End of Fall Semester

Today marks our first official day of winter break, which we've been looking forward to for many weeks now. We just wanted to post a quick update of what we ended up finishing the semester within the garage, and where we're heading for the next semester.


First, Maurice and I worked on doing more work on the fuel tank. We finished making the filler neck cuts into the fuel tank base, and welded it all up to create nearly all of the fuel tank. We had to make a minor modification to the filler neck angle (i.e., it didn't fit with the frame geometry...oops), but overall, we were all very happy with the final product.

Making the first cut into the fuel tank base

Maurice happy with the final product

Close-up of the filler neck welds...after the slight hiccup

Comparison between the new design and the old design...big difference in geometry

The next major project that we were able to accomplish was the beginning of making the wax intake runner molds. We redesigned the molds this year to allow for the wax to properly cool standing straight up (In other words, we added a slight angle to the base). The plan is to wrap each runner in carbon fiber, vacuum bag with epoxy, and then melt the wax out to leave a perfectly formed carbon fiber tube.

Melting the wax to put in the molds

Letting the wax cool down in the molds...mmm

We also fully assembled the intake manifold (both halves and the diffuser/restrictor bell). This includes the velocity stacks that will house the intake runners, and everything was put together with fiberglass reinforced quick-setting epoxy. Once it finished drying, we placed carbon fiber strips covering all seams for both reinforcement and sealing, and the results are shown below.

Put together and waiting for epoxy

Setting the air induction system with epoxy

Final assembled intake - and yes, that is a total weight of under 0.8 pounds

We also mocked up the full exhaust system in an old frame to get the geometry completely right, and then installed it on an old cylinder head clamped to the welding table to finish all of the welding. Overall, we are about 85% complete with all of the exhaust welding.

Exhaust primaries and secondaries mocked up in the frame for tack welding

Exhaust installed on old cylinder head waiting to be fully welded

Not everything we've worked on in the garage has been for the car, though. Kenzie decided that the garage door needed some spicing up, so through her hard work, she mocked up the Duke Motorsports logo on our newly painted garage door.

 

Duke "D" on the garage door

But, the Duke "D" wasn't quite good enough, so to take it up to the next level, Kenzie decided to put a racing flag in the background of the "D" to truly make the Duke Motorsports logo.

The master artist at work

Close to final product minus some final coats and pin-striping

One last, quick update. We officially have the 2013 car frame back from Chappell! We are very thankful for all of the effort he put into finishing the frame quickly and getting it back to us. Everything looks great with it, and we're excited to start the long process of putting the car together! The only thing is that our garage is getting a weeeeee bit crowded.
 

New frame!

Comparing the SolidWorks drawings to the frame

Current status of the garage

We, at Duke Motorsports, want to wish everyone a great holiday break with family and friends. Until 2013...

Pictures of Intake and Frame

 I was just at the garage unwrapping the last half of the carbon fiber intake, and it turned out great! They're definitely much stiffer than last year's design, and I'm also happy with their weight compared with previous designs. We're going to be putting it all together relatively soon, so we'll be sure to measure the differences in weight.

We also received an update from Chappell with the frame, and it looks great! I've included a before and current picture of the frame+jig, so things are definitely starting to get rolling!

Two halves and the diffuser/restrictor

Two intake halves, with a previous iteration in the background

Frame jig before...

Current state of our frame!

Stay tuned for more updates!

Pre-Thanksgiving Update

Duke Motorsports has been very busy the past couple of weeks, so this is going to be a quick run down of all the things we've been up to.

We hosted an E-Social on November 9th, which was a great success. We brought the car up to the main engineering quad and purchased a bunch of pizza to share outside on a beautiful afternoon in North Carolina. We had a lot of great conversations with interested students about Duke Motorsports, and made sure to rev it a few times before we left. Thanks to ESG and all those who helped, it was a great success!.


We also managed to snap my new favorite picture of the car, which not only displays how awesome the car looks in the beautiful fall weather, but also shows some of the E-Quad as well! We also hosted a driving event for the Board of Visitors that were in town on the 10th, and we made sure to have Dean K tear up the track for a bit in the car. It was a great day, and having the opportunity to meet many of our distinguished Pratt alumni was both an honor and a privilege.

 In terms of making parts, it has been very busy. We've had some small issues with the intake manifold, specifically with the epoxy and the molds. I decided to remake the intake molds because they were entirely way too weak for the prying forces we needed to apply, so I made sure to reinforce all of the surface contacts in the new design. I also wanted to make sure it was as smooth as possible, so we decided it would be best to apply a thin layer of epoxy on the fresh molds to smooth over all of the stepped plastic layers, and then we made sure to sand the molds to ensure that they were as smooth as possible to not only make the airflow throughout the intake better, but also to help with releasing the carbon fiber from the mold itself. Another improvement we've done from last year involves the "cross braces" we've added to the intake construction to help mitigate any flexing of the carbon fiber under vacuum generated from the engine. From our initial testing, we've come to realize that these braces are very effective at helping stiffen up and strengthen the entire intake plenum.

We also rapid prototyped our velocity stacks for the new intake system in preparation of finishing the entire plenum soon. I recently made some changes to the runner molds that we fill with wax in order to make our carbon fiber intake runners, and they are currently being printed as I type this blog post up. Today, we finished laying up the *hopefully* last half of the intake plenum which will help finish up the entire intake system once we get the runners started.

We hope to have the entire composite air induction system finished by Christmas break, which would be a huge accomplishment. We've also been making some progress with getting the exhaust system mocked up, and we're almost to the point of starting to tack-weld the primaries in place to continue with the manufacturing of the exhaust system. The goal is to also have that done by Christmas break.

Today, we also tackled a lot of the fuel tank. We have been working closely with a high-school student, Maurice Troy, on this project as part of his senior capstone project. We have managed to make the fuel tank base and the filler neck tubing, and our last step will be to make the necessary cuts to the base for the filler neck and the fuel pick-up box. We spent much of the day in the Pratt Student Machine Shop working on the cutting and bending the fuel tank stock as well as using the lathe to make some suspension a-arm components.

Yoshi working the lathe at the Machine Shop

Jackson making some cuts to the fuel tank stock

Justin and Maurice working on making the necessary measurements for the fuel tank stock

Ivonna making the final cuts on the stock

The finished products, all welded up and ready to go

Overall, these past few weeks have been a little crazy (which is why there has been a relatively large gap in blog postings), but we've been making sure to keep really busy. I can say that I'm very proud of all of our team members who have stepped up to the plate and truly taken the roles of our members who graduated last year. I'm very proud of what we've managed to accomplish thus far, and I can only continue to look forward as we keep cranking through the mountain of work laid before us.

Exhaust Welding Preparation

Thanks Chappell Anderson!

Yesterday we finally got to send out our frame jig, an exciting milestone.  We should have it back in the beginning of January.  In the meantime, we are getting as many parts ready as possible.  

The team wanted to send a big thanks to Chappell Anderson, sitting in the car below, who has been welding the frames for Duke University Motorsports for years.  Thanks Chappell!

Machining and Drivetrain Redesign Braindump

Hi there; I am going to do my best to summarize what I have been working on over the summer and this fall; admittedly, I should have made earlier posts, so this is going to be somewhat of a long braindump:

Phase 1: Summer Planning and Drivetrain Redesign Version 1

Over the summer, I put in significant hours (a) learning Computer Aided Machining and (b) redesigning the drivetrain. I am leading both the Drivetrain and WHUBS teams this year, so I needed to put in some serious hours so that I could hit the ground running this fall.

The Drivetrain (and the accompanying rear portion of the frame/suspension) is the part of the car that is undergoing the most changes this year, mostly because it was the most problematic part of the car last year. The main issues that version 1 of my redesign sought to address were:

1. Last year, we ran too sharp of an angle from the halfshafts to inner tripod housings, so there was significant friction and we actually had the halfshafts pop out of the tripod housings.
2. Last year, we tried to go to a rigid mounting system (no more turnbuckle) for the bearing carriers, but this had unintended consequences when vibrations created a noticeable side-to-side wobble of the drivetrain when we started turning the chain.
3. Last year, the bottom of the left and right bearing carriers were mounted at different locations (so they weren't coaxial, so adjustment (which involved the use of shims) would cause misalignment.
4. There were also some little things within the design (I won't list them all) that I updated/improved to make our CAD model of the drivetrain better.

In order to solve these problems, version 1 of my redesign includes (a) a new turnbuckle system which will solve the vibration and adjustment issues (b) coaxial mounting points for the bearing carriers so that adjustment does not create misalignments and (c) a new mounting location with respect to the frame to cut the halfshaft angle from roughly 10-12 degrees to 5-6 degrees. Below are screen shots of Version 1 of my redesign drivetrain:

Phase 2: Crash Course in Machining

When I arrived at Duke this fall I needed to get practice milling things and using CAM programs to make our parts. I did a little bit last year, but not very much. So, I decided to start small and make all of the small aluminum parts we have on the car, making small improvements/refinements along the way. First I made all 8 of the camber blocks, writing a nice CAM program (including 3D operations which were discovered last year) to make the camber blocks look nicer than last years. Then I made the camber shims, which I decided to redesign so that they are slide-on (making taking them on and off a lot easier) and cutting out excess material (I cut the weight of the camber shims by over 30%); below are pictures of the old and new camber shims. Then I made the ARB support blocks (no change from last year's design) and the front bellcranks (no change from last year's design). I am saving the rear bellcranks for later because Yoshi is going to change them slightly to eliminate current suspension rod interference.

Phase 3: Drivetrain Redesign Version 2 and Machining

I sat down with Dr. Simmons to look at my drivetrain redesign and talk about press fits for bearings (he is teaching me how to dimension things correctly for press fits), and he suggested further redesign, pointing out that the whole o-ring system between the stubshafts and diff caps design that we have been using for years is not a very good design (the o-rings got seriously beat up last year). So, I made Drivetrain Redesign V2 to incorporate a new bearing system that has bearings replacing the o-rings. This involved redesigning the diff caps, stub shafts, and picking out new standard bearings to use. Also, as a little additional features, I decided to add in little guiding extensions on the diff caps that will slide into the diff/rotor so that it is centered better (instead of having the bolts do all of the work). Below are pictures of the of the Drivetrain Redesign V2:

Over Fall Break, I successfully machined the rear sprocket (I am pleased with how it looks), and Dr. Simmons generously took the time to use the CNC lathe in the professional shop to make the general shape of the diff caps (I still need to mill the non-circular stuff and drill holes); the CNC lathe is a much faster and more accurate way to make the diff caps (it would have a long time (at least 5x) to mill the diff caps). I am going to make the bearing carriers this weekend (and maybe finish up the diff caps). Goodfellow is working on the stubshafts. So, considering that we are probably going to reuse Fette's Vette's diff (and I can take the acrylic surround that I made last year, and we can potentially use the brake calipers as well), all that will be left to make to finish the Drivetrain are the brake rotors and tripod housings (which shouldn't be that difficult). I will also have to make the turnbuckles, but that might be something I will wait on to make.

When I am done with the Drivetrain in a couple weeks I will post more actual pictures (instead of just CAD stuff); for now I just have the picture of the rear sprocket I made:

This concludes my brain dump of stuff I have been working on. 

I also want to give a shout-out/thankyou to Dr. Simmons who has been really helpful to me this fall; he has given me valuable design advice and has spent time with us in the garage helping us with whatever we need advice on. 

Update: Mid October

These past few weeks have been very crazy here at the garage. We've been doing a lot of machining, carbon fiber work, and also a good bit of experimenting with wheel speed sensors. However, the big highlight of the past couple of weeks has been our Alumni Driving event. We were fortunate enough to have a weekend that a lot of our alumni could be here to visit, and to make it a little more special for them, we decided to host a driving day for them early one Saturday morning. Overall, it was a fantastic morning, and we all seemed to have a great time. The list of alumni visitors includes Dan Lacher, Joe Goo, Jules Finlay, Will Gardner, Ivan Wang, and John Ingalls. And without further adieu...on to some pictures!

Ladies first...it always applies

"Safety Dan" ripping up the hairpin to the starting line

Joe taking the slalom at blazing speeds

Jules getting ready to show us all what the car can really do

We also had our faculty adviser, Dr. Neal Simmons, swing by with his two daughters to come hang out with us. He brought us some *much needed* coffee and donuts, which helped top off a great day. We made sure he also got in the car as well. 

Getting D-WAIT all warmed up

 

Dr. Simmons demonstrating his extreme driving skills

It was a great event, and we definitely look forward to holding more of these in the future.

Like I said earlier, we have also been pretty busy machining some of the drivetrain components, such as the rear sprocket and differential caps. Instead of using our mill to manufacture the diff caps, Dr. Simmons suggested that he could go up to the professional machine shop and use their CNC lathe to help us out. Over fall break, we went up to the shop with Dr. Simmons and cranked these diff caps out, and they turned out beautifully!

The master at work

Half-way through the operation

Finished: Top side of cap

Finished: Bottom side of cap

We've also been working on the new carbon fiber intake design, but we've come across a couple of snags, including what we believe to be an error in mixing our epoxy solution. I'll make sure to post some pictures soon.