Multichannel pipetting system

A pipetting system comprising:

• a frame comprising a base provided with at least one tray configured to accommodate at least one consumable, and a tower extending from the base and comprising at least one linear guide rail extending along a vertical axis;
• a pipetting head housing at least one pipetting channel provided with an end piece configured to cooperate with a pipetting tip, to receive or dispense a liquid, the pipetting head configured to move translationally along the linear guide rail in at least one predefined range of movement between at least one maximum position of the pipetting head forming a maximum distance from the base and a minimum position of the pipetting head forming a minimum distance from the base;
• a driver to drive the pipetting head translationally comprising:
• a motor to drive the pipetting head translationally, the motor comprising a motor shaft mounted rotatably about a motor axis fixed relative to the frame and orthogonal to the vertical axis;
• a toothed pinion mounted rotatably about the motor axis;
• a motion transmission roller arranged between the motor and the toothed pinion to transmit a rotational movement between the motor and the toothed pinion;
• and
• a rack mounted to be movable translationally along the vertical axis, the rack being integral with the pipetting head to drive the pipetting translationally and the rack being arranged in contact with the toothed pinion, so that a rotation of the toothed pinion results in a translation of the rack along said vertical axis and the translation of the rack along the vertical axis causes the toothed pinion to rotate;
• and
• a first controller comprising:
• a measuring device to measure information representative of a distance of the pipetting head from the base;
• an analyzer to analyze the information representative of the distance of the pipetting head from the base, to determine therefrom a position of the pipetting head;
• and
• a second controller configured to activate the motor according to the position of the pipetting head and at least one predefined stop, said at least one predefined stop being located between said at least one maximum position of the pipetting head and the minimum position of the pipetting head.