I plan to make some inserted bit hollowing tools with arm braces. Two
45deg. 1/2 in pipe couplings and a 6 in nipple for the 'Z' and a 10 in
nipple padded with tape for its tail. I use 3/4 CR bar pipe-threaded for
the 1/2 in coupling at one end and drilled for a bit and tapped for a
setscrew at the other end. Ugly? Yep.

I'm considering whether or not to add a cupped forearm brace or just
make a long paddle to rest against my body. I run a little scared of my
store-bought armbrace because I figure that if it really does brace, I
could fracture my arm with a bad catch. If a shallow cup releases my arm
and can't hurt me with a bad catch then does it brace or just align the
tool and mostly give me a sense of security? I suppose that a catch
basically drives the bit down and the handle up, but If the brace moves
laterally holding a captured forearm is flesh or steel the winner?

OTOH, I haven't heard of any injuries due to using an armbrace and many
beginners as well as competent experienced turners use them, including
those who sell them.

What are the real advantages and potential dangers, _IF ANY, of bracing
a long heavy tool that's hidden inside a hollow form, against your
partially captured forearm? Maybe "partially" is the catchword or is
the risk of fracture just another myth?

This post reminds me Kevin, isn't it time for annual nominations to the
Order of COC? Maybe if we would have them, no one would want to join.



Turn to Safety, Arch
Fortiter



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

"Arch" wrote: (clip) I suppose that a catch basically drives the bit down
and the handle up, but If the brace moves laterally holding a captured
forearm is flesh or steel the winner? (clip)
^^^^^^^^^^^^^^
I have never heard of a broken arm from this, but I have heard of catches
that produced scary arm-twisting. This may sound silly, but how about
putting in a shear-pin to limit the severity of the arm-jolt?

"Arch" wrote in message
...
I plan to make some inserted bit hollowing tools with arm braces. Two
45deg. 1/2 in pipe couplings and a 6 in nipple for the 'Z' and a 10 in
nipple padded with tape for its tail. I use 3/4 CR bar pipe-threaded for
the 1/2 in coupling at one end and drilled for a bit and tapped for a
setscrew at the other end. Ugly? Yep.

Consider one of those auxiliary antirotation toolrest types of handles -
Jamison tool - or one of those swiveling V block rests to get you a broad
support rather than a narrow fulcrum.

"Arch" wrote in message
...
I plan to make some inserted bit hollowing tools with arm braces. Two
45deg. 1/2 in pipe couplings and a 6 in nipple for the 'Z' and a 10 in
nipple padded with tape for its tail. I use 3/4 CR bar pipe-threaded for
the 1/2 in coupling at one end and drilled for a bit and tapped for a
setscrew at the other end. Ugly? Yep.

BIG SNIP.

This post reminds me Kevin, isn't it time for annual nominations to the
Order of COC? Maybe if we would have them, no one would want to join.

====Arch! All ya gotta do the figure the breaking moment of your forearm
or the amount of force required to put your shoulder out of joint. Then
dial in just a bit less than that in a torque wrench and weld that into your
Goldbergian arm brace!

As to folks not wanting to join the COC? Since when did "wanting" have
anything to do with it? COCs are to the manor born and are appointed and in
certain cases elected. I'll start the ball rolling, I nominate you for an
additional term! I would rather have you appointed COC-for-life, but there
may be others who are better qualified! As to a newbie COC, might I, with
some tremulousness, nominate George. I detect the fine quality of
COCishness from some of his posts!*G*

Leif

Arch, there is a certain amount of danger in using the arm brace in a
deep piece. I have a Stewart tool with a lot of mileage on it. The
standard "hooker" is 14 inches. Dennis also sells one that's 21 inches,
and I have one. If you get a catch when you're working 16 inches or
more off the tool rest it can be a dandy. Very arm-wrenching! I speak
from experience.

Perhaps a captive tool such as the Jamieson is the answer for some
people. There are other makes on the market. I have one made by John
Nichols. I feel a lot more secure when working inside a deep piece with
that than with the Stewart.

Wally

(Arch) wrote:

What are the real advantages and potential dangers, _IF ANY, of bracing
a long heavy tool that's hidden inside a hollow form, against your
partially captured forearm? Maybe "partially" is the catchword or is
the risk of fracture just another myth?



Arch, I imagine you remember starting a car with a hand crank. I've started
a car with a hand crank and started an airplane by hand spinning the prop.
In both instances I figured I could fracture an arm, or worse, if my
attention wandered for an instant. Starting the car or plane was not
optional. When I look at the arm brace tool holder, I see something waiting
to eat my arm. And it's optional.

Just my tuppence ha'penny.

Arch,

Hollow tool control is all about two things:

1 - Leverage over the tool that is suspended over the tool rest.
2 - Control of rotation forces due to off-center cutting tips.

I have always heard and subscribe to the rule that for every inch of
tool hanging over the rest, you need five inches behind it. As Wally
mentioned, the Stewart 21" tool is dangerous because you can end up
with almost a 1 to 1 ratio. In the scheme of things, its the cup at
the end of the armbrace that gives you the extra 10" or so of leverage.
Without a good cup, you have given away what little leverage you have.
If you are afraid of injury, scrap the armbrace idea and use a long
handle where you can grip it way back.

The armbrace does seem to give better than average control of the
rotational forces as compared to other noncaptured systems. I
personally have two armbraces and they get used on my largest hollows.
But my favorite hollowing tool is a captured system that removes the
human leverage and torque problem all together. It allows me to focus
on tip control which is what the turning is all about anyway. My
system is good for medium size vessels.

If I may make an unofficial COC statement: why are turners so willing
to drop five grand on a Oneway or a Stubby, but so easily screw around
for hours with plumbing parts to save $50? Arch, Buy the d-mn
armbrace, get in the shop and turn! :-)

Joe FLeming - San Diego

Joe
It takes me about 15 minutes to make an arm brace and two hours to drive to
and back from the nearest store that sells one. Make the darn thing and get
on with turning I say. Besides, making tools is fun.

--
God bless and safe turning
Darrell Feltmate
Truro, NS Canada
www.aroundthewoods.com

Arch
I like the cup on the arm of each of my arm braces. I also like having a 90
degree turn to the handle instead of using a pair of 45's but to each his
own. That is part of the fun of "roll your own" tools.

--
God bless and safe turning
Darrell Feltmate
Truro, NS Canada
www.aroundthewoods.com

Thanks to each for your good responses..

Leo, seems like a practical solution to me. Certainly no more silly than
the first vacuum chuck. I fear shear pins more than armrests because
I've been caught up the creek too many times without a paddle ...or a
shear pin for my outboard motor.

George, I did try adding a T coupling and short nipples to make a wing
to slide on the tool rest, but the contraption was too bulky even for
me. What me weld a nice neat wing to a shaft or heaven forbid, buy one?
Anyway, neatness isn't the same as craftsmanship.

Leif, I thought about your torque wrench, good idea. I am trying to
figure how tight to screw the shaft to the handle so it will slip just
before my ulna breaks. Maybe a loose setscrew for a turner wih a screw
loose. Do you have a formula?

Wally, Stewart and Nichols indeed! We have come a long way since those
1/4 hp sleeve bearings Sears Roebuck Dunlaps.

Lobby, Yeah and those happy days when self starters arrived and we don't
mean aggressive yuppies. Slainte.

Joe, Your usual good summation, but you won't make COC at this rate.
Saving fifty bucks by spending hours is a compliment. More to the point
is my saving fifty cents by wasting days. As with turning a nice bowl,
there is a pleasure in making and using a good tool.

Darrell, I thought the 45s made the tool look sporty & streamlined.
I did use 90deg for a pistol grip, I also inserted a T fitting and 4in
nipple for a 90deg up-handle.


Turn to Safety, Arch
Fortiter



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

Leif Thorvaldson wrote:

====Arch! All ya gotta do the figure the breaking moment of your forearm
or the amount of force required to put your shoulder out of joint. Then
dial in just a bit less than that in a torque wrench and weld that into your
Goldbergian arm brace!

Just do like I do and don't get catches! g


As to folks not wanting to join the COC? Since when did "wanting" have
anything to do with it? COCs are to the manor born and are appointed and in
certain cases elected. I'll start the ball rolling, I nominate you for an
additional term! I would rather have you appointed COC-for-life, but there

Well, Arch was promoted to COC first class some time back, so I guess we
outta maintain his good standing.

may be others who are better qualified! As to a newbie COC, might I, with
some tremulousness, nominate George. I detect the fine quality of
COCishness from some of his posts!*G*

Hmmm. OK, as long as I don't have to always agree with him. Hrmph.
Whatcha say Arch, we gonna vote him in? Lyn gets a vote too of course,
if he's got the radar on...

....Kevin
--
Kevin Miller
http://www.alaska.net/~atftb
Juneau, Alaska
Registered Linux User No: 307357

Chief, if Lyn doesn't jump in and veto the
nomination, I'll propose George if he will use restraint with his "feel
good" essays about his doings down home in 'uppa u s' that we all can
relate to and enjoy. Bah!

Robert, Leif & Lobby can also get a little crotchety from time to time.
Hate for them to wait another year to be inducted, but may be too many
rookies at once, tho as someone said "dilution is the solution to
pollution! COC, 1st class


Turn to Safety, Arch
Fortiter



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

(Arch) wrote:

Chief, if Lyn doesn't jump in and veto the
nomination, I'll propose George if he will use restraint with his "feel
good" essays about his doings down home in 'uppa u s' that we all can
relate to and enjoy. Bah!

Robert, Leif & Lobby can also get a little crotchety from time to time.

I do try to restrain myself here. Really.

Hate for them to wait another year to be inducted, but may be too many
rookies at once, tho as someone said "dilution is the solution to
pollution! COC, 1st class


Turn to Safety, Arch
Fortiter



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

On Fri, 16 Dec 2005 17:36:03 -0900, Kevin Miller
wrote:


As to a newbie COC, might I, with
some tremulousness, nominate George. I detect the fine quality of
COCishness from some of his posts!*G*

Ya THINK??!! (Better be careful or I'll wind up getting nominated my
own self.)

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


September 11, 2001 - Never Forget

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I use armbraces extensively, many hollow forms per week. When I see
discussions like this I am reminded that they are possibly the most
misunderstood tool in the woodturning universe. You *CANNOT* reach far
over the toolrest with those things. With the standard Stewart setup, 8"
deep is about maximum for my comfort level, and I'm good at it. I have a
15" extension that I add which gives me around 33" in front of the handle,
and with all that I figure 12" deep is pushing the limits. When I saw
Clay Foster demonstrate a 30" deep hollow form, he had a bar about 10
feet long that was HEAVY. It gives you an idea of what is really needed
to counterbalance the forces working against you. Use the Stewart tool
within it's limits and it's a wonderful tool. Try to do something you
shouldn't, and you get in trouble.

Kevin's remark about just don't get a catch is not merely a wisecrack,
despite his well deserved reputation for wisecracks, it's for real.
Scraper tip hollowing tools realistically should absolutely never get
catches. All you have to do is keep the tip above center. Then the
rotation of the piece is trying to force the tool away from the wood, not
into the wood which is where catches come from and what can happen when
the tip is below center. This assumes you have drilled a center hole,
make your cuts from the center outward, and don't jam the tip into the end
grain. When sweeping across the bottom, you have to keep the tip below
center, of course.

Arch, post a picture of your plumber brace when you get a working model
you like, I'd love to see it. best wishes,

-mike paulson, fort collins, co