Arm-Z is a concept of a robotic manipulator comprised of linearly joined congruent modules with possibility of relative twist (1 DOF). The advantages of Arm-Z are: economization (mass-production) and robustness (modules which failed can be replaced, also if some fail the system can perform certain tasks). Non-intuitive and difficult control are the disadvantages of Arm-Z. In other words, the combination of non-trivial module shape with forming of practical modular structures and their control (from state A to B) is computationally expensive. However, due to availability of modern computational power, proposed here approach is rational and competitive, especially considering the high cost and sensitivity of non-standard solutions. This paper outlines the general concept of Arm-Z manipulator and presents preliminary work towards making a proof-of-the-concept prototype.