A print head assembly for use in a fused deposition modeling system, the print head assembly comprising: a carriage frame configured to be retained by a gantry mechanism of the fused deposition modeling system that is configured to move the carriage substantially in an x-y plane; a first receptacle configured to securely retain a first removable print head in a manner that prevents the first retained print head from moving relative to the first receptacle during operation of the fused deposition modeling system; a second receptacle configured to securely retain a second removable print head in a manner that prevents the second retained print head from moving relative to the second receptacle during operation of the fused deposition modeling system; at least one suspension mechanism (88, 900, 944) operably connected to the carriage frame wherein the receptacles (46,48) are supported by the at least one suspension mechanism (88, 900, 944), and wherein the at least one suspension mechanism (88, 900, 944) is configured to restrict movement of the receptacles (46, 48) relative to the carriage frame in directions parallel to the x-y plane, while also allowing the received print heads (36, 42) to be controllably moved in a direction parallel to a z-axis; a toggle mechanism (52, 54) for each received print head (36, 42), which is configured to controllably move the receptacles (46, 48) relative to the carriage frame substantially in the direction parallel to the z-axis, wherein the toggle mechanisms comprise a voice coil and a plurality of magnets (224, 228) configured to generate magnetic fields, and wherein the voice coil is disposed at least partially within the generated magnetic fields; and a controller configured to independently operate the toggle mechanisms (52, 54) such that the toggle mechanisms (52, 54) controllably move the received print heads (36, 42) independently of each other. a carriage frame configured to be retained by a gantry mechanism of the fused deposition modeling system that is configured to move the carriage substantially in an x-y plane; a first receptacle configured to securely retain a first removable print head in a manner that prevents the first retained print head from moving relative to the first receptacle during operation of the fused deposition modeling system; a second receptacle configured to securely retain a second removable print head in a manner that prevents the second retained print head from moving relative to the second receptacle during operation of the fused deposition modeling system; at least one suspension mechanism (88, 900, 944) operably connected to the carriage frame wherein the receptacles (46,48) are supported by the at least one suspension mechanism (88, 900, 944), and wherein the at least one suspension mechanism (88, 900, 944) is configured to restrict movement of the receptacles (46, 48) relative to the carriage frame in directions parallel to the x-y plane, while also allowing the received print heads (36, 42) to be controllably moved in a direction parallel to a z-axis; a toggle mechanism (52, 54) for each received print head (36, 42), which is configured to controllably move the receptacles (46, 48) relative to the carriage frame substantially in the direction parallel to the z-axis, wherein the toggle mechanisms comprise a voice coil and a plurality of magnets (224, 228) configured to generate magnetic fields, and wherein the voice coil is disposed at least partially within the generated magnetic fields; and a controller configured to independently operate the toggle mechanisms (52, 54) such that the toggle mechanisms (52, 54) controllably move the received print heads (36, 42) independently of each other.