Huh.

Mounted my sanding disc to my table saw yesterday to ease the edges of
some 1/4" thick mounting brackets for a new top for my mobile
workbench. Started up the saw, everything sounded/seemed fine.

Put my ear protection in. Started to grind a coupla pieces. Weird
noise, but I thought that the sanding disc at work was the cause.
Finished easing the edges and pulled my ear protection outta my ears.
THUNK THUNK THUNK (at 3400 bpm)!

Frick. Something stuck in the saw? Open the cabinet. Nothing. Fire
up the saw again. THUNK THUNK THUNK. Weird. Huh. Take the belt
off. Spin the arbor. Smoooooth. Spin the motor. Smoooth....

Remove belt, try to move pulleys on arbors. Nope. Not by hand.

Put the belt back on. Slowly spin the motor. Thunk. Thunk. Thunk.
Take belt off. Noise gone again. Put belt back on. Thunk. Spin
motor backwards. *Very* light thunk. Check alignment of belt ribs
with pulleys. Adjust so there is 'misalignment' of belt (shift ribs
over 1 slot on one pulley). Thunk disappears briefly, comes back.

Observe both pulleys relative to thunk timing. Hmmm... perfectly
synced with the motor. Damn. Frick. Thing is like maybe a year
old. Well, got a five year warranty. Thank god for that.

So, I have very little desire to remove the motor from this puppy -
three horse's gotta weigh like 150 pounds.... Gonna be a giant PITA
for sure. Maybe it's fixable without removing the motor?

Anyone have a suggestion that isn't gonna make me cry?

TIA

D'ohBoy

Before you dismount the motor, take a real close look at the belt(s).
If there is a crack, or an internal cord problem, it might make
noise. Couple of thoughts:

1. Mark a spot, on the belt, with magic marker, drop of paint, etc.
Watch the spot as it passes over the pulleys to see if the thunk
occurs as it goes around a pulley
2. Even before 1, lightly (and carefully) touch a bar of soap to the
belt surfaces that contact the pulleys. Belt dressing is better but
soap works. If it is a belt problem the noise will probably stop or
change instantly.

If these work, you might need a belt. If not, start thinking bushings
or bearings in the motor or arbor.

simple and worth a try.
RonB

D'ohBoy wrote:
Huh.

Mounted my sanding disc to my table saw yesterday to ease the edges of
some 1/4" thick mounting brackets for a new top for my mobile
workbench. Started up the saw, everything sounded/seemed fine.

Put my ear protection in. Started to grind a coupla pieces. Weird
noise, but I thought that the sanding disc at work was the cause.
Finished easing the edges and pulled my ear protection outta my ears.
THUNK THUNK THUNK (at 3400 bpm)!

Frick. Something stuck in the saw? Open the cabinet. Nothing. Fire
up the saw again. THUNK THUNK THUNK. Weird. Huh. Take the belt
off. Spin the arbor. Smoooooth. Spin the motor. Smoooth....

Remove belt, try to move pulleys on arbors. Nope. Not by hand.

Put the belt back on. Slowly spin the motor. Thunk. Thunk. Thunk.
Take belt off. Noise gone again. Put belt back on. Thunk. Spin
motor backwards. *Very* light thunk. Check alignment of belt ribs
with pulleys. Adjust so there is 'misalignment' of belt (shift ribs
over 1 slot on one pulley). Thunk disappears briefly, comes back.

Observe both pulleys relative to thunk timing. Hmmm... perfectly
synced with the motor. Damn. Frick. Thing is like maybe a year
old. Well, got a five year warranty. Thank god for that.

So, I have very little desire to remove the motor from this puppy -
three horse's gotta weigh like 150 pounds.... Gonna be a giant PITA
for sure. Maybe it's fixable without removing the motor?

Anyone have a suggestion that isn't gonna make me cry?

I'm sure that you've done this, but since you don't say so explicitly I
think it worth mentioning--have you carefully inspected the belt?

"D'ohBoy" wrote in message
...
Huh.

Mounted my sanding disc to my table saw yesterday to ease the edges of
some 1/4" thick mounting brackets for a new top for my mobile
workbench. Started up the saw, everything sounded/seemed fine.

Put my ear protection in. Started to grind a coupla pieces. Weird
noise, but I thought that the sanding disc at work was the cause.
Finished easing the edges and pulled my ear protection outta my ears.
THUNK THUNK THUNK (at 3400 bpm)!

Frick. Something stuck in the saw? Open the cabinet. Nothing. Fire
up the saw again. THUNK THUNK THUNK. Weird. Huh. Take the belt
off. Spin the arbor. Smoooooth. Spin the motor. Smoooth....

Remove belt, try to move pulleys on arbors. Nope. Not by hand.

Put the belt back on. Slowly spin the motor. Thunk. Thunk. Thunk.
Take belt off. Noise gone again. Put belt back on. Thunk. Spin
motor backwards. *Very* light thunk. Check alignment of belt ribs
with pulleys. Adjust so there is 'misalignment' of belt (shift ribs
over 1 slot on one pulley). Thunk disappears briefly, comes back.

Observe both pulleys relative to thunk timing. Hmmm... perfectly
synced with the motor. Damn. Frick. Thing is like maybe a year
old. Well, got a five year warranty. Thank god for that.

So, I have very little desire to remove the motor from this puppy -
three horse's gotta weigh like 150 pounds.... Gonna be a giant PITA
for sure. Maybe it's fixable without removing the motor?

Anyone have a suggestion that isn't gonna make me cry?

Sounds like the bearing are shot.

"Leon" wrote in message
...
Sounds like the bearing are shot.


If the clunk is there when turning by hand, I seriously doubt that the belts
would make any noise if they were bad.

Something else to consider and this has happened to me in the past, If the
set screw/key loosen you can hear a clunking sound as the pulley wiggles
under the pressure of an up to speed motor. I'd check to make sure the set
screw is tight.

On May 10, 9:24*am, "J. Clarke" wrote:
D'ohBoy wrote:
Huh.

Mounted my sanding disc to my table saw yesterday to ease the edges of
some 1/4" thick mounting brackets for a new top for my mobile
workbench. *Started up the saw, everything sounded/seemed fine.

Put my ear protection in. *Started to grind a coupla pieces. *Weird
noise, but I thought that the sanding disc at work was the cause.
Finished easing the edges and pulled my ear protection outta my ears.
THUNK THUNK THUNK (at 3400 bpm)!

Frick. *Something stuck in the saw? *Open the cabinet. *Nothing. *Fire
up the saw again. *THUNK THUNK THUNK. *Weird. *Huh. Take the belt
off. *Spin the arbor. *Smoooooth. * Spin the motor. *Smoooth.....

Remove belt, try to move pulleys on arbors. *Nope. *Not by hand.

Put the belt back on. *Slowly spin the motor. *Thunk. *Thunk. *Thunk.
Take belt off. *Noise gone again. *Put belt back on. *Thunk. *Spin
motor backwards. **Very* light thunk. Check alignment of belt ribs
with pulleys. *Adjust so there is 'misalignment' of belt (shift ribs
over 1 slot on one pulley). *Thunk disappears briefly, comes back.

Observe both pulleys relative to thunk timing. *Hmmm... perfectly
synced with the motor. *Damn. *Frick. *Thing is like maybe a year
old. *Well, got a five year warranty. *Thank god for that.

So, I have very little desire to remove the motor from this puppy -
three horse's gotta weigh like 150 pounds.... *Gonna be a giant PITA
for sure. *Maybe it's fixable without removing the motor?

Anyone have a suggestion that isn't gonna make me cry?

I'm sure that you've done this, but since you don't say so explicitly I
think it worth mentioning--have you carefully inspected the belt?

Actually, no. I looked at it briefly, but nothing really jumped at
me....

And there was a post (here or there or someone) a while back from
someone reviewing or talking about their steel city ribbed single belt
and putting it on wrong originally and messing it (the belt) up....

I have a hard time believing that it could turn so smoothly and thunk-
free by hand *without the belt* but be so messed up *with it* if the
bearings were bad.

Gonna poke at it some more... updates as things change. I'm betting I
hosed that belt by installing it wrong initially. Or the belt was
defective.

Thanks to all! Man, if it ain't my jointer (see my earlier whiny
posts about a twisted fence), it's my table saw, or my bandsaw.

With the bandsaw, I had to mill the lower bearing assembly in order to
pull the bearings back far enough to accommodate a 1/8" blade (within
the specs for the saw) but at least I figured that one out on my own.
Thanks, Rikon!

My brothers and I have a saying (apropos to Mother's Day): If it's
not one thing, it's your mother

D'ohBoy

On Sun, 10 May 2009 10:00:41 -0500, "Leon"
wrote:


"Leon" wrote in message
m...
Sounds like the bearing are shot.


If the clunk is there when turning by hand, I seriously doubt that the belts
would make any noise if they were bad.

Something else to consider and this has happened to me in the past, If the
set screw/key loosen you can hear a clunking sound as the pulley wiggles
under the pressure of an up to speed motor. I'd check to make sure the set
screw is tight.

Also check the fan, I've had it rub against the fan cover.


-Kevin

On May 10, 11:08*am, Kevin wrote:
On Sun, 10 May 2009 10:00:41 -0500, "Leon"

wrote:

"Leon" wrote in message
m...
Sounds like the bearing are shot.

If the clunk is there when turning by hand, I seriously doubt that the belts
would make any noise if they were bad.

Something else to consider and this has happened to me in the past, * If the
set screw/key loosen you can hear a clunking sound as the pulley wiggles
under the pressure of an up to speed motor. *I'd check to make sure the set
screw is tight.

Also check the fan, I've had it rub against the fan cover.

-Kevin

DING DING DING! We have a winner! Leon was right. Thanks! The set
screw in the pulley attached to the motor was loose. Weird that such
a tiny screw could make any difference at all - or would be considered
sufficient to the task, given the forces on that piece.

Okay, so now that I have identified/repaired the source of issues, is
there any possible complications due to that set screw having been
loose? There was also a wedge driven into a keyway that locked the
pulley in place.

Anyhoo... thanks again, Leon.

D'ohBoy

"D'ohBoy" wrote

DING DING DING! We have a winner! Leon was right. Thanks! The set
screw in the pulley attached to the motor was loose.

Don't tell anybody, but Leon is psychic. That is how he figured it out.

He "saw" the problem. G

D'ohBoy wrote:
On May 10, 11:08 am, Kevin wrote:
On Sun, 10 May 2009 10:00:41 -0500, "Leon"

wrote:

"Leon" wrote in message
...
Sounds like the bearing are shot.
If the clunk is there when turning by hand, I seriously doubt that the belts
would make any noise if they were bad.
Something else to consider and this has happened to me in the past, If the
set screw/key loosen you can hear a clunking sound as the pulley wiggles
under the pressure of an up to speed motor. I'd check to make sure the set
screw is tight.
Also check the fan, I've had it rub against the fan cover.

-Kevin

DING DING DING! We have a winner! Leon was right. Thanks! The set
screw in the pulley attached to the motor was loose. Weird that such
a tiny screw could make any difference at all - or would be considered
sufficient to the task, given the forces on that piece.

Okay, so now that I have identified/repaired the source of issues, is
there any possible complications due to that set screw having been
loose? There was also a wedge driven into a keyway that locked the
pulley in place.

Anyhoo... thanks again, Leon.

D'ohBoy
Make sure that the pulleys are aligned properly. It could have wiggled
a bit when the set screw came loose. Misaligned pulleys can cause some
distress for the bearings. Also consider a bit of Loctite or similar
thread goop to keep it in place. My Griz jointer had a this same problem.
mahalo,
jo4hn

"D'ohBoy" wrote in message
...
DING DING DING! We have a winner! Leon was right. Thanks! The set
screw in the pulley attached to the motor was loose. Weird that such
a tiny screw could make any difference at all - or would be considered
sufficient to the task, given the forces on that piece.

Okay, so now that I have identified/repaired the source of issues, is
there any possible complications due to that set screw having been
loose? There was also a wedge driven into a keyway that locked the
pulley in place.

Anyhoo... thanks again, Leon.

D'ohBoy

Consider replacing the set screw with one that has a fresh end. Also you
might consider adding a drop of LocTite, the one that will allow you to
loosen at a future time.

On Sun, 10 May 2009 11:21:37 -0700, jo4hn wrote:

snip
Make sure that the pulleys are aligned properly. It could have wiggled
a bit when the set screw came loose. Misaligned pulleys can cause some
distress for the bearings. Also consider a bit of Loctite or similar
thread goop to keep it in place. My Griz jointer had a this same problem.
mahalo,
jo4hn

Thought I'd add this.. I haven't had Loctite around for years, since I gave up
wrenching, but as a turner I DO have flexible CA..
Seems to work as well, so far, though I'm not sure if it will last as long..
YMWV


mac

Please remove splinters before emailing

On May 14, 8:15 am, Jack Stein wrote:
D'ohBoy wrote:
I'm sure that you've done this, but since you don't say so explicitly I
think it worth mentioning--have you carefully inspected the belt?

Actually, no. I looked at it briefly, but nothing really jumped at
me....

And there was a post (here or there or someone) a while back from
someone reviewing or talking about their steel city ribbed single belt
and putting it on wrong originally and messing it (the belt) up....

I have a hard time believing that it could turn so smoothly and thunk-
free by hand *without the belt* but be so messed up *with it* if the
bearings were bad.

I think it's belt related for sure. Bushings and bearings spinning
around 3400 rpm don't go thunk, thunk, thunk, more like screeeech.

The only thing going around slow enough to go thunk, thunk, thunk is the
belt? That's my take.

Gonna poke at it some more... updates as things change. I'm betting I
hosed that belt by installing it wrong initially. Or the belt was
defective.

Yes, something like that... have you found the problem yet?

Thanks to all! Man, if it ain't my jointer (see my earlier whiny
posts about a twisted fence), it's my table saw, or my bandsaw.

I remember that post, don't remember seeing the actual fix. My guess on
that was technique until you said it happened on edge jointing rather
than face jointing...

My brothers and I have a saying (apropos to Mother's Day): If it's
not one thing, it's your mother

I like that one, already stuck it in my quotes file...

--
Jack
GO PENNS!http://jbstein.com

Hi, Jack -

I actually did solve this one - and posted the issue. But for you, as
you missed it, it was the set screw in the pulley mounted to the motor
shaft. Bout 3/4 turn loose. Surprisingly loud thunk for what it was.

As for the jointer, I have not had the time to solve that one. But I
will attack it at some point...

You're welcome for the quote. That's shareware, free to use but no
distribution without a license....



D'ohBoy

D'ohBoy wrote:

I'm sure that you've done this, but since you don't say so explicitly I
think it worth mentioning--have you carefully inspected the belt?

Actually, no. I looked at it briefly, but nothing really jumped at
me....

And there was a post (here or there or someone) a while back from
someone reviewing or talking about their steel city ribbed single belt
and putting it on wrong originally and messing it (the belt) up....

I have a hard time believing that it could turn so smoothly and thunk-
free by hand *without the belt* but be so messed up *with it* if the
bearings were bad.

I think it's belt related for sure. Bushings and bearings spinning
around 3400 rpm don't go thunk, thunk, thunk, more like screeeech.

The only thing going around slow enough to go thunk, thunk, thunk is the
belt? That's my take.

Gonna poke at it some more... updates as things change. I'm betting I
hosed that belt by installing it wrong initially. Or the belt was
defective.

Yes, something like that... have you found the problem yet?

Thanks to all! Man, if it ain't my jointer (see my earlier whiny
posts about a twisted fence), it's my table saw, or my bandsaw.

I remember that post, don't remember seeing the actual fix. My guess on
that was technique until you said it happened on edge jointing rather
than face jointing...

My brothers and I have a saying (apropos to Mother's Day): If it's
not one thing, it's your mother

I like that one, already stuck it in my quotes file...

--
Jack
GO PENNS!
http://jbstein.com