The support has a rectilinear pole supporting a link (4) attached to a portable tool and to a force generating unit e.g. counterweight. The pole has at the top a pulley (6) fixed on an articulation unit permitting the rotation of the pulley to at least 120 degrees. The pole base is fixed on a plate having 3 sections connected by dismountable assembling units. The pole has a longitudinal groove receiving a carriage with guiding casters. The force generating unit generates a force which is opposed to the weight of the portable tool. The pulley is rotated to at least 120 degrees around an axis parallel to a longitudinal axis of the pole.
