Variable Speed Gearbox
The Voith Vorecon is a device which allows a fixed speed motor to operate at variable speeds. It accomplishes this mechanically rather than electrically like a VFD. Power from the main input shaft is tapped off hydraulically through a hydraulic torque converter with variable impeller blades and added back into the drivetrain through a planetary gear set. The variation in power tapped from the input shaft results in a variation in speed.
I was fascinated with this device when I learned it was included in compressor train I was designing the controls for, and I set to studying it. I even built a planetary gear model (pictured upper right) to help illustrate the mechanism during our controls tests. This helped the operators understand the purpose of the control scheme and startup sequence. Because I had studied the Vorecon so thoroughly and had built the model, the customer asked if I would conduct their operator training for the whole site! I have always enjoyed teaching (both my parents are teachers) so this was a fantastic experience, both preparing the material and presenting it. With any new system, there was a lot of troubleshooting and lessons learned when commissioning these machines. I have since commissioned two Vorecons and learned quite a bit in the process. (Full size Vorecon pictured lower right) |
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The Maverick Flying Car
In the corner of Greenville, South Carolina's TD Convention Center nestled between the various booths of the MTW Global Missions Conference, I met a group that works at a company called I-TEC. I-TEC, or "Indigenous people's Technology and Education Center" is a missionary organization which seeks to help people overcome educational and technology barriers which may deter the indigenous church from growing. One of the ways they have done this is by designing and manufacturing The Maverick Flying Car, a fully DOT and FAA approved vehicle. By directing the power of a 190hp Subaru boxer engine through either a robust ground drive system or a 700lb thrust propeller, the Maverick can conquer any terrain to provide humanitarian relief, transport missionaries to spread the gospel of Jesus, and, with the help of some clever control systems, allow someone completely unfamiliar with aviation to fly in a matter of hours. The Maverick was truly an ingenious vehicle well before I began working to help improve it.
Over the summer of 2014, I was able to work with Beyond Roads LLC, the group responsible for the manufacture and continuous improvement of the Maverick. My main project was to design and construct a vacuum forming machine and part molds to manufacture lightweight body panels for the vehicle. I modeled the entire machine in SolidWorks along with a drive system cover then constructed both. The finished product is seen in the picture to the left, and it protects the CVT drive system from debris and splashes. I consider myself blessed to be able to work on this project; not everyone gets to ride in a flying car in their lifetime, let alone one which is used for such a wonderful purpose. |
Vehicle Dynamics
During the spring semester of 2014, I decided to undertake a course, which would end up being simultaneously the hardest class I had ever taken and my favorite. The class involved linear and non-linear modelling of standard vehicle systems, parameter estimation, autonomous control design, and much more. Aside from the challenging code work, the class had a wonderful lab, which involved taking the GPS and Vehicle Dynamics Lab test vehicle to the NCAT (National Center for Asphalt Technology) track for data acquisition. From normal driving conditions to 1/4 mile acceleration tests, skidpad tests, and double lane change maneuvers, I was able to conduct real-world tests that dramatically influenced the accuracy of the models I was able to create and gave me a better understanding of how vehicle theory plays out in reality.
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Organization, Design, Automation
Through I had planned on being a mechanical engineer since the seventh grade, the first time I was able to exercise my talents and knowledge professionally was at Nemak, an aluminum engine block die casting factory in Sylacauga, Alabama. During my my co-op semesters, I was able to work on real projects, and my colleagues treated me with the respect of a fellow engineer. One of the fundamentals I learned from Nemak was the necessity for organization through the process know as "5S". While self-organization comes naturally and can adapt easily, finding ways to clean and maintain the cleanliness of an area, device, or process requires a circumspect analysis. Working with some of the lean manufacturing engineers helped me to see the large financial and work culture benefits of organization. I found that the engineering behind 5S and other organization techniques encouraged me to improve my personal work ethic and take more ownership of all aspects of the facility.
Designing equipment for the die casting machines and finishing lines was exciting and challenging. My first design contribution was of a lubricant applicator for the die casting machine plunger tip. The mechanism acted as a syringe, extracting lubricant from a holding tank and sending it to the tip and sleeve through a pressurized line. After designing, modeling, and implementing the device, the harsh foundry environment exposed many maintenance issues, which I was able to document and compile. Creating a technical booklet and troubleshooting guide helped the technicians to diagnose mechanism issues rather than simply replacing all the parts. Many times, the tip lube dispenser was not to blame for machine faults, and knowing this lead to better part life data and less downtime. My favorite solo project was a casting feature probe for use on one of the plant finishing lines. The device was used as a backup check for a vision system that determined the type of casting on the conveyor before pack-out by reading certain casting features. A second vision system was also proposed as a backup, but my design cost was nearly half of the alternative. Working with a more complicated assembly helped me appreciate CAD more than I had before. I requested to use it in a class, Concepts of Design and Manufacture, and achieved the highest score overall, winning the O'Neal Austin Best Student Award. Many of my engineering classes became tangible after working at Nemak. Whether working with the other engineers or on my own, Nemak gave me my first opportunity to apply my skills professionally and pursue expertise, even if it was only for one year as a co-op. Not all of my design projects were implemented in my stay; some of them may never make it out to the plant for cost or practicality reasons, but I was excited to brainstorm, create, revise, discard, or invent new ways to continuously improve the factory. |
Personal Engineering Interests
During my free time, I like to design and build go karts on a low budget. Since taking a vehicle dynamics course at Auburn University, my design capabilities have increased greatly. I hope to implement what I learned and what I continue to learn in my personal projects as time allows.
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