Hoping some people can give me their input on this:

I have always made keyseats in shafts by cutting the entire depth in one
pass using the correct diameter slot drill for the keyseat. For example: I
would use a 1/2" diameter slot drill for a 1/2" keyseat, touch the top of
the shaft with the slot drill, raise the table until the slot drill cut its
full diameter on the shaft and then go another 1/4" deep. This has always
worked for me in the past.

The foreman of the facility where I work said this was incorrect. He said
what I should have done was go in with a smaller cutter first, such as
7/16", and then finish with the 1/2" slot drill.

After all, slot drills are made to a minus tolerance. I believe by taking
two cuts, you run the risk of creating an oversize keyseat.

Just wanted to know what other people's thoughts were.

Thanks,

Ted

"Ted Clark" wrote in message
...
Hoping some people can give me their input on this:

I have always made keyseats in shafts by cutting the entire depth in one
pass using the correct diameter slot drill for the keyseat. For example:
I
would use a 1/2" diameter slot drill for a 1/2" keyseat, touch the top of
the shaft with the slot drill, raise the table until the slot drill cut
its
full diameter on the shaft and then go another 1/4" deep. This has always
worked for me in the past.

The foreman of the facility where I work said this was incorrect. He said
what I should have done was go in with a smaller cutter first, such as
7/16", and then finish with the 1/2" slot drill.

After all, slot drills are made to a minus tolerance. I believe by taking
two cuts, you run the risk of creating an oversize keyseat.

Just wanted to know what other people's thoughts were.

Thanks,

Ted


In spite of the fact that many guys cut such things in one pass, I do not
endorse the method. You are at the mercy of too many variables that can
result in a less than acceptable result. It has always been a good idea
to rough dimensions before finishing them. My policy when cutting key
slots, unless they're cut with a Woodruff cutter, is to cut them undersized,
then go to final size. I rarely rely on a cutter the same size of the
keyway, either. It's much nicer to use an undersized one so you can control
center and size. Properly cut, keyways have a relatively close tolerance,
something I don't like to risk ruining because an end mill doesn't cut size.

Harold

..

On Thu, 13 Jan 2005 21:24:27 -0500, "Ted Clark"
wrote:

Hoping some people can give me their input on this:

I have always made keyseats in shafts by cutting the entire depth in one
pass using the correct diameter slot drill for the keyseat. For example: I
would use a 1/2" diameter slot drill for a 1/2" keyseat, touch the top of
the shaft with the slot drill, raise the table until the slot drill cut its
full diameter on the shaft and then go another 1/4" deep. This has always
worked for me in the past.

The foreman of the facility where I work said this was incorrect. He said
what I should have done was go in with a smaller cutter first, such as
7/16", and then finish with the 1/2" slot drill.

I will assume that what you mean by "slot drill" is an end mill. I
can also assume you ended up with an oversize keyway?

After all, slot drills are made to a minus tolerance. I believe by taking
two cuts, you run the risk of creating an oversize keyseat.

When new, they are generally on size, neither over or under within a
pretty tight tolerance.

Just wanted to know what other people's thoughts were.

My thoughts are that he's wrong too. If I want, or need, a tight
fitting keyway, I'll do it with a smaller cutter, but instead of using
an "on size" cutter for the next cut, I move over to each side,
slightly less than half the difference between the size I want and the
cutter I have, then nibble the last thousandths out until the gage
blocks just barely squeeze in. End mills can, and do, walk, and it's
too easy for one to go oversize. "You can always take another cut,
but that putting on tool is a bitch to grind."

Greybeard.

Hoping some people can give me their input on this:

I have always made keyseats in shafts by cutting the entire depth in one
pass using the correct diameter slot drill for the keyseat. For example: I
would use a 1/2" diameter slot drill for a 1/2" keyseat, touch the top of
the shaft with the slot drill, raise the table until the slot drill cut its
full diameter on the shaft and then go another 1/4" deep. This has always
worked for me in the past.

The foreman of the facility where I work said this was incorrect. He said
what I should have done was go in with a smaller cutter first, such as
7/16", and then finish with the 1/2" slot drill.

After all, slot drills are made to a minus tolerance. I believe by taking
two cuts, you run the risk of creating an oversize keyseat.

Just wanted to know what other people's thoughts were.

Thanks,

Ted



According to Machinery's Handbook...............


For milling keyseats, the total depth to feed cutter in from outside of
shaft to bottom of keyseat is M + D, where D is depth of keyseat.
For checking an assembled key and shaft, calliper measurement J between
top of key and bottom of shaft is used. Where J=S-(M+D)+C

The page shows a diagram of a shaft and key and the following
annotations are made.

C = height of key
D = depth of keyseat (or the wall height of the keyway)
E = width of key
J = distance from bottom of shaft to top of key
M = the distance between the top of the shaft and a line passing through
the upper corners or edges of the keyseat
S = diameter of shaft

M is calculated using the formula M=1/2(S-sq.rt.(S^2-E^2))

However an easier approximation to give M within .001" is

M=E^2/4S

As M varies with shaft diameter it is hard to say whether or not your
method is correct without knowing the diameter of the shaft in question.

What I can say though is that I personally have never heard of using two
sizes of cutter to cut a keyway in a shaft and when I was an apprentice
(many moons ago) I was taught the same method as you for a down and
dirty 'shop method'. If the keyway was large (i.e. around 2" wide) I
would probably have taken it in a couple of cuts rather than hogging it
all out in one pass.

--
Larry Green

In article ,
says...



I have always made keyseats in shafts by cutting the entire depth in one
pass using the correct diameter slot drill for the keyseat. For example: I
would use a 1/2" diameter slot drill for a 1/2" keyseat, touch the top of
the shaft with the slot drill, raise the table until the slot drill cut its
full diameter on the shaft and then go another 1/4" deep.


According to Machinery's Handbook...............


For milling keyseats, the total depth to feed cutter in from outside of
shaft to bottom of keyseat is M + D, where D is depth of keyseat.
For checking an assembled key and shaft, calliper measurement J between
top of key and bottom of shaft is used. Where J=S-(M+D)+C

The page shows a diagram of a shaft and key and the following
annotations are made.

C = height of key
D = depth of keyseat (or the wall height of the keyway)
E = width of key
J = distance from bottom of shaft to top of key
M = the distance between the top of the shaft and a line passing through
the upper corners or edges of the keyseat
S = diameter of shaft

M is calculated using the formula M=1/2(S-sq.rt.(S^2-E^2))

However an easier approximation to give M within .001" is

M=E^2/4S

As M varies with shaft diameter it is hard to say whether or not your
method is correct without knowing the diameter of the shaft in question.


The point of all the formulas for M is to get D = C/2; in other words,
the shoulder of the keyseat is bearing in the center of the face of the
key. By using an endmill with a diameter equal to the width of the key
and gaging the depth from the point that the tool cuts full width, Ted
is getting the correct depth (within the limits of how closely one can
tell when the endmill is cutting full width) without having to do the
calculations.

Of course if you accept Harold's advice to use a smaller cutter, and I
do, this technique doesn't work.

Ned Simmons

I had taught my son the same method as Greybeard. When he went to work, they
reamed him for taking too long to do a job. For fast work, get a new cutter
and do it all one pass. Need a rigid machine , my old Bridgeport wouldn't do
this. His trick for depth saves time also. Feed endmill down by hand until
outside edge of endmill just makes contact with shaft - a perfect flat -
then go on down 1/2 of key width. No need to look up in table.

I must say he did this at an auger manufacture place. Lots o' production, no
real tight tolerances. Now, he's working at a tool making outfit. They
threaten to fire guys that f*&^ up a part. All one of and VERY tight
tolerances. Bet quick and dirty wouldn't go at the new place.

Karl

Thanks to everyone who replied to this post. The advice will be put to good
use; sooner than I thought:

The part I made with the keyseat turned out to be scrap ( through no fault
of mine, for other reasons ). I will have to make a new one tomorrow. I am
going to use the approach of going in with a smaller cutter first and then
finishing with the final size of the keyseat.

Fingers crossed,

Ted
"Ted Clark" wrote in message
...
Hoping some people can give me their input on this:

I have always made keyseats in shafts by cutting the entire depth in one
pass using the correct diameter slot drill for the keyseat. For example:
I
would use a 1/2" diameter slot drill for a 1/2" keyseat, touch the top of
the shaft with the slot drill, raise the table until the slot drill cut
its
full diameter on the shaft and then go another 1/4" deep. This has always
worked for me in the past.

The foreman of the facility where I work said this was incorrect. He said
what I should have done was go in with a smaller cutter first, such as
7/16", and then finish with the 1/2" slot drill.

After all, slot drills are made to a minus tolerance. I believe by taking
two cuts, you run the risk of creating an oversize keyseat.

Just wanted to know what other people's thoughts were.

Thanks,

Ted

"Gene Kearns" wrote in message
...
On Thu, 13 Jan 2005 21:24:27 -0500, "Ted Clark"
wrote:


The foreman of the facility where I work said this was incorrect. He
said
what I should have done was go in with a smaller cutter first, such as
7/16", and then finish with the 1/2" slot drill.

After all, slot drills are made to a minus tolerance. I believe by
taking
two cuts, you run the risk of creating an oversize keyseat.


You are quite correct... it is likely that the keyway will be
oversized...


????? Sorry, I don't agree-----

How so? In the hands of a skilled machinist, the odds of achieving
proper size and location are far better when rouging undersized and then
taking additional cuts. The slot will be on location, straight, and
uniform, all of which are *very* difficult to achieve when taking a single
pass, especially on light duty machines. Regardless of the opinion of
anyone that is more interested in making money than doing the job properly,
cutting keyslots in one pass is generally a poor way to get it done. Tool
pressure is always a factor, as is chip load.

Harold

"Gene Kearns" wrote in message
...
snip-----

...another arguable point is that an endmill is a poor choice for
cutting a keyway, unless it can't be performed otherwise.....
--

After reading your last post, I realize that you and I aren't necessarily
talking the same keyway. My experience is in job shop and missile
industry, where cutting a keyway was not something that was done
repetitively, or routinely, so, naturally, the tools used for the job were
those that were at hand. The tools of choice for me, and the shops where
I was employed, just happened to be end mills, and I suspect that unless
most folks are engaged in machining key slots routinely, that would be their
tool of choice, too.

While one may provide a little "Kentucky windage" when cutting a keyway, the
amount of deflection is up for grabs, regardless of the type cutter used.
Feeds and speeds create a myriad of conditions that can't be anticipated.
I think my point is that those of us that prefer to "do it right" and not
abuse, or ignore, tolerance, would not make the cut in one pass, nor would
we expect it to be as good as one cut by our preferred method. Key slots
are tight tolerance, too tight to risk cutting in one pass as far as I'm
concerned. I agree, the key likely fits tightly when the seat is cut in
one pass, but not because of the precision involved, but more so because of
the variations in the key seat. Overall the key is a press fit, but is
likely hitting on the highs alone. The key seat is likely not on (proper)
location, not square, nor a constant width. That kind of work wasn't
acceptable in the industry from which I came.

I took a quick look at your site. Nice job! I'm impressed with your
background.

Harold

I'm getting in this late, I can tell, but as an old practicing engineer from a job shop background, I was taught that part
being assembled (generally the pulley) should be a light push fit while the part over which the part was being fitted
(generally the shaft) should be press fit to the key. With this kind of fit a single pass with an end mill will not get the
job done on any kind of consistent basis. This kind of fit is the only way to prevent wallowing of fits under reversing
loads..which are most kinds of driving loads anyway. The amount of time taken fitting the key, keyway and keyslot directly
reflect on the life of the joint, as much or more than the fit of the bore. A one pass keyway, broached keyslot and a
chopped off piece of keystock, filed to fit, will get a joint that fails that same as an oversized bore will fail. Some
places, the joint requirements are not very high and an oversized joint can be tolerated but even then, it kind of reflects
on the craftsmanship of the person making the joint.
R. Wink


On Sat, 15 Jan 2005 22:42:16 -0800, "Harold & Susan Vordos" wrote:


"Gene Kearns" wrote in message
.. .
snip-----

...another arguable point is that an endmill is a poor choice for
cutting a keyway, unless it can't be performed otherwise.....
--

After reading your last post, I realize that you and I aren't necessarily
talking the same keyway. My experience is in job shop and missile
industry, where cutting a keyway was not something that was done
repetitively, or routinely, so, naturally, the tools used for the job were
those that were at hand. The tools of choice for me, and the shops where
I was employed, just happened to be end mills, and I suspect that unless
most folks are engaged in machining key slots routinely, that would be their
tool of choice, too.

While one may provide a little "Kentucky windage" when cutting a keyway, the
amount of deflection is up for grabs, regardless of the type cutter used.
Feeds and speeds create a myriad of conditions that can't be anticipated.
I think my point is that those of us that prefer to "do it right" and not
abuse, or ignore, tolerance, would not make the cut in one pass, nor would
we expect it to be as good as one cut by our preferred method. Key slots
are tight tolerance, too tight to risk cutting in one pass as far as I'm
concerned. I agree, the key likely fits tightly when the seat is cut in
one pass, but not because of the precision involved, but more so because of
the variations in the key seat. Overall the key is a press fit, but is
likely hitting on the highs alone. The key seat is likely not on (proper)
location, not square, nor a constant width. That kind of work wasn't
acceptable in the industry from which I came.

I took a quick look at your site. Nice job! I'm impressed with your
background.

Harold

"Gene Kearns" wrote in message
...
On Sat, 15 Jan 2005 22:42:16 -0800, "Harold & Susan Vordos"
wrote:

I agree, the key likely fits tightly when the seat is cut in
one pass, but not because of the precision involved, but more so because
of
the variations in the key seat. Overall the key is a press fit, but is
likely hitting on the highs alone. The key seat is likely not on
(proper)
location, not square, nor a constant width. That kind of work wasn't
acceptable in the industry from which I came.


There certainly are different classes of work.... I've never actually
taken a keyway/keyseat very seriously..... it isn't, by definition, a
precision assembly, nor is it particularly well suited to do anything
but bind two parts together that aren't subject to too much relative
motion......

Having worked in the aerospace industry, myself.... I can't think of
any critical assemblies that use a keyway/keyseat.... splines are
generally employed for that purpose.

It isn't that a "precision" keyway/keyseat couldn't be drawn or
milled... as I noted from the example of the rotary compressor drive
shaft... it's just trying to make a silk purse out of a sow's ear.

Most applications will not use a ground key nor a precision broached
keyseat. The keyway may actually be cut into a piece of material
turned in a lathe and not finish ground. To give one of the (3)
features undue attention without attending to ALL with equal
precision....? The designer is just fooling himself. And, IMHO, to
bother with all of that precision hoopla for a lowly keyed-type drive
suggests that your money would be better spent on generating a
spline....

My $.02.....

I took a quick look at your site. Nice job! I'm impressed with your
background.

Blush..... thanks!

You're very welcome. You earned it.

I think it gets down to interpretation. I'm from the era where your
workmanship is a mark of your ability. I was judged, often harshly, on my
ability to do it right, per print, and avoid MRB if at all possible.
That would include cutting the odd keyway, should a demand arise. We
rarely tried to make a silk purse from a sow's ear, as you suggested.

Truth is, a keyway *is* (and should be considered) a precision cut. It
should be a snug fit, not a sloppy one. It should be at right angles to the
shaft, and should be centered properly. They may be treated poorly by the
masses, but R. Wink hit it right on the head.

Keyways that are not snug are prone to premature failure. Cutting them
randomly is not a great idea, nor is cutting them in one pass. That
industry does so and gets away with it is more a comment on the level of
lowering the bar than one of unimportance. It's like the food industry.
How many rat turds are you willing to eat? Industry sets standards that
permit a small amount. Personally, I'll have none, thanks. Same with
machining. I take no shortcuts, nor do I accept anything as "good enough".

Mind you, I'm not trying to tell you how you should be cutting keyways. I'm
simply stating that just because they're treated with contempt by many
doesn't mean they are deserving of the treatment. Same philosophy as
threads and thread measuring. I do it with wires. Most folks think I'm
crazy. I know I'm not, not about threads, anyway! g

Different strokes, apparently.

Harold

In article , Harold & Susan Vordos says...

... The tools of choice for me, and the shops where
I was employed, just happened to be end mills, and I suspect that unless
most folks are engaged in machining key slots routinely, that would be their
tool of choice, too.

This is sort of crazy, to use an end mill when the correct tool
(woodruff key cutter) is so widely available. In a horizontal
machine one can do the job much more reliably and accurately.
I wouldn't think of of using an end mill for the job.

Jim


--
==================================================
please reply to:
JRR(zero) at pkmfgvm4 (dot) vnet (dot) ibm (dot) com
==================================================

On 17 Jan 2005 12:14:59 -0800, jim rozen
wrote:

In article , Harold & Susan Vordos says...

... The tools of choice for me, and the shops where
I was employed, just happened to be end mills, and I suspect that unless
most folks are engaged in machining key slots routinely, that would be their
tool of choice, too.

This is sort of crazy, to use an end mill when the correct tool
(woodruff key cutter) is so widely available. In a horizontal
machine one can do the job much more reliably and accurately.
I wouldn't think of of using an end mill for the job.

Depends on the job, Jim. We did a lot of keyways that had to be full
depth for their entire length, and 1/4" past the end of the key was an
oil seal. Woodruff cutters aren't always an option. It's actually
pretty common.

Greybeard.

"jim rozen" wrote in message
...
In article , Harold & Susan Vordos says...

... The tools of choice for me, and the shops where
I was employed, just happened to be end mills, and I suspect that unless
most folks are engaged in machining key slots routinely, that would be
their
tool of choice, too.

This is sort of crazy, to use an end mill when the correct tool
(woodruff key cutter) is so widely available. In a horizontal
machine one can do the job much more reliably and accurately.
I wouldn't think of of using an end mill for the job.

Jim

What Greybeard said. You don't always have the option for the radius.
Otherwise I fully agree.....and actually prefer a Woodruff key in place of a
square one when it's possible The added benefit of using the Woodruff
cutter is they typically cut the proper width--which is normally reasonably
close tolerance.

Further, does every shop have every width Woodruff? I seriously doubt
it-------but I have a generous supply of end mills, starting with 1/32"
going up to 1". I can cut any size keyway with no trouble, on size, on
location. I use my skills in place of tools. g

Harold

In article , Harold & Susan Vordos says...

Further, does every shop have every width Woodruff? I seriously doubt
it-------

LOL. Harold, the same trick you employ using the end mill works
with the keyseat cutter. You use a narrower one and then just
move it over to finish the cut.

Because I own a horizontal mill, I've grown rather fond of
woodruff key cutters. They actually are handy for a variety of
tasks.

Jim


--
==================================================
please reply to:
JRR(zero) at pkmfgvm4 (dot) vnet (dot) ibm (dot) com
==================================================

On 18 Jan 2005 08:08:02 -0800, jim rozen
wrote:

In article , Harold & Susan Vordos says...

Further, does every shop have every width Woodruff? I seriously doubt
it-------

LOL. Harold, the same trick you employ using the end mill works
with the keyseat cutter. You use a narrower one and then just
move it over to finish the cut.

Because I own a horizontal mill, I've grown rather fond of
woodruff key cutters. They actually are handy for a variety of
tasks.

Jim

Ayup.

G

Gunner

"At the core of liberalism is the spoiled child -
miserable, as all spoiled children are, unsatisfied,
demanding, ill-disciplined, despotic and useless.
Liberalism is a philosphy of sniveling brats." -- P.J. O'Rourke

"jim rozen" wrote in message
...
In article , Harold & Susan Vordos says...

Further, does every shop have every width Woodruff? I seriously doubt
it-------

LOL. Harold, the same trick you employ using the end mill works
with the keyseat cutter. You use a narrower one and then just
move it over to finish the cut.

Because I own a horizontal mill, I've grown rather fond of
woodruff key cutters. They actually are handy for a variety of
tasks.

Jim


Gotcha! And I do that when necessary, too, but it sort of supports those
that create the argument that you risk making scrap because you don't rely
on the tool to make the cut to size. It goes without saying that those
of us that work in the trade don't recognize the risk. :-)

Harold

In article , Harold & Susan Vordos says...

Gotcha! And I do that when necessary, too, but it sort of supports those
that create the argument that you risk making scrap because you don't rely
on the tool to make the cut to size. It goes without saying that those
of us that work in the trade don't recognize the risk. :-)

Most folks understand that end mills flex.
When they do, the surfaces they cut are no longer
where you think they should be, based on a simple
'edge finder, and measure the (still) cutter'
calculation.

Those who don't understand this either don't care
because they're working to 0.010 tolerance - and
there are *plenty* of jobs out there that are done
to +/- 1/64 inch in industry - or they're making
a lot of scrap.

Woodruff key cutters might cut a thou oversized or so,
depending on condition or size. A 1/8 inch end mill
could cut oversize, or offside, by ten thou or so.
Also small end mills will take a while to do a
keyway because they can't do it all in one bite.
Chip clearance becomes a big deal.

This is why I like keyseat cutters.

Jim


--
==================================================
please reply to:
JRR(zero) at pkmfgvm4 (dot) vnet (dot) ibm (dot) com
==================================================

In article ,
jim rozen wrote:
In article , Harold & Susan Vordos says...

Gotcha! And I do that when necessary, too, but it sort of supports those
that create the argument that you risk making scrap because you don't rely
on the tool to make the cut to size. It goes without saying that those
of us that work in the trade don't recognize the risk. :-)

Most folks understand that end mills flex.
When they do, the surfaces they cut are no longer
where you think they should be, based on a simple
'edge finder, and measure the (still) cutter'
calculation.

Agreed. Though the "slot drill" mentioned near the start of
this thread is not just *any* endmill -- it is a two-flute
center-cutting one, which does the best at cutting to width and with
minimal wander, because the sides of the slot are being cut only when
there is absolute minimum side force on the end mill.

The "slot drill" term is apparently more common in the UK than
in the USA -- but the function remains constant.

[ ... ]

Woodruff key cutters might cut a thou oversized or so,
depending on condition or size. A 1/8 inch end mill
could cut oversize, or offside, by ten thou or so.
Also small end mills will take a while to do a
keyway because they can't do it all in one bite.
Chip clearance becomes a big deal.

This is why I like keyseat cutters.

With all the mention of keyseat cutters in horizontal mills, I
don't see (yet) any mention of plain milling cutters for keyseats. They
work very nicely for the task, if you can accept the longer radius at
the end of the cut.

Enjoy,
DoN.
--
Email: | Voice (all times): (703) 938-4564
(too) near Washington D.C. | http://www.d-and-d.com/dnichols/DoN.html
--- Black Holes are where God is dividing by zero ---

"jim rozen" wrote in message
...
In article , Harold & Susan Vordos says...

Gotcha! And I do that when necessary, too, but it sort of supports those
that create the argument that you risk making scrap because you don't
rely
on the tool to make the cut to size. It goes without saying that
those
of us that work in the trade don't recognize the risk. :-)

Most folks understand that end mills flex.
When they do, the surfaces they cut are no longer
where you think they should be, based on a simple
'edge finder, and measure the (still) cutter'
calculation.

Those who don't understand this either don't care
because they're working to 0.010 tolerance - and
there are *plenty* of jobs out there that are done
to +/- 1/64 inch in industry - or they're making
a lot of scrap.

Woodruff key cutters might cut a thou oversized or so,
depending on condition or size. A 1/8 inch end mill
could cut oversize, or offside, by ten thou or so.
Also small end mills will take a while to do a
keyway because they can't do it all in one bite.
Chip clearance becomes a big deal.

This is why I like keyseat cutters.

Jim

Absolutely! I was thinking more on the order of ¼" and above. I've used
my share of small end mills, right down to 1/32". Talk about a piece of
glass! Yep, for those small keyways, there's nothing that competes with a
Woodruff cutter. Interestingly, I have never had a problem with them
cutting oversized, either. In fact, they generally cut snug to the cutter.
Could be the spindle assembly is quite true. Do keep in mind I've run only
my own machines for well over 30 years now.

Like you, I've used Woodruff cutters for many things, not just keyways.

Harold

"DoN. Nichols" wrote in message
...
snip-

With all the mention of keyseat cutters in horizontal mills, I
don't see (yet) any mention of plain milling cutters for keyseats. They
work very nicely for the task, if you can accept the longer radius at
the end of the cut.

Enjoy,
DoN.


Not only nicely, but fast. Ever run something like a #3 K&T mill running a
side cutter in steel? Almost a frightening experience.

Harold

"Tom" wrote in message
...
"DoN. Nichols" wrote:

In article ,
jim rozen wrote:
In article , Harold & Susan Vordos
says...

Gotcha! And I do that when necessary, too, but it sort of supports
those
that create the argument that you risk making scrap because you don't
rely
on the tool to make the cut to size. It goes without saying that
those
of us that work in the trade don't recognize the risk. :-)

Most folks understand that end mills flex.
When they do, the surfaces they cut are no longer
where you think they should be, based on a simple
'edge finder, and measure the (still) cutter'
calculation.

Agreed. Though the "slot drill" mentioned near the start of
this thread is not just *any* endmill -- it is a two-flute
center-cutting one, which does the best at cutting to width and with
minimal wander, because the sides of the slot are being cut only when
there is absolute minimum side force on the end mill.

The "slot drill" term is apparently more common in the UK than
in the USA -- but the function remains constant.

[ ... ]

Woodruff key cutters might cut a thou oversized or so,
depending on condition or size. A 1/8 inch end mill
could cut oversize, or offside, by ten thou or so.
Also small end mills will take a while to do a
keyway because they can't do it all in one bite.
Chip clearance becomes a big deal.

This is why I like keyseat cutters.

With all the mention of keyseat cutters in horizontal mills, I
don't see (yet) any mention of plain milling cutters for keyseats. They
work very nicely for the task, if you can accept the longer radius at
the end of the cut.

Enjoy,
DoN.

Dammit Don, the way this thread was going, I was betting that it'd
be a week before someone mentioned plain milling cutters in a
horizontal mill. You forgot to mention the added value of such
a keyseat: that of a minmised stress riser at the termination.

Tom

Yep, much the same as a Woodruff, but not always possible to use due to
circumstances at hand. Some times you just have to use an end mill! g

Harold

In article ,
Harold & Susan Vordos wrote:

"DoN. Nichols" wrote in message
...
snip-

With all the mention of keyseat cutters in horizontal mills, I
don't see (yet) any mention of plain milling cutters for keyseats. They
work very nicely for the task, if you can accept the longer radius at

[ ... ]

Not only nicely, but fast. Ever run something like a #3 K&T mill running a
side cutter in steel? Almost a frightening experience.

My experience has been limited to my Nichols horizontal mill, a
#40 NMTB taper in the spindle, and a choice of lever feed (rack and
pinion) or leadscrew feed. For a lot of things on that machine,
including cutting keyways, I prefer the lever feed option. It lets me
apply feed until the machine sounds unhappy, and then back off -- except
that so far, I have not had the nerve to push it hard enough for it to
sound unhappy. It just keeps cutting. :-)

Enjoy,
DoN.

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"DoN. Nichols" wrote:

In article ,
jim rozen wrote:
In article , Harold & Susan Vordos says...

Gotcha! And I do that when necessary, too, but it sort of supports those
that create the argument that you risk making scrap because you don't rely
on the tool to make the cut to size. It goes without saying that those
of us that work in the trade don't recognize the risk. :-)

Most folks understand that end mills flex.
When they do, the surfaces they cut are no longer
where you think they should be, based on a simple
'edge finder, and measure the (still) cutter'
calculation.

Agreed. Though the "slot drill" mentioned near the start of
this thread is not just *any* endmill -- it is a two-flute
center-cutting one, which does the best at cutting to width and with
minimal wander, because the sides of the slot are being cut only when
there is absolute minimum side force on the end mill.

The "slot drill" term is apparently more common in the UK than
in the USA -- but the function remains constant.

[ ... ]

Woodruff key cutters might cut a thou oversized or so,
depending on condition or size. A 1/8 inch end mill
could cut oversize, or offside, by ten thou or so.
Also small end mills will take a while to do a
keyway because they can't do it all in one bite.
Chip clearance becomes a big deal.

This is why I like keyseat cutters.

With all the mention of keyseat cutters in horizontal mills, I
don't see (yet) any mention of plain milling cutters for keyseats. They
work very nicely for the task, if you can accept the longer radius at
the end of the cut.

Enjoy,
DoN.

Dammit Don, the way this thread was going, I was betting that it'd
be a week before someone mentioned plain milling cutters in a
horizontal mill. You forgot to mention the added value of such
a keyseat: that of a minmised stress riser at the termination.

Tom

"DoN. Nichols" wrote in message
...
In article ,
Harold & Susan Vordos wrote:

"DoN. Nichols" wrote in message
...
snip-

With all the mention of keyseat cutters in horizontal mills, I
don't see (yet) any mention of plain milling cutters for keyseats.
They
work very nicely for the task, if you can accept the longer radius at

[ ... ]

Not only nicely, but fast. Ever run something like a #3 K&T mill running
a
side cutter in steel? Almost a frightening experience.

My experience has been limited to my Nichols horizontal mill, a
#40 NMTB taper in the spindle, and a choice of lever feed (rack and
pinion) or leadscrew feed. For a lot of things on that machine,
including cutting keyways, I prefer the lever feed option. It lets me
apply feed until the machine sounds unhappy, and then back off -- except
that so far, I have not had the nerve to push it hard enough for it to
sound unhappy. It just keeps cutting. :-)

Enjoy,
DoN.


That's sort of what you do with a K&T, only it's by increasing the power
feed. You simply turn a handle while it's cutting, and it increases with
each half revolution. I've taken cuts in chrome moly with large side
cutters advancing at 10"/min. It's nothing short of amazing to watch the
chips accumulate, all the while the machine isn't even grunting. I'm sure
you can imagine the difference when a K&T may weigh three tons as opposed to
your hand mill, which sounds like it's doing one hell of a bang up job!

Harold

In article , Harold & Susan Vordos says...

That's sort of what you do with a K&T, only it's by increasing the power
feed. You simply turn a handle while it's cutting, and it increases with
each half revolution. I've taken cuts in chrome moly with large side
cutters advancing at 10"/min. It's nothing short of amazing to watch the
chips accumulate, all the while the machine isn't even grunting. I'm sure
you can imagine the difference when a K&T may weigh three tons as opposed to
your hand mill, which sounds like it's doing one hell of a bang up job!

That's what robert bastow used to say about horizontal mills. His
instructions on setting one up involved getting the setup straight,
turning on the spindle, and coolant, and then cranking the feed
by hand until the machine sounded like it was bogging down.

Then back off a bit, and set the automatic feed to keep up with the
hand feed. Then sit back and watch it just **** out chips.

Jim


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