The Assembly Bay button, that was previously greyed out on the Hovertrucks' Toolbar, will become active once the Parts Factory has completed construction.  We'll need to construct one of these so we can assemble and deploy a Combot.  Select a Hovertruck and build an Assembly Bay.  Use any other available Hovertrucks to mine lava or assist in the construction of the Assembly Bay.  Selecting an available Hovertruck and right-clicking upon a building in construction will instruct that Hovertruck to assist in that building's construction.  This will speed up the rate of construction only if the necessary Metajoules are available.  When the Assembly Bay is complete, the player should select his Combot Crew on the playfield and run them into the Assembly Bay by right-clicking.