Thoughts, comments wanted about jointer knife settings

I would suspect the knife setting of about 1/64" above the cutter head
is correct. This is basically the setting for my Powermatic 8"
jointer, as well. Probably a similar setting for all such jointers
(and planers) with similar heads. The recommended setting of the
blade, top-dead-center, above the outfeed table, for my Powermatic, is
what Doug mentions, .002". I would suppose this is applicable for
your Delta.... and other similar jointers. If you can set yours less
than that and be okay, great.

I have a (newish) Delta 15" planer, but haven't had reason to change
blades, yet, so not sure what that knife/head setting is. Eye-balling
it, looks to be a good bit more than 1/64". My brother has a 12"
Powermatic planer and, if I recall, that knife/head setting is a tad
more than 1/64", also.

As for as I know/understand, 1) the knife relative to the head setting
has nothing to do with nor is dependent upon 2) the setting of the
outfeed table relative to the knife/head unit. Those 2 settings are
independent of one another.

Sonny

Marc,

I am not an expert on this, but every jointer maintenance
book, article,etc. that I read say to set the knives at
about the height equal to the top of the outfeed table. That way
when you drop the infeed, you get a bigger cut.

I'd have to go into my reference books, but at the top of
my head this morning, that's how I remember it.

Here's a great article on it:

http://www.woodcentral.com/bparticles/knife_adjustment.shtml

MJ

Doug Miller <[email protected]> wrote in
news:[email protected]:

> marc rosen <[email protected]> wrote in
> news:140b2dc6-d82a-4f2c-bacb-41701a378a89
> @i2g2000vbv.googlegroups.com:
>
>> Hey Gang,
>> I was reading over the knife setting section in the instruction
>> manual for my jointer (8 inch Delta DJ20) and was a bit dismayed
>> about the height specified. The manual recommends setting the blades
>> 0.015 inches (approximately 1/64 th inch) above the circular
>> portion of the cutterhead.
>
> I've had your jointer's baby brother (DJ15) for about twelve years. I
> set my knives with reference to the level of the outfeed table, not
> the cutterhead -- not only is it much easier to measure that way, but
> height above the outfeed table is the only thing that really matters
> anyway.
>
> Set them about 0.002" above the outfeed table, 0.001" if you can
> manage it, regardless of whatever that happens to be above the body of
> the cutterhead, and you'll be golden.

It might be that 1/64" above the cutter head happens to be the outfeed
table height. I don't own the machine and haven't looked at mine that
closely, but it could be coincidence and the manual writer went with a
non-standard point of reference.

Puckdropper

--
Make it to fit, don't make it fit.

Hi MJ and Swingman,
Thanks for the article from Woodcentral and your comments. It has
some similar details to the procedure I am using. MJ, in the Delta
manual it instructs you to set the outfeed table 0.015 inches above
the "round portion " of the cutter head. Then using a straight edge
or a magnetic jig (my approach) you set the blade height off that
table when the cutterhead is at top dead center. It is as you suggest
the same height as the outfeed table but that table height is much
smaller than the allowed cutting depth. I think the head's diameter
is 3.75 inch and I can't recall its speed but I recall it is about
13,000 cuts per miinute. Swing, I see your point (no pun intended)
very well now. As soon as the wood is cut by the blade(s) and passes
over the head its bottom should be at the height of the outfeed table
and not touching the head. I am sure I was incorrectly analyzing this
while I was staring at the stationary head while adjusting the
blades. Damn, after using it for 6 years I can't believe I was
analyzing a dynamic part of it while it was being static and not
realizing what takes place in real time.


Anyway I think I'm back to normal again. Thanks for helping me think
properly.

Marc

"marc rosen" <[email protected]> wrote in message
news:[email protected]...
> Hi MJ and Swingman,
> Thanks for the article from Woodcentral and your comments. It has
> some similar details to the procedure I am using. MJ, in the Delta
> manual it instructs you to set the outfeed table 0.015 inches above
> the "round portion " of the cutter head. Then using a straight edge
> or a magnetic jig (my approach) you set the blade height off that
> table when the cutterhead is at top dead center. It is as you suggest
> the same height as the outfeed table but that table height is much
> smaller than the allowed cutting depth. I think the head's diameter
> is 3.75 inch and I can't recall its speed but I recall it is about
> 13,000 cuts per miinute. Swing, I see your point (no pun intended)
> very well now. As soon as the wood is cut by the blade(s) and passes
> over the head its bottom should be at the height of the outfeed table
> and not touching the head. I am sure I was incorrectly analyzing this
> while I was staring at the stationary head while adjusting the
> blades. Damn, after using it for 6 years I can't believe I was
> analyzing a dynamic part of it while it was being static and not
> realizing what takes place in real time.
>
>
> Anyway I think I'm back to normal again. Thanks for helping me think
> properly.
>
> Marc

This .015 adjustment thing with a round head is also a safety feature in
that it does limit the material removed if you jabbed the wood into the
cutter... With the tables adjusted for a heavy cut the old square head
machines let you ram a board in so deeply that the board could basically
explode. I understand it could also flip the board out of the user's hands
or if you were lucky the belt would slip and it would stall the cutter like
a catch while wood turning.

I took advantage of this cut limiting feature on my shaper today. I was
using the shaper with a straight "safety cutter" to flush cut edging on
plywood. The edging slid along under the fence while the fence was adjusted
so the straight cutter removed just the edging and not the veneer. After the
edging was flushed on the long edges I stuck the ends of the edging under
the fence and carved them away with the cutter. It would only cut a limited
amount at one time as the round body of the cutter only leaves a small
cutting edge exposed. In normal use the cutter would remove wood before it
would hit the cutter body but in the manner I was using it the wood was
contacting the cutter body at times as I fed it in. This worked just fine...
would have been a disaster with a non-safety cutter design!

John

marc rosen <[email protected]> wrote in news:140b2dc6-d82a-4f2c-bacb-41701a378a89
@i2g2000vbv.googlegroups.com:

> Hey Gang,
> I was reading over the knife setting section in the instruction manual
> for my jointer (8 inch Delta DJ20) and was a bit dismayed about the
> height specified. The manual recommends setting the blades 0.015
> inches (approximately 1/64 th inch) above the circular portion of the
> cutterhead.

I've had your jointer's baby brother (DJ15) for about twelve years. I set my knives with reference to the
level of the outfeed table, not the cutterhead -- not only is it much easier to measure that way, but height
above the outfeed table is the only thing that really matters anyway.

Set them about 0.002" above the outfeed table, 0.001" if you can manage it, regardless of whatever
that happens to be above the body of the cutterhead, and you'll be golden.

Puckdropper <puckdropper(at)yahoo(dot)com> wrote in news:4f383c9a$0$1808$c3e8da3
[email protected]:

> Doug Miller <[email protected]> wrote in
> news:[email protected]:
>
>> marc rosen <[email protected]> wrote in
>> news:140b2dc6-d82a-4f2c-bacb-41701a378a89
>> @i2g2000vbv.googlegroups.com:
>>
>>> Hey Gang,
>>> I was reading over the knife setting section in the instruction
>>> manual for my jointer (8 inch Delta DJ20) and was a bit dismayed
>>> about the height specified. The manual recommends setting the blades
>>> 0.015 inches (approximately 1/64 th inch) above the circular
>>> portion of the cutterhead.
>>
>> I've had your jointer's baby brother (DJ15) for about twelve years. I
>> set my knives with reference to the level of the outfeed table, not
>> the cutterhead -- not only is it much easier to measure that way, but
>> height above the outfeed table is the only thing that really matters
>> anyway.
>>
>> Set them about 0.002" above the outfeed table, 0.001" if you can
>> manage it, regardless of whatever that happens to be above the body of
>> the cutterhead, and you'll be golden.
>
> It might be that 1/64" above the cutter head happens to be the outfeed
> table height. I don't own the machine and haven't looked at mine that
> closely, but it could be coincidence and the manual writer went with a
> non-standard point of reference.

I imagine that's the case -- I just wanted to make the point that the actual point of reference should
always be the outfeed table, since that's what the wood rides on.

On 2/12/2012 2:17 PM, marc rosen wrote:

> 13,000 cuts per miinute. Swing, I see your point (no pun intended)
> very well now. As soon as the wood is cut by the blade(s) and passes
> over the head its bottom should be at the height of the outfeed table
> and not touching the head. I am sure I was incorrectly analyzing this
> while I was staring at the stationary head while adjusting the
> blades. Damn, after using it for 6 years I can't believe I was
> analyzing a dynamic part of it while it was being static and not
> realizing what takes place in real time.
>
>
> Anyway I think I'm back to normal again. Thanks for helping me think
> properly.

Hey, understand perfectly ... I do a "doh!" forehead slap at least
once/shop hour. The further from the problem, the easier it is to see
the solution. :)

--
www.eWoodShop.com
Last update: 4/15/2010
KarlCaillouet@ (the obvious)
http://gplus.to/eWoodShop

On 2/12/2012 11:55 AM, marc rosen wrote:
> Hey Gang,
> I was reading over the knife setting section in the instruction manual
> for my jointer (8 inch Delta DJ20) and was a bit dismayed about the
> height specified. The manual recommends setting the blades 0.015
> inches (approximately 1/64 th inch) above the circular portion of the
> cutterhead. If I want to take any cut larger than 1/64 th the woood
> will contact with the cutterhead circumference. The manual states not
> to take more than 1/8 inch cut but it it looks like taking more than a
> 64th I'll be hitting the cylinder. Of course I'm noticing this now
> and not during work time to discuss it with whomever is representing
> Delta these days, but you guys and (maybe,..., hopefully ) gals may be
> able to chime in with your own thoughts.
> If you have another brand jointer could you post its recommended blade
> settings here? Thanks,

Seems like that would depend upon the diameter of the "circular portion
of the cutterhead", and the speed at which it's turning, and the rate at
which the wood was fed (which would probably have to be pretty fast to
exceed the design parameters).

IOW, unless the diameter of the cutter head "cylinder" is pretty large,
and the speed at which it was turning is extremely slow, it should not
be a problem to take the recommended cut depth.

Take a look at the angle at which the cutting edge enters the leading
edge of the wood during the cut ... the smaller the diameter of the
"cylinder" holding the knifes, and the faster it spins, should insure
that the wood would never contact the "cylinder".

I'm pretty sure this is taken into account in the design. Have you had a
problem with this in the past?

Perhaps misunderstanding your problem?

--
www.eWoodShop.com
Last update: 4/15/2010
KarlCaillouet@ (the obvious)
http://gplus.to/eWoodShop

marc rosen wrote:
> Hey Gang,
> I was reading over the knife setting section in the instruction manual
> for my jointer (8 inch Delta DJ20) and was a bit dismayed about the
> height specified. The manual recommends setting the blades 0.015
> inches (approximately 1/64 th inch) above the circular portion of the
> cutterhead. If I want to take any cut larger than 1/64 th the woood
> will contact with the cutterhead circumference.

No, the cutter is ploughing out an arc...cutting forward of as well as at
the top of the arc as it spins.

--

dadiOH
____________________________

dadiOH's dandies v3.06...
...a help file of info about MP3s, recording from
LP/cassette and tips & tricks on this and that.
Get it at http://mysite.verizon.net/xico

Swingman wrote:
> On 2/12/2012 2:17 PM, marc rosen wrote:
>
>> 13,000 cuts per miinute. Swing, I see your point (no pun intended)
>> very well now. As soon as the wood is cut by the blade(s) and passes
>> over the head its bottom should be at the height of the outfeed table
>> and not touching the head. I am sure I was incorrectly analyzing this
>> while I was staring at the stationary head while adjusting the
>> blades. Damn, after using it for 6 years I can't believe I was
>> analyzing a dynamic part of it while it was being static and not
>> realizing what takes place in real time.
>>
>>
>> Anyway I think I'm back to normal again. Thanks for helping me think
>> properly.
>
> Hey, understand perfectly ... I do a "doh!" forehead slap at least
> once/shop hour.

> The further from the problem, the easier it is to see
> the solution. :)
>

Especially, if it's somebody else's problem!

A friend used to comment that the more engineers he invited over to
help, the less any work got done! Everybody is ready to offer an
opinion about the way it ought to be done, but no one reaches for a
shovel. : )

"marc rosen" <[email protected]> wrote in message
news:[email protected]...
> Hey Gang,
> I was reading over the knife setting section in the instruction manual
> for my jointer (8 inch Delta DJ20) and was a bit dismayed about the
> height specified. The manual recommends setting the blades 0.015
> inches (approximately 1/64 th inch) above the circular portion of the
> cutterhead. If I want to take any cut larger than 1/64 th the woood
> will contact with the cutterhead circumference. The manual states not
> to take more than 1/8 inch cut but it it looks like taking more than a
> 64th I'll be hitting the cylinder. Of course I'm noticing this now
> and not during work time to discuss it with whomever is representing
> Delta these days, but you guys and (maybe,..., hopefully ) gals may be
> able to chime in with your own thoughts.
> If you have another brand jointer could you post its recommended blade
> settings here? Thanks,
>
> Marc

I think you are confused, see the reply from MJ. He has it right. WW