• TwoGears2[cnum, point1, rad1, point2, rad2, C] models a gear set. The axes of the two gears point1 and point2 are constrained to be rad1 + rad2 units apart, and the rotational positions of the gears are related as per their respective radii.• The constant C sets the initial rotational positions of the gears.• TwoGears2 constrains two degrees of freedom.

• The constant C, which sets the initial rotation of the gears, is given by the formula C = (rad1 e1 + rad2 e2) where e1 and e2 are determined in the following way. Place the two gears in any valid position and construct a vector from point1 to point2. e1 is the angle, measured in radians, from the constructed vector to the local x axis of gear 1 and e2 is the angle from the constructed vector to the x axis of gear 2.• If the Euler solution method is specified TwoGears2 generates three constraints and add one extra variable to the model.• TwoGears2[cnum, point1, rad1, {sym1, guess}, point2, rad2, C] can be used to explicitly specify the name of the extra variable and its initial guess. Otherwise, a symbol of the form cnum is used.• The first equation in TwoGears2 constrains the two points to lie rad1 + rad2 units apart; the second, and optional third, equation relates the rotation angles of the two gears.• See also: RackAndPinion2, SetConstraints, SetSymbols, SysCon, TwoGears1, TwoPulleys2.