2014 Frame Manufacturing

So we've had a lot happen since our last blogpost. We will be posting a lot more frequently about the teams progress, so expect weekly to biweekly updates!

That being said, our current design has changed quite a bit from what we had in the summer as some of our design goals had to be pushed back a year. The first objective was for us to build the frame. This year we decided to weld the frame ourselves (props to our master welder Costi Shami). After designing the frame exactly how we wanted in CAD, I used VR3 Engineering - Cartesian Tube Profiling to manufacture a laser cut kit with all the tubes that make up the frame. This made assembling and welding the frame so much easier. Even the camber block points were laser cut! We'd like to thank VR3 Engineering for a fantastic frame tube kit!

Cost has been hard at work welding away and we are almost done with the frame! Here is a photo of Costi and the frame from a few weeks ago:

Aero Design Progress 2014

Earlier this summer, I did a lap time simulation study earlier this summer to understand the sensitivity of lap time on a number of parameters (including mass, power, downforce, drag, and mechanical grip).  The results of the lap simulation showed mechanical grip to be the most important parameter, followed by downforce and then mass.  Since there is a limit as to what can be achieved with mechanical grip, past those limits aero is still the biggest enabler for decreasing lap times.

2014 Architecture

After about 3 weeks, we have a basic vehicle architecture for 2014.  This has been a pretty intense period, as three weeks ago the car was a blank assembly.

The highlights:

• 10 inch wheels - affects packaging for WHUBs, suspension, and frame primarily
• Narrower track (~46", front and rear)
• Smaller wheelbase (60")
• Complete frame redesign - no rear box
• Lower occupant positioning - CG focused
• Lots of downforce

Once again, the focus will be on mass, aero, and mechanical grip.  All of these need to be understood on at least a high level to design an architecture, as many of these enablers and decisions will drive packaging.  For example, originally I started with a rear box because I thought diffuser design would dictat my suspension points, but with CFD I've found that I can actually get better downforce with a shorter diffuser (more on why that is in another post).

So let's take a walk through how to set up an architecture:

Recap of 2013 Motorsports Car: Intake

I must say that I still haven't full recovered from the tornado that was the month prior to competition, which is why I haven't had the opportunity to update the blog. However, we did take a lot of pictures of the design and fabrication processes, so I would like to go through all of the progress we made as a team building our car, named OD-13.

Just a quick note: I apologize for any redundancy regarding the pics that may occur...I just want to make sure I cover everything, because there is a large gap in the blog.

I'll start with the intake:

Suspension packaging

The great thing about a brand new design is the design latitude.  The bad thing about a brand new design is... the design latitude. Making everything fit properly is never an easy task, and often requires you to take a step back and look for some very creative options.

With the help of susprog, I think I've finished the first iteration of the suspension packaging. 

The front was relatively easy - I was able to get the motion ratios required and the ARB packaging with pullrods without too much issue.

 The rear on the other hand is much more difficult because of the addition of a driveshaft, frame limitations, aero limitations, and rim clearance.  However, everything fits, the min clearance at static is slightly less than 0.1" (cutting it close, I know), so a lot of the success of this design relies on good tolerances and properly jigging parts during construction.

Design Progress

 Design is moving along at lightning pace right now, with the whole team contributing now.  With lapsim analysis we've been able to figure out what to focus on for this year - the main goals are (in order) to 1) improve grip, 2) improve aero, and 3) reduce mass.  We might be shooting for a narrower width as well due to the nature of the Michigan course, but not sure if a narrower track is worth the reduction in aero area.

A lot of goals 1 and 3 will be accomplished via the 10" Hoosier LC0's (we think - tire data analysis is currently ongoing to verify).  Also, we're looking for significant reduction in CG via driver positioning and packaging optimization.  Weight reduction is looking for a lot of creative design, better analysis to enable less over-design, better CAD accounting for mass, and better manufacturing methods.  CFD analysis has just started today to optimize the aero package for this car, so there's lots of work to do still on that front.

Some teaser shots of what the car might look like next year:

Let the summer design begin...

Let the games begin...

congratulations on another great year!

I would just like to say congratulations to the team for placing 24th this year at Michigan.  A lot of hard work went into this year, and it certainly wasn't an easy competition, but the team got it done.

Team Picture

Going to Chai's for Dinner after a long day of work in the garage has been a motorsports tradition for many years now.  Thanks to the Chai's team for making such great food for so long!

Making Bodywork, Part 3

So yeah, I guess I owe the team (and the readers) a part three to the bodywork fabrication.  Where we left off on part 2 was partway through sanding the first filler coat on the molds.  After all the molds had filler applied and been sanded smooth, we did it again to fill in the little divots and imperfections that remained.  The next step was to tape the molds with a layer of packing tape.  We do this to preserve the molds so that they can be reused - just in case the release coatings don't work as well as they should.

JP Taping the nose cone

Costi taping a sidepod

 Click through for the rest...

3D printed car

So at the end of the year last year we decided to print a model of our car with the 3D printer.  Here is the result:

The 10" printed FSAE car

Because of the size of the model, things had to be beefed up so that they wouldn't snap.  This was a really annoying and time consuming process honestly, but it was worth it.

The STL version of our car- beefed up for scale

Jan-Mid February Update

We have been very busy at the Duke Motorsports garage, both on and off the car. Duke University recently had their spring semester TechConnect and Career Fair events, and we were lucky enough to have GM IT department come to the event. After lunch with some of the recruiters, we brought them down to the garage to show them last year's car and the progress we've made on this year's car. And of course, when given the opportunity to sit in a race car, who could resist? We want to thank them for their hospitality, and that we really enjoyed having them visit us!

Back in Action

Yesterday marked the second Saturday work-day of our semester, and we have definitely hit the ground running! There's something really nice about walking up to the garage and hearing every air tool and powered device creating parts for the new car: the sound of progress.

At the very beginning of the semester, I was invited to attend Maurice's final senior presentation on the fuel tank design for the new car. He did a fantastic job, touching on all of the key design points as well as showing all of the effort he put into creating the fuel tank. We consider ourselves lucky to have had the opportunity to have Maurice come by the garage and work with us, and we're definitely looking into developing a more concrete fellowship between engineering student groups and local high schools for the future.

Maurice giving his presentation