TS tearout on blade exit?
 

I call it tearout for lack of a better term. Whenever I make a rip cut on
my TS with the blade 90 degrees to the TS top, as the board exits the rear
of the blade there is a large (maybe 1/16") tearout on the rearmost portion
of the board (that portion of the board that exits the blade last) as if the
blade were tilted slightly left. Looking at the board from the rear end
grain would look thusly:

------
------
\-----

The first 99% of the stock is dead on 90 degrees to the adjacent face. It's
just the last 1/4" or so.

As a test, I found that if I stop the saw before the stock exits the blade
but after the cut is completed, there is no tearout (I only tried this a
couple of times). It's consistent enough that I have trained myself to rip
larger than necessary and make jointer passes until the damaged end is
removed. I have used featherboards to keep the stock up against the fence,
and aligned and realigned the blade. It only occurs in the very rearmost
portion of the board, about the last 1/4". It does not occur when making a
dado type cut with the same blade through the center of a board, i.e. a kerf
down the center.

What's the deal with this?

--Cheers!
Dukester

"Dukester" wrote in message
...
The first 99% of the stock is dead on 90 degrees to the adjacent face.
It's
just the last 1/4" or so.

As a test, I found that if I stop the saw before the stock exits the blade
but after the cut is completed, there is no tearout (I only tried this a
couple of times). It's consistent enough that I have trained myself to
rip
larger than necessary and make jointer passes until the damaged end is
removed. I have used featherboards to keep the stock up against the
fence,
and aligned and realigned the blade. It only occurs in the very rearmost
portion of the board, about the last 1/4". It does not occur when making
a
dado type cut with the same blade through the center of a board, i.e. a
kerf
down the center.

Do you also get a Zing sound as the board clears the blade?

I could be technique, a board that is not straight, a bad blade, or your TS
needs a serious tune up to align the blade to the miter slot and the fence
to the miter slot.

In article , "Dukester" wrote:
I call it tearout for lack of a better term. Whenever I make a rip cut on
my TS with the blade 90 degrees to the TS top, as the board exits the rear
of the blade there is a large (maybe 1/16") tearout on the rearmost portion
of the board (that portion of the board that exits the blade last) as if the
blade were tilted slightly left. Looking at the board from the rear end
grain would look thusly:

------
------
\-----

The first 99% of the stock is dead on 90 degrees to the adjacent face. It's
just the last 1/4" or so.

On this basis, and because this apparently happens *all* the time, and
because you mention below that you have a jointer and you appear to know what
it's for, we can presumably rule out twisted stock as a cause. :-)

As a test, I found that if I stop the saw before the stock exits the blade
but after the cut is completed, there is no tearout (I only tried this a
couple of times).

That suggests that the table isn't flat, at some point past the leading edge
of the blade. The very first thing I'd check in that regard is the throat
plate. It's not a bit unusual for the plate to not be perfectly even with the
table top, and that can allow the stock to shift, causing problems such as you
describe.

It's consistent enough that I have trained myself to rip
larger than necessary and make jointer passes until the damaged end is
removed. I have used featherboards to keep the stock up against the fence,
and aligned and realigned the blade.

Have you checked the alignment of the fence and splitter, to make sure that
they are *also* square to the table? Sideways pressure from the featherboard
might be enough to twist the stock against a cockeyed fence.

It only occurs in the very rearmost
portion of the board, about the last 1/4". It does not occur when making a
dado type cut with the same blade through the center of a board, i.e. a kerf
down the center.

Yep. Board's supported on *both* sides of the blade, instead of only one.

What's the deal with this?

Probably an uneven throat plate. Lay a straightedge across the plate at the
front, middle, and rear, and along the plate front to back as well, and I'll
bet you see some places where it's uneven. Specifically, I bet it's low on the
side toward the fence, and more so in front than in back.

Tweak the height-adjusting screws as needed, if it has them; otherwise, shim
or file as needed until the plate is dead even with the table all the way
around.

While you have the straightedge out, check the table, too, to make sure it's
flat. If you're using an auxiliary outfeed table, make sure it's dead even
with the saw table, too. Irregularities in both of those areas could also
cause this problem.

You should also check to make sure your splitter and fence are dead square to
the table.

But I think it's most likely to be the throat plate.

--
Regards,
Doug Miller (alphageek at milmac dot com)

Nobody ever left footprints in the sands of time by sitting on his butt.
And who wants to leave buttprints in the sands of time?

Dukester wrote:
removed. I have used featherboards to keep the stock up against the
fence,
and aligned and realigned the blade. It only occurs in the very
rearmost
portion of the board, about the last 1/4". It does not occur when
making a
dado type cut with the same blade through the center of a board, i.e.
a kerf
down the center.

Do you get the same problem if you cut without featherboards?

Bob

Do you get the same problem if you cut without featherboards?

Yes. Identical.

"Leon" wrote in message
. ..
Do you also get a Zing sound as the board clears the blade?

Seems like it "zings" as it exits. I'll check tonight. What does the
"zing" signify?

"Dukester" wrote in message
...

"Leon" wrote in message
. ..
Do you also get a Zing sound as the board clears the blade?

Seems like it "zings" as it exits. I'll check tonight. What does the
"zing" signify?

That you have accurately described the problem, When the blade becomes
loaded from the side vs. straight on, it will typically make that sound as
it exits the wood.

On Mon, 21 Mar 2005 09:21:30 -0600, "Dukester"
wrote:

I call it tearout for lack of a better term. Whenever I make a rip cut on
my TS with the blade 90 degrees to the TS top, as the board exits the rear
of the blade there is a large (maybe 1/16") tearout on the rearmost portion
of the board (that portion of the board that exits the blade last) as if the
blade were tilted slightly left. Looking at the board from the rear end
grain would look thusly:

------
------
\-----

The first 99% of the stock is dead on 90 degrees to the adjacent face. It's
just the last 1/4" or so.

As a test, I found that if I stop the saw before the stock exits the blade
but after the cut is completed, there is no tearout (I only tried this a
couple of times). It's consistent enough that I have trained myself to rip
larger than necessary and make jointer passes until the damaged end is
removed. I have used featherboards to keep the stock up against the fence,
and aligned and realigned the blade. It only occurs in the very rearmost
portion of the board, about the last 1/4". It does not occur when making a
dado type cut with the same blade through the center of a board, i.e. a kerf
down the center.

What's the deal with this?

--Cheers!
Dukester



try a better blade.

"Doug Miller" wrote in message
m...

But I think it's most likely to be the throat plate.


Doug, the throat plate adjustment hit it right on the nail. Sure enough it
was out of keel at the back of the plate. Adjusting it made a square cut on
the first try (and the 2nd, 3rd, 4th,...).

Cheers!
Dukester

In article , "Dukester" wrote:

"Doug Miller" wrote in message
om...

But I think it's most likely to be the throat plate.


Doug, the throat plate adjustment hit it right on the nail. Sure enough it
was out of keel at the back of the plate. Adjusting it made a square cut on
the first try (and the 2nd, 3rd, 4th,...).

Thanks for the followup. Glad to help.

--
Regards,
Doug Miller (alphageek at milmac dot com)

Nobody ever left footprints in the sands of time by sitting on his butt.
And who wants to leave buttprints in the sands of time?

Thanks for posting the follow up. I was lurking curiously and hoped to hear
what the cause was.

Steve P.

"Dukester" wrote in message
...

"Doug Miller" wrote in message
m...

But I think it's most likely to be the throat plate.


Doug, the throat plate adjustment hit it right on the nail. Sure enough
it
was out of keel at the back of the plate. Adjusting it made a square cut
on
the first try (and the 2nd, 3rd, 4th,...).

Cheers!
Dukester