This document provides instructions for machining 27 inch shafts on a lathe. It describes setting up the lathe with a steady rest and centering the workpiece. It then outlines the process of facing off the part, cutting the outer diameter (OD) in steps, and finishing the two hub sections, leaving material for the radii. It stresses checking measurements throughout and making incremental cuts to avoid defects. The final step is to set up for the next operation while avoiding scratches on the finished workpiece.

1. 27 inch shafts
27 inch shafts are shaft that are about 4 inch in biggest OD and very little tolerances
in the other hubs.
1. Find hard jaws and steady rest and set it up
2. Put center drill
3. Put the piece in the machine, tight it up a little, put in the steady rest use a level or
the center drill to figure out where the center of the part is, its easy if u tight it up a
little, put the center drill and see if it does the center right or needs to go up, down or
center.
4. Check the TIR, set it up as best u can, check Tir long ways in the part
5. Tight up the steady rest and face the part off, finish the prebore
6. Put the lifesaver, remove the steady rest and make sure the jaws are very tight
7. Make a first cut in OD, all the way to the piece, from the front to the jaws
8. Check the measure of the OD close to the jaws, the middle of the part and the
edge, if the measures does not match within .003 move your lifesaver tower towards
you if the back is bigger that the front part or against u if the the back is smalled the
the front.
9. Do this until the OD matches up on all sides, do small cuts on medium-high speed
to see how the part is going to behave on smallers cuts, it not the same when you are
making cuts of 50-100, loose up the lifesaver a little if the middle does not match up
with both edges.
10. Cut as much material in OD as u can, but leave around .060 to cut last, in case
that you need to move the piece. You can do cuts of about .080 on high speed, slow
down and cool down the part if u need it.
11. Do the first hub, that is the longest one, leave material for the radious. Finish it if
you dont have to move your piece, measure the front and back side of the part, finish
it as best u can, without passing the limits, ask you supervisor to help sand down the
part if u need it.
12. Finish the second OD, leave material for the radious, if the radious is 5/32 (.156)
multiply that by 2 and add it to the OD (2.362 + .312 = 2.675 ) leave this amount like
a step and .156 in front for the radious. Finish the Hub as best u can and ask for help
to sand down the rest.
13. set up for second operation , make sure that you don't scratch the piece.