No, not about a balancing act to curb influential turners. I'm wondering
about harmonic balancing for my over stressed Nova 3000. The poor thing
is all shook up trying to rotate some heavy rough NIP logs. I've
lessened its agony as much as I can with low speed, a strong heavily
weighted bench, secure tail support, a well trimmed log and all the
usual therapies _including gentle cuts with a sharp spindle roughing
gouge. It continues to move and shake.

I know, I know, "give up and treat yourself to a Stubby, Arch", but what
about trying some harmonic balancing first? I mean a rod with an
adjustable weight. You don't hear much about it these days, but I hope
that if some of you have used or considered this way to quiet a
vibrating lathe you will answer some questions and offer suggestions
and/or opinions pro & con.

I thought of bolting a piece of 1" allthread to one of the holes for the
optional outboard toolrest and adding an adjustable barbell weight
between two bolts at the outboard end. Before I mess around with this,
is this contraption likely to work? If you think it might, where do I
attach this abortion? axial? Radial? Headstock? Bed? Bench? Length of
allthread? size of the weight?
How to tune it? Static? Dynamic? So many questions--so little ability.
I need help.


Turn to Safety, Arch
Fortiter



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

"Arch" wrote in message
...
No, not about a balancing act to curb influential turners. I'm wondering
about harmonic balancing for my over stressed Nova 3000. The poor thing
is all shook up trying to rotate some heavy rough NIP logs. I've
lessened its agony as much as I can with low speed, a strong heavily
weighted bench, secure tail support, a well trimmed log and all the
usual therapies _including gentle cuts with a sharp spindle roughing
gouge. It continues to move and shake.

I know, I know, "give up and treat yourself to a Stubby, Arch", but what
about trying some harmonic balancing first? I mean a rod with an
adjustable weight. You don't hear much about it these days, but I hope
that if some of you have used or considered this way to quiet a
vibrating lathe you will answer some questions and offer suggestions
and/or opinions pro & con.

I thought of bolting a piece of 1" allthread to one of the holes for the
optional outboard toolrest and adding an adjustable barbell weight
between two bolts at the outboard end. Before I mess around with this,
is this contraption likely to work? If you think it might, where do I
attach this abortion? axial? Radial? Headstock? Bed? Bench? Length of
allthread? size of the weight?
How to tune it? Static? Dynamic? So many questions--so little ability.
I need help.


Turn to Safety, Arch
Fortiter



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


Arch, back in 1983 I build a copy of Ed Moulthrop's faceplate lathe. It
weighed about 450 lbs., and some of the pieces I turned weighed more than
the lathe. Needless to say, it moved!! I ended up bracing the lathe with
2" diameter aluminum pipe to the rafters of the shop, along with bolting it
to the floor. This still didn't solve the problem, so I made a 15" diameter
3/8" thick steel disc that I mounted on the outboard end of the spindle.
9/16" holes were drilled every 1 1/4" around the perimeter of the disc. I
also collected about 50 lbs of wheel weights and melted them down, then
poured them into aluminum pie pans. They were poured to varying depths, and
peeled right out of the aluminum when cool. Then I bored 9/16" holes in
them with a spade bit in a drill press. To balance a piece, I would loosen
the belt, let the wood settle down, then put a piece of 1/2" all thread rod
into the top hole in the disc. A nut on each side of the disc held the all
thread rod. Then I would simply slide on the lead weights until it was
nearly statically balanced. It made a huge difference in the speed that I
could turn. However, as you turn, the piece of wood becomes more balanced,
and periodically you have to stop and take off some of the weights.

One piece I turned was rotted throughout one side, and I ended up with 40
lbs of weight on the balancing disc. Without the balancing disc, I could
not have turned the piece at all.

This solution is not perfect, but it will enable you to turn really
out-of-balance pieces.

Hope this helps,
James Johnson

Arch wrote:
No, not about a balancing act to curb influential turners. I'm wondering
about harmonic balancing for my over stressed Nova 3000.

Arch, I start my bowls between centers. Before turning on the power I
support the blank loosely between the point of the drive center and the
point of the live center. With just these two points holding the wood,
it is easy to determine the heavy side. I just keep trying different
spots to balance to wood as closely as possible. When that is achieved,
I tighten up the tailstock. This works really well and is something I
learned from David Ellsworth.

If you try this, keep a sharp eye on how tight the wood is held. With a
heavy chunk of wood and the 'thunk-thunk' of getting it round, the drive
center digs into the wood. You need to keep tightening the tailstock.
But on the bright side, the drive center gets you started on hollowing
the blank! )

Harry

If this thread doesn't attract Lyn Mangiameli, then we know something is
really wrong. I believe he was testing a harmonic balancer about the time
he got sick. The attachment point should be at the headstock. All-thread
sounds like a good idea, but be careful--to work effectively, the balancer
has to be tuned to resonance, which means that it will be vibrating A LOT.
The stresses in the metal near the attachment point could get high enough to
crack the steel, and having threads in that area will make things worse
(stress raiser.)

Arch, you should also recognize that this discussion has gone in two
different directions: you asked about harmonic balancing. A number of the
responses have been about static balancing, which is an entirely different
thing. If you can get a piece in balance, that is good, but it is not
always an option. You may want to turn around an axis that does not go
through the center. You may be turning a piece that is non-uniform in
density. That is where harmonic balancing would be called for.

Yes indeed, where are you Lyn? The responses are interesting to me and I
hope for others, whether or not we ever try harmonic balancing.

James' point about about changing the static balancing weights as the
piece changes into round has me scratching my head. Hadn't thought about
that.

Leo's warning about the stresses on the lathe and the device as they
resonate is scary when I realize that I know nothing about the forces
involved. Also I have no idea of the frequency / wave length range and
if there might be standing waves with nodes & nulls along the rod.

Truth be told, I might seem to know what I'm talking about, but I'm way
over my head here and I'm thinking I better follow Harry's and James'
advice and leave harmonic balancing to mind experiments performed in my
arm chair. Even so, I hope to learn more from someone with knowledge and
experience. Remember that not too long ago vacuum chucking for
woodturning seemed foolish and too dangerous to be considered seriously?


Turn to Safety, Arch
Fortiter



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

Hi Arch

I seem to recall a post and picture of someone trying to make a dynamic
balancer.

If I recall right, he had a a pipe bolted to the headstock vertical and
above, there was a weight that could be raised/lowered to find the best
position to lower the "shakes".

I don't recall how successful it was, also I have no idea as to the
forces involved, or if the device could increase the shake/shudder and
make things worse under certain conditions.

I know counter rotating shafts are used to minimize engine vibrations,
but I have more questions than answers on that.

My way of dealing with the unbalanced blanks has been adding weight to
the lighter side, last time the large 24" willow burl that I did was
screwed to a large MDF platter and weights bolted to the platter, it
worked just fine.

Have fun and take care
Leo Van Der Loo

"Arch" wrote in message
...
No, not about a balancing act to curb influential turners. I'm wondering
about harmonic balancing for my over stressed Nova 3000. The poor thing
is all shook up trying to rotate some heavy rough NIP logs.

You let them lay on one side too long, eh? Wet on one, dry on the other.
Rotating your stock has meaning beyond the market or the lathe.

Those must be some monsters. I dummied up and swung a waterlogged 16x6
piece of hard maple at 680 on mine the other day. Then, just for the heck
of it, I tried to turn it. Call it nostalgia, call it stupid, It was like
the first couple of minutes with Blue and his 600+ minimum speed. Nice to
have 360, and difficult to comprehend anything that would shake the lathe at
180.

Static balance is my answer. Holes, sinkers and screws. Easy to determine
and do, but if you'd rotate your logs a week or two before turning, the
problem'd go away.

No argument here about the superiority of static balancing for
woodturning now and in any future that I can foresee. I just wanted to
remind some of you and inform others that might not know it exists, that
harmonic balancing is a possibility and I think worthy of being
discussed by woodturner's 'pro tem' then archived for later reference.

Perhaps h.b. is a boring subject now, but you never know. Could you
ever have imagined a headstock that swivels and slides? Or a gouge that
won't get mad and lose its temper no matter how hard you grind on it?

WebTv makes posting a url tedious, so to get anyone interested up to
speed (poor choice of phrase) I'll ask someone to post the archived
thread in which Lyn and others, particularly Russ Fairfield, brought
this technique to our attention with good explanations. Not sure if
h.b. was ever published in "More Woodturning". Maybe we can get Russ and
Fred to post an informed review & update. Still hoping others will jump
in re harmonic balancing so we will have a state of the art in mid '06
for reference. Many TIAs.


Turn to Safety, Arch
Fortiter



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

Trivia: The phrase 'movers and shakers' originates in a poem by a Kentuckian
circa 1850 about the industrious Hoosiers across the Ohio at New Albany building
sternwheelers. Dan

Hello Arch,

I've never used the harmonic balancing technique, but I did see it demonstrated
several years ago. At the moment, I can't even remember who was demonstrating
it. I believe it may have been at the first Puget Sound Woodworking Symposium in
2000, but am not sure. The fellow had a bar attached to the lathe bed that stuck
out on the opposite side of the lathe and then a vertical piece of all thread
with two nuts and a weight on it attached at the end of the bar. As I recall, he
balanced out vibration by moving the weight up and down. I'll look in my photo
archives and see if I can find a photo of it. As I recall, it dampened out the
vibration quite well.

Fred Holder
http://www.fholder.com

In article , Arch says...

No argument here about the superiority of static balancing for
woodturning now and in any future that I can foresee. I just wanted to
remind some of you and inform others that might not know it exists, that
harmonic balancing is a possibility and I think worthy of being
discussed by woodturner's 'pro tem' then archived for later reference.

Perhaps h.b. is a boring subject now, but you never know. Could you
ever have imagined a headstock that swivels and slides? Or a gouge that
won't get mad and lose its temper no matter how hard you grind on it?

WebTv makes posting a url tedious, so to get anyone interested up to
speed (poor choice of phrase) I'll ask someone to post the archived
thread in which Lyn and others, particularly Russ Fairfield, brought
this technique to our attention with good explanations. Not sure if
h.b. was ever published in "More Woodturning". Maybe we can get Russ and
Fred to post an informed review & update. Still hoping others will jump
in re harmonic balancing so we will have a state of the art in mid '06
for reference. Many TIAs.


Turn to Safety, Arch
Fortiter



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

I have my lathe sitting on machine mounts. They are some sort of
rubber and dampen the movement of the lathe when turning unbalanced
pieces.

I have also used the spinning plate with counter balancing weights.
I've done this in two ways. One is to use a plywood circle mounted on
the spindle with weights attached. as the turning progresses, the
weight distribution changes and I move the weights. Simply use screws
into the plywood. For very large pieces you can use a large plywood
disk.

The other method I've used and plan to use more often is to use my
jumbo jaws as the plate. Michael Werner uses machine screws into the
bumper holes on the back of the jaws while mounting the turned piece on
the front of the plates with screws. This works great.

Joe Fleming - San Diego

"Arch" wrote in message
...
No, not about a balancing act to curb influential turners. I'm wondering
about harmonic balancing for my over stressed Nova 3000. The poor thing
is all shook up trying to rotate some heavy rough NIP logs. I've
lessened its agony as much as I can with low speed, a strong heavily
weighted bench, secure tail support, a well trimmed log and all the
usual therapies _including gentle cuts with a sharp spindle roughing
gouge. It continues to move and shake.

I know, I know, "give up and treat yourself to a Stubby, Arch", but what
about trying some harmonic balancing first? I mean a rod with an
adjustable weight. You don't hear much about it these days, but I hope
that if some of you have used or considered this way to quiet a
vibrating lathe you will answer some questions and offer suggestions
and/or opinions pro & con.

I thought of bolting a piece of 1" allthread to one of the holes for the
optional outboard toolrest and adding an adjustable barbell weight
between two bolts at the outboard end. Before I mess around with this,
is this contraption likely to work? If you think it might, where do I
attach this abortion? axial? Radial? Headstock? Bed? Bench? Length of
allthread? size of the weight?
How to tune it? Static? Dynamic? So many questions--so little ability.
I need help.
============================
Arch,
Some years ago, I saw an "automatic" or "self balancing" wheel balancer in a
JC Whitney auto parts catalog. I wondered about it at the time, but didn't
try to check it out. It mounted between the tire and the hub, and
dynamically balanced as the vehicle was driven.
I did ask a mechanic about it later, and he said truckers had used somrthing
like that for some time. I always guessed that they used some viscous
material or metal bead material. Don't know if you could find anything lilke
that on the web, or at least some theory on how it would work, but it might
be worth a look.

Ken Moon
Webberville, TX.

Some years ago, I saw an "automatic" or "self balancing" wheel balancer in a
JC Whitney auto parts catalog. I wondered about it at the time, but didn't try
to check it out. It mounted between the tire and the hub, and dynamically
balanced as the vehicle was driven.
I did ask a mechanic about it later, and he said truckers had used somrthing
like that for some time. I always guessed that they used some viscous material
or metal bead material. Don't know if you could find anything lilke that on
the web, or at least some theory on how it would work, but it might be worth a
look.

It was a circular tube, hula-hoop style, with a dozen or so ball bearings inside
and filled with mineral oil. I'm not sure it would have sufficient moment arm
to counteract the large forces in some work.

Dan

"Dan Bollinger" wrote in message
m...
Some years ago, I saw an "automatic" or "self balancing" wheel balancer
in a JC Whitney auto parts catalog. I wondered about it at the time, but
didn't try to check it out. It mounted between the tire and the hub, and
dynamically balanced as the vehicle was driven.
I did ask a mechanic about it later, and he said truckers had used
somrthing like that for some time. I always guessed that they used some
viscous material or metal bead material. Don't know if you could find
anything lilke that on the web, or at least some theory on how it would
work, but it might be worth a look.

It was a circular tube, hula-hoop style, with a dozen or so ball bearings
inside and filled with mineral oil. I'm not sure it would have
sufficient moment arm to counteract the large forces in some work.

Dan
====================

If that works for the small weight differences in a wheel, then a larger one
could be fabricated for large lathe work. Just don't know if the results
would be worth the effort.

Ken

Many thanks to Ken for bringing this up and to Dan for following up,
Could you two and others explain a little about how this works. Maybe
suggest references.


Turn to Safety, Arch
Fortiter



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

Many thanks to Ken for bringing this up and to Dan for following up,
Could you two and others explain a little about how this works. Maybe
suggest references.

I would suggest searching US patents. Patents disclose enough information that a
reasonably adept person could duplicate the work. Dan

Hello Arch,

Lyn wrote an article for More Woodturning, which was published in the June 2002
issue, I've printed that page out to a PDF file and will e-mail it to any who
wish to try making up a balancer for their lathe. Lyn had it mounted on his Nova
3000. This was a Glaser design that was never brought to the market as far as I
know.

Fred Holder
http://www.fholder.com

In article , Arch says...

No, not about a balancing act to curb influential turners. I'm wondering
about harmonic balancing for my over stressed Nova 3000. The poor thing
is all shook up trying to rotate some heavy rough NIP logs. I've
lessened its agony as much as I can with low speed, a strong heavily
weighted bench, secure tail support, a well trimmed log and all the
usual therapies _including gentle cuts with a sharp spindle roughing
gouge. It continues to move and shake.

I know, I know, "give up and treat yourself to a Stubby, Arch", but what
about trying some harmonic balancing first? I mean a rod with an
adjustable weight. You don't hear much about it these days, but I hope
that if some of you have used or considered this way to quiet a
vibrating lathe you will answer some questions and offer suggestions
and/or opinions pro & con.

I thought of bolting a piece of 1" allthread to one of the holes for the
optional outboard toolrest and adding an adjustable barbell weight
between two bolts at the outboard end. Before I mess around with this,
is this contraption likely to work? If you think it might, where do I
attach this abortion? axial? Radial? Headstock? Bed? Bench? Length of
allthread? size of the weight?
How to tune it? Static? Dynamic? So many questions--so little ability.
I need help.


Turn to Safety, Arch
Fortiter



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

Hello Arch,

Lyn wrote an article for More Woodturning, which was published in the June 2002
issue, I've printed that page out to a PDF file and will e-mail it to any who
wish to try making up a balancer for their lathe. (sorry, forgot the e-mail
address . Lyn had it mounted on his Nova 3000. This was
a Glaser design that was never brought to the market as far as I know.

Fred Holder
http://www.fholder.com

In article , Arch says...

No, not about a balancing act to curb influential turners. I'm wondering
about harmonic balancing for my over stressed Nova 3000. The poor thing
is all shook up trying to rotate some heavy rough NIP logs. I've
lessened its agony as much as I can with low speed, a strong heavily
weighted bench, secure tail support, a well trimmed log and all the
usual therapies _including gentle cuts with a sharp spindle roughing
gouge. It continues to move and shake.

I know, I know, "give up and treat yourself to a Stubby, Arch", but what
about trying some harmonic balancing first? I mean a rod with an
adjustable weight. You don't hear much about it these days, but I hope
that if some of you have used or considered this way to quiet a
vibrating lathe you will answer some questions and offer suggestions
and/or opinions pro & con.

I thought of bolting a piece of 1" allthread to one of the holes for the
optional outboard toolrest and adding an adjustable barbell weight
between two bolts at the outboard end. Before I mess around with this,
is this contraption likely to work? If you think it might, where do I
attach this abortion? axial? Radial? Headstock? Bed? Bench? Length of
allthread? size of the weight?
How to tune it? Static? Dynamic? So many questions--so little ability.
I need help.


Turn to Safety, Arch
Fortiter



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

In article . com,
"Joe Fleming" wrote:

I have also used the spinning plate

Who do you think was the very last variety show entertainer who did the
spinning plates on the dowels bit? D'ya think he knew he was the end of
the line? I recall seeing this act as a kid in the '60s and always
thought it fun - when those first plates began wobbling on the stick...

Did this act have an official name? What title does one call the guy who
does it?

--
Owen Lowe

Northwest Woodturners
Pacific Northwest Woodturning Guild
___
Tips fer Turnin': Place a sign, easily seen as you switch on your lathe, warning you to remove any and all rings from your fingers. Called degloving, extended hardware can grab your ring and rip it off your finger. A pic for the strong of stomach: www.itim.nsw.gov.au/go/objectid/2A3AC703-1321-1C29-70B067DC88E16BFC/index.cfm

Besides, rings can easily mar the surface of a turning as you check for finished smoothness.

Owen Lowe wrote:

In article . com,
"Joe Fleming" wrote:

I have also used the spinning plate

Who do you think was the very last variety show entertainer who did the
spinning plates on the dowels bit? D'ya think he knew he was the end of
the line? I recall seeing this act as a kid in the '60s and always
thought it fun - when those first plates began wobbling on the stick...

Did this act have an official name? What title does one call the guy who
does it?


I think they still do this. Seems like I saw one on the tube sometime in
the past 4 or 5 years. Some things just never go out of style. Probably
been plate spinners since plates were invented and probably will be as long
as we've got breakable plates.

Amazing that this came up. Actually I had thought to try turning a
plate and stick a year or two ago when we were discussing magic wands &
batons. Plastic ones are available, cheap and the technique can be
learned easier than with regular plates. The rims are deeper and there
is a dimple in the middle.

We woodturners do range far & wide and it ain't easy to get OT on any
thread.
Spinning plates or cups is as live & well as yo yo's, spinning tops and
frisbees. There are even spinning plate groups and some include
children. Who will be the first here to turn exqusite pink ivory sticks
and plates for their signature pieces?


Turn to Safety, Arch
Fortiter



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

I have turned a bunch of stuff off center that made my lathe shake,
even though it's bolted to 20,000 lbs of concrete, and did something
like what JRJohnson did. I have a bunch of lead diving weights that I
melted down and use to balance the load, however I first try to balance
by bolting to my waste block. I would caution against using the
tailstock if you can avoid it only to reduce the dynamic load on the
headstock bearings.

Even if it's statically balanced, there will be a large load on the two
headstock bearings in opposite directions if the headstock and
tailstock have opposite but perfectly balanced loads. It might not
amount to much turning at low speeds, but 2x speed is 4x the load, and
just think: You're increasing the load on the bearings and the housings
and bolts that hold them in place when balancing on opposite ends of
the headstock, rather than eliminating the dynamic load by static
balancing at the same end of the spindle.

I did a quick calculation on a theoretical lathe with 12" between
bearings and 20" between head and tailstock (= 4" bearing to weights):
the dynamic cyclic bearing loads with 60 lbs unbalanced (equivalent to
about 18 lbs@8" from center at 240 RPM and increases proportional to
the SQUARE of the spindle speed) are 20 and 80 lbs, and this increases
to 100 lbs on each bearing if you balance at the tailstock. Having
bearings farther apart from each other makes it a little nicer:
unbalanced bearing loads if the bearings are 24" apart (same 4" between
bearings and weights) is 10 and 70 lbs, static balancing at the
tailstock would make it more like 80 lbs steady cyclic load on both
bearings.

So it doesn't double the bearing load, but it does increase it
significantly. Anything that can make the whole lathe move on the
ground, I don't want that much load constantly going through my
bearings and the bearing races & housings. It's going to fatigue and
break them eventually.

If you balance on the same end of the spindle by putting weights on the
wood, the unbalanced loads on the bearings will disappear (excepting
the weight of the wood&metal due to gravity, which will not change with
spindle speed).

Owen Lowe writes:

Did this act have an official name? What title does one call the guy who
does it?

"professional plate-spinners" [1]

[1] The Modern Conjurer, C. Lang Neil, 1947
This book includes a section on the technique.

--
Sending unsolicited commercial e-mail to this account incurs a fee of
$500 per message, and acknowledges the legality of this contract.

Arch wrote:
No, not about a balancing act to curb influential turners. I'm wondering
about harmonic balancing for my over stressed Nova 3000. The poor thing
is all shook up trying to rotate some heavy rough NIP logs. I've
lessened its agony as much as I can with low speed, a strong heavily
weighted bench, secure tail support, a well trimmed log and all the
usual therapies _including gentle cuts with a sharp spindle roughing
gouge. It continues to move and shake.

I know, I know, "give up and treat yourself to a Stubby, Arch", but what
about trying some harmonic balancing first? I mean a rod with an
adjustable weight. You don't hear much about it these days, but I hope
that if some of you have used or considered this way to quiet a
vibrating lathe you will answer some questions and offer suggestions
and/or opinions pro & con.

I thought of bolting a piece of 1" allthread to one of the holes for the
optional outboard toolrest and adding an adjustable barbell weight
between two bolts at the outboard end. Before I mess around with this,
is this contraption likely to work? If you think it might, where do I
attach this abortion? axial? Radial? Headstock? Bed? Bench? Length of
allthread? size of the weight?
How to tune it? Static? Dynamic? So many questions--so little ability.
I need help.


Turn to Safety, Arch
Fortiter



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

Arch

I just found this website, and this was the article I was referring to
before, something one could try out if needed.

Have fun and take care
Leo Van Der Loo

Arch wrote:
No, not about a balancing act to curb influential turners. I'm wondering
about harmonic balancing for my over stressed Nova 3000. The poor thing
is all shook up trying to rotate some heavy rough NIP logs. I've
lessened its agony as much as I can with low speed, a strong heavily
weighted bench, secure tail support, a well trimmed log and all the
usual therapies _including gentle cuts with a sharp spindle roughing
gouge. It continues to move and shake.

I know, I know, "give up and treat yourself to a Stubby, Arch", but what
about trying some harmonic balancing first? I mean a rod with an
adjustable weight. You don't hear much about it these days, but I hope
that if some of you have used or considered this way to quiet a
vibrating lathe you will answer some questions and offer suggestions
and/or opinions pro & con.

I thought of bolting a piece of 1" allthread to one of the holes for the
optional outboard toolrest and adding an adjustable barbell weight
between two bolts at the outboard end. Before I mess around with this,
is this contraption likely to work? If you think it might, where do I
attach this abortion? axial? Radial? Headstock? Bed? Bench? Length of
allthread? size of the weight?
How to tune it? Static? Dynamic? So many questions--so little ability.
I need help.


Turn to Safety, Arch
Fortiter



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

(Try this again), I just found this website, it has the article I was
referring to, something easily made if you have a need for it.

http://www3.sympatico.ca/3jdw8/antivibration.htm

Have fun and take care
Leo Van Der Loo

wrote:
Arch wrote:
No, not about a balancing act to curb influential turners. I'm wondering
about harmonic balancing for my over stressed Nova 3000. The poor thing
is all shook up trying to rotate some heavy rough NIP logs. I've
lessened its agony as much as I can with low speed, a strong heavily
weighted bench, secure tail support, a well trimmed log and all the
usual therapies _including gentle cuts with a sharp spindle roughing
gouge. It continues to move and shake.

I know, I know, "give up and treat yourself to a Stubby, Arch", but what
about trying some harmonic balancing first? I mean a rod with an
adjustable weight. You don't hear much about it these days, but I hope
that if some of you have used or considered this way to quiet a
vibrating lathe you will answer some questions and offer suggestions
and/or opinions pro & con.

I thought of bolting a piece of 1" allthread to one of the holes for the
optional outboard toolrest and adding an adjustable barbell weight
between two bolts at the outboard end. Before I mess around with this,
is this contraption likely to work? If you think it might, where do I
attach this abortion? axial? Radial? Headstock? Bed? Bench? Length of
allthread? size of the weight?
How to tune it? Static? Dynamic? So many questions--so little ability.
I need help.


Turn to Safety, Arch
Fortiter



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

" wrote:



(Try this again), I just found this website, it has the article I was
referring to, something easily made if you have a need for it.

http://www3.sympatico.ca/3jdw8/antivibration.htm

Have fun and take care
Leo Van Der Loo


Thanks Leo. I may have to try something like this with the Shopsmith. Do
you know if the effect is linear, eg 5X mass for 3" height?

Lobby
If you try it, you tell us, then we all know, G, no I don't have a
clue how well this works, and the amount of stilling swaying forces by
increasing the distance away from the rotating center, what I do know
is that pipes will bend and bolds shear off etc, if you go past their
limit.

Have fun and take care
Leo Van Der Loo

Lobby Dosser wrote:
" wrote:



(Try this again), I just found this website, it has the article I was
referring to, something easily made if you have a need for it.

http://www3.sympatico.ca/3jdw8/antivibration.htm

Have fun and take care
Leo Van Der Loo


Thanks Leo. I may have to try something like this with the Shopsmith. Do
you know if the effect is linear, eg 5X mass for 3" height?

"Lobby Dosser" wrote in message
news:VFPfg.14910$U_2.13521@trnddc05...

Thanks Leo. I may have to try something like this with the Shopsmith. Do
you know if the effect is linear, eg 5X mass for 3" height?

Basic lever calculation. One lifts four at four to one.

Cute idea, but misguided. Easy to calculate a static solution, but this is
supposed to counter an off-balance dynamic load, which is a bit different.
When the stand and components are rigid, solution is simple.

It's where the load comes past 12:00 where the additional acceleration
begins. At 9:00 it has maximum leverage, but eight is probably best
combined for leverage and acceleration (squared, remember). Putting a
weight straight up in the air is not going to be as effective as hanging it
at 3:00.

Imbalance wants to lift the rear legs off the ground. That's where you
secure things by putting weight low and behind or screwing to the floor,
otherwise known as the big weight. You take the thrust forward by extending
the footprint beyond the swing.

Friend of mine was having problems with vibration on a mustard monster. I
suggested he wedge a touch under the front legs to shift the CG aft. Oddly
enough, it helped. Same principles.

As soon as you have a point of elastic transfer, your calculation must shift
and do a whole new set of vectors.

This is not a lever. The author is misunderstanding his system. To be a
lever the pole must have a fulcrum. There is no fulcrum, just a load at
both ends of a pipe. What I believe is happening here is the length of
the pipe and the mass are acting as a mass spring damping system, and
the action of the weight is not multiplied as you move out along the
pipe. the length of pipe simply acts as a damping spring to reduce
vibration. The unbalanced loads on his lathe and bearing are still
there and things will still vibrate loose and fatigue and break.

Thanks to Leo we now know of someone with personal experience with this
approach to vibration. I've invited John to discuss what he has learned
_using_ his device and to offer any advice and further discussion he
wishes, including general woodturning topics. Maybe Leo can use his
charm to persuade a fellow Canadian Immigrant. I know he would be a
welcome and appreciated addition to rcw.

Thanks Mark, for suggesting another way to look at the problem. I had
dimly seen an analogy to resistance in a resonant LC circuit, but hadn't
thought of a damped spring mass system. My knowledge re the physics of
damped spring mass systems (or any other) is too limited to follow up on
this classic physics example. I hope you will explain a bit more. What
are the actual physical characteristics of our lathe's annoying &
dangerous vibrations. I know mine shakes and that's about all I really
understand. except as with the wood drying problem, I think there must
be different ways to skin a cat. (sorry Ecnerwal)


Turn to Safety, Arch
Fortiter



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

Hello Arch,

I've just placed the article that Lyn wrote on the "Glaser Tunable Vibration
Absorber for Lathes" on Lyn's page at my domain site. This is the one that you
remembered, I'm sure.

Fred Holder
http://www.fholder.com

In article , Arch says...

Thanks to Leo we now know of someone with personal experience with this
approach to vibration. I've invited John to discuss what he has learned
_using_ his device and to offer any advice and further discussion he
wishes, including general woodturning topics. Maybe Leo can use his
charm to persuade a fellow Canadian Immigrant. I know he would be a
welcome and appreciated addition to rcw.

Thanks Mark, for suggesting another way to look at the problem. I had
dimly seen an analogy to resistance in a resonant LC circuit, but hadn't
thought of a damped spring mass system. My knowledge re the physics of
damped spring mass systems (or any other) is too limited to follow up on
this classic physics example. I hope you will explain a bit more. What
are the actual physical characteristics of our lathe's annoying &
dangerous vibrations. I know mine shakes and that's about all I really
understand. except as with the wood drying problem, I think there must
be different ways to skin a cat. (sorry Ecnerwal)


Turn to Safety, Arch
Fortiter



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

I was asked to enter the fray as it were about lathe balancing and on
my site http://www3.sympatico.ca/3jdw8/antivibration.htm I have a
balancing system for a homemade lathe.
These things change and I no longer have the CTC lathe so do not use a
weight mounted high. Instead I use electronic speed control and find
that this is better for turning out of balance wood. (For wood that
will remain out of balance I use counterweights to balance the mass on
the lathe.) The electronic speed control allows the turner to start at
zero RPM, thus large pieces can be mounted and turned and once they
have their high spots turned off the speed can be increased to allow
faster turning.
I do still use my outside lathe but quite frankly the speed control is
so much more convenient that I only use the outside lathe for
relatively small faceplate turning. The counterweights mounted high
above the spindle do work, but they are dependent upon the base being
firmly anchored to the ground too and on the tightness of the bearings.
(Sloppy bearings are the worst thing for turning as the wood will move
as the tool is placed against it, causing all kinds of problems) I
actually found that the base of the lathe was wobbling back and forth
while the massive weights I have mounted high up are sitting relatively
still with a out of round piece turning in the lathe.
There is additional stress on the bearings and I find that I have to
tighten the bearing races on the pillow blocks every now and again.
Fortunately the pillow blocks have this option as some do not.

Many thanks, John. Please continue to participate, but I guess we can
put this idea to bed and let it sleep for a while.


Turn to Safety, Arch
Fortiter



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

The electronic speed control allows the turner to start at
zero RPM...

JD, I gotta stop by your shop someday and see you turning at zero rpm. Isn't
that called 'carving?' LOL!

Dan

Hi Dan

Come to think of it, I always seem to START at 0 rpm, it just ramps up
fast after that. GG :))

Have fun and take care
Leo Van Der Loo

Dan Bollinger wrote:
The electronic speed control allows the turner to start at
zero RPM...

JD, I gotta stop by your shop someday and see you turning at zero rpm. Isn't
that called 'carving?' LOL!

Dan

With out of round pieces I always start the lathe at zero and speed up
to the point where the lathe vibrates too much then turn it down till
it is possible to place the tool on the rest and hold it still.
And sometimes I mount the wood, lock it and carve off bits with a
chainsaw before ever starting the lathe. I guess that is not turning in
the strictest sense of the word....
JD

wrote:
Hi Dan

Come to think of it, I always seem to START at 0 rpm, it just ramps up
fast after that. GG :))

Have fun and take care
Leo Van Der Loo

Dan Bollinger wrote:
The electronic speed control allows the turner to start at
zero RPM...

JD, I gotta stop by your shop someday and see you turning at zero rpm. Isn't
that called 'carving?' LOL!

Dan

"JD" wrote in message
ups.com...
With out of round pieces I always start the lathe at zero and speed up
to the point where the lathe vibrates too much then turn it down till
it is possible to place the tool on the rest and hold it still.
And sometimes I mount the wood, lock it and carve off bits with a
chainsaw before ever starting the lathe. I guess that is not turning in
the strictest sense of the word....
JD

It does the job safely. I cut blanks with the chainsaw, but not after I
bring them in from the woodpile. After that it's round on the bandsaw and
nibble for balance.

All this talk, and no one has mentioned flywheels? Less weight applied at
a greater distance will static balance, and the mass of a flywheel smoothes
a lot of things out.

Hi John

I just did the same thing, I had a piece of cherry, cut from the side
of a log, it was the base of a larger branch, had been sitting in the
shop for at least a year, and started to show signs of splitting, so it
was either use it or chuck it :)) (pun intended), but the shape made
it so that band sawing was not an option, so after measuring I drilled
it for the wood worm screw and put it on my lathe.
After having it swinging around and trying to cut the dry end grain, I
thought sawing a lot of the one sided lump off was a good idea, locked
the lathe and cut most of the lump off, sure made a lot of difference,
I just finished turning it, leaving the bark on partially on the bottom
side and having a nice oval top made for a real beauty IMO.
Of course as always you got to be careful and know what you're doing,
when working with power tools and things that cut.

Have fun and take care
Leo Van Der Loo

JD wrote:
With out of round pieces I always start the lathe at zero and speed up
to the point where the lathe vibrates too much then turn it down till
it is possible to place the tool on the rest and hold it still.
And sometimes I mount the wood, lock it and carve off bits with a
chainsaw before ever starting the lathe. I guess that is not turning in
the strictest sense of the word....
JD

wrote:
Hi Dan

Come to think of it, I always seem to START at 0 rpm, it just ramps up
fast after that. GG :))

Have fun and take care
Leo Van Der Loo

Dan Bollinger wrote:
The electronic speed control allows the turner to start at
zero RPM...

JD, I gotta stop by your shop someday and see you turning at zero rpm. Isn't
that called 'carving?' LOL!

Dan