Thoughts on bearing pillow blocks please
Bruce Matthews
now I've been thinking of a slightly lighter duty version of the head design
on my 12 x 36 metal lathe. But now I've seen a few very large lathes using
the self aligning pillow blocks for the head stock bearings. My experience
in the past has shown me that the 3/4 to 1 inch models, while good, did have
some play in the races and a little in the self aligning ball and socket.
Not much grant you but it was there. So does anyone know of a better class
of pillow block? Or am I worrying about nothing? My current little Delta
sets up a chatter now and then thanks to it's less than ideal bearings and
some play between the rear bearing and the spindle. I don't want any more
of that nonsense in my next lathe.
Bruce Matthews
Vancouver BC
DoN. Nichols
Well ... I'm not sure at what size they start to become
available, but I have seen on bearing assembly in a pillow-block fitted
with oil for continuous lubrication.
These particular *bearings* were self-aligning. The ID of the
outer *race* was a spherical section in which two staggered rows of
barrel-shaped rollers ran, and in which in turn ran an inner race of
appropriate shape to receive the rollers.
As needed, the rollers would shift inside that outer race to
align the rotating parts with the shaft.
The example which I saw was for about a 5" shaft, and perhaps
10" overall diameter, which may be a bit big for your purposes.
Oh -- and the *reason* that I was able to see the bearings was
that they were run 24/7, 1800 RPM, with a big flywheel (about 4"
diameter by about 6" thick), and at the beginning of a long weekend, the
vibration split the rubber hose connecting the oil reservoir with the
pillowblock, and all the oil ran out.
Now -- there was a sensor, designed to shut the system down if
it got too hot -- but it was measuring the temperature of the *oil*
(which was now on the floor, a bit out of reach), so it didn't bother to
call for a shutdown.
So -- when everybody came back after a 3-day weekend, the
bearings in that one pillowblock were screaming in pain. (The other one
was still in great condition, since it had its own reservoir of oil, and
still had a good rubber hose.
It took several days to accumulate the necessary tooling to
disassemble it and replace the bearings. (Both were replaced, on
general principles.) The one which ran dry had rollers about the size
of 35mm film cartridges -- and some of them even *looked* like 35mm film
cartridges, with the steel wiped into a lip like the film light trap.
So -- properly cared for, a pair of these bearings could
probably handle any wood lathe job you might have in mind, though I
suspect that they are rather expensive. :-)
Good Luck,
DoN.
--
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--- Black Holes are where God is dividing by zero ---
Bruce Matthews
for sharing that story. Those kinds of things are always fun to hear about.
Bruce Matthews
"DoN. Nichols" <dnic...@d-and-d.com> wrote in message
news:9tfh3i$bt0$1...@izalco.d-and->
> Well ... I'm not sure at what size they start to become
> available, but I have seen on bearing assembly in a pillow-block fitted
> with oil for continuous lubrication.
> The example which I saw was for about a 5" shaft, and perhaps
> 10" overall diameter, which may be a bit big for your purposes.
>
>......, though I
DejaVU
<tvmfe1r...@corp.supernews.com>:
you need to go and talk to your local bearing supply place.
I'm sure they'll have a a selection of selfaligning adjustable
bearings that will allow you to adjust the endfloat and play.
these normally take the form of adjustable double taper rollers and
your headstock will need at least one of them (the other end can be
ordinary deep groove ball bearings. the taper rollers will take the
end loads whereas ball bearings will not (unless they're angular
contact, then you'll need two of them and an adjustment mechanism
anyway).
the fly in the oinkment may well be the 'selfaligning' bit. unless
the self aligning mechanism is either adjustable for zero play, or
made so, you're not going to get where you want to go that way.
basically you'll need to line bore both bearing mounts in the same
setup so that they are absolutely aligned.
> Bruce Matthews
> Vancouver BC
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Matohato
Dear Bruce,
You might want to try using a rear axle assembly from a junk yard for the
spindle head. Several years ago there was an article in Fine Woodworking about
a guy turning some awesome sized root boles on a face turner he built out of a
junk car rear end, like 4 ft. in diameter!
Matohato
Tom
Take a look at NTN Ultra Class Pillow Blocks. They use
electric motor quality bearings and shouldn't have much play, You can
get more info on their web site at http://www.ntnamerica.com/ Good
luck.
Wayne Cook
wrote:
>
> These particular *bearings* were self-aligning. The ID of the
>outer *race* was a spherical section in which two staggered rows of
>barrel-shaped rollers ran, and in which in turn ran an inner race of
>appropriate shape to receive the rollers.
>
> As needed, the rollers would shift inside that outer race to
>align the rotating parts with the shaft.
>
Called a spherical roller bearing. They're good for a lot more
pressure than the standard ball bearing. They are also available in a
adjustable type unfortunately the adjustable type is rare in
commercial pillow blocks (I think the only ones I've seen have been
custom pillow block housings).
If the guy can make his own housing these would be a great way to
go. The adjustable ones that I've used in the past where made by
Linkbelt. I'm not sure how small they go but I've used as small as
1-1/2" or so in the past.
The only real problem is they're rather expensive when compared to a
standard ball or tapered roller bearing.
> The example which I saw was for about a 5" shaft, and perhaps
>10" overall diameter, which may be a bit big for your purposes.
>
Available in fairly small sizes my Browning book shows down to
1-1/8" and it's likely that smaller ones are available.
Wayne Cook
Shamrock, TX
Ted Edwards
> Not much grant you but it was there. So does anyone know of a better class
> of pillow block? Or am I worrying about nothing? My current little Delta
> sets up a chatter now and then thanks to it's less than ideal bearings and
> some play between the rear bearing and the spindle. I don't want any more
> of that nonsense in my next lathe.
> Bruce Matthews
> Vancouver BC
Go talk to the folks at B.C. Bearing in Burnaby. I always found them
both knowledgeable and helpfull.
Ted
funguy
the way of bearings is there.
"Bruce Matthews" <matt...@smartt.com> wrote in message news:<tvmfe1r...@corp.supernews.com>...
Tim
> go. The adjustable ones that I've used in the past where made by
> Linkbelt. I'm not sure how small they go but I've used as small as
> 1-1/2" or so in the past.
I think I've seen ~1" or so pillow blocks at the hardware store.. $20
or so. Personally I don't know why they'd be carrying them, but they're
there.
Tim
--
"What the? Do we sell French...fries?"
- Abraham Simpson
DoN. Nichols
Bruce Matthews <matt...@smartt.com> wrote:
>Thanks anyway DoN. They are a tad large for what I had in mind.
Maybe not -- Wayne Cook posted another followup to say that he
has a catalog showing them down to 1-1/8", and I think that you would
want something a little bigger than that for your project.
> But thanks
>for sharing that story. Those kinds of things are always fun to hear about.
I thought that it might be time to put that one out there again.
(I've actually still got the surviving bearing, which was going to be
tossed on general principles, but I couldn't let that happen. :-)
There is another story about the same piece of equipment, with
another spectacular failure (thanks to "penny-wise, pound foolish"
practices where it was installed. I've posted it in the past, and will
probably do so again when the right subject comes up.
reg
turning 24-36" bowls and platters on a home made lathe made from an old
truck axle he was using taper lock pillow blocks and a 4 horse BS gas
engine to run it,... don't know if your shooting for that big but
anything's possible,....
Bruce Matthews wrote:
> of that nonsense in my next lathe.
>
> Bruce Matthews
> Vancouver BC
--
Reg* ~~~~Anyone who complains that Windows is a unworkable OS
never owned a hawg(HD),.....~~~~~
Bob May
you see in the Woodwright Shop episodes. I assume that you are really
talking about turning things of larger diameter into bowls and so forth.
For that, I'd just do a pair of roller bearings under tension (auto inside
front bearings usually will do that quite well) and allow them to float with
a ball mount for them to tension against if you are really worried about the
squareness of the bearing in the head.
Machining the whole front side of the head and the hole for the backside of
the head at one pass will pretty much eliminate that problem tho.
--
Bob May
Imagine the terrorist's fun when they realize that their 72 "nubile virgins"
are all lesbians and cranky from it being that time of the month!
Bruce Matthews
much just because you get to where it can throw a guy across the shop but I
think you're right in retrospect. The 1/2 hp in my little delta can be
dragged down pretty easily. I'm limited in how much power I can draw in my
present shop but I can certainly do 1 Hp and just live with slower turning.
Hell, it's a hobby for me right now. Later I might try some stuff for craft
fairs or whatever and I may motor it up. Thanks.
Bruce Matthews
"geoff merryweather" <geo...@bigfoot.com.delete.nospam> wrote in message
news:j78pvtspa4gpleg1g...@4ax.com...
> On Wed, 21 Nov 2001 19:40:17 -0800, "Bruce Matthews"
> <matt...@smartt.com> wrote:
>
> >And I will be talking to the bearing houses about what I'm doing and the
rpm
> >limits on the different designs. Still lots of planning to do. For
those
> >that are interested here are the numbers I'm juggling around right now.
20
> >inch over bed, 18 over toolrest, 2 inch head shaft with 1 1/2x8 tpi nose
and
> >MT2 taper, 56 between centers, traveling headstock to move to tail of bed
> >and convert to large bowl lathe. Drive unit is still very sketchy at
this
> >point but 3/4 hp and lots of speeds are a must. And a weight on around
700
> >to 800 lbs with room for another 200 lbs of sand for vibration damping.
> If you are turning hat large a piece, you will definitely need more
> power. I have 1hp on my Woodfast, and I can slow it down. 2hp+ I would
> have thought.
> Maybe you should look into rec.craft.woodturning as well
> geoff
geoff merryweather
Apacheforge
present shop but I can certainly do 1 Hp and just live with slower turning.
Hell, it's a hobby for me right now. >>
Why dont you belt drive to a flywheel of about 4 ft dia then drive your head
from that. Stored energy and momentum should make the best use of limited
electrical load.Rufo
Wayne Cook
wrote:
>> If the guy can make his own housing these would be a great way to
>> go. The adjustable ones that I've used in the past where made by
>> Linkbelt. I'm not sure how small they go but I've used as small as
>> 1-1/2" or so in the past.
>
>I think I've seen ~1" or so pillow blocks at the hardware store.. $20
>or so. Personally I don't know why they'd be carrying them, but they're
>there.
I can guarantee that those where spherical roller bearing pillow
blocks. That's about right for bottom of the line import ball bearing
pillow blocks. The spherical roller bearings I was talking about cost
about $120 wholesale without the pillow block.
Wayne Cook
Shamrock, TX
Ken Cutt
I would second a trip to B.C. Bearing , no idea what the Burnaby store
is like but the ones in the Okanogan have always worked hard to help me
out . They are not cheap but they carry all the major brands and it is
their only business so these boys have a wealth of experience .
Ken Cutt
Bruce Matthews
little. Another person I've been dealing with that built his own large wood
lathe a few years ago set me straight on the lack of need for real precision
in this type of work. My old lathe chatters so much though that I guess I
was being a little paranoid with this new one. He has gotten about 12 years
out of some standard duty single row ball units and they are still going
strong. And that's with large out of balance stuff, end loads from the tail
stock and interupted cuts. So much for worrying about this part
Anyway, the flange mount or pillow mount options are looking like the way to
go. I can design and build out any tendency for end float and if there IS a
little side play in these classes it's not a big deal because the wood is so
flexible anyway.
And I will be talking to the bearing houses about what I'm doing and the rpm
limits on the different designs. Still lots of planning to do. For those
that are interested here are the numbers I'm juggling around right now. 20
inch over bed, 18 over toolrest, 2 inch head shaft with 1 1/2x8 tpi nose and
MT2 taper, 56 between centers, traveling headstock to move to tail of bed
and convert to large bowl lathe. Drive unit is still very sketchy at this
point but 3/4 hp and lots of speeds are a must. And a weight on around 700
to 800 lbs with room for another 200 lbs of sand for vibration damping.
Thanks for the help all. I'll be back later to let you know how the metal
work part goes. BTW, is there a binaries post group for pics? Oh, there was
a web site associated now that I remember. I lost my links thanks to a
virus but I had one last year. Can anyone help with the link again?
Thanks.
Bruce Matthews
Vancouver Canada
"Bruce Matthews" <matt...@smartt.com> wrote in message
news:tvmfe1r...@corp.supernews.com...
DoN. Nichols
Bruce Matthews <matt...@smartt.com> wrote:
>Thanks to all for the help. Just to let you know I sort of cried wolf a
>little. Another person I've been dealing with that built his own large wood
[ ... ]
>Thanks for the help all. I'll be back later to let you know how the metal
>work part goes. BTW, is there a binaries post group for pics? Oh, there was
>a web site associated now that I remember. I lost my links thanks to a
>virus but I had one last year. Can anyone help with the link again?
>Thanks.
Try: <http://www.metalworking.com/>
and then click on the bar labeled "[ Dropbox ]" and you'll be there.
The first item is a file explaining how to submit items to the dropbox.
Once you have the files there, post here saying what the
filenames you used were. (And remember to include the URL above, so
you don't get a bunch of followups asking "where is the dropbox?".
(Yes, I sometimes forget that part, too.)
Enjoy,