I (finally) bought an 8" "General International" jointer but
I've been having problems with my cuts; the work piece gets
progressively narrower or thinner - I've been getting 1/32" -
3/64" per 7'. After most of a weekend working on this I am
baffled. I understand that an outfeed table set too high can cause
this. So I tried setting it at several levels, including one so low to
the knives that it sniped at the end of the piece and still got a
taper. I also tried to finesse it by bearing down harder at the start
of the cut, then backing off on the pressure towards the end. This
knocked off about 1/64" but still resulted in a taper. I've worked
with a few industrial strength jointers in a wood class and in a mill
but never seemed to have this kind of problem. Then again, I never
measured the result quite so closely.
Could I have done something wrong with the set-up? Is there some kind
of flaw with the jointer? Or is 1/32" - 3/64" within normal
tolerances?
I'd really appreciate any comments and suggestions.
I didn't get from his post the same thing you did, Leon. What I got was
that the jointer is making a tapered cut, which WILL happen either if
the outfeed is too high (progressively SHALLOWER cut), or if the outfeed
table isn't parallel, but sits high at the far end, in which case you'll
get a progressively DEEPER cut. I agree you don't use a jointer to make
parallel surfaces, but you also don't want the jointer to whittle away
more of the wood from one end than the other, either!
Dave
Leon wrote:
> "spalted" <[email protected]> wrote in message
> news:[email protected]...
>
>>I (finally) bought an 8" "General International" jointer but
>>I've been having problems with my cuts; the work piece gets
>>progressively narrower or thinner - I've been getting 1/32" -
>>3/64" per 7'. After most of a weekend working on this I am
>>baffled. I understand that an outfeed table set too high can cause
>>this. So I tried setting it at several levels, including one so low to
>>the knives that it sniped at the end of the piece and still got a
>>taper. I also tried to finesse it by bearing down harder at the start
>>of the cut, then backing off on the pressure towards the end. This
>>knocked off about 1/64" but still resulted in a taper. I've worked
>>with a few industrial strength jointers in a wood class and in a mill
>>but never seemed to have this kind of problem. Then again, I never
>>measured the result quite so closely.
>>Could I have done something wrong with the set-up? Is there some kind
>>of flaw with the jointer? Or is 1/32" - 3/64" within normal
>>tolerances?
>
>
> It really sounds like you are expecting the jointer to do what it was not
> designed to so.
> IF the board ends up with a curved edge or surface, the out feed table
> adjustment is probably the culprit.
> IF the edge or surface that you are running through the jointer is "straight
> and flat" after the pass regardless of how that edge or surface compares to
> the opposite surface or edge, it is working correctly. A jointer is not to
> be used to make parallel edges or surfaces. Opposite parallel edges and
> surfaces are acquired by using a table saw and thickness planer
> respectively.
>
>
"spalted" <[email protected]> wrote in message
news:[email protected]...
>I (finally) bought an 8" "General International" jointer but
> I've been having problems with my cuts; the work piece gets
> progressively narrower or thinner - I've been getting 1/32" -
> 3/64" per 7'. After most of a weekend working on this I am
> baffled. I understand that an outfeed table set too high can cause
> this. So I tried setting it at several levels, including one so low to
> the knives that it sniped at the end of the piece and still got a
> taper. I also tried to finesse it by bearing down harder at the start
> of the cut, then backing off on the pressure towards the end. This
> knocked off about 1/64" but still resulted in a taper. I've worked
> with a few industrial strength jointers in a wood class and in a mill
> but never seemed to have this kind of problem. Then again, I never
> measured the result quite so closely.
> Could I have done something wrong with the set-up? Is there some kind
> of flaw with the jointer? Or is 1/32" - 3/64" within normal
> tolerances?
It really sounds like you are expecting the jointer to do what it was not
designed to so.
IF the board ends up with a curved edge or surface, the out feed table
adjustment is probably the culprit.
IF the edge or surface that you are running through the jointer is "straight
and flat" after the pass regardless of how that edge or surface compares to
the opposite surface or edge, it is working correctly. A jointer is not to
be used to make parallel edges or surfaces. Opposite parallel edges and
surfaces are acquired by using a table saw and thickness planer
respectively.
Check that the outfeed table isn't too high at the far end, meaning the
two tables aren't parallel. That's the scenario that would result in a
progressively deeper cut. Either shim the ways or return the unit.
This assumes that your technique is correct; transfer pressure to the
outfeed table instead of bearing down on the infeed side as you joint
your boards. You've used other units with no problem, so I think the
tables aren't parallel.
Dave
spalted wrote:
> I (finally) bought an 8" "General International" jointer but
> I've been having problems with my cuts; the work piece gets
> progressively narrower or thinner - I've been getting 1/32" -
> 3/64" per 7'. After most of a weekend working on this I am
> baffled. I understand that an outfeed table set too high can cause
> this. So I tried setting it at several levels, including one so low to
> the knives that it sniped at the end of the piece and still got a
> taper. I also tried to finesse it by bearing down harder at the start
> of the cut, then backing off on the pressure towards the end. This
> knocked off about 1/64" but still resulted in a taper. I've worked
> with a few industrial strength jointers in a wood class and in a mill
> but never seemed to have this kind of problem. Then again, I never
> measured the result quite so closely.
> Could I have done something wrong with the set-up? Is there some kind
> of flaw with the jointer? Or is 1/32" - 3/64" within normal
> tolerances?
>
> I'd really appreciate any comments and suggestions.
>
"David" <[email protected]> wrote in message
news:[email protected]...
>I didn't get from his post the same thing you did, Leon. What I got was
>that the jointer is making a tapered cut, which WILL happen either if the
>outfeed is too high (progressively SHALLOWER cut),
Too high, the board tends to have a convex bow on the side run through the
cutter. Too low and the board tends to have a concave bow on the side run
through the cutter. The out feed table is not used to create a taper.
or if the outfeed
> table isn't parallel, but sits high at the far end, in which case you'll
> get a progressively DEEPER cut. I agree you don't use a jointer to make
> parallel surfaces, but you also don't want the jointer to whittle away
> more of the wood from one end than the other, either!
It is almost impossible to prevent straight line taper on a jointer because
the human hand does not provide a very good solid index constant like the
table on a thickness planer or the fence on a TS. With lots of practice and
fewer passes through the jointer you can keep the taper to a minimum. If
the board is not straight to start with a taper is hard to avoid.
In article <[email protected]>, "Leon" <[email protected]> wrote:
>It is almost impossible to prevent straight line taper on a jointer because
>the human hand does not provide a very good solid index constant like the
>table on a thickness planer or the fence on a TS. With lots of practice and
>fewer passes through the jointer you can keep the taper to a minimum. If
>the board is not straight to start with a taper is hard to avoid.
You're missing the point, Leon. The unavoidable slight taper you're talking
about is on the order of a few thousandths of an inch over three or four feet,
if the jointer is set up properly and the operator's technique is good.
The OP is seeing _an_order_of_magnitude_ more taper than that. 3/64" over
seven feet is WAY TOO MUCH.
--
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?
In article <[email protected]>, "Leon" <[email protected]> wrote:
>
>"Doug Miller" <[email protected]> wrote in message
>news:[email protected]...
>> In article <[email protected]>, "Leon"
>> <[email protected]>
>>
>> You're missing the point, Leon. The unavoidable slight taper you're
>> talking
>> about is on the order of a few thousandths of an inch over three or four
>> feet,
>> if the jointer is set up properly and the operator's technique is good.
>>
>> The OP is seeing _an_order_of_magnitude_ more taper than that. 3/64" over
>> seven feet is WAY TOO MUCH.
>
>Understood but maybe you missed the subtitle indicator that he gave,
>
>" the work piece gets progressively narrower or thinner - I've been getting
>1/32" -
>3/64" per 7'. After most of a weekend working on this I am
>baffled.
>
>If you run a piece through the jointer enough times it is going to add up
>and especially if you are a beginner on a board that is not straight.
>"The" work piece gets progressively narrower or thinner over most of the
>weekend. I read that as he has been going over and over and over on the
>same board.
And I took it to mean that he's seeing that much taper on a _single_pass_ and
has been trying all weekend to correct the problem - *not* that he's been
running the *same* board through the jointer all weekend.
Perhaps the OP can clarify.
--
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?
"Doug Miller" <[email protected]> wrote in message
news:[email protected]...
> In article <[email protected]>, "Leon"
> <[email protected]>
>
> You're missing the point, Leon. The unavoidable slight taper you're
> talking
> about is on the order of a few thousandths of an inch over three or four
> feet,
> if the jointer is set up properly and the operator's technique is good.
>
> The OP is seeing _an_order_of_magnitude_ more taper than that. 3/64" over
> seven feet is WAY TOO MUCH.
Understood but maybe you missed the subtitle indicator that he gave,
" the work piece gets progressively narrower or thinner - I've been getting
1/32" -
3/64" per 7'. After most of a weekend working on this I am
baffled.
If you run a piece through the jointer enough times it is going to add up
and especially if you are a beginner on a board that is not straight.
"The" work piece gets progressively narrower or thinner over most of the
weekend. I read that as he has been going over and over and over on the
same board.
On 23 May 2005 12:28:34 -0700, "spalted" <[email protected]> wrote:
>I (finally) bought an 8" "General International" jointer but
>I've been having problems with my cuts; the work piece gets
>progressively narrower or thinner - I've been getting 1/32" -
>3/64" per 7'
============snip snip snip.===========
Once I pass the blades almost all of the pressure I "put" downward on
the board is on the outfeed table... almost nothing on the infeed side
of the blades... But no matter how good your technique is if the
tables are not co-planer... ya got problems...
Like others have noted . cutting on a taper suggests to me that your
outfeed table is NOT co-planer to the infeed ...thus the end (of the
outfeed) table may be slightly higher or lower then the leading edge
of the outfeed table...
I have been using an old Rockwell jointer for close to 40 years and
the outfeed table is fixed...no adjustments possible ..except maybe a
machine shop...
The first few months I had it I blamed the poor results on my newbie
techique...Visited my Dad one weekend and I mentioned my problems
and a quick visit to his shop proved my technique was ok... When I
got home I had to shim the infeed table ....that adjustment held for
over 20 years before I had to re-shim the infeed table,...
Honestly I do not know how badly I could have screwed it up if both
tables were adjustable as most of them are,...
Lots of luck...
Bob Griffiths
"Doug Miller" <[email protected]> wrote in message
news:[email protected]...
>
> And I took it to mean that he's seeing that much taper on a _single_pass_
> and
> has been trying all weekend to correct the problem - *not* that he's been
> running the *same* board through the jointer all weekend.
>
> Perhaps the OP can clarify.
Yeah, I think some pertinent details may have been left out.
"Leon" <[email protected]> wrote in message
news:[email protected]...
>
> "David" <[email protected]> wrote in message
> news:[email protected]...
> >I didn't get from his post the same thing you did, Leon. What I got was
> >that the jointer is making a tapered cut, which WILL happen either if the
> >outfeed is too high (progressively SHALLOWER cut),
>
> Too high, the board tends to have a convex bow on the side run through the
> cutter. Too low and the board tends to have a concave bow on the side run
> through the cutter. The out feed table is not used to create a taper.
>
>
>
> or if the outfeed
> > table isn't parallel, but sits high at the far end, in which case you'll
> > get a progressively DEEPER cut. I agree you don't use a jointer to make
> > parallel surfaces, but you also don't want the jointer to whittle away
> > more of the wood from one end than the other, either!
>
> It is almost impossible to prevent straight line taper on a jointer
because
> the human hand does not provide a very good solid index constant like the
> table on a thickness planer or the fence on a TS. With lots of practice
and
> fewer passes through the jointer you can keep the taper to a minimum. If
> the board is not straight to start with a taper is hard to avoid.
>
>
This is why I usually make two light passes flipping the board end to end
between passes.
Mis-aligned tables will indeed result in curved edges, not "tapered but
straight"