Any help please guys, this is driving me nuts !!
I have a Sphere centre lathe - basically an Atlas 10" with the Timken roller bearings headstock option.
It was previously owned by a time-served engineer, sadly now passed away so I can't ask him, who I'm sure would not have tolerated an inaccurate lathe - so I must have done something.
The nosepiece mandrel on the headstock is apparently running eccentric. My DTI shows a range of 0.16mm from high to low point, at about 80mm in front of the front headstock bearing.
This eccentricity is consistent whether I fit a centre into the MT3 socket, or a faceplate or a 3 jaw chuck to the 1 1/2" x 8tpi nose thread.
I can fit and centre an independant 4 jaw to give very little drift (less than 0.02mm) - not enough patience to obtain zero, but I think it would be achievable.
Unless the spindle is distorted, I cannot work out how this could be happening and how to correct it.
I have recently replaced the belt which entailed removing the spindle from the headstock, all appeared to go by the book :-/ so hopefully that wasn't the cause.
Am considering stripping down the headstock, anybody with any experience? Why does book suggest driving spindle out through bearings rather than unbolting the tops from the split housing blocks?
Any help greatfully received