How do you like your CBN (Cubic Boron Nitride) grinding wheel?
They sound too good to be true but reading about them makes me believe
they're legit and I think I will get one. Traditionall uses to grind
cams/crankshafts, etc.
How do you like yours?
Benefits over alox and others:
1. dissipate heat very well, comparable to a wetstone
2. no dressing required, stay straight/true
3. no dust
4. won't come apart
5. last much longer
Downsides:
1. I don't know, you tell me
On Saturday, December 27, 2014 1:09:58 PM UTC-8, Electric Comet wrote:
> How do you like your CBN (Cubic Boron Nitride) grinding wheel?
> They sound too good to be true but reading about them makes me believe
> they're legit and I think I will get one.
Diamond wheels are chemically unstable in contact with hot ferrous
alloys (hot iron dissolves carbon). So, cubic boron nitride (Borazon)
is often used instead. It's close to diamond in hardness, and about twice
as expensive per gram if you buy the grit. It's a manmade material,
like silicon carbide.
On 12/27/2014 4:08 PM, Electric Comet wrote:
> How do you like your CBN (Cubic Boron Nitride) grinding wheel?
> They sound too good to be true but reading about them makes me believe
> they're legit and I think I will get one. Traditionall uses to grind
> cams/crankshafts, etc.
>
> How do you like yours?
>
> Benefits over alox and others:
> 1. dissipate heat very well, comparable to a wetstone
> 2. no dressing required, stay straight/true
> 3. no dust
> 4. won't come apart
> 5. last much longer
>
> Downsides:
> 1. I don't know, you tell me
>
>
>
add to 4, so you don't need a guard.
So you can use the edge to create unique profiles.
There are sharp edged and rounded edged wheels.
I still think, if you going for this, you might as well go for diamond.
But this is a good alternative at a good price point.
--
Jeff
On 1/1/2015 12:11 PM, Electric Comet wrote:
> On Tue, 30 Dec 2014 12:08:28 -0500
> woodchucker <[email protected]> wrote:
>
>> So in researching the issue. It seems that the home machinist group
>> shares this concept.
>>
>> But in looking at a German company that makes both, diamond and cbn.
>> They do not mention any problems with diamond, but do not metion in
>> it the use of HSS. On the other hand CBN is metioned, and it must be
>> kept cool so as not to crack or weaken the edge of HSS tools. So I am
>
> The CBN wheels I've looked at seem to have enough metal to dissipate
> the heat and keep cool. Unless too much force is applied. The other
> posts and sites say that the wheels stay cool and I read that they
> stay as cool as a wet wheel.
>
>> assuming CBN to be the preferred tool for HSS. But I do know that
>> many CNC machines use diamond to grind carbide.
>
> Does this fact contradict? Or does this follow? What do cnc machines
> use? Tungsten carbide? You mean metal-work cnc?
>
> I noticed that Laguna has a CNC wood lathe and now I wonder what
> they use for the cutting tool.
>
>
>
I saw a video from one of the magazines that showed how Jesada (shitty
company) prepares it's carbide router bits (for wood working). They use
cnc diamond grinding in their machines. Using coolant of course. All
high speed grinding and cutting operations use coolant to keep the tool
from burning up and the cutter from destroying itself.
--
Jeff
On 12/27/2014 9:48 PM, whit3rd wrote:
> On Saturday, December 27, 2014 1:09:58 PM UTC-8, Electric Comet wrote:
>> How do you like your CBN (Cubic Boron Nitride) grinding wheel?
>> They sound too good to be true but reading about them makes me believe
>> they're legit and I think I will get one.
>
> Diamond wheels are chemically unstable in contact with hot ferrous
> alloys (hot iron dissolves carbon). So, cubic boron nitride (Borazon)
> is often used instead. It's close to diamond in hardness, and about twice
> as expensive per gram if you buy the grit. It's a manmade material,
> like silicon carbide.
>
So in researching the issue. It seems that the home machinist group
shares this concept.
But in looking at a German company that makes both, diamond and cbn.
They do not mention any problems with diamond, but do not metion in it
the use of HSS. On the other hand CBN is metioned, and it must be kept
cool so as not to crack or weaken the edge of HSS tools. So I am
assuming CBN to be the preferred tool for HSS. But I do know that many
CNC machines use diamond to grind carbide.
The decisive difference between diamond and CBN:
Diamond
Diamond is pure carbon and the hardest of all known materials. Due to
its hardness, diamond has become increasingly important for machining in
state-of-the-art technology. Today synthetic diamond grit is the
material preferably used in abrasive engineering practice. The starting
substance is carbon in the form of graphite. The synthesis occurs after
extreme pressures and temperatures are applied. Due to its fine
crystalline structure and the resulting properties, e.g. maximum
abrasion resistance and edge-holding quality, diamond is superior to all
other abrading media. Diamond belongs to the super hard group of
cutting materials.
Diamond is restricted by its thermal load capacity if subjected to
temperatures exceeding 700°C, e.g. when grinding steel materials
Applications
Materials that can readily be machined with diamond tools include:
welded and thermal sprayed alloys, electrocarbons, precious and
semiprecious stones, ferrite, fireproof materials, glass-fiber and
carbon-fiber reinforced plastics, glass, graphite, semiconductor
materials, hard metal, ceramics, natural and artificial stones, oxide
ceramics, porcelain and quartz. In exceptional cases cast steel and gray
cast iron can also be machined with diamond tools.
CBN (cubic boron nitride)
CBN is a 100% synthetic product which is the second hardest abrading
medium after diamond. Due to its chemical-physical properties, CBN is
primarily used to process hard-to-machine steels with a high alloy
content and/or hardness. The CBN abrasive grain is manufactured using
virtually the same synthesis technique as for synthetic diamond abrasive
grain. The starting substance for CBN is hexagonal boron nitride. Like
diamond, CBN belongs to the super hard group of cutting materials.
Application
CBN can withstand temperatures of up to 1300°C and has a slight tendency
to react chemically to metals. Due to its fine crystalline structure and
the resulting properties, e.g. a high abrasion resistance and
edge-holding quality, it offers advantages in comparison to conventional
abrading media, especially for grinding hard-to-machine and hardened
steels >55HRC, e.g. HSS or chrome alloyed steels. Lowering the
temperature during grinding prevents changes in the structure of the
material edge zone, and therefore grinding cracks and soft skin
formation. High accuracy regarding dimension, shape and concentricity as
well as long tool life can thus be achieved using CBN grinding tools.
--
Jeff
In article <[email protected]>,
Electric Comet <[email protected]> wrote:
> How do you like your CBN (Cubic Boron Nitride) grinding wheel?
> They sound too good to be true but reading about them makes me believe
> they're legit and I think I will get one. Traditionall uses to grind
> cams/crankshafts, etc.
>
> How do you like yours?
>
> Benefits over alox and others:
> 1. dissipate heat very well, comparable to a wetstone
> 2. no dressing required, stay straight/true
> 3. no dust
> 4. won't come apart
> 5. last much longer
>
> Downsides:
> 1. I don't know, you tell me
I've got 2 80 & 180 grit. Use them for sharpening HSS turning tools. No
dust from the wheels, but I do get steel dust from grinding. Everything
that I have read advises not to use them for non hardened steel. Tools
don't get hot unless you really push them into the wheels (which you
shouldn't do with any wheel). They cut quick, and don't need to be
trued. Which means that I can mark my sharpening jig for different
grinds (spindle gouge or bowl gouge) and switch back and forth
accurately, maintaing the correct grinding angle. The grit is electro
plated to a steel disk, so no worries about it coming apart. I took the
guards off of my grinder, so that I could mount 1 1/2" wide wheels. They
will outlast me. They run much truer than any stone wheel that I ever
had. They are expensive, but worth it. The price does vary, so shop
before you order,
On Sat, 27 Dec 2014 20:54:07 -0500
Dan Kozar <[email protected]> wrote:
>
> I've got 2 80 & 180 grit. Use them for sharpening HSS turning tools.
> No dust from the wheels, but I do get steel dust from grinding.
> Everything that I have read advises not to use them for non hardened
> steel. Tools don't get hot unless you really push them into the
> wheels (which you shouldn't do with any wheel). They cut quick, and
> don't need to be trued. Which means that I can mark my sharpening jig
> for different grinds (spindle gouge or bowl gouge) and switch back
> and forth accurately, maintaing the correct grinding angle. The grit
> is electro plated to a steel disk, so no worries about it coming
> apart. I took the guards off of my grinder, so that I could mount 1
> 1/2" wide wheels. They will outlast me. They run much truer than any
> stone wheel that I ever had. They are expensive, but worth it. The
> price does vary, so shop before you order,
The only downside is higher price but it pays for itself due to
long life and the upsides outweigh that downside. Which really
isn't a downside.
Good to hear first-hand experience. I think I will go with the 180 grit.
On 2014-12-28 19:39:43 +0000, Electric Comet said:
> On Sat, 27 Dec 2014 20:54:07 -0500
> Dan Kozar <[email protected]> wrote:
>
>>
>> I've got 2 80 & 180 grit. Use them for sharpening HSS turning tools.
>> No dust from the wheels, but I do get steel dust from grinding.
>> Everything that I have read advises not to use them for non hardened
>> steel. Tools don't get hot unless you really push them into the
>> wheels (which you shouldn't do with any wheel). They cut quick, and
>> don't need to be trued. Which means that I can mark my sharpening jig
>> for different grinds (spindle gouge or bowl gouge) and switch back
>> and forth accurately, maintaing the correct grinding angle. The grit
>> is electro plated to a steel disk, so no worries about it coming
>> apart. I took the guards off of my grinder, so that I could mount 1
>> 1/2" wide wheels. They will outlast me. They run much truer than any
>> stone wheel that I ever had. They are expensive, but worth it. The
>> price does vary, so shop before you order,
>
> The only downside is higher price but it pays for itself due to
> long life and the upsides outweigh that downside. Which really
> isn't a downside.
>
> Good to hear first-hand experience. I think I will go with the 180 grit.
We've had a CBN for some years now, we were taking a class via the
local woodturning club and D-Way Tools provided the grinder (the owner
is a member). The DW came back from sharpening her tool as said "as
soon as we can afford it, we are getting one:
Dave (D-Way Tools) figures for even a production Pro turner, a CBN
wheel is a life-time buy.
On Sun, 28 Dec 2014 11:51:55 -0500
woodchucker <[email protected]> wrote:
> add to 4, so you don't need a guard.
Which also means a wider wheel can be used.
>
> So you can use the edge to create unique profiles.
> There are sharp edged and rounded edged wheels.
Some wheels also have grinding surface on the side of the wheel.
So you have two surfaces to grind against.
>
> I still think, if you going for this, you might as well go for
> diamond. But this is a good alternative at a good price point.
No, diamond is not comparable for this use. I read that the
other elements in steel cause problems with diamond wheels.
I believe this fact is what inspired GE to create CBN grinding
surfaces.
On 2014-12-28 19:49:26 +0000, Electric Comet said:
> On Sun, 28 Dec 2014 11:51:55 -0500
> woodchucker <[email protected]> wrote:
>
>
>> add to 4, so you don't need a guard.
>
> Which also means a wider wheel can be used.
>
>>
>> So you can use the edge to create unique profiles.
>> There are sharp edged and rounded edged wheels.
>
> Some wheels also have grinding surface on the side of the wheel.
> So you have two surfaces to grind against.
>
>>
>> I still think, if you going for this, you might as well go for
>> diamond. But this is a good alternative at a good price point.
>
> No, diamond is not comparable for this use. I read that the
> other elements in steel cause problems with diamond wheels.
> I believe this fact is what inspired GE to create CBN grinding
> surfaces.
Diamond sux for HSS or HCS, the carbon from the diamond can (and does)
modify the carbon content of the tool and you end up with a steel with
the wrong carbon content
On Sun, 28 Dec 2014 19:04:11 -0800
Ralph E Lindberg <[email protected]> wrote:
> Diamond sux for HSS or HCS, the carbon from the diamond can (and
> does) modify the carbon content of the tool and you end up with a
> steel with the wrong carbon content
Seems to be the other way around. The tool modifies the diamond
wheel and now you have a ineffective diamond wheel and that hurts.
On 12/29/2014 12:46 PM, Electric Comet wrote:
> On Sun, 28 Dec 2014 19:04:11 -0800
> Ralph E Lindberg <[email protected]> wrote:
>
>> Diamond sux for HSS or HCS, the carbon from the diamond can (and
>> does) modify the carbon content of the tool and you end up with a
>> steel with the wrong carbon content
>
>
> Seems to be the other way around. The tool modifies the diamond
> wheel and now you have a ineffective diamond wheel and that hurts.
>
>
>
That's true about soft metals ruining diamond and cbn wheels. But hard
metals should just cut and that's it.
--
Jeff
On 12/28/2014 10:04 PM, Ralph E Lindberg wrote:
> On 2014-12-28 19:49:26 +0000, Electric Comet said:
>
>> On Sun, 28 Dec 2014 11:51:55 -0500
>> woodchucker <[email protected]> wrote:
>>
>>
>>> add to 4, so you don't need a guard.
>>
>> Which also means a wider wheel can be used.
>>
>>>
>>> So you can use the edge to create unique profiles.
>>> There are sharp edged and rounded edged wheels.
>>
>> Some wheels also have grinding surface on the side of the wheel.
>> So you have two surfaces to grind against.
>>
>>>
>>> I still think, if you going for this, you might as well go for
>>> diamond. But this is a good alternative at a good price point.
>>
>> No, diamond is not comparable for this use. I read that the
>> other elements in steel cause problems with diamond wheels.
>> I believe this fact is what inspired GE to create CBN grinding
>> surfaces.
>
> Diamond sux for HSS or HCS, the carbon from the diamond can (and does)
> modify the carbon content of the tool and you end up with a steel with
> the wrong carbon content
>
I have never heard that before. I'll double check that.
I know heat changes the steel, you can change the grain size and
stability, but I had not heard that diamond would change the carbon
content. I didn't think they were exchaning chemical make up, as the
diamond cut with minimal heat.
--
Jeff
On Tue, 30 Dec 2014 12:08:28 -0500
woodchucker <[email protected]> wrote:
> So in researching the issue. It seems that the home machinist group
> shares this concept.
>
> But in looking at a German company that makes both, diamond and cbn.
> They do not mention any problems with diamond, but do not metion in
> it the use of HSS. On the other hand CBN is metioned, and it must be
> kept cool so as not to crack or weaken the edge of HSS tools. So I am
The CBN wheels I've looked at seem to have enough metal to dissipate
the heat and keep cool. Unless too much force is applied. The other
posts and sites say that the wheels stay cool and I read that they
stay as cool as a wet wheel.
> assuming CBN to be the preferred tool for HSS. But I do know that
> many CNC machines use diamond to grind carbide.
Does this fact contradict? Or does this follow? What do cnc machines
use? Tungsten carbide? You mean metal-work cnc?
I noticed that Laguna has a CNC wood lathe and now I wonder what
they use for the cutting tool.
Some more info I came across:
CBN Coating
CBN stands for Cubic Boron Nitride, an abrasive grain that's nearly as
hard as diamond but much better suited for sharpening hardened steel.
Sharpening on diamond wheels produces heat, and from around 170=C2=B0C
causes a chemical reaction between the diamond grain and the steel
alloys which destroys the diamond grain. CBN, on the other hand, only
reacts at above 400=C2=B0C, and is only destroyed at 700=C2=B0C and above.
http://www.mehr-als-werkzeug.de/product/704846/OptiGrind-CBN-Grinding-Wheel=
-Grit--150-x-20-mm.htm
139=E2=82=AC including VAT
Don't know the exchange rate to usd
On 1/10/15, 10:05 AM, Electric Comet wrote:
> Some more info I came across:
>
> CBN Coating
> CBN stands for Cubic Boron Nitride, an abrasive grain that's nearly as
> hard as diamond but much better suited for sharpening hardened steel.
> Sharpening on diamond wheels produces heat, and from around 170°C
> causes a chemical reaction between the diamond grain and the steel
> alloys which destroys the diamond grain. CBN, on the other hand, only
> reacts at above 400°C, and is only destroyed at 700°C and above.
>
>
>
> http://www.mehr-als-werkzeug.de/product/704846/OptiGrind-CBN-Grinding-Wheel-Grit--150-x-20-mm.htm
Similar @ $94
(watch out for any line wrap)
http://www.use-enco.com/CGI/INSRIT?PMAKA=391-5716&PMPXNO=952558&PARTPG=INLMK32
-BR
>
> 139⬠including VAT
>
> Don't know the exchange rate to usd
>
>
>
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