The number in the formula represents the hand speed of the operator (63 inches per second). If your press has a stopping time of one-half second (.5 second), the calculations would be:
D = 63 x .5 = 31.5
The controls would need to be at least 31 1/2 inches from the point of operation.
Reference:
See, Provide additional safeguards when the operator puts one or both hands into the point of operation, WAC 296-806-45526, for additional required safeguards.