I am trying to take 1/2 square O1 down to round for about 3" of the overall
(9") length. I have been using a tool bit chucked up on the toolpost, but a
friend suggested it would be faster to use a tool post mounted grinder.
First, I wonder if he is right, and second, is there a reasonably priced
one, or plans around to make one?

--
Steve Worcester
www.turningwood.com
Better Woodturning through Technology
(And a hell of alotta practice)

"Steve Worcester" wrote in message
...
I am trying to take 1/2 square O1 down to round for about 3" of the overall
(9") length. I have been using a tool bit chucked up on the toolpost, but
a
friend suggested it would be faster to use a tool post mounted grinder.
First, I wonder if he is right, and second, is there a reasonably priced
one, or plans around to make one?


Is the O1 hardened or soft? Cutting metal with a toolbit is virtually always
more efficient than with a grinder.

O1 is easy to cut with a toolbit (HSS or better) when it's soft.

When it's hard, you have to use carbide (or better) or you can grind it. For
an interupted cut such as your situation, grinding is probably ideal. Also,
grinding will probably tolerate a less rigid machine than carbide, ceramic,
cermet, CBN, etc.

Regards,

Robin

On Wed, 19 Jan 2005 19:07:34 -0600, "Steve Worcester"
wrote:

I am trying to take 1/2 square O1 down to round for about 3" of the overall
(9") length. I have been using a tool bit chucked up on the toolpost, but a
friend suggested it would be faster to use a tool post mounted grinder.
First, I wonder if he is right, and second, is there a reasonably priced
one, or plans around to make one?

Iss the O1 hard? if so, the grinder might be faster, otherwise, no.

The second, depends on what you call reasonable. I paid $500 for my
Dumore, and that's reasonable in my book for a used one. New ones,
MicroMark has one that fits the mini lathes, but nothing else.

Greybeard

Steve Worcester wrote:

I am trying to take 1/2 square O1 down to round for about 3" of the overall
(9") length. I have been using a tool bit chucked up on the toolpost, but a
friend suggested it would be faster to use a tool post mounted grinder.
First, I wonder if he is right, and second, is there a reasonably priced
one, or plans around to make one?


Whatever you do, rough it out first on a coarse belt sander or snagging
wheel on the bench grinder (assuming it's hard). That will go a whole lot
quicker than cylindrical grinding in the lathe with a toolpost, where the
infeed will be in thousandths .. - GWE

I have used an angle grinder to rough out the big bumps. Make sure you
protect the ways, that grit is not so good the the lathe.
"Grant Erwin" wrote in message
...
Steve Worcester wrote:

I am trying to take 1/2 square O1 down to round for about 3" of the
overall
(9") length. I have been using a tool bit chucked up on the toolpost, but
a
friend suggested it would be faster to use a tool post mounted grinder.
First, I wonder if he is right, and second, is there a reasonably priced
one, or plans around to make one?


Whatever you do, rough it out first on a coarse belt sander or snagging
wheel on the bench grinder (assuming it's hard). That will go a whole lot
quicker than cylindrical grinding in the lathe with a toolpost, where the
infeed will be in thousandths .. - GWE

"Grant Erwin" wrote in message
...


Whatever you do, rough it out first on a coarse belt sander or snagging
wheel on the bench grinder (assuming it's hard). That will go a whole lot
quicker than cylindrical grinding in the lathe with a toolpost, where the
infeed will be in thousandths .. - GWE

Using a "punch former" (some would know it is a "Harig fixture") on a
surface grinder, I've roughed down material at more than .050"/cut.
Naturally the longditudinal feed is pretty slow, but faster than taking lots
of light cuts.

Of course, the grinder spindle motor has to be reasonably powerful and
coolant is pretty much a requirement if the part of the material being
ground will be used to cut.

Regards,

Robin

Grinding is slow & messy, so only out of necessity. Usually just used for
cleanup after heattreating.

Tony

"Steve Worcester" wrote in message
...
I am trying to take 1/2 square O1 down to round for about 3" of the
overall
(9") length. I have been using a tool bit chucked up on the toolpost, but
a
friend suggested it would be faster to use a tool post mounted grinder.
First, I wonder if he is right, and second, is there a reasonably priced
one, or plans around to make one?

--
Steve Worcester
www.turningwood.com
Better Woodturning through Technology
(And a hell of alotta practice)

Assuming it's hard. Rough grind by hand then make a simple lathe holder for
an air die-grinder to finish.
20 minutes!

"Steve Worcester" wrote in message
...
I am trying to take 1/2 square O1 down to round for about 3" of the overall
(9") length. I have been using a tool bit chucked up on the toolpost, but
a
friend suggested it would be faster to use a tool post mounted grinder.
First, I wonder if he is right, and second, is there a reasonably priced
one, or plans around to make one?

--
Steve Worcester
www.turningwood.com
Better Woodturning through Technology
(And a hell of alotta practice)

Steve Worcester wrote:
I am trying to take 1/2 square O1 down to round for about 3" of the overall
(9") length. I have been using a tool bit chucked up on the toolpost, but a
friend suggested it would be faster to use a tool post mounted grinder.
First, I wonder if he is right, and second, is there a reasonably priced
one, or plans around to make one?


Steve--
If you are able to use a cutting tool (steel not hardened) then do so,
it's definitely faster. Grinding on the lathe is for taking the last few
thousandths off of a hardened piece, on a bearing journal for example.
The grit can really screw up your lathe if you don't go out of your way
to protect the bed, crosslide, spindle bearings, etc. If I have to
grind, I use a whole bunch of newspaper to cover everything and collect
the grit, wetting it all down with WD-40 which I also use as a coolant
so the grit doesn't fly around.

Ken Grunke
http://www.token.crwoodturner.com/

--
take da "ma" offa dot com fer eemayl


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On Wed, 19 Jan 2005 19:07:34 -0600, "Steve Worcester"
wrote:

I am trying to take 1/2 square O1 down to round for about 3" of the overall
(9") length. I have been using a tool bit chucked up on the toolpost, but a
friend suggested it would be faster to use a tool post mounted grinder.
First, I wonder if he is right, and second, is there a reasonably priced
one, or plans around to make one?

I'm a real amateur. I needed to grind a rabbet on a bearing race so
it would fit into a 3" pipe and seat on the shoulder. I built a
grinder that mounted to the toolpost on my lathe. It consists of
little more than steel channel with a $14.95 Harbor Freight 4 1/2"
grinder bolted to it using the 3/8" sockets where a handle could be
mounted. Nothing pretty, but it did work and I've used it a couple
times since where the material was too hard to cut. Definitely cheap
and it works.

Steve Worcester wrote:

I am trying to take 1/2 square O1 down to round for about 3" of the overall
(9") length. I have been using a tool bit chucked up on the toolpost, but a
friend suggested it would be faster to use a tool post mounted grinder.
First, I wonder if he is right, and second, is there a reasonably priced
one, or plans around to make one?

I turned some shanks of carbide brazed cutting tools from 3/4 to 1/2" with my
tool post grinder. To get a high quality finish use some oil. Not so much a
flow, but you can soak the wheel prior to it. Make sure it isn't dripping wet -
just soaked - don't want much fly away and never an un-balanced wheel.

With or without it ground down the shafts nicely. Be sure to lay rags over the
lathe so the grit gets caught in the rag to be thrown away.

Martin

--
Martin Eastburn, Barbara Eastburn
@ home at Lion's Lair with our computer
NRA LOH, NRA Life
NRA Second Amendment Task Force Charter Founder