Shaping and Sharpening Woodturning Tools

Shaping and Sharpening
Woodturning Tools
By Dan Douthart
http://www.gwinnettwoodworkers.com/
http://www.youtube.com/user/gwinnettwoodworkers/videos
Shaping and Sharpening Woodturning Tools
out to the tool handle path and less on
controlling the tool tip on the wheel and the
foot of the jig’s leg firmly seated in the
support arm’s pivot pocket. This does not
make for a very pleasant experience and will
probably mean that you will be hesitant to
sharpen a tool as often as needed.
Intro
This presentation is about shaping and
sharpening wood turning tools. I am going
to explain how I setup up my sharpening
station and the gauges that I use to sharpen
my tools quickly and with repeatability.
Another option is to stand in front of the
grinder with the tool handle to your right
side while sharpening the right wing of the
tool and then switching the tool handle to
your left side to sharpening left wing of the
tool then stand to one side while sweeping
across the nose of the tool to connect the
wings together.
After the lathe, the next most important
piece of woodturning equipment is the
sharpening station.
The setup of your sharpening station needs
the same attention as the setup of your lathe.
Since sharp tools are required for a pleasant
turning experience, your sharpening station
must be a pleasure to use. It needs to be at a
comfortable height with good lighting and
have easy access.
Does any of this sound familiar?
One book that I recently read shows
limbering up exercises to prepare your body
for doing the dance.
The Stance
I often see grinders mounted on a work
bench or a low stand and positioned so that
there is only access from the front of the
grinder. For straight ground tools this not
much of a problem other than being bent
over to reach the low mounted grinder.
Using a pivoting jig such as the Wolverine
Vari-Grind requires some acrobatic moves
to allow the tool’s handle to sweep the
required arc. You can try dancing with the
handle, keeping your body one step ahead of
the handle movement or step back an let the
handle pass between you and the grinder.
For a long handled tool this often requires
holding the tool’s handle in order to make
the sweep back and forth, which makes for
an uncomfortable body position. You end
up concentrating more on keeping your body
June 2013
I prefer to stand facing the side of the
grinder which allows me to look directly
down at the tool’s contact with the grinder
wheel and with my body completely out of
the tool handle path. While standing on the
left side of the grinder, I hold the jig’s leg
with my left hand, keeping it firmly seated in
the support arm’s pivot pocket. My right
hand holds the body of the Vari-Grind jig
and rotates it back and forth, providing full
control over the tip of the tool on the
grinding wheel. I am not at all concerned
about sweeping of the tool handle.
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Dan Douthart
Shaping and Sharpening Woodturning Tools
I was queried as to why I put the finer wheel
on the left side since the Wood Craft grinder
has the finer wheel on the right side. The
reason is that most of my time is spent
sharpening on the finer wheel and I prefer
standing on the left side of the grinder.
My Sharpening Station
My grinder is mounted on a standalone
sharpening station cabinet, which is
positioned so that I have full access around
the station.
I have also installed the Oneway Wheel
Balancing System, which makes grinder run
much smoother. The stamped metal wheel
clamping washers that were supplied with
the grinder are not very precise. The Norton
3X grinding wheel has a 1" center hole and
comes with plastic bushings to fit the wheel
to the 5/8" diameter grinder arbor, which are
also not very precise.
The directions for installing the Norton
wheels show using masking tape to shim and
fill in the gaps, which does not make for a
very true running wheel. After wasting
several days fussing with masking tape, I
ordered the Oneway Wheel Balancing
System and have been very pleased with the
results.
I am using an 8" variable speed Porter Cable
grinder that I purchased at Lowes. Many
people use the slow speed grinder from
Wood Craft, which is often on sale in the
$90 range, but I wanted one with a light.
The 8" Delta grinder also has a light but it is
about ½ again as expensive as this one.
This system comes with machined hubs for
holding the wheels and a 5/8" hole to fit the
motor arbor. The hub has slots for counter
balancing bolts, which allows the wheels to
be balanced perfectly, using the supplied
stand.
As it came out of the box the light would
only work when the motor was running,
which was not to my liking. Therefore, I
made some wiring modifications so that I
can use the light while setting up my jig
with the motor turned off.
I have also replaced the grinding wheels
with Norton 3X wheels. I am using a 46 grit
wheel on the right for shaping and a 80 grit
wheel on the left for sharpening.
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Shaping and Sharpening Woodturning Tools
line to precisely position the grinder so that
the wheels were perpendicular to the front
edge of the mounting board.
The Sharpening System
I am using the Oneway Wolverine
Sharpening System.
The grinder mounting bolt holes were drilled
a bit over size to provide the wiggle room to
allow for the precise positioning of the
grinder.
In order for the jigs to work the same on
both wheels, the bases must be perfectly
aligned with the grinding wheels. Here is
how I accomplished that task.
I marked the center of both grinding wheels
and then used a combination square to
transfer that mark to the front edge of
mounting board.
Starting with a plywood base with the front
edge cut as straight as can be done on my
table saw, I used this straight edge as a
reference for everything else. The width of
the plywood base was ripped to match the
length of the Wolverine bases.
I scribed a line vertically across the front of
the Wolverine base in line with the center of
the slide opening. Presuming that the
flange on the bottom of the base is parallel
with the slide opening, I used a Try Square
along the base flange and the reference edge
of the mounting board to position the base
perpendicular with front reference edge and
with the slide opening centered under the
grinder wheel.
I added a spacer blocks under the grinder to
position the center of the grinder arbor 6
3/8" above the Wolverine base mounting
surface. The Wolverine instruction sheet
shows between 6 1/4" and 6 1/2".
I did not have the same measurement on
both ends of my arbor so I used strips of
Styrene plastic as shims under the grinder
base to get the grinder arbor level with the
base.
This precise mounting of the Wolverine
Bases allows you to shape a tool on the
coarse wheel and then move to the finer
wheel to sharpen all with the same settings
on the Vari-Grind Jig. This accuracy will
also give you the same bevel angle on both
wings of a fingernail gouge.
The Wolverine instruction sheet shows
positioning the grinder with the front surface
of the wheels inline with the front edge of
the base, but since my wheels may not be
exactly the same diameter, I did not use that
as the guide for positioning the grinder. I
used double stick tape to attach a laser
pointer to the side of one grinder wheel and
then rotated the wheel back and forth by
hand to shine the laser across the plywood
platform. I used a Try Square and this laser
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Dan Douthart
Shaping and Sharpening Woodturning Tools
The Turning Tool
Freehand
I use the term “shape” to mean the geometry
of the tool’s cutting area and also as the act
of grinding the tool to achieve the desired
geometry. I use the term “sharpen” as the
act of dressing the bevel to maintain the
cutting edge of the tool.
There are those who profess to shaping and
sharpening their tools by freehand. I have
seen videos by several professional turners
that demonstrate freehand sharpening. They
will proudly roll the tool over on camera to
show the results. Invariably there will be
multiple facets on the bevel instead of a nice
continuous surface. There may even be a
comment that these facets will not affect the
tool’s performance.
It is all about sharpening your tools with
minimal loss of tool steel. To quote David
Ellsworth, when sharpening, “Don’t GRIND
the tool, simply dress the bevel”.
Well, I am a bit anal about that sort of thing.
I am into wood turning for the enjoyment
and enjoy having my tools to look as nice as
they cut.
You only grind the tool when you are doing
the initial shaping or repairing a damaged
cutting edge.
There are many different shapes of turning
tools.
Those who do, also say that freehand
sharpening is much faster then fiddling with
a jig’s setup. Well, I contend that by using
the system that I will be covering, I can
sharpen my tool just as quickly, wasting less
tool steel and ending up with a better
looking tool that I will enjoy using.
For me, it is an evolving process. When I
see technique used in a demo or video that
looks interesting, I will try it myself, which
may require a different tool shape.
There isn’t a single perfect tool shape that
will work with all techniques. Different
techniques often require different tool
shapes.
Jig
Assuming that you will be using a jig such
as the Wolverine Vari-Grind Jig you will
need three pieces of information. The tool
tip extension, the grinding jig leg angle, and
the support arm extension. When it comes to
bowl gouges, you must also be aware of the
flute shape. The three flute shapes are: “V”,
parabolic or elliptical and “U”.
When you see a turning technique that you
would like to try yourself, you will need to
determine how the tool is shaped. In order
to duplicate the shape on your own tool you
will need to note the angle of the bevel at
the nose of the tool and the angle and shape
of the wings and sometimes the flute profile.
June 2013
A given tool shape may not work well with
all flute shapes. If you are attending a
workshop shape your tool to match that of
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Shaping and Sharpening Woodturning Tools
the instructor, providing that your flute
profile is compatible with what the
instructor is using.
nose angle and wing angle and to some
extent the tool profile. The tool’s profile is
ultimately determined by how much time
you spend grinding on each area of the
bevel.
If a pivoting jig such as the Vari-Grind Jig
was used, you may also note the leg angle
and support arm extension that was used,
but the vertical distance from the platform
base to the center of the grinder’s arbor will
also affect these settings so you may not get
the same results at home with the same leg
angle and support arm extension. When you
get home you can use the following
procedure to determine the correct settings
on your grinding system to produce the same
results.
Changing one affects the other, but in this
exercise we will set the leg angle to match
the tool’s nose angle and the support arm
extension to match the wing angle.
Set the support arm extension at some
reasonable distance
1. With the jig’s leg resting in the support
arm basket and the tool’s nose resting on the
grinding wheel, adjust the leg angle so that
the full bevel is against the grinder wheel.
Jig Settings from an Existing Tool
2. Rotate the jig over to either side so that
the tool’s wing is resting against the grinder
wheel. Adjust the support arm extension to
get the full wing bevel is against the wheel.
This is a procedure that I got from the DVD
titled “Bowl Basics the Easy Way with Lyle
Jamieson”.
Set the tool tip protrusion as desired. I have
heard that the exact amount is not critical,
but it needs to be exactly the same every
time that you sharpen the tool.
Repeat steps 1 & 2
At this point the settings will be very close.
Blacken the surface of the bevel with a
Magic Marker and rotate the grinder wheel
by hand with the tool resting on the wheel. A
shiny streak from the cutting edge to the heel
of the bevel will show that you have the
exact setting.
However, the tip protrusion is going to
affect the geometry of the jig, which will
also have some affect on the geometry of the
tool’s shape. Much less than 2" can cause
the jig’s body to come in contact with the
grinding wheel and much over 2" will cause
you to run out of the flat clamping area of
the flute sooner.
Repeat steps 1 & 2 again if you want to fine
tune the settings.
The two adjustments are the jig arm angle
and the support arm extension. These two
settings work together to provide the desired
June 2013
You will now be able to sharpen your tool
and maintain the tool shape that was
provided the instructor.
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Dan Douthart
Shaping and Sharpening Woodturning Tools
Gauges for Quick Repeatability
If you are also using this Vari-Grind Jig with
other settings, you will need some sort of
method of recording these jig settings so that
you keep the tool sharp with minimal effort
and loss of tool steel.
A few years ago, after having watched
several of Jimmy Clewes’s DVDs, I had the
opportunity to attended one of his
workshops. I liked his technique so I had
him shape a spindle gouge and a bowl gouge
to match what he was using in his demo. He
used the same Wolverine Vari-Grind Jig leg
angle for both tools. I used that setting on
my Vari-Grind Jig for several months, when
I saw another technique demonstrated that I
wanted to try. However, it required a
different Vari-Grind Jig leg angle setting. I
made a scribe mark on the Vari-Grind Jig so
that I could return to the exact setting that
Jimmy had used. Well, I liked the results
from this new setting also and made another
scribe mark on the Vari-Grind Jig.
The page shows a photo copy of his VariGrind Jig. That seemed like a good idea, but
instead of photo copying my Vari-Grind Jig
and using a lot of black ink to print it out, I
simply laid the jig with the tool inserted on a
piece of paper and traced around the
significant parts.
Well, I will never claim to be the brightest
light in the forest, but it did not take long for
me to realize that these scribe marks were
not the way to provide for repeatability.
I was checking Doug Thompson’s web site
one day and ran across this paper showing
how his tools are shaped.
That worked well for the Vari-Grind Jig leg
angle, but I still needed a way to quickly set
the extension on the Wolverine support arm.
http://thompsonlathetools.com/images/extra/
Sharpening.pdf
From another Jimmy Clewes tip, I had been
blackening the bevel on the nose of the tool
and then manually rotating the grinder wheel
June 2013
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Dan Douthart
Shaping and Sharpening Woodturning Tools
with the tool bevel rubbing. Then adjusting
the arm extension until I had a shiny streak
where the blackening was rubbed off from
the cutting edge to the heal of the bevel.
This worked, but I wanted a quicker way to
make the support arm setting.
Rudy’s Gauge
Raptor Like Setup Gauge
I got another idea from the Raptor Set Up
Tools in the Craft Supply catalog. With the
support arm at my desired setting, I made a
setup gauge from tempered hardboard
(Masonite) to provide the same function as
the Raptor Set Up Tool.
Rudy used a piece of plywood with various
notches and dimples to set both the support
arm extension and the Vari-Grind Jig leg
angle. The width of the board provides the
support arm extension from the grinding
wheel. The notch on the lower left corner of
the board provides clearance for the grinding
wheel guard. The notch on the upper right
corner is used to position the Vari-Grind Jig
body while adjusting the leg angle so that
the bolt heads fall into the dimples.
The bottom of Rudy’s version was flat and
the lower right corner rested in the support
arm basket, which left room for a
positioning error and required two hands,
one to hold the gauge block and one to move
the support arm.
Why not just buy the Raptor Set Up Tool,
you might ask? Well the Raptor Set Up
Tools are made for various nose angles with
a Vari-Grid arm setting of 23° and that is
not what I want.
After trying Rudy’s version, I made a few
modifications.
This method of repeatability worked well for
me until I was exposed to a different idea
while attending a Rudy Lopez workshop.
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Dan Douthart
Shaping and Sharpening Woodturning Tools
My Modifications to Rudy’s Gauge
This all worked, but it was a bit of a
challenge to get the dimple holes drilled
exactly where I wanted them. Did I mention
that I am bit anal about that sort of detail.
I notched the lower right corner, which
allows the bottom of the jig to rest directly
on the support arm tube instead of the
basket.
That lead to a further modification on the
back side to the gauge.
The hole serves two purposes.
1. A thumb hole for holding the jig firmly
against the support arm tube and adjusting
the position of the support arm with one
hand while locking the support arm with the
other hand.
2. It is also used to hang the jig on the side
of my sharpening station.
I modified the upper right corner notch to
also have two purposes.
The upper blocks hold the Vari-Grind jig
firmly in place while the lower blocks
accurately sets the leg angle.
1. Positioning the body of the Vari-Grind
Jig while adjusting the leg angle
Creating this gauge is quick and easy.
2. Setting the tool’s nose protrusion from
the Vari-Grind Jig.
June 2013
Select some 3/4" by 3/4" stock from the
scrap bin, cut 4 pieces about 3" long. Glue
and nail the upper right block in place along
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Dan Douthart
Shaping and Sharpening Woodturning Tools
vertical the edge of the gauge. With the
Vari-Grind jig set as desired, place the VariGrind Jig body nose against the left side of
this block and tool shaft resting against the
top of the block, glue and nail the upper left
block horizontally against the Vari-Grind Jig
body tail and the tool shaft. Glue and nail
the lower blocks firmly against both sides of
the Vari-Grind Jig leg. If the horizontal
block extends past the edge of the gauge,
trim it of on the table saw so as not to affect
the nose protrusion notch.
The platform is set quickly by using your
thumb in the hole to hold the gauge pins
against the wheel. Then adjust the platform
to fit against the gauges’s straight edge.
The spindle roughing gouge and
conventional grind bowl gouge are
sharpened by holding the tool shaft firmly
against the platform with the left hand or
thumb while rolling the shaft back and forth
with the right hand.
To keep track of which gauge goes with
which tool. I number the gauge and place
the same number on end of the tool’s
handle. If the tool ever gets reshaped, I sand
the old number off and replace it with a new
number.
I sharpen scrapers with the top of the tool
face down on the platform as described in
the “Back to Basics with Jimmy Clewes”
DVD. I hold the scraper firmly against the
platform with my left hand or thumb and the
shaft of the tool in my right hand while
sliding the tool around following the profile
of the scraper.
The Tilting Platform
A burr will be raised on the cutting edge of
the scraper with the face held either up or
down, but of course the platform is adjusted
to match the bevel orientation. Try it both
ways and see which works best for you.
I use the tilting platform for sharpening tools
such as the spindle roughing gouges,
conventional grind bowl gouges and
scrapers. I use gauges as described in the
“Sharpening Woodturning Tools” DVD by
Mike Darlow, to make quick repeatable
settings on the platform.
I have not yet tried Paul Hamler’s technique
of using a burnishing tool to create a work
hardened burr.
The Jool Tool
I have never been very pleased with the
results that I get by sharpening a skew on the
dry grinder using the tilting platform.
The “Back to Basics with Jimmy Clewes”
DVD shows using convex grind on the skew
June 2013
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Shaping and Sharpening Woodturning Tools
instead of the concave grind that is normally
achieved on the grinder wheel. Jimmy
sharpened this profile freehand, by just
using the tilting platform as a support for his
left hand and moving the tool up and down
the wheel with his right hand.
Then Came the Tormek
I had drooled over the Tormek machines for
many years before ever I started dealing with
woodturning tools. After watching DVD’s
and YouTube videos. I finally convinced
myself, in my mind anyway, that I needed to
get one. My Birthday was coming soon, so
it was a perfect time to buy myself a
Birthday present. That’s my story and I am
sticking with it.
Mark Sillay introduced me to a parabolic
grind that he uses on a spindle gouge. He
uses a Jool Tool to sharpen this gouge.
Both of these shapes can be done by
freehand sharpening on a grinding wheel,
but it is much easier to get good results with
the JoolTool
My own un-scientific tests show that I am
getting a better cutting edge that cuts cleaner
and last longer.
At the recent Wood Show, I had two 2hr
turning sessions on Friday and a 2hr session
on Saturday and a 2hr session on Sunday.
At the previous shows I would sharpen my
tools at home every evening after the show.
This year, however, I sharpened my spindle
gouges on Thursday before the show and did
not sharpen them again until Monday
following the show. The spindle gouges
were still cutting nicely at the end of my
Sunday session.
The tool is held against the abrasive on the
bottom side of the wheel. The slots in the
wheel allow you to see exactly where the
abrasive is contacting the tool.
June 2013
One of the complaints of a wet grinder is
that it is slower than a dry grinder. It all
depends on whether you are shaping or
sharpening. Shaping typically requires
removing a significant amount of tool steel
and , yes, the wet grinder is slower. On the
other hand, sharpening is only dressing the
bevel and is not any slower than a dry
grinder and in my opinion gives a superior
cutting edge.
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Shaping and Sharpening Woodturning Tools
The shaping issue is resolved by using the
“Tormek Bench Grinder Mounting Set” on
the course grit dry grinding wheel to do the
shaping. This setup allows you to use the
Tormek jigs on the dry grinder. So you
shape the tool quickly on the dry grinder and
then sharpen it on the wet grinder all with
the same jig settings.
The Tormek produces excellent results on
the skew using the Multi-Jig. The Multi-Jig
will produce either a standard straight
cutting edge or a curved cutting edge similar
to the Richard Raffan or Alan Lacer skews.
There is always a problem with sharpening
an oval skew on a dry grinder. The MultiJig holds the skew by the edges and would
also give excellent results on the oval skew.
The Tormek gauge sets the support arm
extension and the tool protrusion. My
wooden gauge sets the Gouge Jig leg angle.
This is called a Multi-Jig because it has
different inserts. Another insert will handle
straight tools such as the spindle roughing
gouge and the standard grind bowl gouge.
Tormeck also has a platform jig for
sharpening scrapers.
June 2013
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