Tool control?

[Dudley]

I have been learning how to use my tools on green hickory (at least I think it's hickory, but I'm VERY bad at tree identification.) Last night I was "practicing" turning an egg shape, then a ball, then an egg on the same piece of wood--starting with one shape than turning down to the next. I was trying to use a shallow spindle gouge to gain some confidence from the frustration I've been having with the skew (although I am having less problems with the skew) and thought the gouge was getting kind of dull because it was putting out more sand than ribbons. After I sharpened the gouge (with my wolverine and a 120 grit pink wheel) I started having problems with the tool grabbing the wood and taking off large quantities of wood. It was almost like it was pulling itself through the wood and down the cut.

Is it possible that I sharpened the tool wrong or the wood had a soft layer? I'm not sure how long this tree was down before I cut it on Jan. 1st, but I can take the bark off with no tools before I put it between centers and there are some (not alot) of holes in the wood. (BTW there were small white grubs under the bark)

Any help would be greatly appriciated.

 

[MichaelMouse]

Three methods of control on the tool.

1) Anchor - the toolrest keeps the tool from running down with the rotation of the piece. Some folks use angles that defeat this. If you remember your force vectors, it basicall means they have the tool at 45 degrees or more to the rest. More of a lean than a rest.

2) Bevel - and here there's a lot of misconception. The bevel doesn't have to touch across at 90 degrees to the edge, the real stability in a cut comes from the way it registers along its edge while cutting. Don't "ride" the bevel, all you do is start following the bumps in the wood structure or creating more by flexing the wood.

3) Hand - you don't want to take the tool to the work, rather let the work come to the tool. With the kids at school, the best analogy was to carving, where the entry cut is much steeper than the peeling cut.

I'm sure you don't begin the cut without anchoring firmly on the rest, though you will hear a lot about dented rests, so some apparently do. It's an obvious mistake, though.

If you grind your gouge with a variable bevel angle with that jig you make the geometry much more dependent on the hand. Did you add more "fingernail," by chance? This and the combination of work diameter and depth of cut can get you in a position of taking too thick a shaving with no bevel support real quickly. It's a common enough problem with small - and rapidly changing - diameter work to think it may be the case.

Solution is simple if you are speaking of forged or continental pattern gouges - grind with a constant angle bevel. This gives you all the bevel depth control you get with the skew with its constant angle, but retains the dual clearance of a round nose and upturning edges that make the gouge so much easier to learn. The bevel support is best at the same angle, regardless of where on the tool you're cutting. Of course, you'll have to adjust the handle so you're not poking with the nose , rather peeling with the portion under the nose.

Picture of a flat gouge ground at a constant angle. Use the toolrest for angle, rotate left and right without rolling the gouge to minimize "fingernail."

 

[Bill Boehme]

I think what may have happened is that your technique was getting somewhat adapted to the tool being dull and more pressure was being aplied to compensate for the dull edge. Then, when you sharpened the tool, your technique was still the same as it was before sharpening, viz, too much pressure. Think "light touch" when working on shape details -- easy to say, not always so easy to do.

By the way, green hickory is a joy to turn. I have a cluster of hickory trees on my land and I cut up one of the small ones last spring for a turning class. The wood was actually slinging water and the bark could be slipped off by hand.

Bill

 

[Dudley]

Thanks for the replies. I think it may be a combination of both. I was using the gouge fairly dull and I also think I may have ground too much of the sides off creating more of a fingernail shape. Hopefully I will be able to get together with a local club member after I attend this Sat. meeting to get some first hand training. If not, I'll be taking the class offered at woodcraft.