The horizontal axis driven by a toothed belt, while a vertical rack. The first, very compact and very light loads, housing the rack inside the groove of the guide. In the second, already bigger and stronger, the rack was set on a grooved profile 45x90, which can be used for anchoring the load to be moved. The cart in a cross, measures larger than the standard, provides more stability to the vertical slide, and allow us to have longer courses. The last scheme, the evolution of the second description, adds further rigidity to the vertical axis as the double horizontal guide prevents the tendency to oscillation that we can be when you have long runs vertical loadings.