New hand clutch

More an exercise in surface machining than anything else, but we have to make a new one anyways.  Save a little bit of weight too - 100g vs 140g for the old one.  Not a whole lot, but every bit counts, especially when the weight savings is essentially free.

Some pictures of the machining process and the result of some of the 3D toolpaths after the jump.

Updates

Things are moving along fairly well going into exam week.  We're almost done making our second diffuser (in order to reduce weight), which will be done with vacuum bagged foam panels attached together after they have carbon fiber laid onto them.


A pictorial update on progress:

Main diffuser piece in the vacuum bag

The art of Upright making

Hey everyone,
I will explain the whole process we use to make uprights. Once you have your finalized Solidworks model for your upright you need to buy the stock needed for the operation.

Front Upright Solidworks Model

Rear Upright Solidworks Model

Making wing end plates in the Universal Laser Cutter

We are starting to build the wings for the car which means we need to make the end plates for both wings (things that go on the sides of the wings). To make those we decided to make the molds out of foam core. You can first model them on Solidworks as you can see in the figures below:

Front Wing

Rear Wing End Plate

Saturday, Nov 5

 Hey everyone,

This Saturday we have an Engineering Alumni Council (EAC) BBQ at 12.  There will be free food.

We're working as usual Saturday, including carbon fiber work on the intake, cutting and starting to weld the exhaust, a-arms, machining a few more tabs (and working with mastercam), and doing more carbon fiber work for the diffuser.

Just a reminder- I'm holding a vehicle dynamics lecture after dinner (say 7:00).  This will be a repeat of the first lecture I gave on Tuesday.

If you're on east campus, we'll be picking people up from in front of the marketplace at 11:45. 

Progress Update

Right now we're in manufacturing mode.  Mostly machining work at this point, but some carbon fiber stuff as well.  Frame jig is sent off, but we're still waiting on the roll hoops (Chassis Shop apparently ran out of chromoly tubing...couple more weeks to wait).  Most of the little stuff is now machined, including ARB blocks, front bellcranks, a-arm jig and supports, throttle body linkage, and about 30 something tabs.

Next steps - more machining, mostly big stuff now like uprights and lathe work.  Intake is getting close to being finished, exhaust has been started, steel a-arms are on their way, and aero fabrication needs to be done.

Bunch of pictures of machining after the jump.

Announcements and Saturday, Oct 29

This weekend is parents weekend, so I know a lot of you are going to be doing stuff with your parents.  We're not going to be giving rides from marketplace this Saturday - If you want a ride this saturday, send me an email and I'll give you a number that you can call one of us at. 

We're going to be at the Parents Weekend Pratt BBQ on Saturday from 11 til 12:30, so we're probably going to start working after the BBQ (probably 12:30 or so).  We're going to be taking the frame jig over, laying up another intake plenum half, cutting exhaust tubing, and possibly welding the exhaust too.  I'd like to continue building the carbon fiber parts for the diffuser, and we're going to be doing some machining too.  I'll be teaching mastercam again like last week.

As for the vehicle dynamics seminar, I'm going to push the one this saturday back a week because of parents weekend and the basketball game.  The first lecture will be on Tuesday, Nov 1 at 6:00, and I'll give the same lecture again on the following Saturday at 7:00ish (Nov 5).  The first lecture is extremely important - I'm going to be covering tires - and very little will make sense if you aren't familiar with tire behavior.  Let's meet at the garage for this first lecture since I'm not sure what rooms are going to be available yet.

If there are any questions/concerns, let me know.

-Mike

Throttle body, frame jig, and wheel speed sensor

Some quick progress updates:

The frame jig is finished, and all we're waiting on now is our roll hoops.  Hopefully they'll get here soon...

Fall break Updates

It's been a productive (and tiring) fall break for those of us who stayed around for fall break.  We finished machining all the hubs, the steering rack supports, started the diff caps, and a few other small parts.  We also built a new intake diffuser, and two plenum halves that are almost ready to be put together into an intake manifold.  Finally, we started and finished our new undertray/diffuser.

The frame jig is done, and now the only thing we're waiting on is for the tubes to come in so that we can send it off to be welded.  Things are looking pretty good so far.

Diffuser Fabrication

How to make an undertray/diffuser in three easy steps:

Pictures on the process after the jump.

Carbon fiber intake fabrication, Part 1

 New carbon fiber parts: two plenum halves and a diffuser

Autocross with TSCC at UNCG Park and Ride

A few of us went out to an autocross hosted by the Triad Sports Car Club and we definitely had fun - here's a link to the gallery with pictures from Sunday.

Got a little bit sideways across the finish line...

A few more pictures from the gallery after the jump:

CFD Results: Half Car

I recently ran another CFD model for as much of the car as I could realistically get Solidworks Flow Simulation to run - I've found that it has a tendency to crash on larger mesh sizes with no indication as to why it crashes.  As I mentioned before, I've started doing half car models so that I can effectively double the number of cells since the car is symmetric.

New Render Video

The car for this year is almost completely modeled in CAD.  With a fairly major redesign, CAD has been an invaluable tool in making sure everything packages properly.  Packaging is a major part of vehicle design, and CAD allows us to put everything in its final position, visualize how parts will interact, and allow us to check for clearance/interference before we actually build anything.

In addition, modeling parts I think has been a good way for newer members to get experience in Solidworks, and some of their parts have made their way into our full car model.

See the new render video here.  (For some reason the compression on the embedded video is messed up for the first portion of the video - download the video to see it in its full glory)

Intake Manifold Manufacturing

Here is a picture of the new Motorsports Team recruits learning how to make a carbon fiber parts.

Saturday, Oct. 1 Activities

Hey everyone,

We'll be working Saturday as usual starting at noon.  We'll be finishing the frame jig, hopefully starting to machine some frame tubes, building a new impact attenuator, starting on the carbon fiber layup of the intake, machining new parts, doing some solidworks modeling/design, etc.

As usual, we're picking people up from east in front of the marketplace at 11:45.

See you guys in the garage.

Update 09-27-11

Since the last update, we've made some progress.  Details after the jump, but first a new rendering:

More renderings and updates after the jump...

How to Model a Seat in Solidworks

I'm going to do a quick tutorial on how to model something fairly complicated using basic Solidworks surfacing techniques.  As you can see below, at first glance a seat can be somewhat difficult to model due to its curves, but I'll show here how simple this process can be with surfaces.

 

Saturday, Sep. 17 Activites

Hey everyone,

We're going to continue working on the car this week.  We'll do some machining, CAD and modeling work, and keep working on the frame and frame jig.

If you don't have Solidworks yet and want to get a copy, bring a computer (Windows only - Solidworks does not currently support Mac) and we'll get it on your computer.

Once again, we're picking people up on East at 11:45.  Please be out there at 11:45 - if we know you're out there but don't have enough cars at that time, we will send another car to come get you.

Saturday, Sep. 10 Activities

Hi everyone,

First, this Saturday, GE is coming by the garage at noon and they are actively recruiting - bring a resume if you're interested!  They will also be providing lunch for everyone.

This weekend we'll be starting work on the car.  We'll be teaching how to machine, how to weld, and starting work on the frame jig for our new frame this year.  We'll also have a couple of small introductory solidworks projects for those of you interested in CAD work.

Once again, if you're on east campus, we will be picking people up from in front of the marketplace at 11:45. 

New Frame Jig

New frame means new frame jig.  And here it is:

Using the only model I could find (from the 2005-2006 year in fact), I measured our current jig and modified the model accordingly.  To make sure my measurements were correct, I referenced all the points back to the frame points from last year's frame (and may have found a couple of mistakes along the way in last years frame.. oops!), and made a simple modification to accommodate the new frame.  Basically, the upper rear support for the frame tubes will get moved forward, and new plates will be machined for the rest of the frame supports.  About as simple as a new frame jig can get - only one new tube required.

Car rendering

A picture... ...and a quick video

First meeting of the year

First a quick note: we will be at the Pratt E-Social and activities fair this Friday (9/2) from 1-3:30.  We will then go over to the activities fair on East Campus from 4-6.

We're going to have the first meeting of the year for Duke Motorsports this Saturday (9/3) at noon.  We'll meet in Hudson 125 (the big room if you go down the center hallway from the entrance), kick off with a quick introduction presentation, and then head down to the garage for a BBQ/grill session.  Food will be provided.

If you're currently on east campus, we will be picking people up in front of the marketplace and bringing them to Hudson between 11:45 and 12:00 on Saturday.

If there are any questions, feel free to email us at dukeuniversitymotorsports@gmail.com

We will send this information out via the mailing list in a couple days.

Recruiting Events

Thanks to everyone we met yesterday after the Pratt freshmen orientation.  We definitely hope to see all of you around the garage this year!

We will be attending the Activities Fair on Friday, September 2nd from 4-6pm on the East Campus quad.  We will have the car there, so come out and see us!

Another note - if you aren't on our mailing list but want to be added, please email us at dukeuniversitymotorsports@gmail.com

Almost end of summer update

School's starting soon, we have our first recruiting event for orientation week on Wednesday (3:15-4:30 in CIEMAS atrium in case anyone is actually reading this...), and I'm well on my way putting together the full car model (well, half a car, and the other half is mirrored).

Bullet points after the jump...

Active Aero

The one thing I didn't talk about in my last post was active aero.  Active aero opens a whole new can of worms, but I think it's doable (see Oklahoma's car - it's pretty awesome).  I'm taking a different approach, which will be a simpler system consisting of only a moving rear wing.  Anything more seems a bit unrealistic for a one year project.

The benefit of active aero is that you can reduce drag when you don't need downforce, i.e. when you're traveling in a straight line.  Honestly, I don't see any downsides either except for the additional development time and slight weight increase.  Of the aero elements on the car, the rear wing produces almost twice as much drag as the front wing and undertray combined, which is why the rear wing is the active element.

Aero Design

I've outlined why we're doing aero in a previous post; now I'm going to talk about how we're going to do it.  As a recap, we want to maximize downforce while minimize drag and weight.  We have other constraints too, such as the rules, manufacturing capability, and of course time and money.  Even so, we are afforded a great deal of design freedom in aerodynamics.

This year's aero package will consist of a front wing, a rear wing, and an undertray.

Aerodynamics and Vehicle Dynamics

The following write-up is  quick introduction to aerodynamics and how it relates to vehicle dynamics, for those interested.  After the break are snippets of an email I sent to the aero team almost a year ago, and I think it's a good place for those on the team interested in aerodynamics to start.

Aero and CFD

Having spent a good bit of time in the GM Aero Lab this summer, I understand how important a wind tunnel is to developing a good aerodynamic package. But, as a FSAE team on a budget, that's not something that we have available to us at this stage of the vehicle's development. So, our aero package is designed with the tools we do have available, namely computational fluid dynamics (CFD).

If you can't take the heat, don't design an exhaust...

For the new 2012 Duke FSAE car, I've decided to redesign the exhaust system for a number of reasons. The primary reason for redesigning the exhaust system stems from the team's decision to eliminate the rear box from the frame, which shifted the suspension placement on the frame. In other words, the A-arm and halfshaft placement gave me a rather uncomfortable amount of clearance to run the exhaust through. Also, due to the shortened wheelbase, the muffler would be sticking out too far from the back of the car.

Another important consideration was passing the sound test during the tech inspections at competition. We noticed that the decibel readings varied greatly depending on which side of the car the measurement was taken, which we attributed to the valvetrain and intake noise which was recorded when the inspector stood on the left side of the muffler. Therefore, one design aspect that I wanted to incorporate into this year's car was to run the exhaust out of the side of the car in order to eliminate this extra noise to allow us to run a smaller, more free-flowing muffler.

The Big Picture

Another year, another car. So what's new for 2012?

Well, this year's car will be a major redesign from previous years. There will be a large focus on

aerodynamics, and in fact the entire car will be designed with aero in mind. If everything goes to

plan, we will have a new frame redesign to reduce wheelbase and increase stiffness, suspension designed for our aero package, a complete repackaging of the rear half of the car to accommodate the new frame, and hopefully incremental improvements everywhere else. But the overarching theme is downforce.

Why aero?

Summer Update: Frame design

So one design goal that's been floating around for a while is a redesign of the frame, to get rid of the rear box. The main reasons: increase stiffness, shorten the wheelbase, and reduced weight. The disadvantages? Well, all the packaging in the rear has to change: intake, exhaust, radiator, drivetrain, suspension... you get the idea. But we decided at the end of the year last year that it would be feasible if we got the design and repackaging done during the summer. So earlier this summer I decided to redo the back half of the frame to remove the rear box, and sent the frame off to the rules committee for approval on "proper triangulation". It's been six weeks, and I've finally got a response from the rules committee, so the new frame design is a go if we decide to implement it.

The new frame only sheds a couple of pounds, so the weight savings are going to be negligible

with the additional weight of the bearing carriers. We will reduce the wheelbase to 60" this year

with this frame, and this frame should be stiffer, but I haven't run the FEA analysis quite yet. Packaging is on its way - exhaust, radiator, and aero have been redesigned/refitted; intake, suspension, and drivetrain are still in progress.