A balanced flat stroke bi-directional conveyor for conveying object, granular and powder material. The unit utilizes the skewed sine wave trough stroke principle using primary eccentric counterweights wheels driven by a motor running at the secondary speed and equipped with the secondary eccentric counterweight wheels and a third counterweight wheel. The forces not in line with the trough stroke are absorbed with an isolation spring mounted between the drive assembly and the base, while the forces in line with the trough are balanced via a connected balancer.