To have an interference or force fit between mating parts, the tolerances must be such as to create a zero or negative allowance.

In the absence of negative emotion-and therefore the allowance of complete alignment and communication with Source energy-your physical body can reclaim its balance and recover from any imbalance.

When designing FDF system of compact spinning, the negative pressure drops resulting from spindles at the front and back of the machine should be kept within allowance.