Hi, I am Akash Mody
We are a team of students participating in the Formula Student Competition. Our team name is Orion Racing India and our website is: www.orion-racing.com

We will be participating in the Formula Student Germany competition for the third year in 2009.

we are planning to manufacture pedal box and pedals completely made up of aluminium.
what should be the designing constraints i should be lookout for.
Also, what do you think if we use only stainless steel flexible brake linings with T-joints

Akash Mody,
Braking System Head,
Orion Racing India,
K.J. Somaiya college of Engineering.
+91 9867415444.

Make sure it's stiff, the driver puts out a lot of force when he/she panics and slams on the brake. Also, if it's got compliance, the brake pedal looses its "feel" and the driver will have a tough time knowing just how much brake he/she is actually applying.

everything should be secondary to stiffness....a flimsy one that weighs 1/10th of the stiff one is not worth the weight saving. Because if the driver does not feel confident on the brake the car will be slow regardless. And we've had a version of the pedal tray before that it was so flimsy that we are actually flexing it more than putting actual force and building pressure in the line. We were having issue locking brakes, then we stiffenup the pedal tray and the problem went away.....

While you can make an aluminum pedal tray work I would recommend against it. The small weight savings there won't really be worth it. I can say from experience like others have said here the name of the game is stiffness. The big thing to remember with driver inputs is that its not the force required at the pedal face to lock tires, its the force that someone can exert when they panic and slam as hard as they can. While it should not take more than 150lbs to lock your tires certainly someone might exert more on that pedal. Just something to keep in mind.

Scott Mingay
Rutgers FSAE
Suspension Team Leader

We used an aluminum plate last year on our car. To confirm the suspicions of the above posters, it flexes and we are doing something different this year.

We usually make a steel box of 0.75 square tubing with aluminium pedals. This year we had some folded sheet steel brackets that were badly welded and started to crack during brake test. The support has to be strong.

yea, steve o is right on that one...we (Hartford) used a 1/4" laser cut aluminum plate and it yielded BIG TIME in and around the master cylinder mounting flange. The plate was visibly bent after fsae west, and to boot it clearly flexed when a design judge stomped on the brake (he was not happy about the flexing either). In my opinion steel tubing is the best bet for pedal mounting

For the past several years we have mounted our pedals directly to an aluminum honeycomb panel that was bonded into our space frame. The pedals were bolted through the panel with an appropriate "backing plate" on the other side. Even with this set up the panel noticeably flexes and creates a "mushy" feeling.

We have a billet aluminum pedal tray that slides between two square steel frame rails. It's 3/4" billet, and considerable FEA iteration has been put into it. There is no detectable deflection (by foot anyways, there surely is by dial indicator)

Look at the Tilton pieces for example, it's where our ideas came from.

The specific modulus of steel & aluminium are very similar. Therefore the success or failure of a pedal box is down to the designer not the material...

Regards, Ian