I've often wondered about this too. Generally I use 1/4 inch
for 3/4 stock. But have always thought that 3/8 would be better
but then I would only have 3/16 on either side - doesn't seem
like a lot of material.
Ideally, probably a 'sloppy' 5/16 mortise with a tenon made to fit
is probably just about right.
Lou
In article <[email protected]>, J.B.
Bobbitt <[email protected]> wrote:
> I've learned that it depends a lot on how you cut the mortise, and what size
> tool you have to cut the mortise. If you chop the mortise by hand, and you
> have a 3/8" mortise chisel, make the tenon 3/8" thick too.
>
> -JBB
>
> <[email protected]> wrote in message
> news:[email protected]...
> > I am trying to determine Tenon size in relation to thickness of stock.
> > Would 1/3 be about right.
> >
> > 1/4 in tenons on 3/4 stock.
> >
> > Nark
>
>
Have to agree with Patriarch. In another thread, I asked
for help because I was cutting 1/4 mortises with my new
Delta benchtop machine. After 6 mortises, the bit snapped.
On review/input etc, I discovered that I was taking TOO LITTLE
material with each additional plunge of the bit. The auger may
not grab enough material if you attempt only a half-plunge. This
deflects the fragile 1/4 bit enough to snap it. Happened to me.
Larger bits may not be as fragile of course.
I found it better to take 'almost' full, overlapping cuts but proceed
more slowly. See the Wood magazine article from May (I think).
I'm getting a better 1/4 chisel/bit set for sure.
Good luck.
Lou
In article <[email protected]>,
patriarch <patriarch>[email protected]> wrote:
> "Leon" <[email protected]> wrote in
> news:[email protected]:
>
> >
> > "patriarch [email protected]>" <<patriarch> wrote in
> > message news:[email protected]...
> >>
> >> There was a recent thread on this either here, or ABPW. The claim
> >> was
> > that
> >> cutting the partial hole (?) caused a great deal of stress on the
> >> bit/chisel combo. Seems reasonable to me, but, then, my mortising
> >> machine is still in the factory box.
> >
> > While that sorta sounds reasonable. Cutting the first hole produces
> > the most stress. Cutting less wood on the next cut is less stress.
> > Also, since most tennons are not square, the chisel is not cutting 4
> > sides after the first cut. Sharpening the new chisels is the key to a
> > non stress cut.
> >
>
> OK, admitting as I have that MY machine is still in the box...
>
> What I have read indicated that a proper procedure is to cut each end, and
> then work towards the middle. This was/is the method that seems to work
> best when mortising using the drill press and a forstner bit, prior to work
> wih a hand chisel.
>
> Cutting a hole with less than full material seems to strain the bit in that
> case, as well.
>
> Is my assumption correct that the bulk of the cutting comes from the bit,
> rather than the chisel?
>
> Patriarch,
> willing to learn from the experience of others. It's cheaper.
"Wes Stewart" <n7ws_@_yahoo.com> wrote in message
> I use half the thickness of the thinner piece, i.e. 3/8" tenon on 3/4"
> stock.
A question about mortising machines and bit usage. For cutting something
like a 3/8 slot for a tenon, would it be acceptable to use a 1/4" bit and
move it over 1/8" to cut the other side of the slot, or is it only
recommended to use a 3/8" bit?
On Tue, 03 Aug 2004 23:51:35 GMT, "Leon" <[email protected]>
wrote:
>
>Yes, establishing a beginning and end is easier if done in the beginning.
>
-- Leon on Zen and the Art of Mortising.
And, as with all such observations, applicable elsewhere in one's life.
Thank you Zen Master Leon.
-- Igor
I agree 1/3 the stock thickness.....mjh
--
http://members.tripod.com/mikehide2
"Tom" <[email protected]> wrote in message
news:[email protected]...
> >
> >Nark wrote:I am trying to determine Tenon size in relation to thickness
of
> stock.
> >Would 1/3 be about right.
> >
> >1/4 in tenons on 3/4 stock.
> >
> >Nark
>
> Maybe a hair more than that, but it's close enough for me. Tom
> Work at your leisure!
Force would be more evenly distributed if the spur was in contact all the
way around the bit rotated. Entry and exit of the spur laterally would
cause some pretty high instantaneous stresses.
"Leon" <[email protected]> wrote in message
news:[email protected]...
> The single fluke threw everything out of balance and were easily broken.
>
> Probably should have said, the single spur and or fluke created "uneven
> stress" on the bit and they were easily broken.
>
>
I use either 5/16 or 3/8, depending on my mood. Seriously.
1/4 is a bit shy.
David
[email protected] wrote:
> I am trying to determine Tenon size in relation to thickness of stock.
> Would 1/3 be about right.
>
> 1/4 in tenons on 3/4 stock.
>
> Nark
Cut your mortise first, then match the tennon to the mortise. I prefer the
tennoin to be as large as possible with out compromising the outer sides of
the mating piece with the mortise in it.
<[email protected]> wrote in message
news:[email protected]...
> I am trying to determine Tenon size in relation to thickness of stock.
> Would 1/3 be about right.
>
> 1/4 in tenons on 3/4 stock.
>
> Nark
I've learned that it depends a lot on how you cut the mortise, and what size
tool you have to cut the mortise. If you chop the mortise by hand, and you
have a 3/8" mortise chisel, make the tenon 3/8" thick too.
-JBB
<[email protected]> wrote in message
news:[email protected]...
> I am trying to determine Tenon size in relation to thickness of stock.
> Would 1/3 be about right.
>
> 1/4 in tenons on 3/4 stock.
>
> Nark
I usually go with 1/3 of stock thickness - unless there a real good reason
why it should be more (I woundn't go less).
That's a good "rule by thumb".
Brian
<[email protected]> wrote in message
news:[email protected]...
> I am trying to determine Tenon size in relation to thickness of stock.
> Would 1/3 be about right.
>
> 1/4 in tenons on 3/4 stock.
>
> Nark
"patriarch [email protected]>" <<patriarch> wrote in message
> Why would you not want to use a 3/8" bit?
3/8" bit might be dull, might be broken, chipped or even missing. Just a
question that occurred to me. I'd guess that the larger the bit, the more
force it would take to cut the slot. Figured it might be easier to cut a
smaller slot, with multiple cuts needed, but admittedly take more time.
"patriarch [email protected]>" <<patriarch> wrote in message
news:[email protected]...
>
> There was a recent thread on this either here, or ABPW. The claim was
that
> cutting the partial hole (?) caused a great deal of stress on the
> bit/chisel combo. Seems reasonable to me, but, then, my mortising machine
> is still in the factory box.
While that sorta sounds reasonable. Cutting the first hole produces the
most stress. Cutting less wood on the next cut is less stress. Also, since
most tennons are not square, the chisel is not cutting 4 sides after the
first cut. Sharpening the new chisels is the key to a non stress cut.
"Upscale" <[email protected]> wrote in
news:[email protected]:
> "Wes Stewart" <n7ws_@_yahoo.com> wrote in message
>> I use half the thickness of the thinner piece, i.e. 3/8" tenon on 3/4"
>> stock.
>
> A question about mortising machines and bit usage. For cutting something
> like a 3/8 slot for a tenon, would it be acceptable to use a 1/4" bit and
> move it over 1/8" to cut the other side of the slot, or is it only
> recommended to use a 3/8" bit?
>
There was a recent thread on this either here, or ABPW. The claim was that
cutting the partial hole (?) caused a great deal of stress on the
bit/chisel combo. Seems reasonable to me, but, then, my mortising machine
is still in the factory box. I got impatient, waiting for it to ship, and
cut the mortises in the then current project down at the Adult Ed shop.
Why would you not want to use a 3/8" bit?
Patriarch
"Leon" <[email protected]> wrote in
news:[email protected]:
>
> "patriarch [email protected]>" <<patriarch> wrote in
> message news:[email protected]...
>>
>> There was a recent thread on this either here, or ABPW. The claim
>> was
> that
>> cutting the partial hole (?) caused a great deal of stress on the
>> bit/chisel combo. Seems reasonable to me, but, then, my mortising
>> machine is still in the factory box.
>
> While that sorta sounds reasonable. Cutting the first hole produces
> the most stress. Cutting less wood on the next cut is less stress.
> Also, since most tennons are not square, the chisel is not cutting 4
> sides after the first cut. Sharpening the new chisels is the key to a
> non stress cut.
>
OK, admitting as I have that MY machine is still in the box...
What I have read indicated that a proper procedure is to cut each end, and
then work towards the middle. This was/is the method that seems to work
best when mortising using the drill press and a forstner bit, prior to work
wih a hand chisel.
Cutting a hole with less than full material seems to strain the bit in that
case, as well.
Is my assumption correct that the bulk of the cutting comes from the bit,
rather than the chisel?
Patriarch,
willing to learn from the experience of others. It's cheaper.
"patriarch [email protected]>" <<patriarch> wrote in message
news:[email protected]...
>
> OK, admitting as I have that MY machine is still in the box...
Yeah. I remember, I was commenting more on the information that you had
gathered rather than you person experience.
>
> What I have read indicated that a proper procedure is to cut each end, and
> then work towards the middle. This was/is the method that seems to work
> best when mortising using the drill press and a forstner bit, prior to
work
> wih a hand chisel.
Yes, establishing a beginning and end is easier if done in the beginning.
> Cutting a hole with less than full material seems to strain the bit in
that
> case, as well.
>
> Is my assumption correct that the bulk of the cutting comes from the bit,
> rather than the chisel?
Yes. The chisel simply squares up the round hole but the chisel provides
the greatest resistance.
A little of advise if I may, If not immediately, very soon after you start
using your mortiser, sharpen the chisels. LeeValley sells a cone shaped
stone for your drill made to clean the burrs out of the inside end of the
chisel and sharpen it. Just a little bit does a lot so go easy. Then
polish the 4 sides of the chisel at the cutting end. I have a Tormek
sharpener and used the leather buffing wheel to polish the outside of the
chisel. While this may seem like over kill and especially on new chisels,
it will make a great difference in how easily the chisel and bit will plunge
into the work.
I have done it in both maple and poplar using my delta benchtop. It works. I
did not break the bit.
That only means that it *can* be done.
-Steve
"Upscale" <[email protected]> wrote in message
news:[email protected]...
> "Wes Stewart" <n7ws_@_yahoo.com> wrote in message
> > I use half the thickness of the thinner piece, i.e. 3/8" tenon on 3/4"
> > stock.
>
> A question about mortising machines and bit usage. For cutting something
> like a 3/8 slot for a tenon, would it be acceptable to use a 1/4" bit and
> move it over 1/8" to cut the other side of the slot, or is it only
> recommended to use a 3/8" bit?
>
>
"loutent" <[email protected]> wrote in message
news:030820042005131578%[email protected]...
>
> On review/input etc, I discovered that I was taking TOO LITTLE
> material with each additional plunge of the bit. The auger may
> not grab enough material if you attempt only a half-plunge. This
> deflects the fragile 1/4 bit enough to snap it. Happened to me.
The smaller 1/4" bits tend to be fragile. I recall reading several counts
in which the 1/4"ers did in deed fail more often in general. Seems many
makers of small bits make them with only 1 fluke. The bit is basically
destened to be fragile to begin with. The single fluke threw everything out
of balance and were easily broken. Great care had to be taken regardless of
the cut to prevent breaking the bit.
On Tue, 03 Aug 2004 12:00:14 -0400, [email protected] wrote:
|I am trying to determine Tenon size in relation to thickness of stock.
|Would 1/3 be about right.
|
|1/4 in tenons on 3/4 stock.
I use half the thickness of the thinner piece, i.e. 3/8" tenon on 3/4"
stock.
http://www.woodworkersjournal.com/articles/mortiseandtenon.cfm
Wes
On Tue, 03 Aug 2004 19:08:44 GMT, "Upscale" <[email protected]>
wrote:
>A question about mortising machines and bit usage. For cutting something
>like a 3/8 slot for a tenon, would it be acceptable to use a 1/4" bit and
>move it over 1/8" to cut the other side of the slot,
Not really. Morticing machines are basically drills, with a chisel
edge to clean the holes square. If you don't have the centre of the
drill bit supported, cutting performance can suffer greatly. Cutting
2x chisel width is easy, but less than 1.5x is hard.
Some machines and chisels are more tolerant than others - particularly
single spur augers, and those with augers that fit tightly into the
chisel.
--
Smert' spamionam
Here's a good link for you.
http://www.taunton.com/finewoodworking/pages/w00011.asp
Bob S.
<[email protected]> wrote in message
news:[email protected]...
> I am trying to determine Tenon size in relation to thickness of stock.
> Would 1/3 be about right.
>
> 1/4 in tenons on 3/4 stock.
>
> Nark
"Leon" <[email protected]> wrote in message
news:[email protected]...
>
> The smaller 1/4" bits tend to be fragile. I recall reading several counts
> in which the 1/4"ers did in deed fail more often in general. Seems many
> makers of small bits make them with only 1 fluke. The bit is basically
> destened to be fragile to begin with. The single fluke threw everything
out
> of balance and were easily broken. Great care had to be taken regardless
of
> the cut to prevent breaking the bit.
>
The single fluke threw everything out of balance and were easily broken.
Probably should have said, the single spur and or fluke created "uneven
stress" on the bit and they were easily broken.
You'll want to take full cuts with the bit. Smaller cuts, like the
one you propose will flex the bit resulting in a broken bit or a
mortise wall not perpendicular to the bottom (or top)
Polishing the outside faces helps a lot with getting the chisel into
the wood, as does sharpening the edges with a conical stone.
Don't forget to sharpen the auger bit.
On Tue, 03 Aug 2004 19:08:44 GMT, "Upscale" <[email protected]>
wrote:
>"Wes Stewart" <n7ws_@_yahoo.com> wrote in message
>> I use half the thickness of the thinner piece, i.e. 3/8" tenon on 3/4"
>> stock.
>
>A question about mortising machines and bit usage. For cutting something
>like a 3/8 slot for a tenon, would it be acceptable to use a 1/4" bit and
>move it over 1/8" to cut the other side of the slot, or is it only
>recommended to use a 3/8" bit?
>
On Wed, 04 Aug 2004 04:29:05 GMT, "Leon"
<[email protected]> wrote:
>
>"Leon" <[email protected]> wrote in message
>news:[email protected]...
>>
>> The smaller 1/4" bits tend to be fragile. I recall reading several counts
>> in which the 1/4"ers did in deed fail more often in general. Seems many
>> makers of small bits make them with only 1 fluke. The bit is basically
>> destened to be fragile to begin with. The single fluke threw everything
>out
>> of balance and were easily broken. Great care had to be taken regardless
>of
>> the cut to prevent breaking the bit.
>>
>The single fluke threw everything out of balance and were easily broken.
>
>Probably should have said, the single spur and or fluke created "uneven
>stress" on the bit and they were easily broken.
>
especially small diameter single flute straight edged cutters. spirals
are a bit better ballanced.