THE PHYSICS OF RACING: BAJA STYLE

By Stephanie Bandoski ( Neuroscience, ’17)


As a non-engineering student, what intrigued me the most about Baja SAE was the racing. From the little bit of autocross and off-roading I had done in the past, I knew that to drive well, there was a lot more to it than just fun and games. Don’t believe me? Take a look at The Physics of Racing by Brian Beckman, and that only touches upon 2d stuff! Never mind jumps, rocks, mud or any other obstacle we see at Baja SAE competitions.

And why is racing so important to us as a team? Racing is essentially the application of all the designs that went into the car which took the team over half a year to build. It’s the application and use of those designs that prove whether or not the design and manufacture was effective. Without testing how our suspension elements handle going over logs, how do we know what to improve upon next year? Answer is, we don’t.

So, this year, we were so confident in our designs we chose to devote some time to driver training. We didn’t want the limiting factor at competitions to be our drivers’ abilities, but rather be limited by our actual engineering abilities. And it’s amazing how much understanding of physics and engineering was needed in order to drive our car to its limits! It is naive the think that the engineering process and therefore Baja SAE stops at just the manufacture of our car. In order to go full circle and know what to change next year, our knowledge has to extend into the physics of racing.

WHAT’S UNDER ALL THAT MUD?

By Noah Meyers (Mechanical Engineering, ’20)


When I joined the UR Baja team earlier this year, I knew how to use a drill, and I had held a ratchet maybe once or twice before in my life. Within a few weeks, I learned how to use many of the tools our team could access and had begun work on design concepts in SolidWorks. For comparison, I will only be learning CAD software in the classroom this summer, and I don’t know anyone else who would teach me how to use an angle grinder outside of the team. It’s safe to say I’m hooked on Baja, but how did I get so addicted?

When I was at the club activities fair in the fall, I saw a car which I assumed was black underneath all the mud on it. This piqued my interests immediately; I have always had a fascination with cars, but I also saw that this was no ordinary car. When I got to their booth, I learned that students on campus receive an engine, and build the rest so it could compete in off- road racing; I wrote my name on the email list immediately.

Arguably the main reason I have stayed on the team is the amount of practical learning there is when working on a car. I have been heavily involved in the design process for this year’s new car, and I have seen how many parts need to come together for the car to roll, let alone perform well, and I’ve designed some of them myself. Working under the project team lead for suspension, I started work on reducing the weight of our rear hubs. Ultimately that design is not ready for this year’s competition, but I will most certainly be back to finish what I have started.

Even as a new member on the team, I have seen that you need communication between everyone if you want a successful car. You can’t build a car where a shock gets welded to the frame but there is no frame member to transmit the force of the car. If there is a lack of communication between the frame and suspension teams, this could very easily happen, and the results could be catastrophic. What was incredible to a novice like me was that I was still in this integrated mesh of discussion. I attended design board meetings to learn more about the car, and it has truly fascinated me to see everything coming together on time, despite the inevitable hiccups (like the new hubs breaking two weeks before competition). In addition, everyone on the team wants you to learn, they don’t want to be the only ones carrying the weight of design and assembly. This selflessness is what I think makes us an excellent team, because reaching out to the newer members like me will help to only strengthen the team in the long run, and build more connections moving forward.

Competition has been sold to me as the end goal of all the progress we make from year to year. I have only gone to Midnight Mayhem so far, which is not an official competition, instead it’s geared more towards increased freshmen participation on our team. What I do know about official competitions is that we are a top tier team. With all the work we put into the car during the year, between our design, assembly, and post-assembly testing, we are competing amongst some of the best schools in the nation. I have been promised that I will enjoy competition by numerous veterans to the team, and I would hope so. It is where being a team, a communication network where everyone knows their strengths and weaknesses, can replace a flat tire quickly then send the car right back onto the endurance track, or weld an upright back together to keep our car in the mix. This is where we can show our design prowess to the judges, justifying all the decisions we have made regarding the car, and comparing the price of our car to one already in existence. All of this and so much more excites me, and I can’t wait to go to competition in California in less than a week.

This year has been a fantastic freshman year for me, and I owe most of that to the UR Baja team. I have learned valuable career skills not because I had to, but because they were made fun and useful. Not only that, but I learned these traits from people who not too long ago were in my shoes, and now they oversee the design and production of the car. To these people, I want to say thank you for giving me the knowledge I now have, and the knowledge I will continue to absorb in my time on the team. I would truly consider this year and the ones proceeding to be the best of my life thanks to this team.

TESTING, TUNING, AND TWEAKING

By Wendy Snyder (Mechanical Engineering, ’17)


The Baja manufacturing season is typically a full semester of chaos. There are many long days in the shop, numerous late nights, and often a last-minute scramble to finish the car in time for the first competition. At the start of this school year, the team was looking forward to the benefit of having both competitions after the end of the semester, providing ample time for tuning and testing after the car was complete. As we all know too well, nothing changes like plans. After a hectic registration day, it was decided to attend the competition in California on April 27-30th. In addition to many other challenges introduced by attending a competition across the country, the timeline for completing the car was suddenly shortened by an entire month.

            While daunting, the accelerated timeline motivated the team. We managed to meet our goal for completing the chassis and by the date we had set as a goal to have a running car, we had a nearly complete car. The hard work of team members to complete the car on schedule left us with almost an entire month to test, tune and tweak the car prior to competition. Testing and tuning is an important step in the engineering design cycle, one that our team has often struggled to complete in past years due to time and resource constraints.

            With the car complete, we started listing out different aspects of our vehicle that we could measure and test to verify and validate our design and analysis. We started simple, measuring basic properties like vehicle weight and ride height. In response to the difficulties we experienced with our brake system last year, we looked to validate the analytical model we used for brake design this year. To do this, we took a few days to add a set of pressure gauges into the brake circuits to measure the pressure as a function of input force.

            With the help of recent alumni Matt Isbell and our sponsor SimuTech Corp., we were able to get our Hall effect sensors working to collect data on our CVT shift curve. Using the data, we then adjusted our tuning settings to achieve the ideal shift curve determined by our model. During testing, we also measured the vehicle’s top speed using a radar gun.  After determining ideal CVT settings to achieve the desired shift curve for standard driving, we moved to a hill and collected some data to see the response of the CVT in a hill climb scenario.

            Once CVT settings were selected, the remaining time was spent tuning suspension to determine the optimal shock and tire pressures for different obstacles and to improve handling. Utilizing our small on-campus practice track, we drove the vehicle over tabletops, baby graves, logs, and tires. The car handled each obstacle with ease and settings were selected to obtain the smoothest traversal over all obstacles.

            During our testing, we found a few components that required redesign or reinforcement. From each failure, we learned something new about the car, as well as our design and analysis. With the extra month spent testing and tuning, we had time to correct things we found that were wrong and improve what didn’t work quite as expected. All these corrections are valuable time saved at competition since we were able to catch them early and correct them before we even arrived at the site.

            Of course, there are always more things to test and tune. We plan to further test in the time between the California and Kansas competitions once we have the opportunity to see how our car handles at a real competition. One main goal for this time is to use strain gauges for the first time in order to validate some of our load cases. After a year of hard work, the team is in one of the best places we have ever been as we head to competition in California. We are ready to go out, have fun, get dirty, and bring home a trophy!

A UR BAJA SAE FACULTY ADVISOR’S PERSPECTIVE

By Professor Sheryl Gracewski


I have been the faculty advisor for the UR SAE Baja team for over 20 years, so I have witnessed the remarkable evolution of the team. The most obvious growth is in the number of students: currently, about 40 students make significant contributions to the team each year, whereas in the past, there have been teams with as few as 5 members. The surge in numbers has been accompanied by an increase in student diversity, including not only students from a wide variety of ethnic backgrounds, but also from a wider range of majors. For example, economics majors have recently helped the team excel in the Baja competition’s Sale Presentation and electrical engineering majors are developing data acquisition systems to test vehicle performance.

The Team has grown in many more ways than just increasing numbers. By necessity, the Team has refined its organizational structure to handle the additional training and logistics needed for a larger group. It is amazing that the students not only design and fabricate a Baja vehicle each year, but they also train the underclassmen, so that they can take over and be successful the next year. Each year they devise better methods for this training. For example, they have created Wiki pages and are developing training videos to archive critical information.

The Team’s design, analysis, fabrication, and overall engineering skills have also vastly improved, especially over the last several years. Such advances would not have been possible without the support of the Team’s sponsors, local industries, alumni, and the Team’s family and friends. To coordinate the larger number of students contributing to the design, they have set up the Product Data Management system and instituted various systematic methods for CADing their designs in Solidworks. In addition, their knowledge of and access to fabrication techniques has also significantly increased in recent years, with the assistance of local companies. For example, they now design their own gearbox and have it fabricated by local sponsors, whereas in the past they either purchased a gearbox or used a less robust system of chains and sprockets.

The team members, especially the team leaders, seem to have boundless enthusiasm and put in an enormous amount of time and energy into the team. It is not unusual to find 10-20 Baja members working in the shop or Baja office on a Saturday or Sunday. They begin preparing for the next year, on the way home from the last competition of the summer, as they review how well their vehicle performed and where they could improve on the design. They meet (online) weekly starting early in the summer, so they can finish most of the design in the fall semester, and complete fabrication and testing of the car before the first competition in late spring.

Working with the UR SAE Baja Team has been an amazing experience. I have witnessed not only the growth of the team, but also the advancement of the team members, from novices to team leaders and beyond. I enjoy seeing the alumni that support the team and cheer them on at competitions.  I am grateful to have had the opportunity to get to know so many outstanding students.

EXPERIMENTING WITH PLASTIC

By Oscar Ta (Optical Engineering ‘18)


Our Baja team is in partnership with a composite company, Laird Plastics. In previous years, they have been the plastics distributor our team has received materials from. Following up this year, Laird Plastics requested us to test applications for their strongest plastic.

Their material, KyronMAX, offers mechanical properties comparable to metals. For example, KryonMAX is said to have a higher strength-to-weight ratio than steel, which can save volume on design.

We started to test the material by cutting a steering wheel out of a 6’’ by 11’’ sheet of the composite.

Amazingly, the material withstood the heat from a 0.75’’ diameter bit, spinning at 10000rpm on a CNC router. Noticing the unexpected resilience of the material, we raised the idea of testing the material under more stressful conditions.

Natural curiosity pushed us to wonder how it would break. Our next step is to test the material with a part under more stressful conditions than a simple steering wheel. The rear caliper mounting plate on the gearbox is a perfect candidate because it must withstand constant vibration.

A full-fledged report will be written from our Baja team. Hopefully, the results of this partnership will spearhead future company partnerships from our team.

BAJA SAE: A RETROSPECTIVE

By Laurence Lohman (Chemical Engineering, ‘17)


Enzo Ferrari once said “what’s behind you doesn’t matter”, and after almost four years with the Baja team at UR, it does seem almost futile to condense my experiences into a single article. However, Enzo also said that “aerodynamics are for people who can’t build engines”, so his advice may fail occasionally. After four years, seven competitions (with two more coming up), and thousands of hours in the shop, I would like to look back at it all.

I arrived at UR as a freshman with few ideas about what to do with myself. I knew that I wanted to learn about cars, and I also had a compulsion to build things; Baja provided an excellent opportunity to do both. For the first few weekends, I showed up for the car, but then I began to show up for the people. Through the older team members, I learned more than I had ever thought possible. I gained an understanding of best practices for design and fabrication and a new mindset for solving problems. I also learned a variety of new skills that are unknown to most students. These range from SolidWorks and TIG welding to heat treating suspension links in a household oven and living in the basement of Hopeman for a few days before competition. Through all of this, the team fueled my curiosity, motivation, and passion for engineering and racing.

No discussion of Baja would be complete without mentioning competitions, which may be the most memorable parts of my experience here. I was introduced to competition as a freshman at Midnight Mayhem, which reinforced my enthusiasm for the team. As I watched engines being repaired with a hair tie and the spring from a pair of vise grips, I knew that I wanted to learn and contribute as much as I could. Over the next few years, I attended competitions across the country, which provided the most fun and least sleep of my life. I say this despite the trials that competition threw at us; the lowest point was probably 26 hours of nonstop effort to get the brakes working in Tennessee last spring. However, competitions are the culmination of months (if not years) of effort, and seeing the car in action is worth all the late nights and roadblocks. This sense of validation is what keeps us coming back for more, trying to shave ounces from the car and seconds from our lap times.

The Baja team has always been passionate about what we do, but recently, we have become even more driven to be the best. A common characteristic of high-level racing drivers, mountaineers, and fighter pilots is a combination of audacity and humility. To succeed in these pursuits, one must sincerely believe that they are the best, and that they can perform flawlessly under immense pressure. However, one must also recognize that they have little control over the forces around them, and that everything can fail under the best conditions. I believe that successful racing teams must also have these qualities. We must believe in our ability to compete with the top teams; Baja teams do not accidentally finish in the top ten. We must also realize that the difference between first place and ‘Did Not Finish’ can be a single loose bolt or flat tire, and although everything may go wrong, we need to adapt and plan for it. To become a winning team, we must think like a winning team, which we are finally starting to do.

Looking back at my time with Baja, I have countless reasons to thank the team. I have made lifelong friends and gained skills that I would never have otherwise. Together, we have traveled across the country and learned an incredible amount about design, manufacturing, and racing. I think of the team as family, which is helpful because I have probably spent as much time with them as with my actual family over the past few years. More than anything else, I have never met a more committed, motivated, and determined group of people, and I consider myself incredibly lucky to be a part of the team. Thank you.

ENGINEERING EXCELLENCE

By Alan Grier (Mechanical Engineering, ‘17)


For this year’s Baja SAE competitions, the UR Baja team is aiming high: be number one! This may be a lofty aspiration for us, but we don’t just want to be top 20, or even top 10; who doesn’t want to be the best? As the current incarnation of the team grows, gathers more sponsors and resources, and strengthens its alumni network, we have much of what it takes to have the top vehicle at competition. Our competition standings are generally improving, and vehicle performance is also on an upward trend. At least on the design engineering end of things, much of what is enabling our success and improvement is design stability. After numerous cycles of iteration, many of the major vehicle components are changing little from year to year.

After the team was rekindled, the vehicles built took a myriad of forms and changed significantly from year to year. Eventually, the Water Event was dropped from competitions, allowing for major design changes since the Baja cars no longer needed to be amphibious. Over the next several years, the team tried several different rear suspension geometries—solid axle swingarm preceding trailing arm—before settling on H-arms with control links. Initially adopted in the 2015 season, we are now in our third year of the setup. Front suspension geometry has also undergone few changes over the past few years, only requiring minor adjustments due to changes in ride height and wheelbase.

But do not think this is stagnation in our engineering and innovation, not needing to spend great amounts of time designing suspension geometry from scratch has allowed us to research and pursue other areas for improvement! Last year we began experimenting with a sway-bar to help decrease the vehicle’s turning radius and generally improve maneuverability. While there were a few hiccups at first, we identified the problems have devised solutions for this year. This will be a huge benefit for the Maneuverability Event and the Endurance Race.

And although I am highlighting suspension, the other project teams have had similar experiences. We are at a point where we can focus on “the little things”: refining the designs we currently have, dropping weight from overdesigned components, finding cheaper and faster manufacturing methods, and ultimately doing more long-term research. A few projects we’re currently working on are engineering our own brake components (calipers specifically), switching to aluminum for certain tie rods and possibly control arms, and researching an injection moldable carbon-composite that Laird Plastics—a local sponsor—has given us.

Some projects—namely aluminum tie rods—are on a path to be implemented in the current year’s vehicle, while others are still years away from implementation on the vehicle. The time we have saved has enabled us to place a larger emphasis on longer-term research projects and ensure that designs are truly well-engineered before seeing use on a competition vehicle. And given our team’s current trajectory, we will continue only to rise in the rankings and be number one. Meliora.

2016-2017 USABILITY OVERVIEW

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By Oscar Ta (Optical Engineering, ’18)


Brakes: Calculations & Part Selection

To stop the rotors is to stop the rotations of the wheels; this is our starting point to backtrace forces to the input force from a driver’s heel. These forces are related to the dimensions of brake components by multiple formulae. To select brake components, we adjust these dimensions to propagate calculations for braking force in the rear and front braking systems. The braking system was designed to these criteria:

1) 60%:40% front-to-rear static braking force distribution

2) contains a biasing mechanism to create a 35%:65% front-to-rear dynamic braking force distribution.

Combined Bias Bar & Brake Pedal

The brake pedal is designed with a pedal ratio of 7.2, which higher than that of the previous year’s manufactured pedal. For packaging efficiency, we modify last year’s design to achieve this higher pedal ratio for the same length pedal. Our modification places the pivot point at a higher position than the output links to the master cylinder. In addition, our output link will have a built-in biasing mechanism. This built-in mechanism consists of a fixed bearing within the pedal and a rotating bolt connected to links, which connect to the master cylinders.

Segmented Steering Column

To increase comfort and decrease egress time, we plan to implement a segmented steering column. A top-segment will be connected to a bottom-segment via a universal joint with yokes at the junction. The top-half of the steering column is currently in design with the steering wheel with the Laird Plastic steering wheel (see below). The bottom-half is also currently in design while selecting rack-and-pinion placement. Currently, we are working on steering effort calculations.

Custom Rear Brake Caliper

As an experimental project for future years, we plan to custom-make calipers. To start, we model the selected rear caliper in CAD. Then it is modified for specific dimensions, such as mounting points, rotor spacing, and bleeding nipple placement. We will determine manufacturability in our next procedure.

Laird Plastic Research

In partnership with Laird Plastics, we plan to manufacture a steering wheel to compare an experimental plastic material versus a steering wheel made of conventional metal. The experimental plastic is projected to have better strength-to-weight as steel. A butterfly steering wheel was designed in CAD and was tested in a preliminary FEA simulation. With the steering effort calculations, we plan to refine our FEA simulation. The next step is to manufacture the steering wheel samples for testing.

BAJA AS AN ECONOMIST

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By Scott Saucier (Political Science and Economics, ’18)


Baja SAE is well known among the college engineering community. However, outside of that group, it remains a mystery for most. I am interested in business, politics, and economics, so to most, it does not make sense that I participate in Baja. For that reason, when I talk about Baja — which I do a lot — people either forget I am not an engineer or ask me why I am not. My response is generally along the lines of “I don’t need to be an engineer to be a part of Baja” or “I don’t want to be an engineer. I just want to do Baja.” Most people who participate in Baja see it as a practical application of engineering theory and nothing more. While it is, indeed, an application of engineering theory, it is also much more.

As a double social science major, I find a great deal of satisfaction in my participation in Baja. For one, I have been able to explore my interest in working on cars and racing, both of which are passions of mine but irrelevant to my majors. Is Baja just a hobby for me? Absolutely not. While I joined Baja because I wanted to pursue my passions, it has become an incredibly useful tool to further my education and future career prospects. I have moved up through the ranks rather quickly, becoming business manager as a sophomore. In title alone, being the business manager for a Baja team will be useful in a job interview. On top of that, I have learned a great deal. I am far more capable working on a team, more adept at research and organization, and I have learned how to work with business professionals in the real world environment when seeking sponsorships. Without Baja, I would be stuck living out my college days just working through one economic model after another, just to get a degree in something that sounds relevant. Now I get to do that and work with people as if I am an associate in a real world business, an analog to engineers realistically applying their theories through Baja.

In the end, I put a great deal of work into Baja and I have hardly even contributed to any design. I let the engineers take care of that. What I am able to do is work on our cars. I get to fabricate, build, and repair parts of the cars. With the knowledge I have collected by working closely with a team of engineers, I have learned enough about engineering to the extent that I am able to contribute to relevant discussions about our cars. These contributions I have mentioned come more from my own diverse interests than what my majors say I should be doing. Let’s say, for instance, that I had zero interest in the cars. We can say that I never touch the cars or participate in shop hours. I would probably be less effective at my job, but I would still be able to contribute a great deal to the team. I am able to budget and put in orders. I am able to work with sponsors. I am able to help the team run as effectively as possible. Figuring in the passion I have for our cars and competition, I am able to contribute a unique skill set to my Baja team.

As I said, I have never designed anything. I am not an engineer, but I am a relevant and impactful member of the team. Sure, it may take a bit more explaining to convince a potential employer that Baja sets me apart from other applicants, but that does not mean I will not get that point across in the end. In fact, I would say Baja sets me apart from those in my areas of study while my areas of study set me apart from the plethora of engineers in Baja, both to my benefit. In the end, my major does not have any impact on my ability to Baja.

THE NEW FACE OF EXTERIOR DESIGN

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By Mario Gutierrez (Mechanical Engineering, ’19)


This year the exterior design team faces new challenges with a wide variety of new solutions. Ranging from new stickers to a whole new CVT cooling system, the team is ready to innovate and use new technology in the car. As always, Exterior Design is charge of:

  1. protecting the driver and components from the hazardous environment
  2. facilitating the maintenance process in the car
  3. adding an identity to the vehicle by adding sponsors, numbers, stickers, colors, and ideas
  4. ensuring the delivery of an aesthetic final product to garner respect from the community

The first and most complex issue the team faces is cooling down the continuously variable transmission (CVT) in the rear of the car. The CVT can reach a maximum temperature of 120 oC (248 oF) because of the heat trapped inside the cover and the belt. This high amount of heat can be a major detriment when racing in an endurance race and can also affect the general performance of the car. The plan of action is simple: changing the material of the cover from fiberglass to aluminum sheet with mesh. Although it might seem a little unusual to transition from fiberglass to aluminum, the main reason for this is that aluminum can absorb the heat generated on the inside, unlike fiberglass, which insulates the enclosed system and prevents heat from flowing out. Therefore, to ensure the success of this new project, we are incorporating a cooling fan to the primary shaft of the CVT, this together with a mesh on the side of the cover, will allow heat to exit and reduce to temperature by nearly 30% (with respect to a CVT without this system)*.

Since we are committed to the improvement of all the components in the car, we will starting concentrating in those that are specifically vital for maintenance. For example, one of the projects we are working on currently is adding a hinge to the front to allow axial movement of one of the body panels to access the brakes, brake fluid reservoirs, steering wheel rack, pedals, and more (basically the same idea behind the hood of a car but in a Baja vehicle).

These are only some of the projects we are currently working on. This season brings new challenges since we are building a brand new car, and it’s also a great opportunity to innovate and show how the University of Rochester can generate new solutions in the world of automotive engineering and Baja racing.

*JSAE 20139073 / SAE 2013-32-9073

Experimental Investigations of Forced Air Cooling for Continuously Variable Transmission(CVT)

Abhishek Lakhanlal Vaishya

ELECTRONICS TEAM UPDATES FOR 2016-2017

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By Harel Biggie (Electrical Engineering, ’18)


Below I will outline the recent changes to the electronics team, and the updates we are planning for the 2017 season. I have enjoyed being the electronics team PTL and I look forward to seeing the improvements the electronics team has made implemented on the 2017 car.

Midnight Mayhem

Midnight Mayhem provided an excellent training opportunity for Ian Lawson and An  Ho (two new members), to learn about wiring a Baja Car. The 2016-2017 Electronics team is relatively young but the new members are learning quite quickly. Both Ian and An are now fully capable of wiring the kill switches, brake lights, auxiliary lights, and any other components needed for the 2017 car.

At Midnight Mayhem live data was collected for the first time using a Raspberry Pi with an accelerometer. The box was placed on the Rochester Car for the endurance race and recorded data for the entire time the car was in action. The data still needs to be processed but more information about the engine vibrations is needed to do this. We will run static cases on the engine when the Rochester car is reconstructed from the damage at Midnight Mayhem. However, having data from an actual competition is a first for the team and should lead to even more solid designs in the future.

Hall Effect Sensors

Thanks to the work of my predecessor, David Gonzalez, some of the leg work for getting the hall effect sensors up and running was already done. The previous system was capable of recording data at a low resolution of 30 rpm. To improve this resolution, the RPM calculations are now done offline which allows the hall effect sensor to run at its maximum rate. The preliminary results from this change look promising but more testing still needs to be conducted once the Rochester Car is fixed. The system will be ready to go for 2017, allowing us to measure the engine rpm as well as the ratio from the transmission.

Data Collection With Matt Isbell

This year the team was fortunate enough to have one of our alumni, Matt Isbell, return to help with data collection. SimuTech Group, where Matt is employed, is able to provide us with strain gauges and accelerometers. In preliminary trials, it was determined that the engine vibrations need to be dampened in order to obtain more accurate data. The team is looking into accomplishing this for the 2017 car, and that will provide us with more load cases and verification of our designs. Many thanks to Matt and SimuTech Group for all of their help.

RAINBOW ROAD IN KENTUCKY

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By Aaron Goldin (Mechanical Engineering, ’20)


When I told some of my friends back in high school that I had joined the Baja team here at the University of Rochester, they asked me two things: who in their right mind would trust me to drive an off-road vehicle, and what does car racing have to do with engineering anyway?

Baja is an engineering club. Sure, the goal, if you will, of the club is to design, build, and compete with the best off-road vehicle against colleges across the country and world in various events. But the winners are not the teams with the best drivers. Yes. You need to know how to drive the car. You need to fly around corners at 30mph like nobody’s business. You even need to know what to do when you get stuck a foot deep in the mud (wiggle the wheel madly). But none of those things determine the winners. The best team is the one that builds the best car.

Going into Baja, I was under the impression that each team could build any car they wanted, then fight for the number one spot in a sort of Mario-Kart-In-Real-Life setting—I pictured carts shaped like giant rubber duckies, giant strollers, and maybe even a Harambe-themed vehicle. Unlike Mario-Kart, however, winning the race is not about having the hippest car; it’s about building a system designed specifically with the competition in mind. You need aerodynamics. You need a car that has the ability to turn to avoid crashing into trees. The key is that creativity is permitted, but you need to think about the implications of every decision.

That said, it’s not like the carts are all boring skeletons of steel; if you want to put flashing lights and a funky-sounding horn on it too, that’s allowed. Most of the vehicles at Midnight Mayhem, the annual midnight race in Kentucky, were covered in all kinds of psychedelic colors.

Engineering is about being creative, even when it looks like there isn’t any space left for creative thought. There’s a requirement for the type of motor you can use, a specification for the arrangement of your wheels, rules about the very materials you can build your cars out of. It seems there’s barely even room to design. But when you’re at a competition, there’s clearly a difference. Some cars move at breathtaking speed, but can barely turn. Some carts are so heavy with gearboxes and extra frame pieces that they can hardly make it up a hill.  Others—and this actually happened—look like they’re doing great until they plunge down a hill, lose traction, and do a full-frontal flip. In this competition, the team with the best engineers, not the best drivers, is the one that emerges victorious.

If you want to see pictures from Midnight Mayhem, please click here!

2016-2017 SUSPENSION OVERVIEW

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By Mike Macfarlane (Mechanical Engineering, ’17)


The hard work and dedication of the suspension designers of previous years resulted in an excellent system for the 2016 season. This puts me in the highly enviable position of working to improve upon the previous year’s design without having to make radical, complicated departures from what has already been designed. The refinements I currently have planned will be briefly discussed below:

Geometry optimizations

The primary goal of this year’s geometry is to increase the ride height to 11 inches. In addition, the rest length of the shocks at race settings (15.2 inches) was accounted for in the design. Along with other small considerations, this goal will ensure that the  suspension adheres to the design plans. Furthermore, the new gearbox necessitated an increase in wheelbase relative to last year, resulting in slight changes to the Ackerman geometry (outboard tab moves slightly inwards towards the frame) and a slight increase in theoretical turning radius.

Roll-bar

A new addition to the car last year, the roll-bar can greatly improve high speed maneuverability by allowing the inside rear tire to lift off the ground at lower speeds than would otherwise be possible. The previous roll-bar appeared to be too stiff and caused understeer at the Rochester maneuverability event, so this year a looser roll-bar is planned. As a test, a modified version of last year’s roll-bar was tested at Midnight Mayhem and appeared to solve the understeering issue. I would like to further test this stiffness setting before incorporating it on this year’s design but such testing has been delayed by frame repairs.

Weight Reduction Efforts

This season we will begin experimenting with new weight reduction methods by introducing aluminum tie-rods. The challenge with aluminum is not designing it to prevent failure but manufacturing it. Both tie rods will require threaded inserts and a hex piece (for ease of suspension tuning) to be welded on to the tube, which in turn necessitates heat-treating of the finished tie rod. Aluminum 6061 has a rather complicated heat treatment process, but the 7005 alloy (which has a slightly higher elastic modulus than 6061) has a heat treatment so simple, it can be done in a household oven. In future years, as we gain confidence in our ability to manufacture aluminum suspension components as well as the ability of these parts to hold up in an endurance race, more elements of the suspension might be made from 7005.

Design for in-house manufacturing

A major goal this year is to manufacture our own uprights using the Prototrak in Taylor Hall. The major obstacle is demonstrating our competence with CNC machining to the school, which is being accomplished by manufacturing replacement uprights for the 2014 car. A modified design has already been completed (reinforced upper A-arm mount, angled outboard steering mount), and a nylon prototype will be produced this coming week. For the new car, both the front and rear uprights will receive slight modifications as well, though the geometry of their mounting points (with the exception of the outboard steering mounts) will remain mostly unchanged. These modifications are intended to increase the ease of manufacturing, to ensure that both can be machined in three set-ups with no more than three tools.

2016-2017 FRAME OVERVIEW

frame

By Kaven Marte (Mechanical Engineering, ’19)


Rear bracing

The rear bracing is one of the most difficult parts to design because of the interface between the various subsystems required on the car, namely drivetrain, suspension, and usability. Reducing the size of the bracing to lose weight is another major difficulty. It is vital to make sure that the bracing has enough space while packing it as tight as possible to reduce the overall weight.

Firewall

The firewall is one of the most important features of the car, as it separates the cockpit from the drivetrain and engine (protecting the driver). As there are many rules regarding the firewall, it is rather difficult to reduce its width. This year, one of the main goals is to reduce the width of the firewall in order to reduce the air resistance. This width reduction will help the team with both top speed and weight reduction from last year’s model.

SIMs

The SIMs are the lateral members of the roll-cage that seal the driver into the roll-cage. In last year’s model, the SIMs were straight members. However, this year’s model will feature a bend, crucial to reduce the width of the firewall. Because of this change, the cockpit will be made more ergonomic, allowing the driver more torso and leg room. This year’s model will also include a lower mounting point on the firewall, allowing the driver to egress much quicker and easier.

Load Cases

Load cases are incorporated into our design to model the stresses at different parts of the car. We modeled load cases on frontal impact, frontal roll-over, and engine/gearbox loading. The load cases will also be physically tested in order to verify our stress analysis in particular points, with the help of recent alumnus Matt Isbell (‘16) and Simutech Group.

2016-2017 DRIVETRAIN OVERVIEW

 

drivtrain

By Gilead Biggie (Mechanical Engineering, ’18)


The primary goal of my design this year is to improve the acceleration from last year’s Baja Car. In order to achieve this goal, I selected a CVT (Continuously Variable Transmission) produced by Gaged for the upcoming season. For the past few seasons, the team has a run a CVT produced by CVTech with an overall ratio of 3.5:1 to 0.45:1. The Gaged CVT selected for this season has an overall ratio of 3.9:1 to 0.9:1. In my research, I found that having a higher low end on the CVT ratio is a better fit for a Baja car due to the limitations of the engine. The Briggs and Stratton Engine we are required to use only produces 10 HP which isn’t enough power to fully utilize a 0.45:1 minimum ratio.

Another crucial factor in my decision to run a Gaged CVT was the ability to tune the CVT on the car, a feature that will save crucial time in the tuning process. The ability to tune while on the car will be useful in competition as well, should fine tuning need to occur since large tuning adjustments are not allowed. In addition, to have tuning options on the car the Gaged CVT also has 14 different adjustments to tune the CVT. These added tuning options will allow the team to fully understand and tune the CVT. With these ample tuning options also comes unmatched support from Gaged. This support was another important factor in the decision to run Gaged.

This decision significantly reduces the overall weight of the drivetrain system and car. The Gaged CVT itself weighs about 14 pounds. significantly less than the 22 pound CVTech CVT. In addition, the increased high-end ratio of 3.9 allows for a significantly smaller gearbox ratio, meaning a lighter gearbox. To further reduce the weight of the gearbox, I also reduced the thickness of the gears. This was possible due to lower forces on the gears from the lower gear ratio.

Currently, I am working on designing the gear case to closely wrap around the gear assembly, maximizing weight savings. Once the gear case is complete, the design process will shift towards engine and gear case mounting. This year, we will be implementing a mechanism to tension the CVT belt in order to prevent overheating due to belt slippage. Overheating of the CVT will also be combated in this year’s design through the inclusion of a fan mounted to the CVT primary and an air duct, in collaboration with the exterior design project team.

These improvements to the drivetrain design should allow our car to perform better in the acceleration, hill climb, suspension and traction, and maneuverability events at competition. These improvements will also be seen on endurance day throughout the 4-hour endurance race.