Over the years,I've read and heard repeated warnings by various experts
that driving a blank onto a morse tapered spur center while it's on the
lathe will damage the bearings. It would of course, damage an obsolete
outboard cup (---point thrust bearing, but I wonder about the ball
bearings used on woodturning lathes of the sizes and types that most of
us use.

The warnings must be true, but for me it seems I have a mild case of
Charlie's bumble bee syndrome. Maybe I've been lucky not to be stung
yet, but I've driven many blocks onto MT spur centers while inserted
into the spindle and haven't heard that ominous rumble yet.

I can see that if a spindle is axially free except for being locked onto
the bearings, banging it axially would damage the
bearings. Are the spindles of most of our lathes attached to the
bearings tightly enough to cause damage by axial pressure? Not
according to the instructions for removing the spindle from some popular
machines. I'm _not talking about cartridge, roller, angular, etc. types.

If the spindle is restrained by collars or pulleys and floats fairly
easily thru the bearings why is the bearing damaged?. What part of the
_bearing (forgetting spindle, pulleys, bearing seats and castings) is
damaged by seating a wood blank onto a spur center that's already in the
spindle taper? I'm often wrong. What am I missing this time?

Have any of you damaged bearings by illegally banging an innocent blank
onto a spur center while it's in the spindle taper?


Turn to Safety, Arch
Fortiter


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

Got me Arch. I fugure if I can not whump the piece on the spur center the
lathe is going to have a hard time with an unbalanced 50 pound burl being
roughd at high speed or any speed for that matter.
Darrell
---
God bless and safe turning
Darrell Feltmate
Truro, NS
http://aroundthewoods.com
http://roundopinions.blogspot.com
"Arch" wrote in message
...

Over the years,I've read and heard repeated warnings by various experts
that driving a blank onto a morse tapered spur center while it's on the
lathe will damage the bearings. It would of course, damage an obsolete
outboard cup (---point thrust bearing, but I wonder about the ball
bearings used on woodturning lathes of the sizes and types that most of
us use.

The warnings must be true, but for me it seems I have a mild case of
Charlie's bumble bee syndrome. Maybe I've been lucky not to be stung
yet, but I've driven many blocks onto MT spur centers while inserted
into the spindle and haven't heard that ominous rumble yet.

I can see that if a spindle is axially free except for being locked onto
the bearings, banging it axially would damage the
bearings. Are the spindles of most of our lathes attached to the
bearings tightly enough to cause damage by axial pressure? Not
according to the instructions for removing the spindle from some popular
machines. I'm _not talking about cartridge, roller, angular, etc. types.

If the spindle is restrained by collars or pulleys and floats fairly
easily thru the bearings why is the bearing damaged?. What part of the
_bearing (forgetting spindle, pulleys, bearing seats and castings) is
damaged by seating a wood blank onto a spur center that's already in the
spindle taper? I'm often wrong. What am I missing this time?

Have any of you damaged bearings by illegally banging an innocent blank
onto a spur center while it's in the spindle taper?


Turn to Safety, Arch
Fortiter


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

Darrell Feltmate wrote:

Got me Arch. I fugure if I can not whump the piece on the spur center the
lathe is going to have a hard time with an unbalanced 50 pound burl being
roughd at high speed or any speed for that matter.
Darrell
---
God bless and safe turning
Darrell Feltmate
Truro, NS
http://aroundthewoods.com
http://roundopinions.blogspot.com
"Arch" wrote in message
...

Over the years,I've read and heard repeated warnings by various experts
that driving a blank onto a morse tapered spur center while it's on the
lathe will damage the bearings. It would of course, damage an obsolete
outboard cup (---point thrust bearing, but I wonder about the ball
bearings used on woodturning lathes of the sizes and types that most of
us use.

The warnings must be true, but for me it seems I have a mild case of
Charlie's bumble bee syndrome. Maybe I've been lucky not to be stung
yet, but I've driven many blocks onto MT spur centers while inserted
into the spindle and haven't heard that ominous rumble yet.

I can see that if a spindle is axially free except for being locked onto
the bearings, banging it axially would damage the
bearings. Are the spindles of most of our lathes attached to the
bearings tightly enough to cause damage by axial pressure? Not
according to the instructions for removing the spindle from some popular
machines. I'm _not talking about cartridge, roller, angular, etc. types.

If the spindle is restrained by collars or pulleys and floats fairly
easily thru the bearings why is the bearing damaged?. What part of the
_bearing (forgetting spindle, pulleys, bearing seats and castings) is
damaged by seating a wood blank onto a spur center that's already in the
spindle taper? I'm often wrong. What am I missing this time?

Have any of you damaged bearings by illegally banging an innocent blank
onto a spur center while it's in the spindle taper?


Turn to Safety, Arch
Fortiter


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







Haven't ever damaged bearings, but have managed to get the spur center
stuck in the taper a couple of times....

--Rick

Hi Arch

I've made this comment before, that a car or truck can go down the
road at 70 MPH or more, keeping al that weight up while hitting bumps
and ruts, and doing this day after day, while in most cases no one
ever takes a second look at them.

Then when someone wants to hammer an essentially sharp object into a
soft medium (wood), cries are heard, that one is destroying the
bearings by doing so.

Ever looked at the hammer drill people use, those iddy biddy bearings
get whacked a thousand times and just keep on ticking.

Running a bearing at high speed with constant high side pressure,
developing high heat will ruin a bearing much faster, even that will
take some time to happen, as first the lubricant will run out or
degrade, and than the frictions will get higher and the head
ultimately will destroy the bearing.

With lathes the biggest problem IMO is the cheaper bearings used, with
only shields in them, that do not keep out the dust and grit, those
will die untimely, not by driving a wooden stick onto a sharp spur,
and that is my opinion.

Have I damaged bearings ??, yes I'm afraid so, I do confess to have
hit large ball bearings with a sledge hammer to get at the balls, we
played games with them, when my Dad found out, he was not impressed,
I do remember that.

Don't remember what the bearings came out of, it was wartime material,
and the bearing balls where at least an inch in size as I seem to
recall.

Have fun and take care
Leo Van Der Loo


On May 6, 5:25 pm, (Arch) wrote:
Over the years,I've read and heard repeated warnings by various experts
that driving a blank onto a morse tapered spur center while it's on the
lathe will damage the bearings. It would of course, damage an obsolete
outboard cup (---point thrust bearing, but I wonder about the ball
bearings used on woodturning lathes of the sizes and types that most of
us use.

The warnings must be true, but for me it seems I have a mild case of
Charlie's bumble bee syndrome. Maybe I've been lucky not to be stung
yet, but I've driven many blocks onto MT spur centers while inserted
into the spindle and haven't heard that ominous rumble yet.

I can see that if a spindle is axially free except for being locked onto
the bearings, banging it axially would damage the
bearings. Are the spindles of most of our lathes attached to the
bearings tightly enough to cause damage by axial pressure? Not
according to the instructions for removing the spindle from some popular
machines. I'm _not talking about cartridge, roller, angular, etc. types.

If the spindle is restrained by collars or pulleys and floats fairly
easily thru the bearings why is the bearing damaged?. What part of the
_bearing (forgetting spindle, pulleys, bearing seats and castings) is
damaged by seating a wood blank onto a spur center that's already in the
spindle taper? I'm often wrong. What am I missing this time?

Have any of you damaged bearings by illegally banging an innocent blank
onto a spur center while it's in the spindle taper?

Turn to Safety, Arch
Fortiter

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

" wrote:

Have I damaged bearings ??, yes I'm afraid so, I do confess to have
hit large ball bearings with a sledge hammer to get at the balls, we
played games with them, when my Dad found out, he was not impressed,
I do remember that.

Don't remember what the bearings came out of, it was wartime material,
and the bearing balls where at least an inch in size as I seem to
recall.


Steelies!! They were banned from most marble contests and horrendous
arguments broke out between seven year olds over whether or not to allow
them.

When you hit a glass marble with a Steelie, you could sometimes see the
chips fly.

(Do flying chips get this back on topic?)

Rick Frazier wrote:


Haven't ever damaged bearings, but have managed to get the spur center
stuck in the taper a couple of times....

--Rick



I bang the center off lathe first with a rubber mallet. Then, if needed,
bang the wood when mounting.

Just remember to always wear your safety glasses when shooting a steelie at
a glass marble.


David Peebles
Lyons, Ohio
Revolutions Woodturning
www.bowlturner.com
"Lobby Dosser" wrote in message
news:rPx%h.2279


When you hit a glass marble with a Steelie, you could sometimes see the
chips fly.

(Do flying chips get this back on topic?)

Ah yes, I had a hard lesson in the facts of life when about seven I
sadly learned that an older boy said that we were playing keepsies. His
shooter was a ball bearing, mine was a big aggie. Don't remember if we
were playing big ring or little ring, but he always lagged closer to the
line, shot first and the games were over before I got to shoot.

On topic or off doesn't matter as long as it will pry up posts from old
friends like Rick & Dave plus the always welcomed comments from Darrell,
Leo and Lobby. Thanks y'all.

Leo, I don't know if it's true, but I've heard stories that in WW2 B29s
were hit and damaged by steel balls when they bombed the Nazi bearing
factories. Maybe some of those bearings landed in Holland.


Turn to Safety, Arch
Fortiter


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

"Arch" wrote in message
...

Over the years,I've read and heard repeated warnings by various experts
that driving a blank onto a morse tapered spur center while it's on the
lathe will damage the bearings. It would of course, damage an obsolete
outboard cup (---point thrust bearing, but I wonder about the ball
bearings used on woodturning lathes of the sizes and types that most of
us use.

Lots of experts out there, but most folks take convention as wisdom.

I'm guessing that if you drive enough on the inner race you might be able to
shorten the life of the bearing. I remember the way to get steelies, which
played against steelies in my neighborhood, was to put the outer race on two
blocks and drive the inner. The cold chisel method resulted in more damage
to the chisel than the hardened races.

Now with preloaded tapered roller bearings, you could screw up the preload
and get more damage faster. Or tapered sintered bronze. Maybe that's where
it comes from.

Over the years,I've read and heard repeated warnings by various experts
that driving a blank onto a morse tapered spur center while it's on the
lathe will damage the bearings.

Sounds like one for MythBusters. A large axial force, whether by hammer or arbor
press, can and does damage bearings. Ball bearings can carry a large radial
load, but their ability to carry an axial load is a fraction of their radial
load. Hence the warnings. I doubt that the light whack of setting a spindle on a
drive center is going to cause problems in a heavy duty lathe.

I can see that if a spindle is axially free except for being locked onto
the bearings, banging it axially would damage the
bearings. Are the spindles of most of our lathes attached to the
bearings tightly enough to cause damage by axial pressure?

Most commercial lathes' spindles are retained by the front set of bearings
alone; not the rear set, which are often made to float, but occasionally both. l
have never seen a case of the spindle being held in place by anything else
except the bearing(s) such as the pulley. How could it/? The pulley is not fixed
to the headstock. It is the front set that takes all the abuse, hence they are
often larger, double, or roller bearings instead of ball. Mine is an 1.5 inch
bore double angled roller bearing, weighs about five pounds.

Dan