A support for a hollow cylindrical paperboard yarn core and for engagement with a cantilevered drive spindle assembly, the spindle assembly having a hub and an elongate rod-shaped spindle rigidly affixed to the hub in cantilever fashion, the hub defining exterior drive surfaces, the spindle being of smaller diameter than the drive surfaces, the support comprising: a proximal-end support member configured to be mounted on the hub, the proximal-end support member defining a through-passage for receiving the spindle therethrough and having interior mating surfaces configured to mate with the drive surfaces of the hub so that the proximal-end support member is constrained to rotate with the hub, the proximal-end support member being configured to be removably received into a proximal end of a paperboard yarn core so as to locate the proximal end of the core coaxially with respect to a rotational axis of the spindle assembly, the proximal-end support member comprising core-engaging elements for engaging a cylindrical inner surface of the core so as to cause the core to rotate with the proximal-end support member, and further comprising urging elements operable to urge the core-engaging elements radially outwardly into engagement with the inner surface of the core; and a distal-end support member configured to be removably inserted into a distal end of the core, the distal-end support member having a core-engaging portion configured to engage the interior surface of the core near the distal end thereof and having a spindle-engaging portion rigidly affixed to the core-engaging portion, the spindle-engaging portion defining a bore configured to receive a distal end of the spindle so as to orient the distal-end support member coaxially with respect to the rotational axis, the core-engaging portion of the distal-end support member in turn locating the distal end of the core coaxially with respect to the rotational axis, wherein the proximal-end support member includes a yarn-guiding surface. a proximal-end support member configured to be mounted on the hub, the proximal-end support member defining a through-passage for receiving the spindle therethrough and having interior mating surfaces configured to mate with the drive surfaces of the hub so that the proximal-end support member is constrained to rotate with the hub, the proximal-end support member being configured to be removably received into a proximal end of a paperboard yarn core so as to locate the proximal end of the core coaxially with respect to a rotational axis of the spindle assembly, the proximal-end support member comprising core-engaging elements for engaging a cylindrical inner surface of the core so as to cause the core to rotate with the proximal-end support member, and further comprising urging elements operable to urge the core-engaging elements radially outwardly into engagement with the inner surface of the core; and a distal-end support member configured to be removably inserted into a distal end of the core, the distal-end support member having a core-engaging portion configured to engage the interior surface of the core near the distal end thereof and having a spindle-engaging portion rigidly affixed to the core-engaging portion, the spindle-engaging portion defining a bore configured to receive a distal end of the spindle so as to orient the distal-end support member coaxially with respect to the rotational axis, the core-engaging portion of the distal-end support member in turn locating the distal end of the core coaxially with respect to the rotational axis, wherein the proximal-end support member includes a yarn-guiding surface.