Grinding a steering ball
BUGATTI steering arms have the ball end integral with the arm, and no doubt others makes use this system rather than a removable ball fitted with a taper and nut.
As the arms are bent, it is not possible to fit them to a lathe chuck for a regrind if they are not too worn. Discard any that are worn through the case hardening and do not be tempted to weld them as the arms are of heat treatable steel and likely to crack and snap off like carrots-not a healthy type of steering arm.
I have ground them by hand by using a mounted point about one inch diameter with a spherical recess in the working end and holding this in a chuck of an electric motor running at about 1500 rpm.
The trick is to blue the ball with a large Texta felt tip pen to check where the grinding is taking place, noting that there is no grinding taking place right in the centre of the tool and cutting progressively more towards the outer diameter.
Constantly measure the ball with a micrometer or dial vernier and hasten slowly.
The final touch is to tear off a 1 in square of emery cloth and push it into the grinding tool recess and polish the whole ball end this way. A slightly worn grinding tool works best. Start with #120 grit, followed by #220 and #400.
I have managed to recover a ball end within one thou with care using this method.