Percentile model rule book/competition

[Jacob Suchsland]

Hi I'm Jacob with the Northern Illinois University team, I was wondering what exactly the difference if any is there between the percy model that is shown in the rule book where there are 3 circles and distances between the centers and the full body they used at competition. I know the model at comp had bent knees and rounded feet. I would guess the general shape both would fit in are the same but i feel that the full body might restrict or allow different designs. Has anyone come across anything that using one model could change a design over the other? and is there a way to get a model like the one that is used at comp.

[tromoly]

If I'm reading this right, are you asking if the "bent knees" on the Percy used during tech has any effect on designs? Sorry if I'm missing something, not quite sure what you're asking.

At my school years ago someone built a Percy torso using 1"x1/4" steel strapping and wood circles, then a few years ago his "legs" were added using a straight piece of steel tubing. Nothing fancy and the cars have passed Percy no problem since our Percy grew a leg. Build it according to the rulebook and your're golden.

[Bemo]

The template which is used during scrutineering should be the same as described in the rules (three circles connected by straights). The legs mit be made from a solid bar or from some sort of wire. In any case the "legs" give you the position in which the bottom circle has to be placed in the seat. The distance given in the rules from that bottom circle to the pedal surface has to be measured in a straight line in any case.

In the design event the ergonomics judges may of course choose additional templates to check if the car can be driven by people of different sizes etc. But this is only interesting for the design scoring. For scrutineering only the template given in the rules is of interest.

[Jacob Suchsland]

Tromoly, sorry that i was very clear but yes. I don't believe there would be a design issue but just in case.

Bemo, the template they used at comp for out tech inspection was slightly different. I wish i had a picture of it but i remember that the leg section wasn't a straight pole. Untitled.jpg
its a poor example but this is how i remember the legs look like. But from what you said the look of the model doesn't matter as long as the distances from the seat and pedals are the same as what the rule book says.

[tromoly]

Personally, I'd say the footwell template will have a much larger effect on chassis design than Percy's knees will.

[Bemo]

It is as you say, it does not really matter how the legs of percy look like, as long as the distances are correct. At FSG we are using a wire for that distance instead of something rigid, because with some car designs it is quite difficult to put a percy in with rigid legs. But that's not your problem, it is the problem of the scrutineers. It should not have any influence on your car design.

[Michael Royce]

Jacob,
The device used at the Michigan competition did indeed have a shaped leg and foot, but the distance from the "H", or Hip Point, the center of the lower 200 mm diameter circle, to the "ball of the foot", was correct at 915 mms. Mark and Jeff, two of the Chief Tech Inspectors at MIS, tell me that they did it to help maneuver the device over low mounted steering racks. But that if the "knee" interfered with anything, they would remove the "leg and foot" and revert to using a tape measure!

So, to answer your question, Bemo is correct, when in doubt the Rules prevail.

Michael Royce.