A rotary to linear actuator comprising: (a) a nut having a threading; (b) a spindle having an external threading and positioned at least partially within the nut; and (c) a drive shaft in communication with the nut to rotate the nut; wherein rotation of the drive shaft rotates the nut, and the threading of the nut engages the external threading of the spindle to move the spindle axially away from the drive shaft to drive a piston.