So there I was routing a 15" long 5/16 deep slot in some hard maple with
a 1/4 inch bit on a 1/2 inch shank and 12 inches into the cut the bit
sheared. This bit was one of those green Woodcraft bits that they put
on sale from time to time. I was using a pretty slow feed rate, but my
guess is that the bit failed due to heat. Any thoughts?
Larry
On Oct 8, 8:20=A0pm, Leon <lcb11211@swbelldotnet> wrote:
> On 10/8/2011 4:05 PM, Gramp's shop wrote:
>
> > So there I was routing a 15" long 5/16 deep slot in some hard maple wit=
h
> > a 1/4 inch bit on a 1/2 inch shank and 12 inches into the cut the bit
> > sheared. This bit was one of those green Woodcraft bits that they put o=
n
> > sale from time to time. I was using a pretty slow feed rate, but my
> > guess is that the bit failed due to heat. Any thoughts?
>
> > Larry
>
> Sounds like you might have been cutting too deep, especially in hard
> maple. =A0I would have made it in 2 passes.
If the finish quality matters at all, always in more than
one pass. Single pass in maple guarantees scorching.
On Sun, 9 Oct 2011 09:58:52 -0400, "dadiOH" <[email protected]>
wrote:
>Gramp's shop wrote:
>> So there I was routing a 15" long 5/16 deep slot in some hard maple
>> with a 1/4 inch bit on a 1/2 inch shank and 12 inches into the cut
>> the bit sheared. This bit was one of those green Woodcraft bits that
>> they put on sale from time to time. I was using a pretty slow feed
>> rate, but my guess is that the bit failed due to heat.
>
>> Any thoughts?
>
>Buy a new bit.
New bit, shallower cuts, and time to let the bit cool between passes.
The smaller the bit, the more quickly they overheat. DAMHIKT
--
Never trouble another for what you can do for yourself.
-- Thomas Jefferson
On Sat, 08 Oct 2011 16:05:57 -0500, Gramp's shop <[email protected]>
wrote:
>So there I was routing a 15" long 5/16 deep slot in some hard maple with
>a 1/4 inch bit on a 1/2 inch shank and 12 inches into the cut the bit
>sheared. This bit was one of those green Woodcraft bits that they put
>on sale from time to time. I was using a pretty slow feed rate, but my
>guess is that the bit failed due to heat. Any thoughts?
>
>Larry
How deep the cut? Any burning on the wood? Did the cutting edges
fail or looked burned? Or did the bit shear off below the cutters?
Was it sharp?
Inquiring minds want to know.
-Zz
On Sat, 08 Oct 2011 20:19:57 -0500, -MIKE- <[email protected]>
wrote:
>On 10/8/11 8:12 PM, Gramp's shop wrote:
>> The cuts was 5/16 deep. No burning on the wood. Cutting edges still look
>> good. Bit sheared off below the cutters. Factory sharp carbide with very
>> little use up to now.
>>
>
>I say again, bad bit. Those $5 woodcraft closeout bits are suspect to
>begin with. Depends on the lot. From what I hear, they were having
>issues with material later in production and may have switched suppliers
>when they changed the name of their house brand to WoodRiver.
>
>I still contend that 5/16" on a 1/4" bit is no sweat. With a high
>quality bit, 5/16" *is* a shallow pass. Only taking 1/2 diameter (1/8")
>is certainly safe, but also paranoid. Were your sucking out the sawdust?
I agree, defective bit.
-Zz
"dadiOH" <[email protected]> wrote in message
news:[email protected]...
> Gramp's shop wrote:
>> On 10/8/2011 9:21 PM, Robatoy wrote:
>>> On Oct 8, 5:05 pm, Gramp's shop<[email protected]> wrote:
>>>> So there I was routing a 15" long 5/16 deep slot in some hard maple
>>>> with a 1/4 inch bit on a 1/2 inch shank and 12 inches into the cut
>>>> the bit sheared. This bit was one of those green Woodcraft bits
>>>> that they put on sale from time to time. I was using a pretty slow
>>>> feed rate, but my guess is that the bit failed due to heat. Any
>>>> thoughts? Larry
>>>
>>> Having worked with a few routers and bits over the last 40 years, a
>>> 5/16 deep pass, blind (aka dado) for a 1/4" bit is not very much.
>>> BUT... to do such a cut properly, one should use an upcut spiral,
>>> because no matter what your're cutting, with whatever kind of tool,
>>> it is all about getting rid of the chips. The OP reported no
>>> burning, so I can assume that there was a nice balance of cutting
>>> speed and feed speed..and keeping in mind that Hard maple can be
>>> pretty damned hard...BUT there was no burning and yet the bit broke.
>>> The above information tells me the bit was defective/crap... but
>>> there is another possibility. Gramp... did the bit scream? ( like a
>>> bit can in hard maple)? I mean a high pitched scream? The bit could
>>> have been oscillating from side to side, whilst still cutting and
>>> not burning.. just whipping. That would be a high frequency
>>> sonic/vibration event that broke the bit. Where it broke would
>>> support that possibility. Then again, I could be talking shit.
>>
>> Well, I wouldn't call it a scream, but the tonal pitch certainly
>> changed to a higher pitch. There was significant noise coming from
>> me when I discovered the sumbitch sheared and my old replacement bit
>> was pretty much close to dead. I bought a Bosch replacement at the
>> big box, but I do have an upcut bit that I hadn't considered using. I'll
>> try it tomorrow. Thanks!
>
> Lock it down tight. Those spiral bits can pull themselves out of the
> collet and all of a sudden you are cutting deeper than you want.
Also clean the bit shank and the inside of the collet with a little lacquer
thinner, this will remove any oil film that can cause a bit to move out of
the collet.
I have had a couple of 1/4 inch shank bits fail on me. They were cheap bits
bought as a set from Canadian Tire, a source of cheap tools in Canada. I
have learned to never push them, even a little.
On Sat, 08 Oct 2011 16:05:57 -0500, Gramp's shop <[email protected]>
wrote:
>So there I was routing a 15" long 5/16 deep slot in some hard maple with
>a 1/4 inch bit on a 1/2 inch shank and 12 inches into the cut the bit
>sheared. This bit was one of those green Woodcraft bits that they put
>on sale from time to time. I was using a pretty slow feed rate, but my
>guess is that the bit failed due to heat. Any thoughts?
>
>Larry
I go by the rule that the depth of the cut should never be more than
the diameter of the cutter.
--
Jack Novak
Buffalo, NY - USA
On Oct 8, 4:17=A0pm, Nova <[email protected]> wrote:
> On Sat, 08 Oct 2011 16:05:57 -0500, Gramp's shop <[email protected]>
> wrote:
>
> >So there I was routing a 15" long 5/16 deep slot in some hard maple with
> >a 1/4 inch bit on a 1/2 inch shank and 12 inches into the cut the bit
> >sheared. =A0This bit was one of those green Woodcraft bits that they put
> >on sale from time to time. =A0I was using a pretty slow feed rate, but m=
y
> >guess is that the bit failed due to heat. =A0Any thoughts?
>
> >Larry
>
> I go by the rule that the depth of the cut should never be more than
> the diameter of the cutter.
> --
> Jack Novak
> Buffalo, NY - USA
I take shallow passes too. But I also have to wonder if the bit was
defective. How old was it.
This is one reason I transitioned over to 1/2" shank bits. I had a
1/4" bit fail several years ago and felt a little lucky I didn't get
hurt.
RonB
On Oct 8, 5:05=A0pm, Gramp's shop <[email protected]> wrote:
> So there I was routing a 15" long 5/16 deep slot in some hard maple with
> a 1/4 inch bit on a 1/2 inch shank and 12 inches into the cut the bit
> sheared. =A0This bit was one of those green Woodcraft bits that they put
> on sale from time to time. =A0I was using a pretty slow feed rate, but my
> guess is that the bit failed due to heat. =A0Any thoughts?
>
> Larry
Having worked with a few routers and bits over the last 40 years, a
5/16 deep pass, blind (aka dado) for a 1/4" bit is not very much.
BUT... to do such a cut properly, one should use an upcut spiral,
because no matter what your're cutting, with whatever kind of tool, it
is all about getting rid of the chips. The OP reported no burning, so
I can assume that there was a nice balance of cutting speed and feed
speed..and keeping in mind that Hard maple can be pretty damned
hard...BUT there was no burning and yet the bit broke.
The above information tells me the bit was defective/crap... but there
is another possibility. Gramp... did the bit scream? ( like a bit can
in hard maple)? I mean a high pitched scream? The bit could have been
oscillating from side to side, whilst still cutting and not burning..
just whipping. That would be a high frequency sonic/vibration event
that broke the bit. Where it broke would support that possibility.
Then again, I could be talking shit.
On Oct 8, 10:49=A0pm, -MIKE- <[email protected]> wrote:
> On 10/8/11 9:21 PM, Robatoy wrote:
>
>
>
>
>
>
>
>
>
> > On Oct 8, 5:05 pm, Gramp's shop<[email protected]> =A0wrote:
> >> So there I was routing a 15" long 5/16 deep slot in some hard maple wi=
th
> >> a 1/4 inch bit on a 1/2 inch shank and 12 inches into the cut the bit
> >> sheared. =A0This bit was one of those green Woodcraft bits that they p=
ut
> >> on sale from time to time. =A0I was using a pretty slow feed rate, but=
my
> >> guess is that the bit failed due to heat. =A0Any thoughts?
>
> >> Larry
>
> > Having worked with a few routers and bits over the last 40 years, a
> > 5/16 deep pass, blind (aka dado) for a 1/4" bit is not very much.
> > BUT... to do such a cut properly, one should use an upcut spiral,
> > because no matter what your're cutting, with whatever kind of tool, it
> > is all about getting rid of the chips. The OP reported no burning, so
> > I can assume that there was a nice balance of cutting speed and feed
> > speed..and keeping in mind that Hard maple can be pretty damned
> > hard...BUT there was no burning and yet the bit broke.
> > The above information tells me the bit was defective/crap... but there
> > is another possibility. Gramp... did the bit scream? ( like a bit can
> > in hard maple)? I mean a high pitched scream? The bit could have been
> > oscillating from side to side, whilst still cutting and not burning..
> > just whipping. That would be a high frequency sonic/vibration event
> > that broke the bit. Where it broke would support that possibility.
> > Then again, I could be talking shit.
>
> You're always talking shit. =A0Even when it's good shit, it's still shit.
> =A0 =A0:-)
>
Well I oughtta
On Oct 9, 11:43=A0am, "EXT" <[email protected]> wrote:
> "dadiOH" <[email protected]> wrote in message
>
> news:[email protected]...
>
>
>
>
>
>
>
>
>
> > Gramp's shop wrote:
> >> On 10/8/2011 9:21 PM, Robatoy wrote:
> >>> On Oct 8, 5:05 pm, Gramp's shop<[email protected]> =A0wrote:
> >>>> So there I was routing a 15" long 5/16 deep slot in some hard maple
> >>>> with a 1/4 inch bit on a 1/2 inch shank and 12 inches into the cut
> >>>> the bit sheared. =A0This bit was one of those green Woodcraft bits
> >>>> that they put on sale from time to time. =A0I was using a pretty slo=
w
> >>>> feed rate, but my guess is that the bit failed due to heat. =A0Any
> >>>> thoughts? Larry
>
> >>> Having worked with a few routers and bits over the last 40 years, a
> >>> 5/16 deep pass, blind (aka dado) for a 1/4" bit is not very much.
> >>> BUT... to do such a cut properly, one should use an upcut spiral,
> >>> because no matter what your're cutting, with whatever kind of tool,
> >>> it is all about getting rid of the chips. The OP reported no
> >>> burning, so I can assume that there was a nice balance of cutting
> >>> speed and feed speed..and keeping in mind that Hard maple can be
> >>> pretty damned hard...BUT there was no burning and yet the bit broke.
> >>> The above information tells me the bit was defective/crap... but
> >>> there is another possibility. Gramp... did the bit scream? ( like a
> >>> bit can in hard maple)? I mean a high pitched scream? The bit could
> >>> have been oscillating from side to side, whilst still cutting and
> >>> not burning.. just whipping. That would be a high frequency
> >>> sonic/vibration event that broke the bit. Where it broke would
> >>> support that possibility. Then again, I could be talking shit.
>
> >> Well, I wouldn't call it a scream, but the tonal pitch certainly
> >> changed to a higher pitch. =A0There was significant noise coming from
> >> me when I discovered the sumbitch sheared and my old replacement bit
> >> was pretty much close to dead. =A0I bought a Bosch replacement at the
> >> big box, but I do have an upcut bit that I hadn't considered using. I'=
ll
> >> try it tomorrow. =A0Thanks!
>
> > Lock it down tight. =A0Those spiral bits can pull themselves out of the
> > collet and all of a sudden you are cutting deeper than you want.
>
> Also clean the bit shank and the inside of the collet with a little lacqu=
er
> thinner, this will remove any oil film that can cause a bit to move out o=
f
> the collet.
>
> I have had a couple of 1/4 inch shank bits fail on me. They were cheap bi=
ts
> bought as a set from Canadian Tire, a source of cheap tools in Canada. I
> have learned to never push them, even a little.
Good advice.
In article <[email protected]>, [email protected] says...
>
> Gramp's shop wrote:
> > On 10/8/2011 9:21 PM, Robatoy wrote:
> >> On Oct 8, 5:05 pm, Gramp's shop<[email protected]> wrote:
> >>> So there I was routing a 15" long 5/16 deep slot in some hard maple
> >>> with a 1/4 inch bit on a 1/2 inch shank and 12 inches into the cut
> >>> the bit sheared. This bit was one of those green Woodcraft bits
> >>> that they put on sale from time to time. I was using a pretty slow
> >>> feed rate, but my guess is that the bit failed due to heat. Any
> >>> thoughts? Larry
> >>
> >> Having worked with a few routers and bits over the last 40 years, a
> >> 5/16 deep pass, blind (aka dado) for a 1/4" bit is not very much.
> >> BUT... to do such a cut properly, one should use an upcut spiral,
> >> because no matter what your're cutting, with whatever kind of tool,
> >> it is all about getting rid of the chips. The OP reported no
> >> burning, so I can assume that there was a nice balance of cutting
> >> speed and feed speed..and keeping in mind that Hard maple can be
> >> pretty damned hard...BUT there was no burning and yet the bit broke.
> >> The above information tells me the bit was defective/crap... but
> >> there is another possibility. Gramp... did the bit scream? ( like a
> >> bit can in hard maple)? I mean a high pitched scream? The bit could
> >> have been oscillating from side to side, whilst still cutting and
> >> not burning.. just whipping. That would be a high frequency
> >> sonic/vibration event that broke the bit. Where it broke would
> >> support that possibility. Then again, I could be talking shit.
> >
> > Well, I wouldn't call it a scream, but the tonal pitch certainly
> > changed to a higher pitch. There was significant noise coming from
> > me when I discovered the sumbitch sheared and my old replacement bit
> > was pretty much close to dead. I bought a Bosch replacement at the
> > big box, but I do have an upcut bit that I hadn't considered using. I'll
> > try it tomorrow. Thanks!
>
> Lock it down tight. Those spiral bits can pull themselves out of the collet
> and all of a sudden you are cutting deeper than you want.
Also, if possible use a featherboard. Usually when I break a bit it's
because I didn't have the work's movement solidly constrained.
On 10/8/2011 4:05 PM, Gramp's shop wrote:
> So there I was routing a 15" long 5/16 deep slot in some hard maple with
> a 1/4 inch bit on a 1/2 inch shank and 12 inches into the cut the bit
> sheared. This bit was one of those green Woodcraft bits that they put on
> sale from time to time. I was using a pretty slow feed rate, but my
> guess is that the bit failed due to heat. Any thoughts?
>
> Larry
Sounds like you might have been cutting too deep, especially in hard
maple. I would have made it in 2 passes.
The cuts was 5/16 deep. No burning on the wood. Cutting edges still
look good. Bit sheared off below the cutters. Factory sharp carbide
with very little use up to now.
On 10/8/2011 5:32 PM, Zz Yzx wrote:
> On Sat, 08 Oct 2011 16:05:57 -0500, Gramp's shop<[email protected]>
> wrote:
>
>> So there I was routing a 15" long 5/16 deep slot in some hard maple with
>> a 1/4 inch bit on a 1/2 inch shank and 12 inches into the cut the bit
>> sheared. This bit was one of those green Woodcraft bits that they put
>> on sale from time to time. I was using a pretty slow feed rate, but my
>> guess is that the bit failed due to heat. Any thoughts?
>>
>> Larry
>
> How deep the cut? Any burning on the wood? Did the cutting edges
> fail or looked burned? Or did the bit shear off below the cutters?
> Was it sharp?
>
> Inquiring minds want to know.
>
> -Zz
On 10/8/11 4:05 PM, Gramp's shop wrote:
> So there I was routing a 15" long 5/16 deep slot in some hard maple with
> a 1/4 inch bit on a 1/2 inch shank and 12 inches into the cut the bit
> sheared. This bit was one of those green Woodcraft bits that they put on
> sale from time to time. I was using a pretty slow feed rate, but my
> guess is that the bit failed due to heat. Any thoughts?
>
> Larry
Bad bit. 5/16" *is* a shallow pass.
--
-MIKE-
"Playing is not something I do at night, it's my function in life"
--Elvin Jones (1927-2004)
--
http://mikedrums.com
[email protected]
---remove "DOT" ^^^^ to reply
On 10/8/11 8:12 PM, Gramp's shop wrote:
> The cuts was 5/16 deep. No burning on the wood. Cutting edges still look
> good. Bit sheared off below the cutters. Factory sharp carbide with very
> little use up to now.
>
I say again, bad bit. Those $5 woodcraft closeout bits are suspect to
begin with. Depends on the lot. From what I hear, they were having
issues with material later in production and may have switched suppliers
when they changed the name of their house brand to WoodRiver.
I still contend that 5/16" on a 1/4" bit is no sweat. With a high
quality bit, 5/16" *is* a shallow pass. Only taking 1/2 diameter (1/8")
is certainly safe, but also paranoid. Were your sucking out the sawdust?
--
-MIKE-
"Playing is not something I do at night, it's my function in life"
--Elvin Jones (1927-2004)
--
http://mikedrums.com
[email protected]
---remove "DOT" ^^^^ to reply
On 10/8/11 9:21 PM, Robatoy wrote:
> On Oct 8, 5:05 pm, Gramp's shop<[email protected]> wrote:
>> So there I was routing a 15" long 5/16 deep slot in some hard maple with
>> a 1/4 inch bit on a 1/2 inch shank and 12 inches into the cut the bit
>> sheared. This bit was one of those green Woodcraft bits that they put
>> on sale from time to time. I was using a pretty slow feed rate, but my
>> guess is that the bit failed due to heat. Any thoughts?
>>
>> Larry
>
> Having worked with a few routers and bits over the last 40 years, a
> 5/16 deep pass, blind (aka dado) for a 1/4" bit is not very much.
> BUT... to do such a cut properly, one should use an upcut spiral,
> because no matter what your're cutting, with whatever kind of tool, it
> is all about getting rid of the chips. The OP reported no burning, so
> I can assume that there was a nice balance of cutting speed and feed
> speed..and keeping in mind that Hard maple can be pretty damned
> hard...BUT there was no burning and yet the bit broke.
> The above information tells me the bit was defective/crap... but there
> is another possibility. Gramp... did the bit scream? ( like a bit can
> in hard maple)? I mean a high pitched scream? The bit could have been
> oscillating from side to side, whilst still cutting and not burning..
> just whipping. That would be a high frequency sonic/vibration event
> that broke the bit. Where it broke would support that possibility.
> Then again, I could be talking shit.
You're always talking shit. Even when it's good shit, it's still shit.
:-)
--
-MIKE-
"Playing is not something I do at night, it's my function in life"
--Elvin Jones (1927-2004)
--
http://mikedrums.com
[email protected]
---remove "DOT" ^^^^ to reply
Gramp's shop wrote:
> So there I was routing a 15" long 5/16 deep slot in some hard maple
> with a 1/4 inch bit on a 1/2 inch shank and 12 inches into the cut
> the bit sheared. This bit was one of those green Woodcraft bits that
> they put on sale from time to time. I was using a pretty slow feed
> rate, but my guess is that the bit failed due to heat.
> Any thoughts?
Buy a new bit.
--
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
Gramp's shop wrote:
> On 10/8/2011 9:21 PM, Robatoy wrote:
>> On Oct 8, 5:05 pm, Gramp's shop<[email protected]> wrote:
>>> So there I was routing a 15" long 5/16 deep slot in some hard maple
>>> with a 1/4 inch bit on a 1/2 inch shank and 12 inches into the cut
>>> the bit sheared. This bit was one of those green Woodcraft bits
>>> that they put on sale from time to time. I was using a pretty slow
>>> feed rate, but my guess is that the bit failed due to heat. Any
>>> thoughts? Larry
>>
>> Having worked with a few routers and bits over the last 40 years, a
>> 5/16 deep pass, blind (aka dado) for a 1/4" bit is not very much.
>> BUT... to do such a cut properly, one should use an upcut spiral,
>> because no matter what your're cutting, with whatever kind of tool,
>> it is all about getting rid of the chips. The OP reported no
>> burning, so I can assume that there was a nice balance of cutting
>> speed and feed speed..and keeping in mind that Hard maple can be
>> pretty damned hard...BUT there was no burning and yet the bit broke.
>> The above information tells me the bit was defective/crap... but
>> there is another possibility. Gramp... did the bit scream? ( like a
>> bit can in hard maple)? I mean a high pitched scream? The bit could
>> have been oscillating from side to side, whilst still cutting and
>> not burning.. just whipping. That would be a high frequency
>> sonic/vibration event that broke the bit. Where it broke would
>> support that possibility. Then again, I could be talking shit.
>
> Well, I wouldn't call it a scream, but the tonal pitch certainly
> changed to a higher pitch. There was significant noise coming from
> me when I discovered the sumbitch sheared and my old replacement bit
> was pretty much close to dead. I bought a Bosch replacement at the
> big box, but I do have an upcut bit that I hadn't considered using. I'll
> try it tomorrow. Thanks!
Lock it down tight. Those spiral bits can pull themselves out of the collet
and all of a sudden you are cutting deeper than you want.
--
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
In news:[email protected],
Gramp's shop <[email protected]> typed:
> So there I was routing a 15" long 5/16 deep slot in some
> hard maple with a 1/4 inch bit on a 1/2 inch shank and 12
> inches into the cut the bit sheared. This bit was one of
> those green Woodcraft bits that they put on sale from
> time to time. I was using a pretty slow feed rate, but
> my guess is that the bit failed due to heat. Any
> thoughts?
> Larry
Well, from what I can see, the overheating ate the bit hardness and hitting
that second knot in the wood at that unreasonably high speed I saw you
using, was the cause. Oh, and since you bottomrf out the bit, you diidn't
get a perfect alignment either; it was wobbling just befors t broke. But
that's all I could see from here.
On 10/8/2011 9:21 PM, Robatoy wrote:
> On Oct 8, 5:05 pm, Gramp's shop<[email protected]> wrote:
>> So there I was routing a 15" long 5/16 deep slot in some hard maple with
>> a 1/4 inch bit on a 1/2 inch shank and 12 inches into the cut the bit
>> sheared. This bit was one of those green Woodcraft bits that they put
>> on sale from time to time. I was using a pretty slow feed rate, but my
>> guess is that the bit failed due to heat. Any thoughts?
>>
>> Larry
>
> Having worked with a few routers and bits over the last 40 years, a
> 5/16 deep pass, blind (aka dado) for a 1/4" bit is not very much.
> BUT... to do such a cut properly, one should use an upcut spiral,
> because no matter what your're cutting, with whatever kind of tool, it
> is all about getting rid of the chips. The OP reported no burning, so
> I can assume that there was a nice balance of cutting speed and feed
> speed..and keeping in mind that Hard maple can be pretty damned
> hard...BUT there was no burning and yet the bit broke.
> The above information tells me the bit was defective/crap... but there
> is another possibility. Gramp... did the bit scream? ( like a bit can
> in hard maple)? I mean a high pitched scream? The bit could have been
> oscillating from side to side, whilst still cutting and not burning..
> just whipping. That would be a high frequency sonic/vibration event
> that broke the bit. Where it broke would support that possibility.
> Then again, I could be talking shit.
Well, I wouldn't call it a scream, but the tonal pitch certainly changed
to a higher pitch. There was significant noise coming from me when I
discovered the sumbitch sheared and my old replacement bit was pretty
much close to dead. I bought a Bosch replacement at the big box, but I
do have an upcut bit that I hadn't considered using. I'll try it
tomorrow. Thanks!
"Gramp's shop" wrote in message news:[email protected]...
So there I was routing a 15" long 5/16 deep slot in some hard maple with
a 1/4 inch bit on a 1/2 inch shank and 12 inches into the cut the bit
sheared. This bit was one of those green Woodcraft bits that they put
on sale from time to time. I was using a pretty slow feed rate, but my
guess is that the bit failed due to heat. Any thoughts?
-------------------------------------------------------------------------------------------------
If it was cutting full diameter, that is the hardest cut a router bit can
do. Depth should be half the diameter for a cut like that. A 1/4 inch cutter
does not benefit by a 1/2 inch shank. The transition in cross section sets
up a stress riser that negates the advantage of the larger shank.