I had several dated bits that were in need of upgrading. Never having
used Freud, I purchased a few.
I always inspect a new bit before use and I noticed a potential
problem with one of them - an ogee bit. On the interior or center of
the cardide cutter, each cutter has a weld only at the top and bottom
- the center portion is void of a weld. If only one cutter had this
type of weld, I would think it was a defect. However, because each
cutter has the same type of weld, which by the way is symmetric and
neatly done, it looks to be intentional.
Is there a reason for this type of weld or do I just have a defective
bit?
Thanks,
Dave
"Bay Area Dave" <[email protected]> wrote in message
news:[email protected]...
> ah, like what I just cleaned off my WWII the other day. now it's all
> pretty and shiny again!
Here is a funny situation.. I was cleaning my WWII Saturday after cutting
up a LOT of Ipe. Ipe is a VERY hard wood and besides the brown saw dust,
you also get a bright Yellowy Green "Powdery Dust".
Any way that yellow dust reacts with body sweat and citrus based cleaners.
I use CMT's Formula 2050 to clean my bits and blades. When your sweat or
the citrus based cleaner touches the yellow dust it instantly turns "BLOOD
RED". Needless to say the first few times I worked with Ipe I thought that
I had severely cut myself.
Just thought I'd let the group know that I spoke with Freud today.
The technical rep said that the gaps in the weld along the center of
the carbide cutter are NORMAL and part of Freud's new design that
they're phasing in on several different bits. He said the idea behind
the gaps is to provide additional air movement and hence heat
dissipation at the center of the bit. Not all of Freud's bits have
this design yet but eventually they will.
Dave
Bay Area Dave <[email protected]> wrote in message news:<[email protected]>...
> Freud stuff is pretty much ok, Dave. I'd do as Dex suggested and just
> give them a polite call Monday morning.
>
> dave
>
> Dave wrote:
>
> > I had several dated bits that were in need of upgrading. Never having
> > used Freud, I purchased a few.
> >
> > I always inspect a new bit before use and I noticed a potential
> > problem with one of them - an ogee bit. On the interior or center of
> > the cardide cutter, each cutter has a weld only at the top and bottom
> > - the center portion is void of a weld. If only one cutter had this
> > type of weld, I would think it was a defect. However, because each
> > cutter has the same type of weld, which by the way is symmetric and
> > neatly done, it looks to be intentional.
> >
> > Is there a reason for this type of weld or do I just have a defective
> > bit?
> >
> > Thanks,
> > Dave
Could be BS from Freud but I find it unlikely that a manufacturer,
which has built a reputation for producing primarily high-end tools,
would eliminate 1/8 of an inch of brazing to reduce cost; while
sacrificing quality, performance, and consumer safety. I also find it
unlikely that this decision was made without any testing whatsoever.
I mean do you really think someone was sitting in the board room of a
mulit-million dollar corporation one day and just said: "I have an
great idea to reduce the manufacturing cost of our router bit line,
let's give it a go without conducting any safety or performance
research - whatcha guys think?" I could be wrong, just my opinion.
I would be interested in hearing from someone who purchases a newer
lot 5/16 radius roman ogee bit to see if it has the same type of weld
though.
Dave
"Edwin Pawlowski" <[email protected]> wrote in message news:<[email protected]>...
> "LD" <[email protected]> wrote in message
>
> > The shaft of the bit acts as a heatsink.
> > Any gaps between the carbide and the shaft will impair cooling.
> > This *new design* may work well enough, but it won't run cooler.
>
> After the heatsink is sunk where does the heat go? Why would not increased
> air flow not make a difference? What is the actual heat flow across the
> section that is welded versus the open area?
>
> Seems as though we are dealing in supposition and have no facts to back up
> anything. Could be BS from Freud as cost of welding is reduced, but than
> again, they may have spent a million bucks doing sophisticated testing.
> Until I see numbers on one side or the other, I'll keep an open mind.
> Ed
Don't know, but I'd go compare the brazing on your bit with the others of
its type by taking it back. If the others are fully brazed, as are all I've
seen, give it back.
Come to think, with the brittleness of carbide, I'd give back anything that
wasn't fully and firmly supported.
"Dave" <[email protected]> wrote in message
news:[email protected]...
> I always inspect a new bit before use and I noticed a potential
> problem with one of them - an ogee bit. On the interior or center of
> the cardide cutter, each cutter has a weld only at the top and bottom
> - the center portion is void of a weld. If only one cutter had this
> type of weld, I would think it was a defect. However, because each
> cutter has the same type of weld, which by the way is symmetric and
> neatly done, it looks to be intentional.
Did they address the brittleness of unsupported carbide?
Hate to be their Beta tester and eat a chunk of carbide after impacting a
knot.
"Dave" <[email protected]> wrote in message
news:[email protected]...
> Just thought I'd let the group know that I spoke with Freud today.
>
> The technical rep said that the gaps in the weld along the center of
> the carbide cutter are NORMAL and part of Freud's new design that
> they're phasing in on several different bits. He said the idea behind
> the gaps is to provide additional air movement and hence heat
> dissipation at the center of the bit. Not all of Freud's bits have
> this design yet but eventually they will.
Point is, there are more efficient means of heat transfer. In the case of
the router bit, metal-to-metal is by far more effective than air, and with
no flow-through provisions, I fear the only thing blowing smoke here is the
rep the OP spoke with.
"Edwin Pawlowski" <[email protected]> wrote in message
news:[email protected]...
>
> > > >
> > > In a watercooled engine, water is the heatsink. It would not
> > > be such a good idea to drain the water to increase airflow.
>
> True, but once the water carries the heat to the radiator, you need
airflow
> to remove the heat from the water. Try eliminating the airflow. Or you
> need one hell of a water tank to absorb all the heat.
>
> Ed
> [email protected]
> http://pages.cthome.net/edhome
>
>
Nice point, but don't push the second paragraph too close to the cliff, it
won't fly. Heat sunk into the metal flows out of the metal at a distance.
Greater warmed surface, greater outflow. Also, trapped air pockets don't
cool. Regardless the usability, the reason given is BS. Probably saves a
dime a dozen.
Wonder if they whistle?
"Edwin Pawlowski" <[email protected]> wrote in message
news:[email protected]...
>
> "George" <[email protected]> wrote in message
> news:[email protected]...
> > Point is, there are more efficient means of heat transfer. In the case
of
> > the router bit, metal-to-metal is by far more effective than air, and
with
> > no flow-through provisions, I fear the only thing blowing smoke here is
> the
> > rep the OP spoke with.
>
> More efficient, but there is a limit. My point is that no one can
criticize
> the idea unless they can back it up with facts. I've not seen any.
>
> The cutting edge build up heat and transfers it to the shaft. The shaft
> heats up and transfers it to the router. There is a maximum amount of
heat
> it can absorb in a given time and once that is reached, the cutting edge
> will overheat if friction continues to heat it. If two spots are enough
to
> reach the thermal capacity of the heatsink's ability to absorb it, other
> means may then become more efficient to dissipate the heat. Maybe air
flow
> will help. I honestly don't know, but I'm not going to deny Freud's claim
> unless I could prove it was BS.
> Ed
>
>
Find an eighth-grader with his physical science book and review
conduction/convection.
A physics text with computation might be a bit much for you until you get
the concepts down.
"Edwin Pawlowski" <[email protected]> wrote in message
news:[email protected]...
>
> "George" <[email protected]> wrote in message
> news:[email protected]...
> > Nice point, but don't push the second paragraph too close to the cliff,
it
> > won't fly. >
>
> I'm sure you'll never agree, but neither will you come up with a fact
> showing heat buildup and flow rates.
>
> Maybe they can make them whistle and change pitch if you cut at the wrong
> depth.
> Ed
>
>
And without the white goo, nothing works! Just that little bit of "air"
slows the transfer.
Oh yes, the fan is necessary precisely because air, with its lower (and with
heat, lowering) density can't remove the heat available from the metal
quickly enough with its widely-spaced molecules, and requires a fresh supply
from the fan.
"LD" <[email protected]> wrote in message
news:[email protected]...
>
> ----- Original Message -----
> From: "Edwin Pawlowski" <[email protected]>
>
> >Why do they put cooling fans on computer chips and auto radiators?
>
> The fan isn't on the chip..The fan is on the heatsink and the heatsink is
on
> the chip.
> Most AMD chips will self destruct in seconds without a heatsink, DAMHIKT
> That auto radiator arguement is not applicable (it doesn't hold water :-)
>
> >You can still build heat at the source if the sink cannot absorb it fast
> enough.
>
> Exactly! Greater contact area yields more rapid heat transfer.
Nope, I'm not grasping at straws, but standing on science.
"Edwin Pawlowski" <[email protected]> wrote in message
news:[email protected]...
>
> Fan? Oh wait, fan = spinning router bit. OK we do agree then.
>
>
> > >
> > In a watercooled engine, water is the heatsink. It would not
> > be such a good idea to drain the water to increase airflow.
True, but once the water carries the heat to the radiator, you need airflow
to remove the heat from the water. Try eliminating the airflow. Or you
need one hell of a water tank to absorb all the heat.
Ed
[email protected]
http://pages.cthome.net/edhome
Didn't know that! All I've heard about Ipe is that it's one tough
hombre. (and expensive)
dave
Leon wrote:
> "Bay Area Dave" <[email protected]> wrote in message
> news:[email protected]...
>
>>ah, like what I just cleaned off my WWII the other day. now it's all
>>pretty and shiny again!
>
>
> Here is a funny situation.. I was cleaning my WWII Saturday after cutting
> up a LOT of Ipe. Ipe is a VERY hard wood and besides the brown saw dust,
> you also get a bright Yellowy Green "Powdery Dust".
>
> Any way that yellow dust reacts with body sweat and citrus based cleaners.
> I use CMT's Formula 2050 to clean my bits and blades. When your sweat or
> the citrus based cleaner touches the yellow dust it instantly turns "BLOOD
> RED". Needless to say the first few times I worked with Ipe I thought that
> I had severely cut myself.
>
>
"Bay Area Dave" <[email protected]> wrote in message
news:9%[email protected]...
> Didn't know that! All I've heard about Ipe is that it's one tough
> hombre. (and expensive)
Not too expensive but that all depends on where you live. I am buying it
for about $6.50 per BF.
"George" <[email protected]> wrote in message
news:[email protected]...
> Did they address the brittleness of unsupported carbide?
>
> Hate to be their Beta tester and eat a chunk of carbide after impacting a
> knot.
No kidding... The idea makes since but it seems that the carbide should be
fully supported. Seems an air gap would simply fill with debris.
ah, yeah, what Tom said...I think...or not. What DID you say, Tom?
That Freud knows what they are doing? :)
I love those 50 cent words like "adiabatic"! "Delta T" is a great term
to sprinkle around from time to time. Is that when what you get when
Delta Force meets Mr. T?
dave
Tom Bergman wrote:
> I will hypothesize a completely contrarian argument to what's been
> constructed so far. One could argue that the ideal bit would have NO
> heat transfer between the carbide cutter and the body. In such a
> design, the carbide would more quickly heat up to it's stabilization
> temperature, i.e., the temperature at which it dissipates (largely
> through convection, spinning through the air at 20,000 rpm, I would
> guess convection doesn't amount to diddley-squat after the first
> couple minutes) the same amount of heat it generates. While the
> temperature of the carbide may be higher (marginally after a few
> minutes as compared to heating the entire bit imo), the temperature
> gradients throughout the carbide would be smaller. This would result
> in more even thermal expansion of the carbide, better retention of the
> profile, probably reduced vibration, and potentially less stress at
> the carbide/braze and certainly the braze/body interfaces created by
> the thermal expansion (or least a more even stress).
>
> With the heat sink model bit, there will be a relatively large delta T
> between the carbide cutter and the shaft, as compared to the preceding
> description (the delta T across the carbide will be very small,
> although the T will be higher), thus you have all kinds of differing
> thermal expansion rates and corresponding stresses induced.
>
> Now I can speculate that the ventilated router bit, aka the Freud
> model, is a reasonable compromise given you need to braze the
> carbide, and all such materials have high thermal conductivity as
> metals (and sufficient flexibility). By increasing airflow behind the
> carbide (although how they keep it filling with crud is beyond me) you
> reduce the heat transfer to the bit by lowering the temperature of the
> carbide and at the same time reduce the T of the carbide overall
> (although I'd think you'd have higher stress than the adiabatic
> interface model first described).
>
> Or it could all be cost-saving BS.
>
>
> "George" <[email protected]> wrote in message news:<[email protected]>...
>
>>Point is, there are more efficient means of heat transfer. In the case of
>>the router bit, metal-to-metal is by far more effective than air, and with
>>no flow-through provisions, I fear the only thing blowing smoke here is the
>>rep the OP spoke with.
>>
>>"Edwin Pawlowski" <[email protected]> wrote in message
>>news:[email protected]...
>>
>>>>> In a watercooled engine, water is the heatsink. It would not
>>>>>be such a good idea to drain the water to increase airflow.
>>>
>>>True, but once the water carries the heat to the radiator, you need
>>
>> airflow
>>
>>>to remove the heat from the water. Try eliminating the airflow. Or you
>>>need one hell of a water tank to absorb all the heat.
>>>
>>>Ed
>>>[email protected]
>>>http://pages.cthome.net/edhome
>>>
>>>
----- Original Message -----
From: "Dave" <[email protected]>
Newsgroups: rec.woodworking
Sent: Monday, March 01, 2004 9:15 AM
Subject: Re: Defective Freud Router Bit? - Response from Freud
>He said the idea behind
> the gaps is to provide additional air movement and hence heat
> dissipation at the center of the bit. Not all of Freud's bits have
> this design yet but eventually they will.
This sounds like deep Freud BS. The shaft of the bit acts as a heatsink.
Any gaps between the carbide and the shaft will impair cooling.
This *new design* may work well enough, but it won't run cooler.
I pay too much for all hardwoods here. the cheapest, poplar, is around
$2 bucks a board foot. It's disgusting how expensive stuff is in the
Bay Area. If I didn't have a house with Prop. 13 tax coverage I'd have
left the area.
dave
Leon wrote:
> "Bay Area Dave" <[email protected]> wrote in message
> news:9%[email protected]...
>
>>Didn't know that! All I've heard about Ipe is that it's one tough
>>hombre. (and expensive)
>
>
>
> Not too expensive but that all depends on where you live. I am buying it
> for about $6.50 per BF.
>
>
"LD" <[email protected]> wrote in message
> Seriously? It goes to where there is less heat. Up the shaft, collet,
pole
> pieces, windings...
> Routers have a fan in the housing. Eventually heat is radiated or
conducted
> into the surroundings,
> Then into the universe.
Sure, but along the way there are non-mettalic parts that do not transfer
the heat very well and the heat will build up at the source if it is not
carried away fast enough. Routers are made to spin its, not cool things.
>
> >Why do they put cooling fans on computer chips and auto radiators?
>
> The fan isn't on the chip..The fan is on the heatsink and the heatsink is
on
> the chip.
> Most AMD chips will self destruct in seconds without a heatsink, DAMHIKT
> That auto radiator arguement is not applicable (it doesn't hold water :-)
Right, but the heatsink alone is not capable of doing the job, thus the
cooling fan required on many chips. Same with the auto radiator, even
moreso. The water is the heatsink, but it cannot take the heat away from
the engine fast enough, so it is assited by air flowing over a radiator.
Eliminate the air and you need a larger mass of water. Air Cooled ingines
have limits for the same reason.
>
> I did not intend to impune Freud products, management or their families.
> I own a few F bits and blades. They perform fine
> Maybe the new weld contact actually has a greater cross section and really
> does
> enhance cooling. Or, maybe, whomever spoke to original poster was either
> uninformed or dismissive. Maybe it was coffee break.
My point in this was that you can't just make blanket statements that Freud
is wrong unless you can back it up with fact applicable to the particular
situation. It may be pure BS, but neither of us had actual measurements to
prove them right or wrong.
"Bay Area Dave" <[email protected]> wrote in message
news:[email protected]...
> are you sure? there are billions of vehicles on the roads with radiators
> relying on air passing through the fins to keep ole nellie from blowing
up.
>
> dave
>
In a watercooled engine, water is the heatsink. It would not
be such a good idea to drain the water to increase airflow.
I'd bet if you gave the fine folks at Freud a call or email, they could tell
you real quick. IF it is a defect, they probably would exchange it for you
promptly. Freud has a reputation for both great products and excellent
customer service. I would give them a shot at it before posting to a forum.
DexAZ
"Dave" <[email protected]> wrote in message
news:[email protected]...
> I had several dated bits that were in need of upgrading. Never having
> used Freud, I purchased a few.
>
> I always inspect a new bit before use and I noticed a potential
> problem with one of them - an ogee bit. On the interior or center of
> the cardide cutter, each cutter has a weld only at the top and bottom
> - the center portion is void of a weld. If only one cutter had this
> type of weld, I would think it was a defect. However, because each
> cutter has the same type of weld, which by the way is symmetric and
> neatly done, it looks to be intentional.
>
> Is there a reason for this type of weld or do I just have a defective
> bit?
>
> Thanks,
> Dave
"George" <[email protected]> wrote in message
news:[email protected]...
> Find an eighth-grader with his physical science book and review
> conduction/convection.
>
> A physics text with computation might be a bit much for you until you get
> the concepts down.
I read the book. Show me the figures proving that in this particular
situation that heat dissipation it better with solid versus vented. I've
not seen one number from you proving that there is enough mass to dissipate
the heat properly. I've not seen your computation on this particular
situation and until I do, you're just blowing hot air.
I'm not disputing that metal conducts better than air, but if the metal
reaches its capacity and you can't add more metal, the gap is not a
hindrance. You are not able to carry through the entire equation. Did you
do any testing? Do you know what temperature and specific heats is
involved?
You brought up the book on physics, but you've yet to provide real facts to
support the router bit heat transfer information. What numbers do you
suggest we use for the calculations?
Ed
Uhhhhh, tell my ex-wife that! If you want her phone number, look on any
truckstop bathroom wall. I'm sure it's there.
--
"Cartoons don't have any deep meaning.
They're just stupid drawings that give you a cheap laugh."
Homer Simpson
Jerry© The Phoneman®
"LD" <[email protected]> wrote in message
news:[email protected]...
>
> "Bay Area Dave" <[email protected]> wrote in message
> news:[email protected]...
> > are you sure? there are billions of vehicles on the roads with radiators
> > relying on air passing through the fins to keep ole nellie from blowing
> up.
> >
> > dave
> >
> In a watercooled engine, water is the heatsink. It would not
> be such a good idea to drain the water to increase airflow.
>
>
>
>
>
cool, thanks for getting back to us on the weld thing, Dave. I'm never
shy about calling a manufacturer for clarifications on products I buy or
are contemplating purchasing. Good to know the weld style is by design.
dave
Dave wrote:
> Just thought I'd let the group know that I spoke with Freud today.
>
> The technical rep said that the gaps in the weld along the center of
> the carbide cutter are NORMAL and part of Freud's new design that
> they're phasing in on several different bits. He said the idea behind
> the gaps is to provide additional air movement and hence heat
> dissipation at the center of the bit. Not all of Freud's bits have
> this design yet but eventually they will.
>
> Dave
>
> Bay Area Dave <[email protected]> wrote in message news:<[email protected]>...
>
>>Freud stuff is pretty much ok, Dave. I'd do as Dex suggested and just
>>give them a polite call Monday morning.
>>
>>dave
>>
>>Dave wrote:
>>
>>
>>>I had several dated bits that were in need of upgrading. Never having
>>>used Freud, I purchased a few.
>>>
>>>I always inspect a new bit before use and I noticed a potential
>>>problem with one of them - an ogee bit. On the interior or center of
>>>the cardide cutter, each cutter has a weld only at the top and bottom
>>>- the center portion is void of a weld. If only one cutter had this
>>>type of weld, I would think it was a defect. However, because each
>>>cutter has the same type of weld, which by the way is symmetric and
>>>neatly done, it looks to be intentional.
>>>
>>>Is there a reason for this type of weld or do I just have a defective
>>>bit?
>>>
>>>Thanks,
>>>Dave
----- Original Message -----
From: "Edwin Pawlowski" <[email protected]>
Newsgroups: rec.woodworking
Sent: Tuesday, March 02, 2004 7:09 PM
Subject: Re: Defective Freud Router Bit? - Response from Freud
>
> I'd be willing to give it a shove off the cliff. At least until someone
> comes up with a real fact, real numbers.
The coeficient of thermal conducrtion for steel is approx 2000 times that
for air.
There are a lot of factors here, so I will spot you an order of magnitude.
Still >200
>Heat flows out to where to?
Seriously? It goes to where there is less heat. Up the shaft, collet, pole
pieces, windings...
Routers have a fan in the housing. Eventually heat is radiated or conducted
into the surroundings,
Then into the universe.
>Why do they put cooling fans on computer chips and auto radiators?
The fan isn't on the chip..The fan is on the heatsink and the heatsink is on
the chip.
Most AMD chips will self destruct in seconds without a heatsink, DAMHIKT
That auto radiator arguement is not applicable (it doesn't hold water :-)
>You can still build heat at the source if the sink cannot absorb it fast
enough.
Exactly! Greater contact area yields more rapid heat transfer.
I did not intend to impune Freud products, management or their families.
I own a few F bits and blades. They perform fine
Maybe the new weld contact actually has a greater cross section and really
does
enhance cooling. Or, maybe, whomever spoke to original poster was either
uninformed or dismissive. Maybe it was coffee break.
frickin' typos! make that, "Is that what you get when
Delta Force meets Mr. T?"
dave
Bay Area Dave wrote:
> ah, yeah, what Tom said...I think...or not. What DID you say, Tom? That
> Freud knows what they are doing? :)
>
> I love those 50 cent words like "adiabatic"! "Delta T" is a great term
> to sprinkle around from time to time. Is that when what you get when
> Delta Force meets Mr. T?
Dave,
I apologize for any misinformation there has been some about the
reason for the gap in the carbide on your bit. It is correct that we
put the gap there purposefully. The primary reason for this is that it
makes the carbide seat more consistently. It also allows for the
different heat contraction/expansion rates between the carbide and the
steel body that occurs during and after the brazing process. Since
carbide is brazed only on the flat back side and not on the edges
there is not an issue of strength. This change will eventually take
place on all of our bits.
Charles M
Freud, Inc.
[email protected] (Dave) wrote in message news:<[email protected]>...
> Just thought I'd let the group know that I spoke with Freud today.
>
> The technical rep said that the gaps in the weld along the center of
> the carbide cutter are NORMAL and part of Freud's new design that
> they're phasing in on several different bits. He said the idea behind
> the gaps is to provide additional air movement and hence heat
> dissipation at the center of the bit. Not all of Freud's bits have
> this design yet but eventually they will.
>
> Dave
>
> Bay Area Dave <[email protected]> wrote in message news:<[email protected]>...
> > Freud stuff is pretty much ok, Dave. I'd do as Dex suggested and just
> > give them a polite call Monday morning.
> >
> > dave
> >
> > Dave wrote:
> >
> > > I had several dated bits that were in need of upgrading. Never having
> > > used Freud, I purchased a few.
> > >
> > > I always inspect a new bit before use and I noticed a potential
> > > problem with one of them - an ogee bit. On the interior or center of
> > > the cardide cutter, each cutter has a weld only at the top and bottom
> > > - the center portion is void of a weld. If only one cutter had this
> > > type of weld, I would think it was a defect. However, because each
> > > cutter has the same type of weld, which by the way is symmetric and
> > > neatly done, it looks to be intentional.
> > >
> > > Is there a reason for this type of weld or do I just have a defective
> > > bit?
> > >
> > > Thanks,
> > > Dave
>
>Dave,
>
>I apologize for any misinformation there has been some about the
>reason for the gap in the carbide on your bit. It is correct that we
>put the gap there purposefully. The primary reason for this is that it
>makes the carbide seat more consistently. It also allows for the
>different heat contraction/expansion rates between the carbide and the
>steel body that occurs during and after the brazing process. Since
>carbide is brazed only on the flat back side and not on the edges
>there is not an issue of strength. This change will eventually take
>place on all of our bits.
>
>Charles M
>Freud, Inc.
Eureka!!!!! I've finally done it!!!!! The worlds first liquid nitrogen
cooled router bits!!!!!!!!
"Ticking away the moments that make up a dull day,fritter and waste the
hours in an offhand way......"
>>Dave,
>>
>>I apologize for any misinformation there has been some about the
>>reason for the gap in the carbide on your bit. It is correct that we
>>put the gap there purposefully. The primary reason for this is that it
>>makes the carbide seat more consistently. It also allows for the
>>different heat contraction/expansion rates between the carbide and the
>>steel body that occurs during and after the brazing process. Since
>>carbide is brazed only on the flat back side and not on the edges
>>there is not an issue of strength. This change will eventually take
>>place on all of our bits.
>>
>>Charles M
>>Freud, Inc.
>
hey! I bet it has to do with allowing them to grind the sides of the
teeth before brazing....
"George" <[email protected]> wrote in message
news:[email protected]...
> Nice point, but don't push the second paragraph too close to the cliff, it
> won't fly. Heat sunk into the metal flows out of the metal at a distance.
> Greater warmed surface, greater outflow. Also, trapped air pockets don't
> cool. Regardless the usability, the reason given is BS. Probably saves
a
> dime a dozen.
>
> Wonder if they whistle?
I'd be willing to give it a shove off the cliff. At least until someone
comes up with a real fact, real numbers. Heat flows out to where to? At
what rate? What is the temperature rise? Why do they put cooling fans on
computer chips and auto radiators? You can still build heat at the source
if the sink cannot absorb it fast enough.
I'm sure you'll never agree, but neither will you come up with a fact
showing heat buildup and flow rates.
Maybe they can make them whistle and change pitch if you cut at the wrong
depth.
Ed
I will hypothesize a completely contrarian argument to what's been
constructed so far. One could argue that the ideal bit would have NO
heat transfer between the carbide cutter and the body. In such a
design, the carbide would more quickly heat up to it's stabilization
temperature, i.e., the temperature at which it dissipates (largely
through convection, spinning through the air at 20,000 rpm, I would
guess convection doesn't amount to diddley-squat after the first
couple minutes) the same amount of heat it generates. While the
temperature of the carbide may be higher (marginally after a few
minutes as compared to heating the entire bit imo), the temperature
gradients throughout the carbide would be smaller. This would result
in more even thermal expansion of the carbide, better retention of the
profile, probably reduced vibration, and potentially less stress at
the carbide/braze and certainly the braze/body interfaces created by
the thermal expansion (or least a more even stress).
With the heat sink model bit, there will be a relatively large delta T
between the carbide cutter and the shaft, as compared to the preceding
description (the delta T across the carbide will be very small,
although the T will be higher), thus you have all kinds of differing
thermal expansion rates and corresponding stresses induced.
Now I can speculate that the ventilated router bit, aka the Freud
model, is a reasonable compromise given you need to braze the
carbide, and all such materials have high thermal conductivity as
metals (and sufficient flexibility). By increasing airflow behind the
carbide (although how they keep it filling with crud is beyond me) you
reduce the heat transfer to the bit by lowering the temperature of the
carbide and at the same time reduce the T of the carbide overall
(although I'd think you'd have higher stress than the adiabatic
interface model first described).
Or it could all be cost-saving BS.
"George" <[email protected]> wrote in message news:<[email protected]>...
> Point is, there are more efficient means of heat transfer. In the case of
> the router bit, metal-to-metal is by far more effective than air, and with
> no flow-through provisions, I fear the only thing blowing smoke here is the
> rep the OP spoke with.
>
> "Edwin Pawlowski" <[email protected]> wrote in message
> news:[email protected]...
> >
> > > > >
> > > > In a watercooled engine, water is the heatsink. It would not
> > > > be such a good idea to drain the water to increase airflow.
> >
> > True, but once the water carries the heat to the radiator, you need
> airflow
> > to remove the heat from the water. Try eliminating the airflow. Or you
> > need one hell of a water tank to absorb all the heat.
> >
> > Ed
> > [email protected]
> > http://pages.cthome.net/edhome
> >
> >
"George" <[email protected]> wrote in message
news:[email protected]...
> Point is, there are more efficient means of heat transfer. In the case of
> the router bit, metal-to-metal is by far more effective than air, and with
> no flow-through provisions, I fear the only thing blowing smoke here is
the
> rep the OP spoke with.
More efficient, but there is a limit. My point is that no one can criticize
the idea unless they can back it up with facts. I've not seen any.
The cutting edge build up heat and transfers it to the shaft. The shaft
heats up and transfers it to the router. There is a maximum amount of heat
it can absorb in a given time and once that is reached, the cutting edge
will overheat if friction continues to heat it. If two spots are enough to
reach the thermal capacity of the heatsink's ability to absorb it, other
means may then become more efficient to dissipate the heat. Maybe air flow
will help. I honestly don't know, but I'm not going to deny Freud's claim
unless I could prove it was BS.
Ed
I just got a mental picture of someone with a spritzer bottle dutifully
cooling their router bit with a cooling spray of water. :) They could
route and raise the grain in one operation.
dave
LD wrote:
> "Bay Area Dave" <[email protected]> wrote in message
> news:[email protected]...
>
>>are you sure? there are billions of vehicles on the roads with radiators
>>relying on air passing through the fins to keep ole nellie from blowing
>
> up.
>
>>dave
>>
>
> In a watercooled engine, water is the heatsink. It would not
> be such a good idea to drain the water to increase airflow.
>
>
>
>
>
"George" <[email protected]> wrote in message
news:[email protected]...
> And without the white goo, nothing works! Just that little bit of "air"
> slows the transfer.
>
> Oh yes, the fan is necessary precisely because air, with its lower (and
with
> heat, lowering) density can't remove the heat available from the metal
> quickly enough with its widely-spaced molecules, and requires a fresh
supply
> from the fan.
Fan? Oh wait, fan = spinning router bit. OK we do agree then.
are you sure? there are billions of vehicles on the roads with radiators
relying on air passing through the fins to keep ole nellie from blowing up.
dave
LD wrote:
> ----- Original Message -----
> From: "Dave" <[email protected]>
> Newsgroups: rec.woodworking
> Sent: Monday, March 01, 2004 9:15 AM
> Subject: Re: Defective Freud Router Bit? - Response from Freud
>
>
>
>>He said the idea behind
>>the gaps is to provide additional air movement and hence heat
>>dissipation at the center of the bit. Not all of Freud's bits have
>>this design yet but eventually they will.
>
>
>
> This sounds like deep Freud BS. The shaft of the bit acts as a heatsink.
> Any gaps between the carbide and the shaft will impair cooling.
> This *new design* may work well enough, but it won't run cooler.
>
>
"LD" <[email protected]> wrote in message
> The shaft of the bit acts as a heatsink.
> Any gaps between the carbide and the shaft will impair cooling.
> This *new design* may work well enough, but it won't run cooler.
After the heatsink is sunk where does the heat go? Why would not increased
air flow not make a difference? What is the actual heat flow across the
section that is welded versus the open area?
Seems as though we are dealing in supposition and have no facts to back up
anything. Could be BS from Freud as cost of welding is reduced, but than
again, they may have spent a million bucks doing sophisticated testing.
Until I see numbers on one side or the other, I'll keep an open mind.
Ed
wouldn't 10-20,000 RPM loosen debris?
dave
Leon wrote:
> "George" <[email protected]> wrote in message
> news:[email protected]...
>
>>Did they address the brittleness of unsupported carbide?
>>
>>Hate to be their Beta tester and eat a chunk of carbide after impacting a
>>knot.
>
>
>
> No kidding... The idea makes since but it seems that the carbide should be
> fully supported. Seems an air gap would simply fill with debris.
>
>
Freud stuff is pretty much ok, Dave. I'd do as Dex suggested and just
give them a polite call Monday morning.
dave
Dave wrote:
> I had several dated bits that were in need of upgrading. Never having
> used Freud, I purchased a few.
>
> I always inspect a new bit before use and I noticed a potential
> problem with one of them - an ogee bit. On the interior or center of
> the cardide cutter, each cutter has a weld only at the top and bottom
> - the center portion is void of a weld. If only one cutter had this
> type of weld, I would think it was a defect. However, because each
> cutter has the same type of weld, which by the way is symmetric and
> neatly done, it looks to be intentional.
>
> Is there a reason for this type of weld or do I just have a defective
> bit?
>
> Thanks,
> Dave
Sounds as if what Freud did is eliminate the need for a precisely machined
face to mate to the carbide, if we can believe the "representative's" post.
Could be good, could be bad, but we know it doesn't cool anything but the
price of manufacture.
"todd" <[email protected]> wrote in message
news:[email protected]...
> Well, I don't know what you're referring to, but all "adiabatic" means is
> that there is no heat transfer involved.
>
Well, I don't know what you're referring to, but all "adiabatic" means is
that there is no heat transfer involved.
todd
"John Crea" <[email protected]> wrote in message
news:[email protected]...
> And unless you are compresing AIR in confined space, "adiabiatic" does
> NOT apply here
>
> John
>
> On Wed, 03 Mar 2004 18:20:19 GMT, Bay Area Dave <[email protected]> wrote:
>
> >ah, yeah, what Tom said...I think...or not. What DID you say, Tom?
> >That Freud knows what they are doing? :)
> >
> >I love those 50 cent words like "adiabatic"! "Delta T" is a great term
> >to sprinkle around from time to time. Is that when what you get when
> >Delta Force meets Mr. T?
> >
> >dave
> >
> >Tom Bergman wrote:
> >
> >> I will hypothesize a completely contrarian argument to what's been
> >> constructed so far. One could argue that the ideal bit would have NO
> >> heat transfer between the carbide cutter and the body. In such a
> >> design, the carbide would more quickly heat up to it's stabilization
> >> temperature, i.e., the temperature at which it dissipates (largely
> >> through convection, spinning through the air at 20,000 rpm, I would
> >> guess convection doesn't amount to diddley-squat after the first
> >> couple minutes) the same amount of heat it generates. While the
> >> temperature of the carbide may be higher (marginally after a few
> >> minutes as compared to heating the entire bit imo), the temperature
> >> gradients throughout the carbide would be smaller. This would result
> >> in more even thermal expansion of the carbide, better retention of the
> >> profile, probably reduced vibration, and potentially less stress at
> >> the carbide/braze and certainly the braze/body interfaces created by
> >> the thermal expansion (or least a more even stress).
> >>
> >> With the heat sink model bit, there will be a relatively large delta T
> >> between the carbide cutter and the shaft, as compared to the preceding
> >> description (the delta T across the carbide will be very small,
> >> although the T will be higher), thus you have all kinds of differing
> >> thermal expansion rates and corresponding stresses induced.
> >>
> >> Now I can speculate that the ventilated router bit, aka the Freud
> >> model, is a reasonable compromise given you need to braze the
> >> carbide, and all such materials have high thermal conductivity as
> >> metals (and sufficient flexibility). By increasing airflow behind the
> >> carbide (although how they keep it filling with crud is beyond me) you
> >> reduce the heat transfer to the bit by lowering the temperature of the
> >> carbide and at the same time reduce the T of the carbide overall
> >> (although I'd think you'd have higher stress than the adiabatic
> >> interface model first described).
> >>
> >> Or it could all be cost-saving BS.
> >>
> >>
> >> "George" <[email protected]> wrote in message
news:<[email protected]>...
> >>
> >>>Point is, there are more efficient means of heat transfer. In the case
of
> >>>the router bit, metal-to-metal is by far more effective than air, and
with
> >>>no flow-through provisions, I fear the only thing blowing smoke here is
the
> >>>rep the OP spoke with.
> >>>
> >>>"Edwin Pawlowski" <[email protected]> wrote in message
> >>>news:[email protected]...
> >>>
> >>>>>> In a watercooled engine, water is the heatsink. It would not
> >>>>>>be such a good idea to drain the water to increase airflow.
> >>>>
> >>>>True, but once the water carries the heat to the radiator, you need
> >>>
> >>> airflow
> >>>
> >>>>to remove the heat from the water. Try eliminating the airflow. Or
you
> >>>>need one hell of a water tank to absorb all the heat.
> >>>>
> >>>>Ed
> >>>>[email protected]
> >>>>http://pages.cthome.net/edhome
> >>>>
> >>>>
>
And unless you are compresing AIR in confined space, "adiabiatic" does
NOT apply here
John
On Wed, 03 Mar 2004 18:20:19 GMT, Bay Area Dave <[email protected]> wrote:
>ah, yeah, what Tom said...I think...or not. What DID you say, Tom?
>That Freud knows what they are doing? :)
>
>I love those 50 cent words like "adiabatic"! "Delta T" is a great term
>to sprinkle around from time to time. Is that when what you get when
>Delta Force meets Mr. T?
>
>dave
>
>Tom Bergman wrote:
>
>> I will hypothesize a completely contrarian argument to what's been
>> constructed so far. One could argue that the ideal bit would have NO
>> heat transfer between the carbide cutter and the body. In such a
>> design, the carbide would more quickly heat up to it's stabilization
>> temperature, i.e., the temperature at which it dissipates (largely
>> through convection, spinning through the air at 20,000 rpm, I would
>> guess convection doesn't amount to diddley-squat after the first
>> couple minutes) the same amount of heat it generates. While the
>> temperature of the carbide may be higher (marginally after a few
>> minutes as compared to heating the entire bit imo), the temperature
>> gradients throughout the carbide would be smaller. This would result
>> in more even thermal expansion of the carbide, better retention of the
>> profile, probably reduced vibration, and potentially less stress at
>> the carbide/braze and certainly the braze/body interfaces created by
>> the thermal expansion (or least a more even stress).
>>
>> With the heat sink model bit, there will be a relatively large delta T
>> between the carbide cutter and the shaft, as compared to the preceding
>> description (the delta T across the carbide will be very small,
>> although the T will be higher), thus you have all kinds of differing
>> thermal expansion rates and corresponding stresses induced.
>>
>> Now I can speculate that the ventilated router bit, aka the Freud
>> model, is a reasonable compromise given you need to braze the
>> carbide, and all such materials have high thermal conductivity as
>> metals (and sufficient flexibility). By increasing airflow behind the
>> carbide (although how they keep it filling with crud is beyond me) you
>> reduce the heat transfer to the bit by lowering the temperature of the
>> carbide and at the same time reduce the T of the carbide overall
>> (although I'd think you'd have higher stress than the adiabatic
>> interface model first described).
>>
>> Or it could all be cost-saving BS.
>>
>>
>> "George" <[email protected]> wrote in message news:<[email protected]>...
>>
>>>Point is, there are more efficient means of heat transfer. In the case of
>>>the router bit, metal-to-metal is by far more effective than air, and with
>>>no flow-through provisions, I fear the only thing blowing smoke here is the
>>>rep the OP spoke with.
>>>
>>>"Edwin Pawlowski" <[email protected]> wrote in message
>>>news:[email protected]...
>>>
>>>>>> In a watercooled engine, water is the heatsink. It would not
>>>>>>be such a good idea to drain the water to increase airflow.
>>>>
>>>>True, but once the water carries the heat to the radiator, you need
>>>
>>> airflow
>>>
>>>>to remove the heat from the water. Try eliminating the airflow. Or you
>>>>need one hell of a water tank to absorb all the heat.
>>>>
>>>>Ed
>>>>[email protected]
>>>>http://pages.cthome.net/edhome
>>>>
>>>>