You need to get rid of the play in the headstock bearings before you can make any meaningful measurements of the bed or taper socket runout etc. If its an M type Drummond, adjustment is described on the Yahoo Drummond Group page, in the files section. It is a simple procedure.

I would not worry too much about the taper socket run out. Maybe a reamer given one or two turns to remove any burrs and see how that affects your readings. But you rarely use the spindle taper socket for anything, so it does not matter if it runs out. Even turning between centres, you use a soft centre and turn it true every time you use it, or on the Drummond with gap bed its best to hold a soft centre in the chuck and turn it true and use a bent drive dog to use the chuck to drive the job.

Running a reamer down an out-of-true hole will generally not make it run true. The reamer follows the existing hole, so if it starts wonky, it ends wonky.

I fitted a second thrust bearing to my M-type that was already performing satisfactorily and found no difference in its performance so am not sure what benefits it might bestow.

Edited By Hopper on 23/06/2018 10:39:36