work on designing a new motor housing, as well as looking for alternative motor manufacturers, just in case MacMotors falls through.

This week we changed the direction of our project and narrowed our responsibilities down. Instead of building a motor from Sapphire Motor's designs, we are just going to buy a motor from a manufacturer and modify it to fit our specifications. David, our mentor, told us to look at hub motors for electric bikes. Because ebike motors are built for two supports, I've been researching ways to modify the motor to work off one support, because the motor will only be attached to the bogie on one end. I've come to the conclusion that replacing the inner shaft with something heavier will create a cantilever effect and work best. Also, there is the issue of the motor's housing. Right now a lot of the motors have a large spoke radius, and won't fit on our current bogie design. So, we may need to redesign the housing.

During this week I spent a lot of time researching motor theory and electromagnetism. We decided to build our own motor using designs David, our mentor from Sapphire Motors is letting us use. Despite this, I felt like further research was needed, because if we can't understand the drawing files David is providing, we won't be successful in building our motor.

This week we had our first set of lightning talks. To complete this task, my group and I came together and went over what we discussed with our mentor David, what we were able to research individually, and what we feel we still need to know to design and build a high power brushless DC motor. After presenting our lightning talk, the group came together again, and further discussed the specification this motor would require, what type of motor we would build. We eventually decided on an 8 inch diameter, brushless DC inrunner motor. We left the class that day with the goal of having a more concrete plan for the motor by the next class, as well as getting more research done.

Hello, My name is Adhithyan Vaiyapuri, and I am going into my fourth year of BSME at San Jose State University. I hope to specialize in Thermal Design. I want to work on the Spartan Superway project because I am passionate about the public transportation. As someone who uses the public transportation system regularly, I am often dissatisfied with the current system and it's inefficiency. The Spartan Superway project is an exciting new method of public transportation that will make the system better, and I am excited to have the chance to be a part of it's creation.