Greetings fellow turners,
I am relatively new to turning but not woodworking. I have 88 spindles I need to turn for a set of chairs. I have been practicing my skew chisel technique in regards to putting that final smooth cut surface on the spindles so I can avoid any sanding. The trouble I am having is that when I “push” the skew chisel along the axial direction of the spindle with the long point facing up, I get these spiral gouges in the spindle, which coincides with vibration of the spindle. I tried “pulling” the chisel with the long point facing down, and that avoids the vibration, but I am still not satisfied with the final cut quality. What am I doing wrong?
Jim
Replies
How long and how thick are the blanks, and what is the wood?
If the spindle is long and relatively thin you are getting harmonic chatter .Try reducing the tailstock pressure a little, if that fails build or buy a spindle steady rest.You can try supporting the back of the spindle opposite the cutting edge with your hand the way professional turners used to do.Just be smart about where you put your fingers relative to pinch points
Have you looked at some of the many Youtube videos on using a skew? When using it for smoothing, you usually work on or near the top of the work piece, raising the tool rest. This one shows proper body movement which is important in control.
http://www.youtube.com/watch?v=qT0Lp0AtMo8&feature=related
Thanks for the replies.
I am turning cherry 7/8" final diam and 18-20 inches long. I am sure harmonic vibration is a factor due to the gemoetry of my spindles. I turned a piece of pine 2" diam and 5" long and the Spiral gouges were drastically reduced, but still there. I guess it takes some practice, an ultra sharp blade, and maybe a steady rest. I'll try the "steady hand" technique first though.
Also, I imagine if I smooth the center 5-6" or so first, and then go to the ends, that will help?
There is a "thread cutting"
There is a "thread cutting" effect that's possible, which would lead the skew sideways at just the correct rate to continue the spiral. Don't know how to avoid, as I've fought that myself more than once. Might not be what you're experiencing.
You should be sanding the spindles. Get your skew technique as smooth as you can but finish with the sandpaper. Not only are you asking more out of the technique than is reasonable but you will get much more reliable surface prep by sanding than ANYONE could straight off the skew.
planing with skew
I agree with all of the comments that have been made. Steady with opposite hand (on side opposite the tool rest), raise tool rest so it's just below top of wood, take light cuts. Skew will be directly on the top of the piece, not in front of it. Another thing you can do is maintain the mass of the piece by turning the contour on one segment and then smoothing that, before reducing thickness on the next segment. If you thin down the whole thing first and then try to smooth it it will whip and vibrate more, producing your "spirals". A little sanding is going to help, but a lot of sanding can reduce the crispness of the turnings.
use of skew
Surely you are having chatter poblems. The spindle flexes under the pressure of the chisel. The work-piece must be supported, either by a steady-rest or by the hand held under the work-piece. That sounds frightening, but is really quite easy. I've turned red-oak spindles 30" long at 3/8" diameter using that method. Give it a try on some scrap. Wear an old cloth glove if necessary. I've also used a steady-rest, using wheels from yard-sale skates. Those wheels have very nice ball-bearings, and resiliant tires. Keeping the skew very sharp and using light pressure will help. Good luck!
Tom Higby
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