The Turning Dilema - RPMs vs Risk (semi-long)

I come to turning from The World of Norm (other heroes - Krenov, Maloof
and Nakashima). I can adequately use handtools - chisels, dovetail
saws, hand planes, cabinet scrapers, some carving gouges, and can set up
and safely use a joiner, planer, table saw, shaper, SCMS, router - in or
out of a table, drill press, drum sander, OSS. Mortising machine etc. .
I’ve got feather boards, hold downs, blade guards and push sticks - and
use them. I can put a good edge on just about anything flat backed with
a flat bevel - using a Tormek, diamond plates or japanese water stones -
with or without a jig. And I can read grain adequately - on flat stock.

In The World of Norm, I can mechanically limit the degrees of freedom of
movement of both the tool and the stock. With turning, at least the
center/ spindle turning I’ve been playing with (for me, if it’s fun it’s
playing), it’s the very dynamic brain/ eye / hand coordination that
concerns me. Initiating a “cut” properly and completing it properly is
requiring far more concentration, coordination and, frankly, stress than
it probably should. And RPMs seems to be one of the major causes of my
low to moderate anxiety.

In The World of Norm, the RPMs of the thing biting off pieces of wood is
typically fixed - the more teeth chewing, the smaller each bite is. The
slower you feed the stock to the teeth the smaller each bite is. It’s
Biting Off More Than You Can Chew which raises all the hell - and
launches things - at what seems to be at least Mach 3.

In The World of Turning, you’ve got but a single “tooth” - the chisel,
gouge or scraper, tool angle, feed rate and RPMs determine the “bite”
size. AND, in The World of Turning, unlike in The World of Norm, the
“tooth” can follow the grain of the wood - and if it does all hell can
break loose.

And that leads to my dilema. At 500 RPMS, things happen 1/3rd slower
than at 1200 RPMs - eight “bites” per second vs 20 “bites” per second.
I “know” that my reaction time is greater than a half a second so when a
catch happens, it really doesn’t make much difference whether it happens
in 1/10th of a second or 5/100ths of a second - it’s happened before I
can possibly react.

Now the Mr. Spock part of my brain says “More bites per second, the
smaller each bite, and, logically, that’s safer.”. But my white
knuckles, clenched teeth - and sometimes “cheeks”, are telling me -
“SCREW LOGIC - SLOW IT DOWN!”.

So my questions a
1. Recomended roughing to round with a 1/2” or 3/4”
roughing gouge RPMS, given the following:
- starting with up to 1 1/2” square stock
- 10 to 14 inches between centers and stock
“approximately” centered
2. Recomended RPMS for spindle turning a 1 inch
cylinder 10 - 14 inches long.
3. When you’re turning parts down to pretty small
diameters, do you want to work at higher RPMS
or lower?
4. Is “best RPMs” a function of the type of wood?
I know that pine crushes rather than cuts when
using bench chisels while maple, cherry, walnut
and, my favorite, mahogany cut nice and clean.

So much to learn, so many mistakes to try and avoid.

(Turned some year old prunings from a plumb tree.
Nice stuff - and FREE! Fun, this turning thing)

charlie b
aka The Rotationiste in training

"charlie b" wrote in message
...
The Turning Dilema - RPMs vs Risk (semi-long)




But my white
knuckles, clenched teeth - and sometimes "cheeks", are telling me -
"SCREW LOGIC - SLOW IT DOWN!".

They're right. It's not so much the number of bites as it is Newton.
Remember MV(squared)?

I try to keep at pucker factor six, maximum.

So my questions a
1. Recomended roughing to round with a 1/2" or 3/4"
roughing gouge RPMS, given the following:
- starting with up to 1 1/2" square stock
- 10 to 14 inches between centers and stock
"approximately" centered

500 is good, no more than a thousand.

2. Recomended RPMS for spindle turning a 1 inch
cylinder 10 - 14 inches long.

Same-o

3. When you're turning parts down to pretty small
diameters, do you want to work at higher RPMS
or lower?

You want to keep a light touch with a sharp tool. Speed? Same-o

4. Is "best RPMs" a function of the type of wood?
I know that pine crushes rather than cuts when
using bench chisels while maple, cherry, walnut
and, my favorite, mahogany cut nice and clean.


Best rpms are the ones you feel comfortable with. Favor lower, because the
odd chunk that may unexpectedly depart will leave with less available energy
to bust your chops.

So much to learn, so many mistakes to try and avoid.

How about some "rules?"

First rule is to avoid anything thrown by the lathe. Don't stand in harm's
way at startup, listen and watch for signs that anything's working loose.
Keep your on/off switch near the tail of the lathe where you won't have to
reach through the zone, either.

Second rule is never give away leverage. Keep the toolrest close. It gives
you greater mechanical advantage, serves as an iron barrier between you and
the work.

Third rule is to be methodical - always A-B-C.

Anchor the tool to the rest. Turning is about rotating things against a
fixed tool to make them round, after all.

Bevel to the wood. Lay it right down , then English your way into the cut,
letting the bevel guide on the space it's made for itself after it begins.

Cut for the curl. Your shavings should be curls, preferably continuous
twisted curls, and they should fall, not fly.

Before you reach to turn off the lathe, disengage the tool from the cut,
lift the bevel, then remove it from the rest. Willing to bet 75% of catches
and curses happen because of inattention, not during the cutting, but the
(inadequate) clearing.

In article , "George" George@least
wrote:

How about some "rules?"

First rule is to avoid anything thrown by the lathe. Don't stand in harm's
way at startup, listen and watch for signs that anything's working loose.
Keep your on/off switch near the tail of the lathe where you won't have to
reach through the zone, either.

And wear a full face shield rated for impact protection...with a hard
hat if you like. Things don't always jump the way you think they will. A
faceful of wood that's traveling away from the lathe is a bad, painful,
and often expensive thing. A faceshield can be had for $10 and up.
Cheaper to buy it before the first time, rather than before the second
time.

Cranking up the speed is a crutch, and mostly a modern-era crutch.
Doubly so if you're not doing production turning where 5 minutes more
time will impact your income in a bad way. Some expert has claimed
(IIRC) that you need never turn above 1000 RPM (or was it 300?). I'd
certainly rather have a lathe that went from 100 to 1000 than 500 to
5000.

You must control the tool - despite the motor, turning is still
essentially a hand-tool activity, and requires user control of the tool
(unless you're using a spindle-copying jig, and thats not really
turning, IMHO.) Practice on firewood for a while - cheap, guilt-free if
it gets damaged beyond reclaiming, and gives you experience.

--
Cats, coffee, chocolate...vices to live by

I like it slow.

I'm turning bowls and plates, and I start at 450, and final cut at 950 rpm.
That's it. I do get a smoother cut at the higher speed, so I shift to it
after the piece is round and all the corners are gone.

I've done less spindle turning, but it has been very satisfactory at the low
end of the range.

I figure the less speed, the less momentum, the smaller the bruise when it
hits me.

I do speed things up to 1500 rpm when I polish the wax. I had a 12"
laminated plate (old butcher block counter) delaminate on me at that speed.
The knot on my arm is still there after two weeks.

It's not the bite you are taking that causes the problem, it's the bit that
the chisel takes when it develops a mind of its own.

I don't like to do white knuckle turning. If I'm putting finger prints into
the tool handle, I stop and do a dry run to see where the tool edge is. If
I get tense, I catch.

It's a wonderful sport.

Walt C






"charlie b" wrote in message
...
The Turning Dilema - RPMs vs Risk (semi-long)

I come to turning from The World of Norm (other heroes - Krenov, Maloof
and Nakashima). I can adequately use handtools - chisels, dovetail
saws, hand planes, cabinet scrapers, some carving gouges, and can set up
and safely use a joiner, planer, table saw, shaper, SCMS, router - in or
out of a table, drill press, drum sander, OSS. Mortising machine etc. .
I've got feather boards, hold downs, blade guards and push sticks - and
use them. I can put a good edge on just about anything flat backed with
a flat bevel - using a Tormek, diamond plates or japanese water stones -
with or without a jig. And I can read grain adequately - on flat stock.

In The World of Norm, I can mechanically limit the degrees of freedom of
movement of both the tool and the stock. With turning, at least the
center/ spindle turning I've been playing with (for me, if it's fun it's
playing), it's the very dynamic brain/ eye / hand coordination that
concerns me. Initiating a "cut" properly and completing it properly is
requiring far more concentration, coordination and, frankly, stress than
it probably should. And RPMs seems to be one of the major causes of my
low to moderate anxiety.

In The World of Norm, the RPMs of the thing biting off pieces of wood is
typically fixed - the more teeth chewing, the smaller each bite is. The
slower you feed the stock to the teeth the smaller each bite is. It's
Biting Off More Than You Can Chew which raises all the hell - and
launches things - at what seems to be at least Mach 3.

In The World of Turning, you've got but a single "tooth" - the chisel,
gouge or scraper, tool angle, feed rate and RPMs determine the "bite"
size. AND, in The World of Turning, unlike in The World of Norm, the
"tooth" can follow the grain of the wood - and if it does all hell can
break loose.

And that leads to my dilema. At 500 RPMS, things happen 1/3rd slower
than at 1200 RPMs - eight "bites" per second vs 20 "bites" per second.
I "know" that my reaction time is greater than a half a second so when a
catch happens, it really doesn't make much difference whether it happens
in 1/10th of a second or 5/100ths of a second - it's happened before I
can possibly react.

Now the Mr. Spock part of my brain says "More bites per second, the
smaller each bite, and, logically, that's safer.". But my white
knuckles, clenched teeth - and sometimes "cheeks", are telling me -
"SCREW LOGIC - SLOW IT DOWN!".

So my questions a
1. Recomended roughing to round with a 1/2" or 3/4"
roughing gouge RPMS, given the following:
- starting with up to 1 1/2" square stock
- 10 to 14 inches between centers and stock
"approximately" centered
2. Recomended RPMS for spindle turning a 1 inch
cylinder 10 - 14 inches long.
3. When you're turning parts down to pretty small
diameters, do you want to work at higher RPMS
or lower?
4. Is "best RPMs" a function of the type of wood?
I know that pine crushes rather than cuts when
using bench chisels while maple, cherry, walnut
and, my favorite, mahogany cut nice and clean.

So much to learn, so many mistakes to try and avoid.

(Turned some year old prunings from a plumb tree.
Nice stuff - and FREE! Fun, this turning thing)

charlie b
aka The Rotationiste in training

Charlie b wrote: ...snip.... at least the center/ spindle turning ...snip..
Initiating a "cut" properly and completing it properly is requiring far more
concentration, coordination and, frankly, stress than it probably should.
And RPMs seems to be one of the major causes of my low to moderate anxiety."

Hi Charlie,
First, relax. Second, forget RPMs as a number rather hear and feel
speed of the turning wood according to the wood, you and the tool. I
think RPMs should only be for car mechanics.

**Charlie: "In The World of Turning, you've got but a single "tooth" - the
chisel,
gouge or scraper, tool angle, feed rate and RPMs determine the "bite"
size."

No, you have your hand or touch and the cutting edge of the tool; this
remains the same if your RPMs are 10 or 3,000.

**Charlie b: asks rules for:
1. Recomended roughing to round with a 1/2" or 3/4"
roughing gouge RPMS, given the following:
- starting with up to 1 1/2" square stock
- 10 to 14 inches between centers and stock
"approximately" centered

A 3/4" roughing gouge is a little big for a 1 1/2" square stock that is 10 -
14" long.
IF you must have RPMs, I'd use minimum 1,000 with a LIGHT touch. The
lower the speed on spindle turning (especially 12" + length) is going to
cause catches and not be a pleasant experience. If you use a LIGHT wispy
cut until the blank is just about rounded, you won't have chatter or
catches. And unless you're turning thin stemmed flowers, chances are you
are turning spindles and using dry wood so forget the curls because it's all
going to be chips.

** Charlie: "2. Recomended RPMS for spindle turning a 1 inch
cylinder 10 - 14 inches long.
3. When you're turning parts down to pretty small
diameters, do you want to work at higher RPMS
or lower?
4. Is "best RPMs" a function of the type of wood?"

Take some maple, cherry, walnut or, your favorite, mahogany and practice.
Don't practice on pine or punky wood because you'll get frustrated. Try
roughing that 1 1/2" blank with a bowl gouge, any size, see how that feels.
Do not worry about flying projectiles because most spindles will crack and
both sections will fall before they fly.........bowls fly!

Charlie, I've been supporting myself with architectural reproduction work
(aka spindle turning) for over 10 years. I've gotten catches and broken a
lot of very thin spindles. I don't try to beat the clock so I guess I
couldn't be labeled as a production turner.

Some times you have to lower the speed for a nice clean cut, some times you
have to raise the speed for a nice clean cut and some times you just aren't
going to get a nice clean cut (throw that piece of wood away and get a
better one). I rough with a roughing gouge, a skew, a bowl gouge and/or a
detail gouge.

Again, relax and forget the risk vs rpms because the only risk is (as George
said) "inattentiveness". There really are no hard fast rules except BE
CAREFUL; use whatever tool feels and works good for you, use whatever speed
you like or get the best results. Try them all then decide for yourself
what works for you.

Now go have fun.

Ruth
www.torne-lignum.com

charlie b wrote:

snip


(Turned some year old prunings from a plumb tree.

Going to make some plumb bobs, eh?

--
Gerald Ross
Cochran, GA

But I forgot all about the Amnesia
Conference!!





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"Ecnerwal" wrote: (clip) Cheaper to buy it before the first time, rather
than before the second time.(clip)
^^^^^^^^^^^^^^^^

Good way of putting it. I like economy of words, so I won't say more.

Good way of putting it. I like economy of words, so I won't say more.

I second that on ALL the great info and guidance. I especially like
the advice on using the tools you are comfortable with at speeds you
like.

I recently gave a demo on turning 1" to 2" mushrooms on multiaxis so I
could make the stem lean over and look a little dimensioned, not round.


After I turn the cap, I use only my diamond point parting tool for
hollowing the cap, turning the multi-axis stem, and them the base. I
have a finished mushroom in 10 minutes that requires very little
sanding.

No one could get past me using the parting chisel so extensively.
Making a mushroom I use the tool as a skew, a scraper, and a detail
gouge. Not a single person in my club will even try it...

I took a class years ago from a guy that told me that he just ground
his tools the way they seem to work best for him, and never worried
about the "right tool" or the "right grind".

I have been on that track ever since. You should see what I have done
to my poor 3/8" bowl gouge...

But I am at the point where I can turn my lamp pulls, mushrooms, candle
bases etc. all day long and actually use about 4 tools all day long.

The only thing I would add that is hidden in some of these postings is
to practice, practice, practice. Learn the most popular grinds, then
modify to suit yourself. The best thing I would say on top of all
the good stuff you have gotten is to join a woodturning club. Most of
the guys there in any of the clubs I have visited are great about
showing technique. A modification in stance, a small angle change in
how you hold a tool, and sometimes just finding out what the tools do
is a tremedous leg up.

Good luck!

Post your questions here... there are some great folks that are pretty
generous with their time to teach.

Say like... Ruth for example.

Robert

When I started seriously thinking about getting into woodworking
I found rec.woodworking. Got a lot of good advice, direction and
help from a lot of knowledgable, talented people. Now, when
I can I try to follow their example and lend a helping hand
when I can.

This group is a lot calmer AND just as helpful. I think I'm
gonna like hanging out here as well. Thanks - much
appreciated. Hope I can be an beneficial addition to the group.

charlie b

(I took the midi lathe off my bench and semi-put it away
for a while. Had to do that so I wouldn't try turning
toothpicks. This turning thing is really addictive - and
a lot less expensive than what it costs to build solid wood
furniture and the like. Have a To Do List I have to get
back to - utility shelves, a big gate with arched top and panels,
a table to glue up, a cabinet for younger son's LPs (he's
a retro throw back) a door and drawer faces to put on
to finish my sharpening station cabinet AND the coopered
door mini-cabinet for router bits. Play time's over
for now - back to "work")

In article ,
charlie b wrote:

3. When you’re turning parts down to pretty small
diameters, do you want to work at higher RPMS
or lower?
4. Is “best RPMs” a function of the type of wood?
I know that pine crushes rather than cuts when
using bench chisels while maple, cherry, walnut
and, my favorite, mahogany cut nice and clean.

Hello Rotationista,

I'll echo what Ruth said about relaxing. Catches happen - it's a part of
the risk of creating work in which the person is in complete,
unrestricted control of the cutting edge. People are fallible when
presenting a sharp edge to spinning wood. But if you're tense and stiff
the outcome could be injurious or at the least unsettling to your
confidence. A moderately light touch is all that's required.

Think about feeding a board across a jointer or into a table saw. Being
tense and pushing against the machine's ability to cut is bound to lead
to an "event" or an injury. When you push against the cut you'll be off
balance if something at the point of the cut changes - leading to a
potentially nasty situation.

A similar understanding is in order for woodturning. Allow the legs,
shoulders, arms and fingers to control the rate of cut as well as the
direction. (As Ellsworth recommends in one of his videos, let the large
muscles do the majority of the work and let the small muscles put in the
delicate work.) Take light cuts. No, lighter than that. Allow the edge
of the tool to do the work. If you do happen to present the edge
incorrectly and get a catch your balance won't be affected and the tool
isn't in a death grip which will worsen the catch. A moderately light
touch allows you to pull back more quickly and there's no body weight in
the cut that you've got to reverse direction and pull back.

My personal preference for lathe speed is either 1250 or 1800 rpm - and
85% of the time it's 1800. I turn a fair number of spindles and start
out there. The only time I turn more slowly is when I have an unbalanced
piece and the only times I turn faster is when polishing. I generally
turn my bowls at 1800 and the alabaster rock I've been trying out lately
goes at 1250.

After 4 years of turning a lot of wood, I still get catches. But they
haven't been disastrous for about 3.5 years now - they're usually just a
spiral gouge that screws up a bead on my last finessing pass. Ain't that
always the way?

--
Owen Lowe

Northwest Woodturners,
Cascade Woodturners,
Pacific Northwest Woodturning Guild
___
Safety Tip'o'th'week: Never grind aluminum and steel or iron on the same
machine or workstation - Thermite.
http://www.hanford.gov/lessons/sitell/ll01/2001-36.htm

Owen wrote: ....snip.....
After 4 years of turning a lot of wood, I still get catches. But they
haven't been disastrous for about 3.5 years now - they're usually just a
spiral gouge that screws up a bead on my last finessing pass. Ain't that
always the way?


Why is that, Owen?!? And that "last finessing pass" could easily be done
with the 120 grit tool. : ) Have you ever had a really cool spiral
gouge and wish you could intentionally reproduce it?

Ruth
www.torne-lignum.com
"CLTL"

Gerald Ross wrote:
charlie b wrote:
=20
snip
=20
=20
(Turned some year old prunings from a plumb tree.
=20
=20
Going to make some plumb bobs, eh?
=20


I think he was giving it to us straight up - no juicy stuff here --=20
course it will pass.


--=20
Will R.
Jewel Boxes and Wood Art
http://woodwork.pmccl.com
The power of accurate observation is commonly called cynicism by those=20
who have not got it.=94 George Bernard Shaw

On Wed, 17 Aug 2005 18:19:02 -0400, "George" George@least wrote:

snip
Before you reach to turn off the lathe, disengage the tool from the cut,
lift the bevel, then remove it from the rest. Willing to bet 75% of catches
and curses happen because of inattention, not during the cutting, but the
(inadequate) clearing.

So damn true.... It's just SO easy to catch the edge of a goblet or the side of
a bowl when you think the cut is "over" but haven't got the chisel out of reach
of the wood...

I hate when that happens.. one of those things that make you feel really dumb
when you do it, because you "know better"..


mac

Please remove splinters before emailing

One question that always comes up at demos that I (or anyone else does)
is "At what speed are you turning?" On my lathe, the speed knob fell
off, and just won't stay on any more, plus the readout is on the back
side of the lathe (PM3520). I always say to turn at what ever speed you
feel comfortable with. Rough bowl blanks, turn the lathe up until it
starts to wobble and vibrate, then back it off until it is smooth. I
turn all bowls on the lower speed range, so small ones will finish turn
at 1750. When I started, I didn't turn over 500. With spindles, it is
the same way. I turn out a number of basting brushes. When starting, I
would turn in the 500 range also. Now 3000 seems slow. Adjust speeds to
your comfort level. Start slow and work your way up.
robo hippy

On Wed, 17 Aug 2005 23:19:39 GMT, Ecnerwal
wrote:


Cranking up the speed is a crutch, and mostly a modern-era crutch.
Doubly so if you're not doing production turning where 5 minutes more
time will impact your income in a bad way. Some expert has claimed
(IIRC) that you need never turn above 1000 RPM (or was it 300?). I'd
certainly rather have a lathe that went from 100 to 1000 than 500 to
5000.

I think speed is a relative thing.. I've turned small goblets (3/4" - 1 1/2"
diameter) at 850 or 1,100... but when I'm roughing a 12 inch bowl, I wish the
Min. speed of my lathe was a lot less than 450....

I've considered changing the pulleys, since it (jet 1442) has 8 speeds and I've
never used anything over the 4th speed... I can't imagine turning ANYTHING at
3,000 rpm..



mac

Please remove splinters before emailing

On Wed, 17 Aug 2005 22:50:11 -0700, charlie b wrote:

When I started seriously thinking about getting into woodworking
I found rec.woodworking. Got a lot of good advice, direction and
help from a lot of knowledgable, talented people. Now, when
I can I try to follow their example and lend a helping hand
when I can.

This group is a lot calmer AND just as helpful. I think I'm
gonna like hanging out here as well. Thanks - much
appreciated. Hope I can be an beneficial addition to the group.

charlie b

(I took the midi lathe off my bench and semi-put it away
for a while. Had to do that so I wouldn't try turning
toothpicks. This turning thing is really addictive - and
a lot less expensive than what it costs to build solid wood
furniture and the like. Have a To Do List I have to get
back to - utility shelves, a big gate with arched top and panels,
a table to glue up, a cabinet for younger son's LPs (he's
a retro throw back) a door and drawer faces to put on
to finish my sharpening station cabinet AND the coopered
door mini-cabinet for router bits. Play time's over
for now - back to "work")

Charlie... while you're doing your flat work, add another item to your list...
design a stand for your midi and get it off the bench..

With your design and woodworking talents, you could make a very functional stand
that would probably include tool holders, shaving catcher, wheels, etc., etc...



mac

Please remove splinters before emailing

On Wed, 17 Aug 2005 23:25:58 -0700, Owen Lowe wrote:

hmm... Owen has got me thinking, which is a GOOD thing.. *g*

I used to be constantly worried about things launched off the lathe... and
thinking back on the 15 or 20 times (at least) that this has happened, none has
done much more than drop and roll...

OTOH, most of the tools that I use for flat work have me worried about kick
back, which IMO is worse than a bowl falling off the lathe..


Hello Rotationista,

I'll echo what Ruth said about relaxing. Catches happen - it's a part of
the risk of creating work in which the person is in complete,
unrestricted control of the cutting edge. People are fallible when
presenting a sharp edge to spinning wood. But if you're tense and stiff
the outcome could be injurious or at the least unsettling to your
confidence. A moderately light touch is all that's required.

Think about feeding a board across a jointer or into a table saw. Being
tense and pushing against the machine's ability to cut is bound to lead
to an "event" or an injury. When you push against the cut you'll be off
balance if something at the point of the cut changes - leading to a
potentially nasty situation.

A similar understanding is in order for woodturning. Allow the legs,
shoulders, arms and fingers to control the rate of cut as well as the
direction. (As Ellsworth recommends in one of his videos, let the large
muscles do the majority of the work and let the small muscles put in the
delicate work.) Take light cuts. No, lighter than that. Allow the edge
of the tool to do the work. If you do happen to present the edge
incorrectly and get a catch your balance won't be affected and the tool
isn't in a death grip which will worsen the catch. A moderately light
touch allows you to pull back more quickly and there's no body weight in
the cut that you've got to reverse direction and pull back.

My personal preference for lathe speed is either 1250 or 1800 rpm - and
85% of the time it's 1800. I turn a fair number of spindles and start
out there. The only time I turn more slowly is when I have an unbalanced
piece and the only times I turn faster is when polishing. I generally
turn my bowls at 1800 and the alabaster rock I've been trying out lately
goes at 1250.

After 4 years of turning a lot of wood, I still get catches. But they
haven't been disastrous for about 3.5 years now - they're usually just a
spiral gouge that screws up a bead on my last finessing pass. Ain't that
always the way?



mac

Please remove splinters before emailing

"charlie b" wrote in message
...

Now the Mr. Spock part of my brain says "More bites per second, the
smaller each bite, and, logically, that's safer.". But my white
knuckles, clenched teeth - and sometimes "cheeks", are telling me -
"SCREW LOGIC - SLOW IT DOWN!".


In my opinion, you are going at the problem from the wrong side.

Of course the higher speeds should be used only when you feel safe
(and I mean _safe_) to use them.

Your problem is not the speed (was it Ralph Nader who coined the
phrase "Unsafe at any speed"?) but the danger of getting a catch.

The cure is not in choosing a slower speed, which only leads to
"slower" catches, but learning to present the different tools to
the piece in a safe, non-catching manner.

There _are_ ways and means, you know, as soon as you
find yourself a qualified instructor.

In sports, they say that He who coaches himself has a fool for a trainee.

This is doubly true in woodturning, since the tools of the trade
are much sharper than most sportinggear.

Bjarte

In article .com,
"robo hippy" wrote:

I always say to turn at what ever speed you
feel comfortable with. Rough bowl blanks, turn the lathe up until it
starts to wobble and vibrate, then back it off until it is smooth. I
turn all bowls on the lower speed range, so small ones will finish turn
at 1750. When I started, I didn't turn over 500. With spindles, it is
the same way. I turn out a number of basting brushes. When starting, I
would turn in the 500 range also. Now 3000 seems slow. Adjust speeds to
your comfort level. Start slow and work your way up.

Have you ever seen Jimmy Clewes demonstrate? He cranks the speed up to
max and leaves it there. Quite a few in the front row of the group made
nervous chuckles and shrank in their seats a tad but I'm sure Clewes
wouldn't do it if he had any doubts.

He commented something on the lines that higher speeds make a smoother
and more controlled cutting action - if I remember right.

--
Owen Lowe

Northwest Woodturners,
Cascade Woodturners,
Pacific Northwest Woodturning Guild
___
Safety Tip'o'th'week: Never grind aluminum and steel or iron on the same
machine or workstation - Thermite.
http://www.hanford.gov/lessons/sitell/ll01/2001-36.htm

"Owen Lowe" wrote in message
news
He commented something on the lines that higher speeds make a smoother
and more controlled cutting action - if I remember right.

Wonder how he explains the cut you get with a carving tool at considerably
below 5 fpm?

George wrote:

Best rpms are the ones you feel comfortable with. Favor lower, because the
odd chunk that may unexpectedly depart will leave with less available energy
to bust your chops.


I think it was John Jordan that said "If you think a piece is turning fast,
then it is too fast!"

Because of reaction time, faster can be better - less time for you to drive
your tool into a position to cause a catastrophic catch. But keep your
turning to a comfortable speed - that speed will go up over time as you gain
more confidence.


How about some "rules?"

First rule is to avoid anything thrown by the lathe. Don't stand in harm's
way at startup, listen and watch for signs that anything's working loose.
Keep your on/off switch near the tail of the lathe where you won't have to
reach through the zone, either.

Second rule is never give away leverage. Keep the toolrest close. It gives
you greater mechanical advantage, serves as an iron barrier between you and
the work.

Third rule is to be methodical - always A-B-C.

Anchor the tool to the rest. Turning is about rotating things against a
fixed tool to make them round, after all.

Bevel to the wood. Lay it right down , then English your way into the cut,
letting the bevel guide on the space it's made for itself after it begins.

Cut for the curl. Your shavings should be curls, preferably continuous
twisted curls, and they should fall, not fly.

Before you reach to turn off the lathe, disengage the tool from the cut,
lift the bevel, then remove it from the rest. Willing to bet 75% of catches
and curses happen because of inattention, not during the cutting, but the
(inadequate) clearing.


Corollary to the last, before you turn on the lathe, get the tool away from
the work, then approach the tool rest FIRST, then the turning wood.

Owen Lowe wrote:
He commented something on the lines that higher speeds make a smoother
and more controlled cutting action - if I remember right.

For roughing down a spindle (turning it from a square section to a
cylinder) the higher speed makes it easier for the weight of your body
to overcome the percussive effect the corners of the wood have as they
slam into the cutting edge.

The limiting factor of course is the speed the lathe will turn the
workpiece without vibration. A sharp tool, properly presented, will
reduce the force on the tool.

Confidence too is important. You need to be confident the work piece is
securely mounted and isn't going to come flying off. Beginners can
sometimes benefit from adjusting the drive belt so it will slip if they
have a catch; or use a Stebcenter to drive the workpiece. Start with
light cuts; when you approach the wood with the roughing gouge let the
heel of the bevel touch the wood first, then carfully raise the handle
until the cutting edge starts cutting, then make your cut along the
length of wood.

CharlieB made a very astute observation:
"In The World of Norm, I can mechanically limit the degrees of freedom
of movement of both the tool and the stock. With turning, at least the
center/ spindle turning I’ve been playing with (for me, if it’s fun it’s
playing), it’s the very dynamic brain/ eye / hand coordination that
concerns me. Initiating a “cut” properly and completing it properly is
requiring far more concentration, coordination and, frankly, stress than
it probably should."

Yes, woodturning with unrestrained hand-held tools is very much a manual
skill. It starts with where you place your feet and ends with how you
manipulate and control the tool, getting feedback from touch, eyes and
ears. Just like an athlete has to train their body parts to work
together, so does a woodturner.


--
Derek Andrews, woodturner

http://www.seafoamwoodturning.com
http://chipshop.blogspot.com
http://groups.yahoo.com/group/toolrest/

Pounding the pulpit in ,
charlie b did expound thusly:

In The World of Turning, you've got but a single "tooth" - the chisel,
gouge or scraper, tool angle, feed rate and RPMs determine the "bite"
size. AND, in The World of Turning, unlike in The World of Norm, the
"tooth" can follow the grain of the wood - and if it does all hell can
break loose.

And that leads to my dilema. At 500 RPMS, things happen 1/3rd slower
than at 1200 RPMs - eight "bites" per second vs 20 "bites" per second.
I "know" that my reaction time is greater than a half a second so when a
catch happens, it really doesn't make much difference whether it happens
in 1/10th of a second or 5/100ths of a second - it's happened before I
can possibly react.

Here's where your Mr. Spock part must be otherwise occupied. Do Vulcan's
take smoko's?

In the World Of Norm, if you take too big a bite you risk biting the hand
that... so naturally you slow down the feed rate.

In the World of Turning it's exactly the same, except you've only got one
tooth and it's not moving. It's not making *any* bites per second; you
could say it's making one continuous bite. At low RPM your feeding less
feet per minute to that single tooth than you would at high at high RPM. If
it's biting the hand, slow down the feed rate by dropping the RPM!

Now the Mr. Spock part of my brain says "More bites per second, the
smaller each bite, and, logically, that's safer.". But my white
knuckles, clenched teeth - and sometimes "cheeks", are telling me -
"SCREW LOGIC - SLOW IT DOWN!".

No, what's really happening is the Mr Spock part has shown he really does
have a human side and logic based on faulty premises is dangerous to your
enterprise while Scottie, down in the bowels of the ship, is screaming "She
cannae take much more ae this! Get a new Science Officer!"

--
- Andy
----------------------------------------------------------------------
No tools are lost by lending, except those you wanted to keep.

Do you mean PLUM ? ? ?


"WillR" wrote in message
. ..
Gerald Ross wrote:
charlie b wrote:

snip


(Turned some year old prunings from a plumb tree.


Going to make some plumb bobs, eh?



I think he was giving it to us straight up - no juicy stuff here --
course it will pass.


--
Will R.
Jewel Boxes and Wood Art
http://woodwork.pmccl.com
The power of accurate observation is commonly called cynicism by those
who have not got it.” George Bernard Shaw

In article ,
"Ruth Niles" wrote:

After 4 years of turning a lot of wood, I still get catches. But they
haven't been disastrous for about 3.5 years now - they're usually just a
spiral gouge that screws up a bead on my last finessing pass. Ain't that
always the way?


Why is that, Owen?!? And that "last finessing pass" could easily be done
with the 120 grit tool. : ) Have you ever had a really cool spiral
gouge and wish you could intentionally reproduce it?

120 tool - haven't got one. My coarsest tool is 220.

I have tried to get the spiral intentionally, but with a 500 RPM lowest
speed it's a toughie.

--
Owen Lowe

Northwest Woodturners,
Cascade Woodturners,
Pacific Northwest Woodturning Guild
___
Safety Tip'o'th'week: Never grind aluminum and steel or iron on the same
machine or workstation - Thermite.
http://www.hanford.gov/lessons/sitell/ll01/2001-36.htm

On Sat, 20 Aug 2005 19:32:57 -0500, "Barry N. Turner"
wrote:

maybe it was a very straight tree?

Do you mean PLUM ? ? ?


"WillR" wrote in message
...
Gerald Ross wrote:
charlie b wrote:

snip


(Turned some year old prunings from a plumb tree.


Going to make some plumb bobs, eh?



I think he was giving it to us straight up - no juicy stuff here --
course it will pass.



mac

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