• TwoPulleys5[cnum, axis1, rad1, {alpha, guess}, axis2, rad2, dist, C] models a pair of pulleys and a belt. The axes of the two pulleys, axis1 and axis2, are constrained to be parallel and dist units apart, and the origins of these two axes are constrained to be adjacent.• The rotational positions of the two pulleys are related as per their respective radii.• TwoPulleys5 constrains five degrees of freedom.

• The symbol alpha tracks the spin of axis1, relative to a vector spanning from axis1 to axis2.• The constant C, which sets the initial positions of the pulleys, is given by the formula C = rad1 e1 - rad2 e2. e1 and e2 are determined in the following way. Place the two pulleys in any valid orientation and construct a vector from the origin of axis1 to that of axis2. e1 is the angle, in radians, measured from the constructed vector to the reference direction of axis1, and e2 is the angle from the vector to the reference direction of axis2.• TwoPulleys5 generates six constraint equations and introduces one new variable, hence constraining five degrees of freedom.• The first two equations in TwoPulleys5 constrain axis1 to be parallel to axis2, the third equation constrains the origin of axis2 to lie adjacent to axis1, the fourth equation constrains the axes to be dist units apart, and the fifth and sixth equations relate the value of the variable alpha to the rotational displacements of the pulleys.• See also: OrthogonalGears5, ParallelGears5, SetConstraints, SetSymbols, SysCon, TwoPulleys4.