Froneck
Titanium
- Joined
- Dec 4, 2010
- Location
- McClure, PA 17059
My customer uses 1-1/2" SS 304 square shafts to drive conveyer belt sprockets. OAL 47", one side is turned 1.250 X 5" (no problem) other side same diameter X 15" (Problem) I set them up in P&W 16" newer Model C lathe, I chuck the square in 12" 4 jaw chuck, measure back 15" and indicate the flats of the square best I can due to material is not perfect square. Center drill the end. Cut to about 1-3/8 diameter with CNMG6** insert. No problem but when I remove the center stresses in the shaft move it sometime over 1/8" or more. Sometime the stress is so great it moves so that the square side I just indicated is running quite a bit out. (1/4" TIR.)
The lathe has the power to cut the square round in one cut and done on the short side. But on the long side I take a light .050" and when I notice the square running out remove the shaft. Chuck the the 15" side in another 24" lathe and straighten until it runs reasonably well. Re-chuck in P&W take another few cuts and have to straighten again. Seems like every time I straighten then re-cut it returns to where it was prior to straightening. After getting to 1-3/8" OD I put the shaft between centers and find it running out quite a bit and straighten again. taking .010" total cuts, I get 2 passes before the shaft about 2" from the live center is running out. Cutting with DNMG 55° insert. Again every time I straighten the shaft it returns back to the same amount of run-out after .020 removal. Thought now the square shaft is running out due to holding between centers. Is there anything I can do to lessen the run-out without sending the shafts for stress relieving?? Being it is a poultry plant shaft requirement is NOW! They need it yesterday! The Idler shafts 137" length cut round 1.250" X 5" both sides are easily done with no need to straighten.
The lathe has the power to cut the square round in one cut and done on the short side. But on the long side I take a light .050" and when I notice the square running out remove the shaft. Chuck the the 15" side in another 24" lathe and straighten until it runs reasonably well. Re-chuck in P&W take another few cuts and have to straighten again. Seems like every time I straighten then re-cut it returns to where it was prior to straightening. After getting to 1-3/8" OD I put the shaft between centers and find it running out quite a bit and straighten again. taking .010" total cuts, I get 2 passes before the shaft about 2" from the live center is running out. Cutting with DNMG 55° insert. Again every time I straighten the shaft it returns back to the same amount of run-out after .020 removal. Thought now the square shaft is running out due to holding between centers. Is there anything I can do to lessen the run-out without sending the shafts for stress relieving?? Being it is a poultry plant shaft requirement is NOW! They need it yesterday! The Idler shafts 137" length cut round 1.250" X 5" both sides are easily done with no need to straighten.