Page 2 of 2 FirstFirst 12
Results 16 to 18 of 18

Thread: Wobble

  1. #16
    Join Date
    Feb 2008
    Location
    E TN, near Knoxville
    Posts
    6,196

    turning out-of-balance blanks

    Quote Originally Posted by Randy Hogan View Post
    ...It appears that the ballast weight of the machine is not substantial enough for the size of work I'm turning. ..
    A friend of mine turned lots of out-of-balance big blanks outboard on a small Delta lathe with no ballast. His solution was to fasten the lathe to the wall of the garage with long pipe clamps. The mass of the building was the ballast. Maybe try something more easily reversible like that first?

    The cast iron lathe bed can easily twist and is often overlooked. As a quick check put centers in the head and tailstocks, slide them close, and adjust one leg leveler until the points align. This will probably remove most of any misalignment. Since the floor may not be perfectly level I do this every time I move a lathe, even a few inches.

    JKJ

  2. #17
    Join Date
    Apr 2012
    Location
    Great Falls, VA
    Posts
    776
    Quote Originally Posted by Randy Hogan View Post
    I swept the shavings for the first time in awhile from around the base of the lathe. I noticed the whole thing had 'walked' several inches to the left. I've had, what appeared to be 'whole machine vibration' at the headstock end when I'm taking a big bite with a gouge at a fairly fast feed rate. I've checked and leveled the legs a couple times. It appears that the ballast weight of the machine is not substantial enough for the size of work I'm turning. I'm sure all of this isn't helping my wobble problem, although I have done some work recently without much run out at all. I think my next step is to put in some anchors in my concrete floor and anchor strap the head stock end down as tight as I can get it and see if this eliminates the vibration. When I first installed the lathe I had no vibration whatsoever so something obviously has changed. In addition, with a 22" swing, it doesn't appear the overall mass of the G0766 is heavy enough to handle it. The largest bowl I've turned is 16". But then again I'm new and I might be all wet.
    Randy, sorry you're having so much trouble. FWIW, one of my lathes is a G0766 that I've had for three years. No trouble at all turning bowls from heavy green blanks that begin at quite close to the full 22" swing. That's without adding ballast, and without anchoring the legs to the concrete floor. I have the legs sitting on 4" discs cut from an anti-fatigue mat of the type sold by Woodcraft, and that has eliminated any "walking", even when the workpiece is somewhat out of balance. You might want to try that before you resort to fixed anchors (which can cause other problems). Clearly something is going wrong for there to be so much vibration, but I'm quite sure it's not because your lathe doesn't have enough mass to turn to its full swing.

    But if you want more mass, you can easily add another 350 lbs simply by building a ballast box and loading it with seven 50 lb. bags of masonry sand. I did that with my other lathe, which is a G0733 (18" swing) that I've had for six years. When I first got it, I added 450 lbs. of sand in a ballast box (it's a longer lathe, so more space for ballast), thinking it would be necessary. It helps dampen vibration, to be sure, but I've found that if the blanks are prepared well, and rpms kept low until they are balanced, it really isn't necessary. I would not bother doing it again, which is why I've not done it with the G0766.
    Last edited by David C. Roseman; 09-14-2018 at 10:49 PM.

  3. #18
    All good points gentlemen! Your responses have given me at least 3 options to check out prior to me strapping the machine to the floor.

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •