An assembly machine for producing multicomponent cigarettes, each comprising a number of portions, which have a central axis and comprise at least one portion defined by a filter element, and at least another portion defined by an aromatic, preferably tobacco-based, element; the assembly machine comprising: a combining unit for forming groups of portions, each comprising at least two different first portions (3A, 3B, 3C) aligned axially and contacting end to end, and in which the groups of portions travel perpendicularly to their central axis; the combining unit comprises a number of structurally identical feed stations, each for supplying a respective first portion (3A, 3B, 3C) to form the groups of portions; and each feed station comprises an insertion drum, which receives the groups of portions from a preceding feed station or creates the groups of portions, receives respective first portions (3A, 3B, 3C), and inserts the respective first portions (3A, 3B, 3C) into the groups of portions; a first wrapping unit, which receives a succession of groups of portions, aligned axially and contacting end to end, from the combining unit, feeds the groups of portions perpendicularly to their central axis, and winds a single first sheet of wrapping material around the whole circumference of each group of portions; wherein the first wrapping unit comprises: a wrap feed unit for supplying sheets of wrapping material; and a second wrapping unit, which receives a succession of groups of portions from the first wrapping unit, feeds the groups of portions perpendicularly to their central axis, and winds a single second sheet of wrapping material around the whole circumference of each group of portions which extends for the entire width of each group of portions; the assembly machine further comprising a tip-turning drum at the end of assembly machine on which one line of cigarettes is turned into the same orientation as another line of cigarettes alongside it, thus converting the two side by side lines of cigarettes into one line of cigarettes. a combining unit for forming groups of portions, each comprising at least two different first portions (3A, 3B, 3C) aligned axially and contacting end to end, and in which the groups of portions travel perpendicularly to their central axis; the combining unit comprises a number of structurally identical feed stations, each for supplying a respective first portion (3A, 3B, 3C) to form the groups of portions; and each feed station comprises an insertion drum, which receives the groups of portions from a preceding feed station or creates the groups of portions, receives respective first portions (3A, 3B, 3C), and inserts the respective first portions (3A, 3B, 3C) into the groups of portions; a first wrapping unit, which receives a succession of groups of portions, aligned axially and contacting end to end, from the combining unit, feeds the groups of portions perpendicularly to their central axis, and winds a single first sheet of wrapping material around the whole circumference of each group of portions; wherein the first wrapping unit comprises: a wrap feed unit for supplying sheets of wrapping material; and a second wrapping unit, which receives a succession of groups of portions from the first wrapping unit, feeds the groups of portions perpendicularly to their central axis, and winds a single second sheet of wrapping material around the whole circumference of each group of portions which extends for the entire width of each group of portions; the assembly machine further comprising a tip-turning drum at the end of assembly machine on which one line of cigarettes is turned into the same orientation as another line of cigarettes alongside it, thus converting the two side by side lines of cigarettes into one line of cigarettes.