Hi,
I have a nice 10" bench grinder and would like to mount a diamond or
green grinding wheel on it for side grinding lathe bits. Mostly high
speed steel with the occational carbide.

I read and have been told never to grind on the sides of my existing
80 and 120 grit wheels.

I can't afford a dedicated carbide grinder so I want to convert my
bench grinder into a more usefull machine. I really only use my
grinder for lathe bits.

Any information would be appreciated.

Rod
San Francisco

On Nov 26, 9:01*am, rodjava wrote:
Hi,
I have a nice 10" bench grinder and would like to mount a diamond or
green grinding wheel on it for side grinding lathe bits. *Mostly high
speed steel with the occational carbide.

I read and have been told never to grind on the sides of my existing
80 and 120 grit wheels.

I can't afford a dedicated carbide grinder so I want to convert my
bench grinder into a more usefull machine. *I really only use my
grinder for lathe bits.

Any information would be appreciated.

Rod
San Francisco

I'm sorry if my question is vauge.

What I would like to know is what brand, make and model number of Type
5 wheel are you using on your bench/pedistal grinder for HHS tool
bits. Also. the same info for carbide grinding..

Thank you in advance,

Rod
San Francisco

On Nov 26, 1:23*pm, rodjava wrote:
What I would like to know is what brand, make and model number of Type
5 wheel are you using on your bench/pedistal grinder for HHS tool
bits. Also. the same info for carbide grinding..

Thank you in advance,

Rod
San Francisco- Hide quoted text -

I do not use a type 5 wheel to grind tool bits. I just use a regular
aluminun oxide wheel. A coarse one to get the general shape and then
a fine one that I got at Boeing Surplus. Grinding lathe bits does not
require angles to be precise except maybe for threading. And you can
get threading bits precise using a cheap gage.


Dan

On Nov 26, 10:31*am, " wrote:
On Nov 26, 1:23*pm, rodjava wrote:

What I would like to know is what brand, make and model number of Type
5 wheel are you using on your bench/pedistal grinder for HHS tool
bits. Also. the same info for carbide grinding..

Thank you in advance,

Rod
San Francisco- Hide quoted text -

I do not use a type 5 wheel to grind tool bits. *I just use a regular
aluminun oxide wheel. *A coarse one to get the general shape and then
a fine one that I got at Boeing Surplus. *Grinding lathe bits does not
require angles to be precise except maybe for threading. *And you can
get threading bits precise using a cheap gage.

Dan

Dan,
Thanks for your advice.

I would like the option of grinding on the side of the wheel. That's
why I was looking for a type 5.

Rod

On Nov 26, 11:35*am, rodjava wrote:
On Nov 26, 10:31*am, " wrote:





On Nov 26, 1:23*pm, rodjava wrote:

What I would like to know is what brand, make and model number of Type
5 wheel are you using on your bench/pedistal grinder for HHS tool
bits. Also. the same info for carbide grinding..

Thank you in advance,

Rod
San Francisco- Hide quoted text -

I do not use a type 5 wheel to grind tool bits. *I just use a regular
aluminun oxide wheel. *A coarse one to get the general shape and then
a fine one that I got at Boeing Surplus. *Grinding lathe bits does not
require angles to be precise except maybe for threading. *And you can
get threading bits precise using a cheap gage.

Dan

Dan,
Thanks for your advice.

I would like the option of grinding on the side of the wheel. That's
why I was looking for a type 5.

Rod- Hide quoted text -

- Show quoted text -

Both green and diamond wheels are really unsuited for HSS bits, only
carbide. I'd use a aluminum oxide cup wheel of about 40 grit or so
for HSS if I was stuck with a bench grinder. Side grinding on a
straight wheel really IS NOT the way to go. As it is, I use a belt
grinder and a 40 grit belt for rough shaping, 80 grit for finishing
with a few licks on a diamond hone plate afterwards. Others will have
their own procedures. I have a bench grinder I inherited and was
using, it seldom gets any play since I've gotten the belt grinder.

Stan

In article
,
rodjava wrote:

Hi,
I have a nice 10" bench grinder and would like to mount a diamond or
green grinding wheel on it for side grinding lathe bits. Mostly high
speed steel with the occational carbide.

If you try to grind steel on a diamond wheel, you will ruin the diamond
wheel very quickly. Diamond wheels are for carbide.

For steel you need wheels that do not contain carbon in any form.
Aluminum oxide and zirconium oxide are standard.

As others have mentioned, a belt sander is very good for rough shaping
HSS.

You will also need to make or buy a holder for the HSS bit you are
shaping. Finger holding doesn't work - forces too high, bit also gets
quite hot.

Joe Gwinn

"rodjava" wrote in message
...
Hi,
I have a nice 10" bench grinder and would like to mount a diamond or
green grinding wheel on it for side grinding lathe bits. Mostly high
speed steel with the occational carbide.

I read and have been told never to grind on the sides of my existing
80 and 120 grit wheels.

I can't afford a dedicated carbide grinder so I want to convert my
bench grinder into a more usefull machine. I really only use my
grinder for lathe bits.

Any information would be appreciated.

Rod
San Francisco

If you'd like to read some of my ravings about sharpening HSS, the selection
of grinding wheels, and grinders, here's a link of a multitude of posts I've
made on the Chaski board. I didn't compile the file, but it was compiled
with my approval.

http://www.savefile.com/files/915454


I'm very outspoken about the subject of offhand grinding of toolbits----and
have provided some guidelines that you may find useful. Or not. One of
the points I make is learning to sharpen HSS without using a tool rest or
other cheat devices. If you develop the skill, there is no better way
aside from using a tool & cutter grinder.

Harold

On Wed, 26 Nov 2008 17:56:02 -0500, Joseph Gwinn
wrote:

In article
,
rodjava wrote:

Hi,
I have a nice 10" bench grinder and would like to mount a diamond or
green grinding wheel on it for side grinding lathe bits. Mostly high
speed steel with the occational carbide.

If you try to grind steel on a diamond wheel, you will ruin the diamond
wheel very quickly. Diamond wheels are for carbide.

For steel you need wheels that do not contain carbon in any form.
Aluminum oxide and zirconium oxide are standard.

As others have mentioned, a belt sander is very good for rough shaping
HSS.

You will also need to make or buy a holder for the HSS bit you are
shaping. Finger holding doesn't work - forces too high, bit also gets
quite hot.

Joe Gwinn


Depending on the size..an old drill chuck works just fine for holding
bits while grinding. generally an old 1/2" drill chuck will do most
everything in the hobby shop

Gunner

"They couldn't hit an elephant at this dist..."
Maj. Gen. John Sedgewick, killed by a sniper in 1864 at the battle of Spotsylvania

In article ,
Gunner Asch wrote:

On Wed, 26 Nov 2008 17:56:02 -0500, Joseph Gwinn
wrote:

In article
,
rodjava wrote:

Hi,
I have a nice 10" bench grinder and would like to mount a diamond or
green grinding wheel on it for side grinding lathe bits. Mostly high
speed steel with the occational carbide.

If you try to grind steel on a diamond wheel, you will ruin the diamond
wheel very quickly. Diamond wheels are for carbide.

For steel you need wheels that do not contain carbon in any form.
Aluminum oxide and zirconium oxide are standard.

As others have mentioned, a belt sander is very good for rough shaping
HSS.

You will also need to make or buy a holder for the HSS bit you are
shaping. Finger holding doesn't work - forces too high, bit also gets
quite hot.

Joe Gwinn


Depending on the size..an old drill chuck works just fine for holding
bits while grinding. generally an old 1/2" drill chuck will do most
everything in the hobby shop

I do that too, but the chuck was a bit big and I didn't want to grind
it, so I made a holder on the lathe from some 5/8" 1018 steel rod that
is smaller and therefore easier to use, but it's slower to insert or
remove the bit (as the bit is held by a setscrew).

Joe Gwinn

On Nov 29, 8:37*am, Joseph Gwinn wrote:
In article ,
*Gunner Asch wrote:





On Wed, 26 Nov 2008 17:56:02 -0500, Joseph Gwinn
wrote:

In article
,
rodjava wrote:

Hi,
I have a nice 10" bench grinder and would like to mount a diamond or
green grinding wheel on it for side grinding lathe bits. *Mostly high
speed steel with the occational carbide.

If you try to grind steel on a diamond wheel, you will ruin the diamond
wheel very quickly. *Diamond wheels are for carbide.

For steel you need wheels that do not contain carbon in any form. *
Aluminum oxide and zirconium oxide are standard.

As others have mentioned, a belt sander is very good for rough shaping
HSS.

You will also need to make or buy a holder for the HSS bit you are
shaping. *Finger holding doesn't work - forces too high, bit also gets
quite hot.

Joe Gwinn

Depending on the size..an old drill chuck works just fine for holding
bits while grinding. * generally an old *1/2" drill chuck will do most
everything in the hobby shop

I do that too, but the chuck was a bit big and I didn't want to grind
it, so I made a holder on the lathe from some 5/8" 1018 steel rod that
is smaller and therefore easier to use, but it's slower to insert or
remove the bit (as the bit is held by a setscrew).

Joe Gwinn- Hide quoted text -

- Show quoted text -

Thanks to everybody that responded to my question.

It looks like there is no such 10" type 5 grinding wheel for HSS. But
that's no longer a problem with my side grinding question. Several
people that I talked to as well as info from groups like this, tell me
that side grinding on a type 1 wheel on my bench grinder is OK. Just
as long as you don't apply too much preassure. I'm only grinding
lathe bits on the side of the wheel and only breifly. All done by
hand.

I'm sure that some HSM won't agree. I'm willing to do it because it's
my home shop. I would not do it in another shop with first asking if
it's OK.

Rod
San Francisco

rodjava wrote:
... I'm willing to do it because it's
my home shop. I would not do it in another shop with first asking if
it's OK.

It sounds to me like you're thinking about what damage might happen to
the wheel. The real issue is what damage might happen to _you_. If a
wheel breaks from side grinding it's like an explosion, with sharp
pieces flying about at great speed.

Be careful,
Bob

On Nov 27, 3:20*am, "Harold and Susan Vordos" wrote:
...
http://www.savefile.com/files/915454

Too big, I don't have enough time left this month.

I'm very outspoken about the subject of offhand grinding of toolbits----and
have provided some guidelines that you may find useful. *Or not. * *One of
the points I make is learning to sharpen HSS without using a tool rest or
other cheat devices. * If you develop the skill, there is no better way
aside from using a tool & cutter grinder.

Harold

You can practice freehand with 1/4" key stock. Hold it against the
motor housing (watch wheel vs fingers) to reestablish the angle.
I've found I can grind a lathe bit quite close to final shape with an
angle grinder, which cuts faster and cooler than my A36 bench grinder
wheel. As with a milling vise, the bit needs to be balanced by another
one on the other end of the jaw or it will swivel away from the disk
too easily. Soft jaw pads help. It's especially good for the long
undercut on an inside threading bit.

This is where I grind steel on the carbide wheel. I sharpen the bit as
well as I can on the coarse A36 side, then lightly polish it for a
second or two on the carbide wheel, which normally grinds brazed bits.
Both leave a hollow grind so that a hand-held stone is self-aligning
but has to cut only a narrow strip along the top and bottom edges. I
stopped grinding on a face wheel because the flat surface is more
difficult to touch up without decreasing the front clearance angle too
much.

A conical stone in a Dremel will grind a smooth inside radius easily,
for corner rounding & thread end finishing bits.

jw

"Jim Wilkins" wrote in message
...
snip---

I've found I can grind a lathe bit quite close to final shape with an
angle grinder, which cuts faster and cooler than my A36 bench grinder
wheel.

That comes as no surprise. The wheels that come with bench grinders are
not suited to grinding HSS, regardless of what you might read. They are far
too hard, so they don't cut, they rub, heating the bits instead of grinding
them. If you apply that wheel to mild steel, as you proposed, it appears
to function better----but HSS is mild steel, and that's the problem. When
you match the wheel to the material, it grinds quickly, with minimal heat.
I cover all of that in that large download.


This is where I grind steel on the carbide wheel. I sharpen the bit as
well as I can on the coarse A36 side, then lightly polish it for a
second or two on the carbide wheel, which normally grinds brazed bits.

I'm not here to say it doesn't work. It does. However, when you grind
ferrous materials with silicon carbide, the wheel is instantly dulled by
dissolution. Iron has a strong affinity for carbon, which it will gather
from any source possible. That's why you shouldn't grind steel with
diamonds, unless they are run slowly, well below the point where they
achieve red heat.

What you're doing isn't considered good practice as a result. No matter, as
long as you're happy with the results. You've be far happier with a diamond
wheel, properly applied.

Harold

On Nov 30, 2:02*am, "Harold and Susan Vordos" wrote:
"Jim Wilkins" wrote in message
...

What you're doing isn't considered good practice as a result. No matter, as
long as you're happy with the results. You've be far happier with a diamond
wheel, properly applied.

Harold

I wish I had enough good grinders with the proper wheels for each
job, and more importantly enough space for them and the grit they
scatter. My pedestal grinder is IN the doorway to the shop. I also
have an underpowered but portable 5" bench grinder with a wheel
reserved for TIG tungstens and a (chipped) diamond dish wheel for
polishing carbide, and a surface grinder. ... I just sharpened my
block plane on it, ~0.0001" per pass. It's what made the shop too
crowded to add anything else. It blows its sparks and grit at the wood
stove, which doesn't care. I couldn't pass it up for $100.

Except for the pedestal and surface grinders I do all grinding
and sanding outdoors to protect the other machines from grit. The
pedestal grinder is too top-heavy to put on wheels. When I push hard
on it, it leans back safely against the door frame.

I think a low-budget home shop could get away with a good-sized
pedestal grinder with coarse and fine Al wheels for steel, and for
carbide a small portable bench grinder with a SiC and a diamond wheel
if you can find a used one cheap. The small diamond saw blades might
work??? I put the SiC wheel on the powerful grinder to handle masonry
hammer drill bits and chipped carbide lathe tools.

Even the Enco and HF carbide/diamond tool grinders are far more
expensive than I can justify, being old and retireded. My stuff is
from second-hand stores, auctions and yard sales, what was available
rather than the right machine for the job, but good enough for a hobby
shop.

A decent belt sander sharpens woodworking tools pretty well. I
have an indecent $49.95 belt/disk and a 1x30 Delta, both with sheet
metal backup platens that aren't really flat. Otherwise they do most
of the work of a fine Al2O3 wheel on the pedestal grinder. I made a
new pulley for the belt/disk sander that holds a 6" carbide face wheel
but the motor is too small and the table too flimsy for serious
grinding.

Jim Wilkins