Titanium 20mm rear wheel spindle, 348mm long
This is a long spindle, 348mm. The customer specified a modification on the original spec, intead of having external nuts he wanted bolts to screw inside the spindle. I tapped the spindle 16×1 and made 7075 alloy end caps to screw in.
Being so long the spindle suffered from deflection as normal. To get the belly out of it i turn it to finished size at each end and measure where the belly starts and ends, then turn it off with pressure on the tool post, measuring after each cut. It is time consuming but i can usually get them true to within half a thou or so.
Measuring and marking