Cutting Corners - Eccentricly

I’m hoping there are some Escoulen followers / eccentric turners in the
group who can answer the following questions

When turning multipe centers eccentrics

1. For a given pair of “centers”, do you turn at the
“null point” where there’s the least “shadow” or
at the most eccentric point where the “shadow”
is greatest?

2. For a given pair of “centers”, do you cut in
a cove at each then beads in between or cut
the beads first then the coves connecting them?

Have posted a pic to alt.binaries.pictures.woodworking
"Eccentric Turning Experiments"
as examples of

a) flat bottom coves at the null points with a bead
cut in the flat area of each cove
b) coves cut at the maximum "shadow" point
and beads connecting them

The blanks were 3/4" x 1 1/4" cherry
with 5 "centers" on each diagonal.

The coves were done with a detail/spindle
gouge and the beads done with a skew.

I've learned HOW to turn eccentric pieces
but I can't foresee the basic outcome prior
to actually turning the piece. Other than
Escoulen's site, is there any other site
that goes into the planning part of eccentric
turning?

Fun stuff this turning thing.

charlie b

I've turned quite a bit of eccentric stuff over the years and have most, if not
all, of the chucks on the market to do this sort of work. From my experinece, I
think the answer to both of your questions is: It Depends! It depends on what
you are trying to do. A lot of Escoulin's work is made up of many pieces. I
really liked his small eccentric spoon that I saw him demonstrate a year or so
ago at the Utah Woodturning Symposium. That is done from a single piece of wood.

It's been many years since I did much experimenting with between centers
eccentric turning. I normally started at one end and worked toward the other and
tried to always make the high points, I suppose you are calling those beads, to
come together at a sharp edge and whenever possible turned at all points on the
part. You never cut back into a previously turned area and you always do your
sanding of a particular offset before going to the next offset point on your
design.

Today, the only between centers eccentric things I do is oval hammer handles. I
started doing these several years ago when a fellow ask me how to do it. He said
a fellow in New Zealand had recommended he contact me. Well, I had never turned
an oval hammer handle, but I told him what I would do if I was going to try to
turn one. Then I decided to go into the shop to see if what I told him would
work. I had just finished giving it a try when my wife walked into the shop
carrying her hammer in her hand. The handle had just broken. That afternoon, I
turned a new oval handle for her hammer.

It takes lots of practice to turn exactly what you want to create with
multi-center turning. What you are doing is the right approach, lot's of
practice pieces. I think everything can be worked out mathematically for a given
offset and then all of those mathematical images combined to make up a complete
plan of the shape you plan to create. It is easier to practice and try out
techniques until you began to form a picture in your mind of what you will get
if you do a certain thing.

I doubt that I've answered any of your questions so that you can easily proceed
to creating superior eccentric pieces. Just start simple and build on those
first simple trials.

Perhaps, in a few weeks, I can have more to report, since my wife purchased the
new Escoulin chuck from Craft Supplies for my Christmas present. This thing has
more adjustments than I have ideas.

Fred Holder
http://www.fholder.com

In article , charlie b says...

Cutting Corners - Eccentricly

I’m hoping there are some Escoulen followers / eccentric turners in the
group who can answer the following questions

When turning multipe centers eccentrics

1. For a given pair of “centers”, do you turn at the
“null point” where there’s the least “shadow” or
at the most eccentric point where the “shadow”
is greatest?

2. For a given pair of “centers”, do you cut in
a cove at each then beads in between or cut
the beads first then the coves connecting them?

Have posted a pic to alt.binaries.pictures.woodworking
"Eccentric Turning Experiments"
as examples of

a) flat bottom coves at the null points with a bead
cut in the flat area of each cove
b) coves cut at the maximum "shadow" point
and beads connecting them

The blanks were 3/4" x 1 1/4" cherry
with 5 "centers" on each diagonal.

The coves were done with a detail/spindle
gouge and the beads done with a skew.

I've learned HOW to turn eccentric pieces
but I can't foresee the basic outcome prior
to actually turning the piece. Other than
Escoulen's site, is there any other site
that goes into the planning part of eccentric
turning?

Fun stuff this turning thing.

charlie b

Fred Holder wrote:

Today, the only between centers eccentric things I do is oval hammer
handles. I started doing these several years ago when a fellow ask me
how to do it. He said a fellow in New Zealand had recommended he
contact me. Well, I had never turned an oval hammer handle, but I told
him what I would do if I was going to try to turn one. Then I decided
to go into the shop to see if what I told him would work. I had just
finished giving it a try when my wife walked into the shop carrying
her hammer in her hand. The handle had just broken. That afternoon, I
turned a new oval handle for her hammer.



So, how do you turn Ovals? Thanks.

charlie b wrote:
Cutting Corners - Eccentricly

I'm hoping there are some Escoulen followers / eccentric turners in the
group who can answer the following questions

When turning multipe centers eccentrics

1. For a given pair of "centers", do you turn at the
"null point" where there's the least "shadow" or
at the most eccentric point where the "shadow"
is greatest?

2. For a given pair of "centers", do you cut in
a cove at each then beads in between or cut
the beads first then the coves connecting them?

Have posted a pic to alt.binaries.pictures.woodworking
"Eccentric Turning Experiments"
as examples of

a) flat bottom coves at the null points with a bead
cut in the flat area of each cove
b) coves cut at the maximum "shadow" point
and beads connecting them

The blanks were 3/4" x 1 1/4" cherry
with 5 "centers" on each diagonal.

The coves were done with a detail/spindle
gouge and the beads done with a skew.

I've learned HOW to turn eccentric pieces
but I can't foresee the basic outcome prior
to actually turning the piece. Other than
Escoulen's site, is there any other site
that goes into the planning part of eccentric
turning?

Fun stuff this turning thing.

charlie b

There may be a starting point here...

http://www.the-sot.com/
http://www.the-sot.com/library.html
http://www.turners.org/OTOrgan.htm

If it works...
http://www.elliptical-turning-associ...blications.htm


As long as you know the terms to search for...

http://www.google.ca/search?hl=en&q=...e+Search&meta=

For your entertainment...
http://www.oldschwambmill.org/resear...les/mecca.html

"charlie b" wrote in message
...
Cutting Corners - Eccentricly

I'm hoping there are some Escoulen followers / eccentric turners in the
group who can answer the following questions

When turning multipe centers eccentrics

1. For a given pair of "centers", do you turn at the
"null point" where there's the least "shadow" or
at the most eccentric point where the "shadow"
is greatest?

2. For a given pair of "centers", do you cut in
a cove at each then beads in between or cut
the beads first then the coves connecting them?

Have posted a pic to alt.binaries.pictures.woodworking
"Eccentric Turning Experiments"
as examples of

a) flat bottom coves at the null points with a bead
cut in the flat area of each cove
b) coves cut at the maximum "shadow" point
and beads connecting them

The blanks were 3/4" x 1 1/4" cherry
with 5 "centers" on each diagonal.

The coves were done with a detail/spindle
gouge and the beads done with a skew.

I've learned HOW to turn eccentric pieces
but I can't foresee the basic outcome prior
to actually turning the piece. Other than
Escoulen's site, is there any other site
that goes into the planning part of eccentric
turning?

Fun stuff this turning thing.

charlie b
============================
Charlie,
I'm sure I can't answer your questions properly since I don't really
understand all I know about using the Escoulen chuck. I've watched him do
his magic, and much of this is due to the chuck he designed and uses. It is
not a purely "multi axis centers" devise. It uses a ball and socket design
that allows indexing as well as tilt adjustments. This permits you to have
adjustments beyond what we would consider as multi axis. In multi axis, we
can start at A center, then move the work piece to a different location on
either end, or both ends. Any of these movements will give you a specific
range of cuts. There must be a way to figure out how these different axis
points will/can affect the final turning shape, but I haven't figured it out
yet. My best advise is to experiment, and to take notes on what positions
you use, and what the end results are. When I get time, that's what I want
to do. Also, I've considered trying to buil a wooden version of the Escoulen
chuck to experiment with. Good luck.

Ken Moon
Webberville, TX.

From the December 2001 issue of More Woodturning:

"First you need to design the cross
section at each end of the handle. You
need to have a square blank of the proper
size and a couple of inches longer than
your handle. Without drawings, I’m not
sure that I can explain how to determine
where to put your multi-center holes.
Take the drawing of one of the cross
sections and locate a center that will be
halfway between the top and bottom of
the oval and between the two sides. Take
a compass and draw a circle about this
that passes over, or through, the center
of the top and bottom of the oval.
Draw a horizontal line through the
center point and place the compass on
the side of the oval and mark a line on
the center line opposite this side. Do the
same for the other side. I believe this
will mark the offset needed for that end
of the handle. Repeat this operation for
the other end. Then making sure your
square block is large enough to
accomodate this offset, mark off the
exact centers at each end and draw a
horizontal line to layout your offset. Layout
the center points and offset points
on each end.

"Now, mount the block on the lathe
and turn it round to the shape that you
desire making sure that each end is of
the diameter of the up and down dimension
of your oval. Now. shift out to the
offset points on one side and turn until
you are almost halfway through at the
top and bottom of the oval. Then, shift
to the other set of offset points and do
this again. You should have a near oval
and a little sanding to blend it in should
make it very presentable.

Like I said, I haven’t made one, but
this would be my approach to doing so. I
hope it is clear. Graphically, it seems logical.

This stirred my interest, so I had to
find out if my instructions would really
work. I went out to the shop and turned
a handle out of dry Cherry. I turned on
the offsets until the turning on each side
joined on a nice little ridge. I used a skew
to be able to get the smoothest cut. Then,
I returned it to original center and sanded
with a strip of 150 grit sandpaper. It became
oval quickly. The process that I
had described for Don did work."

I've never tried this say to make an oval bowl or platter, but it might work
also. Incidentally, my book, "A Guide to Work-Holding on the Lathe", contains a
description of how to do this and provides the layout drawings plus some photos
as well.

Fred Holder
http://www.fholder.com



In article nrluf.5682$7f7.3125@trnddc08, Lobby Dosser says...

Fred Holder wrote:

Today, the only between centers eccentric things I do is oval hammer
handles. I started doing these several years ago when a fellow ask me
how to do it. He said a fellow in New Zealand had recommended he
contact me. Well, I had never turned an oval hammer handle, but I told
him what I would do if I was going to try to turn one. Then I decided
to go into the shop to see if what I told him would work. I had just
finished giving it a try when my wife walked into the shop carrying
her hammer in her hand. The handle had just broken. That afternoon, I
turned a new oval handle for her hammer.



So, how do you turn Ovals? Thanks.

Even with no abbreviations, acronyms or insider jargon the terms used in
eccentric turning can be confusing, at least for me. I think of
eccentric turning as limited to either "multi axis between centers" or
"single or multi axis on a single center not concentric with the spindle
axis". To me, inside-out, pumping, oval chucks, rose engines,
ornamental turning and voodoo are all separate entities distinct from
eccentric turning. This may not be accurate nor a good way to consider
eccentric turning.

I hope Fred, Ken, Charlie and others will post an outline and/or suggest
terms that we can all use to describe turning that's not on a single
axis that's coaxial. Unless, of course, I'm the only one who gets
confused and fits another definition of eccentric.


Turn to Safety, Arch
Fortiter



http://community.webtv.net/almcc/MacsMusings

"Ken Moon" wrote: (clip) Also, I've considered trying to build a wooden
version of the Escoulen chuck to experiment with. (clip)
^^^^^^^^^^^^^^^
I have built a coupl;e of vacuum chucks that simulate the action of the
Escoulen chuck. Turn a wooden, faceplate-mounted piece of wood to a
spherical shape, and feed your vacuum through the spindle. Turn a sort of
flat bowl to stick to the spherical surface by vacuum. Attach your work
piece to this. You will be able to slide this off axis and hold it in
various positions, much as Escoulen does. To fully simulate Escoulen's
chuck, the spherical surface should be convex.

However, I prefer to use a concave spherical surface, which results in
having the work spin with the unsupported end on axis. This has some
advantages:
1.) It is less hazardous.
2.) It permits you to use tailstock support.
3.) Cuts that are made on the end of the piece, where it is weakest, are
made on axis--interrupted cutting (cutting air) is minimized, so there is
much less danger of catching and breaking the piece.

"Fred Holder" wrote: (clip) I've never tried this say to make an oval bowl
or platter, but it might work also. (clip)
^^^^^^^^^^^^^^^^^
It will work on the outside, but the best you can achieve on the inside will
be a round cut. The minute you so offset, you'll see that the side that is
not being cut will run into the tool. If you want uniform walls, you will
have to do some hand carving.

Referring now to the outside, you are making an "oval" by blending two
different radii. For larger work, the transition between the end radius and
the side radius will not blend as well (you will see a sharp edge at the
transition) and sanding to correct this will become more difficult.

Hello Arch,

I think of multi-center turning and eccentric turning as one and the same;
however, in the manual that comes with the new Escoulen Reversed ball and socket
chuck, which I received as a Christmas Present from my wife, they define the
action of the chuck as being able to do three types of work:

1. Turn off center with the axis parallel to the spindle
2. Eccentric turning, in changing the angle of the axis
3. and combining both of the previous possibilities.

The chuck is currently mounted on my Nova DVR Lathe and ready to try out, as
soon as I can decide what I want to try with it.

In essence, Number 1 above is the same as placing a piece of wood between
centers and then offsetting it from center the same amount on each end.
Number 2 above is the same as placing a piece of wood between centers and then
offsetting the tailstock end off center, which is what happens with the ball and
socket chuck. I don't know of a way to accomplish the third, which is a
combination of both forms of offset.

Jean-Fancois Escoulen considers the work done by his ball and socket chuck to be
eccentric. Robert Sorby considers the work done by their eccentric chuck to be
eccentric although it basically performs the actions described in 1 above. It is
all multi-center turning.

Fred Holder
http://www.fholder.com


In article , Arch says...

Even with no abbreviations, acronyms or insider jargon the terms used in
eccentric turning can be confusing, at least for me. I think of
eccentric turning as limited to either "multi axis between centers" or
"single or multi axis on a single center not concentric with the spindle
axis". To me, inside-out, pumping, oval chucks, rose engines,
ornamental turning and voodoo are all separate entities distinct from
eccentric turning. This may not be accurate nor a good way to consider
eccentric turning.

I hope Fred, Ken, Charlie and others will post an outline and/or suggest
terms that we can all use to describe turning that's not on a single
axis that's coaxial. Unless, of course, I'm the only one who gets
confused and fits another definition of eccentric.


Turn to Safety, Arch
Fortiter



http://community.webtv.net/almcc/MacsMusings

On Tue, 3 Jan 2006 11:26:08 -0500, (Arch) wrote:

Even with no abbreviations, acronyms or insider jargon the terms used in
eccentric turning can be confusing, at least for me.

I consider pretty much anything turned by myself as an eccentric
turning. Others?


--
Chuck *#:^)
chaz3913(AT)yahoo(DOT)com
Anti-spam sig: please remove "NO SPAM" from e-mail address to reply.


September 11, 2001 - Never Forget

----== Posted via Newsfeeds.Com - Unlimited-Unrestricted-Secure Usenet News==----
http://www.newsfeeds.com The #1 Newsgroup Service in the World! 120,000+ Newsgroups
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Fred Holder wrote:

Incidentally, my book, "A Guide to Work-Holding on the Lathe",
contains a description of how to do this and provides the layout
drawings plus some photos as well.


(Hanging head in shame) Just took me 20 minutes to find your book and about
15 seconds to find the diagram and instructions! As you can tell, I've only
read what I thought were the 'good bits' in your very fine book. Guess I
really need to do a cover to cover.

Thanks, Fred.

LD

(Chuck) wrote:

On Tue, 3 Jan 2006 11:26:08 -0500, (Arch) wrote:

Even with no abbreviations, acronyms or insider jargon the terms used
in eccentric turning can be confusing, at least for me.

I consider pretty much anything turned by myself as an eccentric
turning. Others?

Im not sure about the Product, but any time I am turning it fits the
definition of Eccentric turning.

Fred Holder wrote:
Jean-Fancois Escoulen considers the work done by his ball and socket chuck to be
eccentric. Robert Sorby considers the work done by their eccentric chuck to be
eccentric although it basically performs the actions described in 1 above. It is
all multi-center turning.

I think they are both right.

My dictionary defines eccentric (in the context we are looking at)
simply as 'not having the same centre as another'.

According to wikipedia eccentric is the opposite of concentric
http://en.wikipedia.org/wiki/Eccentric
http://en.wikipedia.org/wiki/Concentric

"In mechanical engineering, an eccentric is a wheel that rotates on an
axle that is displaced from the focus of the circle described by the
wheel..."

I suspect that in most mechanical applications the axes are parallel to
one another.

Therefore I suggest that the case where the axes are not parallel is
just a special case of eccentric. If there is not already a word or
phrase that describes this special case, maybe there should be.

Other variations to consider are the possibilities that the axes are
either convergent or non-convergent. (they either intersect at some
point, or never meet)

--
Derek Andrews, woodturner

http://www.seafoamwoodturning.com
http://chipshop.blogspot.com - a blog for my customers
http://www.seafoamwoodturning.com/TheToolrest/ - a blog for woodturners

Arch wrote:

Even with no abbreviations, acronyms or insider jargon the terms used in
eccentric turning can be confusing, at least for me. I think of
eccentric turning as limited to either "multi axis between centers" or
"single or multi axis on a single center not concentric with the spindle
axis". To me, inside-out, pumping, oval chucks, rose engines,
ornamental turning and voodoo are all separate entities distinct from
eccentric turning. This may not be accurate nor a good way to consider
eccentric turning.

I hope Fred, Ken, Charlie and others will post an outline and/or suggest
terms that we can all use to describe turning that's not on a single
axis that's coaxial. Unless, of course, I'm the only one who gets
confused and fits another definition of eccentric.


I was asking about between centers "eccentric" turning using different
center points on each end of the blank. If you put the drive center
on
one corner of a square cross section blank and the tail stock live
center
on the diagonally opposite corner of the blank
- you'll have a "null point" at the middle of the length of the blank
- you'll have the maximum shadow at each end of the blank

Line drawing illustrations would make this easier but I'll see what
I can do with ASCII "illustrations"

o
\ / ----- maximum "shadow
\ /
X ---- null point - minimum "shadow"
/ \
max shadow - / \
o

It's easier to turn at the "null point(s)" because there's
less "shadow" and therefore less chatter.

At a given null point, you can cut either a cove or a bead.

| : | | : |
\ : / --cove / : \ ----
bead
/ : \ \ : /
| : | | : |

Examing Escoulen's photos of this type of eccentric between
centers turning, it appears that he cuts the "coves" first then
turns the beads between them

The trick is to turn a piece that has a bead flow into an
adjacent cove which flows into another adjacent bead

OR

To have the intersection of a bead and a cove come out
as a nice clean line rather than a semi-wide groove.

There is another approach that comes out like a car engines
crank shaft. Because you're turning in heavy "shadows"
and no continuous wood along the long axis it's a bit
trickier to turn

+---+
| |
0-+ | +-0
| |
+---+


I'm trying to develop a graphical method which will
allow me to visualize the options for a given pair of
"centers" and the results. Will post example
illustations with text instructions in

alt.binaries.pictures.woodworking

and post a message here when it's up to see and
critique

Pity this group doesn't allow pictures. Sure
would make things easier.

charlie b

"charlie b" wrote in message
...
Arch wrote:

Even with no abbreviations, acronyms or insider jargon the terms used in
eccentric turning can be confusing, at least for me. I think of
eccentric turning as limited to either "multi axis between centers" or
"single or multi axis on a single center not concentric with the spindle
axis". To me, inside-out, pumping, oval chucks, rose engines,
ornamental turning and voodoo are all separate entities distinct from
eccentric turning. This may not be accurate nor a good way to consider
eccentric turning.

I hope Fred, Ken, Charlie and others will post an outline and/or suggest
terms that we can all use to describe turning that's not on a single
axis that's coaxial. Unless, of course, I'm the only one who gets
confused and fits another definition of eccentric.


I was asking about between centers "eccentric" turning using different
center points on each end of the blank. If you put the drive center
on
one corner of a square cross section blank and the tail stock live
center
on the diagonally opposite corner of the blank
- you'll have a "null point" at the middle of the length of the blank
- you'll have the maximum shadow at each end of the blank

Line drawing illustrations would make this easier but I'll see what
I can do with ASCII "illustrations"

o
\ / ----- maximum "shadow
\ /
X ---- null point - minimum "shadow"
/ \
max shadow - / \
o

It's easier to turn at the "null point(s)" because there's
less "shadow" and therefore less chatter.

At a given null point, you can cut either a cove or a bead.

| : | | : |
\ : / --cove / : \ ----
bead
/ : \ \ : /
| : | | : |

Examing Escoulen's photos of this type of eccentric between
centers turning, it appears that he cuts the "coves" first then
turns the beads between them

The trick is to turn a piece that has a bead flow into an
adjacent cove which flows into another adjacent bead

OR

To have the intersection of a bead and a cove come out
as a nice clean line rather than a semi-wide groove.

There is another approach that comes out like a car engines
crank shaft. Because you're turning in heavy "shadows"
and no continuous wood along the long axis it's a bit
trickier to turn

+---+
| |
0-+ | +-0
| |
+---+


I'm trying to develop a graphical method which will
allow me to visualize the options for a given pair of
"centers" and the results. Will post example
illustations with text instructions in

alt.binaries.pictures.woodworking

and post a message here when it's up to see and
critique

Pity this group doesn't allow pictures. Sure
would make things easier.

charlie b
=======================
Charlie,
To get the crankshaft type turning, you need to have one central axis, then
have multiple centers clustered around the center axis. You can turn a
different throw for each center of the cluster. That would give you a
crankshaft with a number of throws equal the number of centers you had laid
out. But you can also lay out a center and, as an example, 2 other points
midway out the diagonal run from corner to corner of the square stock you'll
be working. Then you can turn throws alternating between the 2 centers, for
any number that strikes your fancy. These would be 180 degrees apart, and
would be like a standard V-8, which has pairs of throws that turn together.

Then you can move either end of the above illustration, and move the other
end of the blank to the opposite side, and you'll have something more in
line with your first illustration. This is what I would refer to eccentric,
and the crankshaft type I'd call multiaxis. Now this may be incorrect, but
I've been wrong before; thought I was wrong but I wasn't. ( :-)

Ken Moon
Webberville, TX

Thanks to all you respondents to my query.
Like rec.woodworking, this group has some
very knowlegeable folks willing to share
hard earned experience and insights.

I have "A Guide To Work-Holding On The Lathe"
but hadn't connect Fred to it, though I realized
this group's Fred had quite a bit of turning
experience. To have the skills and experience
to turn just about anything you can think of
is wonderful. To be able to explain it well
enough for someone else to do it is a more
difficult task - especially when limited to
"text only".

While Trial & Error is one way to get to
being able to "see" the finished piece
before actually turning it , I'd prefer a
method that let's me "see" the piece via
a less haphazard path.

What I'm looking for, and am working on a
set of instructions - with illustrations, is
a method to develop a "plan"/drawing for a
-"between centers"
- "vary the center points"
-"coves first, then the in between beads"
or
"beads first, then the coves connecting them"
turned "spindle". Eccentric bowls I'll leave
for someone else.

I've posted a first cut at a "beads first" method
to alt.binaries.pictures.woodworking
with the subject line

Eccentric Turning - Between Centers Eccentric Turning"Plan" Method

The attached file is a 48K GIF file that is about
a page and a half of illustrations with accompanying
text instructions. Feedback, comments. questions
and constructive criticism will be appreciated.

If, with the help of this group, a set of
simple, fairly easy to follow, instructions
can be developed it can go into the Knowledge
Pool and hopefully will
a) get someone to try something they
didn't think they could do because
it seemed too confusing or too hard
b) make it easier for folks who have
already gotten into "eccentric turning"
to work out an idea BEFORE turning
a bunch of trial and error pieces.

Am now working on a set of instructions,
usig the same basic approach, for a
"coves first" method. Will post it to
a.b.p.w when it's done.

charlie b