The application of the mortar is mimiced by a syringe extruder mechanism mounted on one of the gantries.  The adhesive is dipensed by the extruder after every subsequent brick course over them. The syringe here is held in by friction and can be quickly pulled out and replaced with another one as the volume of the adhesive inside decreases.

Although in the final version of the machine the extruder will consist of a continous screw feed nozzle which will be fed by a mixer mounter over the gantry top.