The Atlas lathes had a special feature for the (tailstock end) leadscrew bearings.  A feature that was often not understood and one that has frequently been removed when they have been replaced with a "Better" home made replacement!

    The bearing was purposely made weak, so that it would fail under excessive load.  The main purpose of this was so that, should the carriage strike an obstruction (such has the headstock or chuck) while under power feed or threading, the bearing would break allowing the leadscrew to back out of the headstock end assembly until it came free of the drive key.  By thus failing the leadscrew, carriage, change gears, and other expensive parts where protected from damage.

    Not understanding this many older lathes have had the bearing replaced with a stronger fabricated assembly, when either it failed as it should have, or because the machinist felt the need to improve the "weak" factory part!

    The other problem that can be faced by the lathe owner is having to replace the factory original part, that is still on the lathe, after an accident.

    A wonderful suggestion that was given by a member of one of my E-mail forums was to fabricate a new part using a strong outer hosing with an inner sintered bronze bearing core!  The inner core is a slip fit (so that it can back out of the outer housing under load), and is held in place by an aluminum (not crimped, just held in place by gravity) rivet.  The rivet will hold the bearing securely, until an excessive strain is placed on the leadscrew.  The rivet will shear under the stress, and the bearing can then slide out of the housing.  The OD of the bearing has to be larger than the leadscrew and any washers or bushings that are on the inner side of the leadscrew!  After such an accident the old rivet pieces are removed and the parts are reassembled with a new rivet.

    Below is a drawing of the factory bearings, for those of you who may wish (or need) to make a new bearing.  the drawing can be a starting point for designing your new part.  The drawings are for the 10" (top) and 6" (bottom) lathes.  I think the 12" lathe used the same bearing as the 10", but I am not positive!  I will be measuring the one on my lathe, when the opportunity presents itself (read when there is not presently a workpiece mounted ready for machining :-> ), and will add that information to this page.