Here is an Ultimate Frisbee I created based off the regulation dimensions provided by the U.S. Ultimate Frisbee Organization. The current model is 100% to scale but obviously can be shrank to fit your print bed! 

This is the 3rd rendition of this frisbee, I tested the first 2 using a hard PLA filament for the whole body, which with support turned out fantastic and flew like your average Ultimate Frisbee. I also tried printing with a flexible filament to hopefully alleviate some of the negatives of a hard plastic disc but found it pretty floppy when thrown.

Recommended setting:

Layer Height: 0.15  but could use 0.2

Walls: 2

Infill: 25%    Grid pattern

Top/Bottom Patterns: Concentric

Side note: If you have a dual head printer I would highly recommend printing the main body in a flexible filament and set the infill to a PLA or other hard filament. I did this for my last print and the frisbee is squishy in all the good ways, yet firm in all the right places. Fly's like a dream and wont knock out your teeth if you get hit with it!

Enjoy!