Shaft warpage

Hello

Going to build a lathe spindle very similar design has one used in the mini lathe, but a step up in size and with a tad bigger bore of 1'', will be using EN16T steel,

what I would like to know is. when it's all been turned down to size, will the shaft start to move about/start warping?

will the shaft need to have any hardening treatment, as I will be using en16t , i take it that the T stands for already pre tempered up to a certain degree and this should be fine for a lathe shaft

Thank

lee

I think the T means heat treated, for hobby use I would think unhardened will be fine, it would move if heated after finish turning. For jobs like yours I would rough turn to near size and leave it for a few weeks, but doubt you need to.

I would rough out the outside dimensions to within 15 thou and drill the bore to within .010 thou,and leave for some time,say a month outside in the sun and rain,this will relieve some stress,years ago castings were left out to so called "weather" the daily variation in temperature made the castings expand and contract so gradually relieving the internal stresses . more modern methods to speed up the process have been to raise the temperature in an oven and leave to cool,round bar does not get too many internal stresses,square bar can get severe stresses due to the rolling or drawing process. I have some rectangular key steel En 9 which is so full of stress that I have to heat to red heat for 15 mins and leave to cool.

Ok

Tthank you for the Advice, most appreciated

lee