Dp

"D'ohBoy"

10/05/2009 6:47 AM

HELP!: Thunk, thunk, thunk....

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


This topic has 13 replies

LM

"Lee Michaels"

in reply to "D'ohBoy" on 10/05/2009 6:47 AM

10/05/2009 2:05 PM


"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>


Dp

"D'ohBoy"

in reply to "D'ohBoy" on 10/05/2009 6:47 AM

14/05/2009 5:23 AM

On May 14, 8:15 am, Jack Stein <[email protected]> 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

r

in reply to "D'ohBoy" on 10/05/2009 6:47 AM

10/05/2009 7:00 AM

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

Lr

"Leon"

in reply to "D'ohBoy" on 10/05/2009 6:47 AM

10/05/2009 4:59 PM


"D'ohBoy" <[email protected]> wrote in message
news:[email protected]...
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.

jj

jo4hn

in reply to "D'ohBoy" on 10/05/2009 6:47 AM

10/05/2009 11:21 AM

D'ohBoy wrote:
> On May 10, 11:08 am, Kevin <[email protected]> wrote:
>> On Sun, 10 May 2009 10:00:41 -0500, "Leon"
>>
>> <[email protected]> wrote:
>>
>>> "Leon" <[email protected]> wrote in message
>>> news:[email protected]...
>>>> 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

Dp

"D'ohBoy"

in reply to "D'ohBoy" on 10/05/2009 6:47 AM

10/05/2009 9:03 AM

On May 10, 9:24=A0am, "J. Clarke" <[email protected]> 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. =A0Started up the saw, everything sounded/seemed fine.
>
> > Put my ear protection in. =A0Started to grind a coupla pieces. =A0Weird
> > 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. =A0Something stuck in the saw? =A0Open the cabinet. =A0Nothing. =
=A0Fire
> > up the saw again. =A0THUNK THUNK THUNK. =A0Weird. =A0Huh. Take the belt
> > off. =A0Spin the arbor. =A0Smoooooth. =A0 Spin the motor. =A0Smoooth...=
.
>
> > Remove belt, try to move pulleys on arbors. =A0Nope. =A0Not by hand.
>
> > Put the belt back on. =A0Slowly spin the motor. =A0Thunk. =A0Thunk. =A0=
Thunk.
> > Take belt off. =A0Noise gone again. =A0Put belt back on. =A0Thunk. =A0S=
pin
> > motor backwards. =A0*Very* light thunk. Check alignment of belt ribs
> > with pulleys. =A0Adjust so there is 'misalignment' of belt (shift ribs
> > over 1 slot on one pulley). =A0Thunk disappears briefly, comes back.
>
> > Observe both pulleys relative to thunk timing. =A0Hmmm... perfectly
> > synced with the motor. =A0Damn. =A0Frick. =A0Thing is like maybe a year
> > old. =A0Well, got a five year warranty. =A0Thank god for that.
>
> > So, I have very little desire to remove the motor from this puppy -
> > three horse's gotta weigh like 150 pounds.... =A0Gonna be a giant PITA
> > for sure. =A0Maybe 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

Dp

"D'ohBoy"

in reply to "D'ohBoy" on 10/05/2009 6:47 AM

10/05/2009 9:53 AM

On May 10, 11:08=A0am, Kevin <[email protected]> wrote:
> On Sun, 10 May 2009 10:00:41 -0500, "Leon"
>
> <[email protected]> wrote:
>
> >"Leon" <[email protected]> wrote in message
> >news:[email protected]...
> >> Sounds like the bearing are shot.
>
> >If the clunk is there when turning by hand, I seriously doubt that the b=
elts
> >would make any noise if they were bad.
>
> >Something else to consider and this has happened to me in the past, =A0 =
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. =A0I'd check to make sure th=
e 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

md

mac davis

in reply to "D'ohBoy" on 10/05/2009 6:47 AM

11/05/2009 7:12 AM

On Sun, 10 May 2009 11:21:37 -0700, jo4hn <[email protected]> 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

JC

"J. Clarke"

in reply to "D'ohBoy" on 10/05/2009 6:47 AM

10/05/2009 10:24 AM

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?

JS

Jack Stein

in reply to "D'ohBoy" on 10/05/2009 6:47 AM

14/05/2009 8:15 AM

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

Lr

"Leon"

in reply to "D'ohBoy" on 10/05/2009 6:47 AM

10/05/2009 10:00 AM


"Leon" <[email protected]> wrote in message
news:[email protected]...
> 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.

Lr

"Leon"

in reply to "D'ohBoy" on 10/05/2009 6:47 AM

10/05/2009 9:56 AM


"D'ohBoy" <[email protected]> wrote in message
news:[email protected]...
> 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.

Kl

Kevin

in reply to "D'ohBoy" on 10/05/2009 6:47 AM

10/05/2009 12:08 PM

On Sun, 10 May 2009 10:00:41 -0500, "Leon"
<[email protected]> wrote:

>
>"Leon" <[email protected]> wrote in message
>news:[email protected]...
>> 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


You’ve reached the end of replies