Any topic including segmented turning
Al Geller Open form bowls, natural edge bowls, bowl design
Any topic including hollow turning freehand
Jim Rinde Anything to do with using and turning resins, turning goblets, hollow turning
with a boring bar with/without a laser
Miniatures; tool making and metal work
Basic turning; he is learning to do segmental work
Gary Toro Anything you want to make
Any topic (if he doesn't know how, he will learn it with you)
Turning of the Month - Bruce
Berger, "Triumphant Ribbon"
Questions and Answers (Q&A)
This is a new feature of the monthly Newsletter. Send your
questions to the newsletter editor, Ron Lindsay,
He will forward each question to our panel of experts. We will get answers
to each question from at least two of our experts and publish them in a future
newsletter in this Q&A section.
Here is our first Q&A:
Why are some bowl gouges ground with a V shaped center and other
bowl gouges are ground in a U shaped center?
the design of the hollow portion of a bowl gouge
the turning process?
A: (Al Geller) All my gouges have either a "U" or a
"V" shaped groove cut into them.
The "V" shaped groove is round at the bottom so that the real
difference to the groove is the slope of the sides of the groove.
I know that Thompson makes a truly round shaped groove in his
bowl gouge, and I do not believe that it has an advantage to a U or V.
The round profile provides a lot more steel under the groove
surface to give you a stiffer tool, but the round groove will, I think,
result in a catchier tool, like a spindle gouge.
For me, the main difference between a
"U" or "V" profile is [apparent] when I shear cut the exterior of a
bowl. The straight sides of
a "U" profile results in a straighter edge whereas a "V" grind has a
more rounded edge. The
differences are minimal. I
believe that the "U" profile is somewhat safer in that it is harder to
get a catch with it. These
comments are based upon a single-angle bowl grind jig which I do not
alter based upon tool size or groove shape.
I have one 1/2" bowl [gouge] with a very
open [shape]--almost similar to round, but it is a very open "V".
Because of its shape, the edge is very
acute - maybe 30 degrees - and this gouge makes a super-sharp
shear cut tool. I use
this tool only for final cuts
since the edge angle is smaller and dulls quicker.
A: (Sam Turner) I have both the "V" (Glaser) and
"U" (Oneway) shaped gouges in my tool kit.
I've used both for several years
and have done my best to research the difference in the various books
and periodicals in my limited library.
The bottom line for me, my opinion, is that there isn't much difference.
I tend to use my "U" shaped
gouges the most. They seem to be more prone to giving a smoother cut. I
think the reason is that the "U" shape provides a less abrupt transition
at the bottom of the flute, making the gouge more controllable. However,
the "V" shaped flute creates a smaller cutting surface on the wood
because of its sharper transition at the bottom of the flute.
This usually means a more controllable cut because less wood is
being removed where the gouge contacts the wood.
Obviously my last two statements
seem to contradict each other. The problem is there are other
factors involved, such as the properties of the HSS that control
durability and sharpness of the edge doing the cutting.
I know a sharper edge means a
more controllable cut. I
have read that a more durable steel may be more difficult to get as
sharp as a less durable steel. Of
course this creates the trade-off of having a sharper edge and having to
resharpen more often.
I think that a far more important consideration than flute shape is how
well you sharpen your tools.
The best sharpening job is one that creates a bevel with a single facet
and a symmetrical shape. Honing
the edge of your tools, at least for the final finish cuts, is very
helpful in getting both the shape and finish you're looking for.
My advice is to try both flute shapes and see if you can tell the
difference. I'm not sure I can.
But, I seem to go back to my
Oneway "U" gouges most often, and so they must work better for me.
Please remember that there are
many ways to accomplish your goal. Some
turners use scrapers instead of gouges and produce very nice work.
The important thing is to try
different techniques and use what works for you.
A: (Steve Langton) See
A: (Ron Lindsay) See