Open for suggestion and criticism first car

You might also want to consider that many experienced teams struggle with the resistance requirements of FSAE Electric when building monocoques.

Ha, not much I can add that hasn't been said already! Big Bird, as usual, hit the most important things. My only tidbits to add:

1. Chassis design, taking the "one big bracket" idea further:

~~a. Get shocks, rockers, push/pull rods located very very soon in the process, as that's a large part of where your wheel loads go, and with a small car it can be very difficult to integrate them well later.

~~b. Kinematics? Without a complete set of a-arms I can already see that the front roll center is a "normal-ish" height, but the rear is probably going to be around the CG. Might want to consider that. Also looks like the a-arms are nearly equal length...another thing to consider.

~~c. Size: Last year our team built a car with the templates being the #1 size criteria. That's all great in tech inspection, but then when the real world hits and you need add a shifter, wiring, etc., you have created a ton of headaches. I also found that car unbearable to sit in, and despite many years experience with FSAE cars I could not pass egress at Formula North. I gave it about a dozen tries, kicked the floor pan out, and then decided to quit before I damaged anything else. At that point I couldn't get under 7s, and in the past it never took more than a couple tries. For the record I'm 6 ft., 195 lbs (about a 90% male), and in pretty good physical condition. It sucks spending so much time and effort designing and building a car that less than 90% of your team are physically able to drive.

~~d. Size part II: Few people in FSAE think about serviceability. Small cars, especially monocoques, are impossible to work on. And if you don't think you are going to spend a significant amount of time fixing things on the car, you should stop and get back in touch with reality. http://fsae.com/groupee_common/emoti...on_biggrin.gif

2. A-arms:

~~a. As mentioned, don't use rod ends in bending (aka REIB...it's a big enough problem it has its own acronym). Google that for an article from Pat's Corner that goes into detail on that.

~~b. Also as mentioned, with the shallow angle a-arm loads will be huge, even more so with the rear-swept a-arms. I would be doubly worried about the mounts pulling out of the monocoque.

3. Big Bird is spot-on with the types of personalities you will most likely unfortunately have to deal with. The majority have all the ego that comes with being published in many journals, but are completely lost in a shop, and even more lost on a racetrack. They live in a magical dream world where any parts that need to be fabricated are sent off to a magic machine shop in the sky, and cost is often not nearly as much of a practical concern. And god speed on working with them...that is yet another one of the inherent challenges with FSAE.

To add to the comments above about monocoque size, if you have not already I would suggest doing some test samples and figuring out what you need to meet the SES requirements, especially the side impact rules. It's hard to see in the pictures how close the templates are to the outside surface of the monocoque, assuming you have a female mold you need to make sure you have enough space to fit in a structure that is thick enough to meet the stiffness and strength requirements in the rules.

Robert is right, we almost missed a season due to that very fact, and we had to come up with some radical metal/CF combination in certain areas to avoid excessing local bending deformation...

Hey guys,

Sorry for the long time to respond, we were occupied doing some paper work.

Replying to everybody.

We already started a new cockpit concept. We changed the ergonomics and we made it a little bigger to enhance the rear suspension geometry.

The REIB seems like a problem very difficult to overcome, but we're making a deeper research and always suggestions are welcome.

We're using Optimum g software to assist us locate the suspension parts and trying to achieve our initial goals.

At the moment we're doing your schedule, looking for sponsor and new team members.

I'll be posting pictures in the future.

Thanks you guys. You gave us some really good points to work on. Much appreciated!!!

To overcome REIB isn't so hard. Just use ball bearings in a milled part. I think the reason why teams are continuing doing it, is they think of it as a comfortable way to adjust camber.
But there are much more elegant ways of solving that problem than using REIB, which have to be of ridiculous dimension to withstand the bending loads.
This is a design competition! Look at solutions from other teams. There's quite a lot of material around the internet.

Thiago,

REIB, from a different point of view.

Z