ORIGINAL: Foxy
Just one issue I see... Wheel diameter is not 3.5cm. More like 6.5.
Oh yes I mean radius. 3.5 is radius. So 7 is diameter. But everything in the formula is correct cause I use 2*pi*Radius = pi*Diameter so it's the same. In fact if I put diameter=6.5 -> radius=3.25 so that makes it even slower...