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Thread: Lathe bore to small for stock need to turn ends Help?

  1. #11
    Join Date
    Nov 2010
    Location
    Portland Oregon
    Posts
    548

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    Wow, Is all I can say!
    This group is awesome, this is exactly what I needed, thinking outside of the box. I'm going to try the steady rest and see if things reach, if not the second idea of mounting it to the cross slide and using a boring head. The other will be to add length and cut to finish. The shaft is going to have pillow block bearings on each end with eccentric collars so I need to be bearing slip fit accurate.

    Again great help!

    TX
    Mr fixit for the family
    Chris

  2. #12
    Join Date
    Feb 2014
    Posts
    504

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    Your lathe is too short for a normal steady rest job. My 9x48" SB could handle about 28" between centers, slightly more if you remove the tailstock and use the steady rest.

    Stuff like this is partly why I moved to larger lathes. I've honestly never wished I had the old 9" SB back.

  3. #13
    Join Date
    Mar 2011
    Location
    Los Angeles California
    Posts
    72

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    If you try to use the steady rest set-up, be prepared for some accurate adjusting of the steady - if only a tiny bit out, the steady will 'walk' the other end right out of the chuck, even with the jaws clamped tight - you'll first notice a slight change at the steady end - good luck
    Richard in Los Angeles

  4. #14
    Join Date
    Jul 2005
    Location
    Chester, NH
    Posts
    5,196

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    Start with a shaft about 2" longer than required. Pull the tailstock and install steady-rest. Put on your 4-jaw and hold ~1" of the shaft in the chuck. Dial it in, making sure the other end is properly supported in the steady to prevent it from flopping around. Cut the bearing journal and part mostly off. Leave yourself a little nub to keep it from bending the shaft when it parts. Remove and break off stub or hacksaw through the nub. Dress with file. Repeat for other end.

    IMHO, I would do this long before I'd consider mounting the shaft to the cross-slide and trying to do this with a boring head...

  5. #15
    Join Date
    Sep 2015
    Location
    NW Illinois
    Posts
    314

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    I have threaded the ends of a 7' long cylinder barrel on a lathe 30" between centers. You need to start with material a little longer than finish dimension. Chuck up one end. Hold the overhanging end in a steady rest. Turn the required diameter next to the chuck. Part off the end held in the chuck. Flip, Repeat.

  6. #16
    Join Date
    Dec 2015
    Location
    Chilliwack, BC, Canada
    Posts
    2,305

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    Quote Originally Posted by Fasttrack View Post
    Start with a shaft about 2" longer than required. Pull the tailstock and install steady-rest. Put on your 4-jaw and hold ~1" of the shaft in the chuck. Dial it in, making sure the other end is properly supported in the steady to prevent it from flopping around. Cut the bearing journal and part mostly off. Leave yourself a little nub to keep it from bending the shaft when it parts. Remove and break off stub or hacksaw through the nub. Dress with file. Repeat for other end.

    IMHO, I would do this long before I'd consider mounting the shaft to the cross-slide and trying to do this with a boring head...
    I agree with this idea. It's the one really easy way that you can do this job with the least fuss.

    If the shafts are already cut to length the weld then part off solution begins to sound good. Or another option is to roughly center than drill a hole in each end and thread it with something like 1/4-20. Then "chuck" that threaded hole onto a short stub of 3/4" round that is also drilled and tapped. Use a short length of all thread as a stud. You can glue or pin the stud into the chucking piece. Mount that piece in a four jaw so you can center the shaft to whatever tolerance you require and which is consistent with the shaft's surface finish. This method still requires the use of a steady rest that puts the shaft very near to being correctly in line. Machine the ends as required.

    You'd set the jaws of the steady by bringing the steady in close to the chuck. Chuck up one of the shafts so it's inserted as deeply as it can in the chuck and centered. Bring the jaws in until they touch and lock them. Now when you set the steady at the tail stock end of the machine the jaws will hold the shafts centered well enough.

    Drilling and tapping for this form of "screw chuck" is likely as easy or easier than setting up than welding. But it's not as easy as starting out with 3 inch longer shafts than you require and chucking each end to do the reducing then parting off.

  7. #17
    Join Date
    Nov 2010
    Location
    Portland Oregon
    Posts
    548

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    Hello Group,
    My friend brought over the shaft stock today, and guess what, It longer than he needs, so I have a much better setup now. Chuck and steady rest, turn to size and repeat. My steady rest by the way just got new fingers with bearings, so I will get to try it out for the first time.
    Thanks for the great suggestions everyone.

    TX
    Mr fixit for the family
    Chris

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