I have this pre war 13" Holbrook lathe , its really almost ready to be melted down .It weighs over 1.5 ton and its only got a short bed .
Anyway the back plate is jammed on the spindle . Holbrook used a double register on the spindle nose , a 2 1/4" BSF thread 3/4" long is between the two registers
Advice on another forum . Is to machine up a tapered plug and use the plug locked in the spindle taper to hold the spindle .
I have measured the taper in the spindle. it is .025" per inch or .3" per foot . I cannot find any taper like that in any books I have . I need to know the angle to off set my top slide . Can anyone work out the maths .... ?
Some pics of the nightmare . BTW the gearbox is almost a work of art ! The spindle runs in 3"diameter white metal bearings .
Mike