Hi Group,

Want to know if anyone in the San Diego area has a surface grinder big
enough to handle a 24x8 inch machine table. I've been searching for how
come I can't seem to make flat surfaces that are actually parallel to
the other side...and measuring about .0015" in variation as I run the
mill table in/out on the Y axis. Wierd thing is it seems backwards, the
table gets closer to the spindle as I move out away from the machine
base. So I want to know the table top is flat...have already tried
fiddling with the bolts on the vertical slide of the table, no joy
there. Can anyone suggest where I might get this done, without breaking
the social security bank?

Thanks,
Bill

"Bill Martin" wrote in message
...
Hi Group,

Want to know if anyone in the San Diego area has a surface grinder big
enough to handle a 24x8 inch machine table. I've been searching for how
come I can't seem to make flat surfaces that are actually parallel to the
other side...and measuring about .0015" in variation as I run the mill
table in/out on the Y axis. Wierd thing is it seems backwards, the table
gets closer to the spindle as I move out away from the machine base. So I
want to know the table top is flat...have already tried fiddling with the
bolts on the vertical slide of the table, no joy there. Can anyone suggest
where I might get this done, without breaking the social security bank?

Thanks,
Bill

You can measure flatness of the table first, Bill, without grinding it. But
knee-type milling machines are subject to several types of inherent,
geometrical traverse errors, so it's more likely that your problem lies
there. Somewhere there is a good, illustrated explanation of this. Maybe
someone knows where it could be found online.

Do you have a precision straightedge and a dial indicator?

--
Ed Huntress

Bill Martin wrote:

Hi Group,

Want to know if anyone in the San Diego area has a surface grinder big
enough to handle a 24x8 inch machine table. I've been searching for how
come I can't seem to make flat surfaces that are actually parallel to
the other side...and measuring about .0015" in variation as I run the
mill table in/out on the Y axis. Wierd thing is it seems backwards, the
table gets closer to the spindle as I move out away from the machine
base. So I want to know the table top is flat...have already tried
fiddling with the bolts on the vertical slide of the table, no joy
there. Can anyone suggest where I might get this done, without breaking
the social security bank?

Most likely the way slides are worn, not the table itself. There are
several things that all need to be right for the machine to cut square.
Assuming this is a knee mill like a Bridgeport, both the top of the knee and
the bottom of the saddle need to be straight. Second, the bottom of the
saddle and the top of the table need to be parallel. Between these, there
is also the X axis slide, and there could be wear there too that is
throwing the Y out of alignment.

Jon

On Sun, 03 Apr 2011 11:43:37 -0700, Bill Martin
wrote:

Hi Group,

Want to know if anyone in the San Diego area has a surface grinder big
enough to handle a 24x8 inch machine table. I've been searching for how
come I can't seem to make flat surfaces that are actually parallel to
the other side...and measuring about .0015" in variation as I run the
mill table in/out on the Y axis. Wierd thing is it seems backwards, the
table gets closer to the spindle as I move out away from the machine
base. So I want to know the table top is flat...have already tried
fiddling with the bolts on the vertical slide of the table, no joy
there. Can anyone suggest where I might get this done, without breaking
the social security bank?

Thanks,
Bill


There is a place in LA that does Blanchard grinding up to about 20 feet
by 30 feet.

I cant remember the name..perhaps John Carrol might know.

Gunner

--

"You can have peace. Or you can have freedom. Don't ever count on having both at once."
Robert A. Heinlein

On 04/03/2011 11:51 AM, Ed Huntress wrote:
"Bill wrote in message
...
Hi Group,

Want to know if anyone in the San Diego area has a surface grinder big
enough to handle a 24x8 inch machine table. I've been searching for how
come I can't seem to make flat surfaces that are actually parallel to the
other side...and measuring about .0015" in variation as I run the mill
table in/out on the Y axis. Wierd thing is it seems backwards, the table
gets closer to the spindle as I move out away from the machine base. So I
want to know the table top is flat...have already tried fiddling with the
bolts on the vertical slide of the table, no joy there. Can anyone suggest
where I might get this done, without breaking the social security bank?

Thanks,
Bill

You can measure flatness of the table first, Bill, without grinding it. But
knee-type milling machines are subject to several types of inherent,
geometrical traverse errors, so it's more likely that your problem lies
there. Somewhere there is a good, illustrated explanation of this. Maybe
someone knows where it could be found online.

Do you have a precision straightedge and a dial indicator?


I have a dial indicator that does .0001", which is what I measured with
earlier today. No precision straightedge, but what made me suspect the
table surface is this: I have an optical flat disc salvaged from an old
instrument for I know not what purpose, but sliding the disc across the
table in "Y" direction, there seem to be some height changes at the edge
of the table slots. I can more feel it than see it, so maybe not enough
to worry about? This is a pretty old machine, a Gorton O16-A, built in
1954 it looks. Could indeed be just wear everywhere! Any pointers to
measurement "how to" info would be appreciated!

Bill

"Bill Martin" wrote in message
...
On 04/03/2011 11:51 AM, Ed Huntress wrote:
"Bill wrote in message
...
Hi Group,

Want to know if anyone in the San Diego area has a surface grinder big
enough to handle a 24x8 inch machine table. I've been searching for how
come I can't seem to make flat surfaces that are actually parallel to
the
other side...and measuring about .0015" in variation as I run the mill
table in/out on the Y axis. Wierd thing is it seems backwards, the table
gets closer to the spindle as I move out away from the machine base. So
I
want to know the table top is flat...have already tried fiddling with
the
bolts on the vertical slide of the table, no joy there. Can anyone
suggest
where I might get this done, without breaking the social security bank?

Thanks,
Bill

You can measure flatness of the table first, Bill, without grinding it.
But
knee-type milling machines are subject to several types of inherent,
geometrical traverse errors, so it's more likely that your problem lies
there. Somewhere there is a good, illustrated explanation of this. Maybe
someone knows where it could be found online.

Do you have a precision straightedge and a dial indicator?


I have a dial indicator that does .0001", which is what I measured with
earlier today. No precision straightedge, but what made me suspect the
table surface is this: I have an optical flat disc salvaged from an old
instrument for I know not what purpose, but sliding the disc across the
table in "Y" direction, there seem to be some height changes at the edge
of the table slots. I can more feel it than see it, so maybe not enough to
worry about? This is a pretty old machine, a Gorton O16-A, built in 1954
it looks. Could indeed be just wear everywhere! Any pointers to
measurement "how to" info would be appreciated!

Bill

I wish I could help with the measurement, and I have two books on the
subject of rebuilding and tuning machine tools, but they're in my storage
and I haven't looked at them in 20 years.

I'm hoping someone will have a link to a very nicely illustrated explanation
of such errors -- I remember seeing it in print a few decades ago.

An optical flat might be hard to read, as sensitive as they are. And a
little rounding at the edges of the T-slots is no surprise in an old
machine.

By the time they had the sag errors all figured out, sometime in the 1930s,
builders were building-in some correction factors. Sometimes they
overcorrected. It's not completely obvious, and you can really chase your
tail trying to figure out where the problem is.

A good straightedge would really help -- either the kind used by machine
tool rebuilders or just a knife-edge precision blade. I have one made by
Starrett, 18" long.

If you're ambitious, you can get any old straightedge quite close to
straight by laying it on a piece of craft paper, tracing the edge with a
razor-trimmed chisel-edge pencil, and then carefully flopping the tool over
its own edge, and tracing again. File or stone the high spots. When you get
too close for the pencil marks to be clear, use a razor to cut a fine line
in the paper, in place of the pencil. You can get surprisingly close if you
have patience and you're careful.

--
Ed Huntress

On 04/03/2011 04:38 PM, Ed Huntress wrote:
"Bill wrote in message
...
On 04/03/2011 11:51 AM, Ed Huntress wrote:
"Bill wrote in message
...
Hi Group,

Want to know if anyone in the San Diego area has a surface grinder big
enough to handle a 24x8 inch machine table. I've been searching for how
come I can't seem to make flat surfaces that are actually parallel to
the
other side...and measuring about .0015" in variation as I run the mill
table in/out on the Y axis. Wierd thing is it seems backwards, the table
gets closer to the spindle as I move out away from the machine base. So
I
want to know the table top is flat...have already tried fiddling with
the
bolts on the vertical slide of the table, no joy there. Can anyone
suggest
where I might get this done, without breaking the social security bank?

Thanks,
Bill

You can measure flatness of the table first, Bill, without grinding it.
But
knee-type milling machines are subject to several types of inherent,
geometrical traverse errors, so it's more likely that your problem lies
there. Somewhere there is a good, illustrated explanation of this. Maybe
someone knows where it could be found online.

Do you have a precision straightedge and a dial indicator?


I have a dial indicator that does .0001", which is what I measured with
earlier today. No precision straightedge, but what made me suspect the
table surface is this: I have an optical flat disc salvaged from an old
instrument for I know not what purpose, but sliding the disc across the
table in "Y" direction, there seem to be some height changes at the edge
of the table slots. I can more feel it than see it, so maybe not enough to
worry about? This is a pretty old machine, a Gorton O16-A, built in 1954
it looks. Could indeed be just wear everywhere! Any pointers to
measurement "how to" info would be appreciated!

Bill

I wish I could help with the measurement, and I have two books on the
subject of rebuilding and tuning machine tools, but they're in my storage
and I haven't looked at them in 20 years.

I'm hoping someone will have a link to a very nicely illustrated explanation
of such errors -- I remember seeing it in print a few decades ago.

An optical flat might be hard to read, as sensitive as they are. And a
little rounding at the edges of the T-slots is no surprise in an old
machine.

By the time they had the sag errors all figured out, sometime in the 1930s,
builders were building-in some correction factors. Sometimes they
overcorrected. It's not completely obvious, and you can really chase your
tail trying to figure out where the problem is.

A good straightedge would really help -- either the kind used by machine
tool rebuilders or just a knife-edge precision blade. I have one made by
Starrett, 18" long.

If you're ambitious, you can get any old straightedge quite close to
straight by laying it on a piece of craft paper, tracing the edge with a
razor-trimmed chisel-edge pencil, and then carefully flopping the tool over
its own edge, and tracing again. File or stone the high spots. When you get
too close for the pencil marks to be clear, use a razor to cut a fine line
in the paper, in place of the pencil. You can get surprisingly close if you
have patience and you're careful.


Ok, you gave me motivation...I checked out my 12" Mitutoyo metal ruler
on a small surface plate, and it seems pretty decent for straightness.
So I put it across the mill table, with a light behind it, and do NOT
see light leaking under the edge of the ruler. So sounds like the table
is flat enough for most purposes, certainly mine. All of the ways on
this machine, old as it is, still show a lot of scrape marks. Could be I
just need to make allowances for how it is... not a big problem for most
things I might attempt.

Bill

Bill Martin fired this volley in news:inb2hj$pik$1
@dont-email.me:

Wierd thing is it seems backwards, the table
gets closer to the spindle as I move out away from the machine
base.

Bill...

that's not un-intuitive, it's exactly what's to be expected.

It isn't the table's surface that is worn, but the ways. Near the
center, where most of the work has taken place, they're worn down
considerably. Near the ends, they are not worn; thus, they are "higher".

Don't grind the table, scrape the ways.

LLoyd

"Bill Martin" wrote in message
...
On 04/03/2011 04:38 PM, Ed Huntress wrote:
"Bill wrote in message
...
On 04/03/2011 11:51 AM, Ed Huntress wrote:
"Bill wrote in message
...
Hi Group,

Want to know if anyone in the San Diego area has a surface grinder big
enough to handle a 24x8 inch machine table. I've been searching for
how
come I can't seem to make flat surfaces that are actually parallel to
the
other side...and measuring about .0015" in variation as I run the mill
table in/out on the Y axis. Wierd thing is it seems backwards, the
table
gets closer to the spindle as I move out away from the machine base.
So
I
want to know the table top is flat...have already tried fiddling with
the
bolts on the vertical slide of the table, no joy there. Can anyone
suggest
where I might get this done, without breaking the social security
bank?

Thanks,
Bill

You can measure flatness of the table first, Bill, without grinding it.
But
knee-type milling machines are subject to several types of inherent,
geometrical traverse errors, so it's more likely that your problem lies
there. Somewhere there is a good, illustrated explanation of this.
Maybe
someone knows where it could be found online.

Do you have a precision straightedge and a dial indicator?


I have a dial indicator that does .0001", which is what I measured with
earlier today. No precision straightedge, but what made me suspect the
table surface is this: I have an optical flat disc salvaged from an old
instrument for I know not what purpose, but sliding the disc across the
table in "Y" direction, there seem to be some height changes at the edge
of the table slots. I can more feel it than see it, so maybe not enough
to
worry about? This is a pretty old machine, a Gorton O16-A, built in 1954
it looks. Could indeed be just wear everywhere! Any pointers to
measurement "how to" info would be appreciated!

Bill

I wish I could help with the measurement, and I have two books on the
subject of rebuilding and tuning machine tools, but they're in my storage
and I haven't looked at them in 20 years.

I'm hoping someone will have a link to a very nicely illustrated
explanation
of such errors -- I remember seeing it in print a few decades ago.

An optical flat might be hard to read, as sensitive as they are. And a
little rounding at the edges of the T-slots is no surprise in an old
machine.

By the time they had the sag errors all figured out, sometime in the
1930s,
builders were building-in some correction factors. Sometimes they
overcorrected. It's not completely obvious, and you can really chase your
tail trying to figure out where the problem is.

A good straightedge would really help -- either the kind used by machine
tool rebuilders or just a knife-edge precision blade. I have one made by
Starrett, 18" long.

If you're ambitious, you can get any old straightedge quite close to
straight by laying it on a piece of craft paper, tracing the edge with a
razor-trimmed chisel-edge pencil, and then carefully flopping the tool
over
its own edge, and tracing again. File or stone the high spots. When you
get
too close for the pencil marks to be clear, use a razor to cut a fine
line
in the paper, in place of the pencil. You can get surprisingly close if
you
have patience and you're careful.


Ok, you gave me motivation...I checked out my 12" Mitutoyo metal ruler on
a small surface plate, and it seems pretty decent for straightness. So I
put it across the mill table, with a light behind it, and do NOT see light
leaking under the edge of the ruler. So sounds like the table is flat
enough for most purposes, certainly mine. All of the ways on this machine,
old as it is, still show a lot of scrape marks. Could be I just need to
make allowances for how it is... not a big problem for most things I might
attempt.

Bill

That's the way it often goes with old machines, particularly knee mills.
It's not generally much of a hardship. In the really old days, no one
considered a mill to be a precision machine, anyway.

--
Ed Huntress

"Ed Huntress" wrote in message
...

"Bill Martin" wrote in message
...
On 04/03/2011 11:51 AM, Ed Huntress wrote:
"Bill wrote in message
...
Hi Group,

Want to know if anyone in the San Diego area has a surface grinder big
enough to handle a 24x8 inch machine table. I've been searching for how
come I can't seem to make flat surfaces that are actually parallel to
the
other side...and measuring about .0015" in variation as I run the mill
table in/out on the Y axis. Wierd thing is it seems backwards, the
table
gets closer to the spindle as I move out away from the machine base. So
I
want to know the table top is flat...have already tried fiddling with
the
bolts on the vertical slide of the table, no joy there. Can anyone
suggest
where I might get this done, without breaking the social security bank?

Thanks,
Bill

You can measure flatness of the table first, Bill, without grinding it.
But
knee-type milling machines are subject to several types of inherent,
geometrical traverse errors, so it's more likely that your problem lies
there. Somewhere there is a good, illustrated explanation of this. Maybe
someone knows where it could be found online.

Do you have a precision straightedge and a dial indicator?


I have a dial indicator that does .0001", which is what I measured with
earlier today. No precision straightedge, but what made me suspect the
table surface is this: I have an optical flat disc salvaged from an old
instrument for I know not what purpose, but sliding the disc across the
table in "Y" direction, there seem to be some height changes at the edge
of the table slots. I can more feel it than see it, so maybe not enough
to worry about? This is a pretty old machine, a Gorton O16-A, built in
1954 it looks. Could indeed be just wear everywhere! Any pointers to
measurement "how to" info would be appreciated!

Bill

I wish I could help with the measurement, and I have two books on the
subject of rebuilding and tuning machine tools, but they're in my storage
and I haven't looked at them in 20 years.

I'm hoping someone will have a link to a very nicely illustrated
explanation of such errors -- I remember seeing it in print a few decades
ago.

An optical flat might be hard to read, as sensitive as they are. And a
little rounding at the edges of the T-slots is no surprise in an old
machine.

By the time they had the sag errors all figured out, sometime in the
1930s, builders were building-in some correction factors. Sometimes they
overcorrected. It's not completely obvious, and you can really chase your
tail trying to figure out where the problem is.

A good straightedge would really help -- either the kind used by machine
tool rebuilders or just a knife-edge precision blade. I have one made by
Starrett, 18" long.

If you're ambitious, you can get any old straightedge quite close to
straight by laying it on a piece of craft paper, tracing the edge with a
razor-trimmed chisel-edge pencil, and then carefully flopping the tool
over its own edge, and tracing again. File or stone the high spots. When
you get too close for the pencil marks to be clear, use a razor to cut a
fine line in the paper, in place of the pencil. You can get surprisingly
close if you have patience and you're careful.

--
Ed Huntress


In place of a straight edge and indicator, you can also use an optical
technique. Mount a mirror on the side of a flat-bottomed block, and look at
the change in vertical angle of reflected light as it is moved down the
table. This is the technique used to calibrate granite surface plates.
Usually an autocollimator is used to measure the angle, but a poor man's
substitute is to look at the height of a reflected laser pointer on a far
wall. Of course this method measures change in tilt versus position which
then requires a little math to convert to change in height of the table. The
goverment has a publication on how do do this:
http://www.osti.gov/bridge/product.b...osti_id=650156

On 04/03/2011 05:20 PM, Lloyd E. Sponenburgh wrote:
Bill fired this volley in news:inb2hj$pik$1
@dont-email.me:

Wierd thing is it seems backwards, the table
gets closer to the spindle as I move out away from the machine
base.

Bill...

that's not un-intuitive, it's exactly what's to be expected.

It isn't the table's surface that is worn, but the ways. Near the
center, where most of the work has taken place, they're worn down
considerably. Near the ends, they are not worn; thus, they are "higher".

Don't grind the table, scrape the ways.

LLoyd
Yeah, that makes sense. I did notice that the vertical change was not
exactly linear with position, which is very consistent with your
diagnosis. Not likely that I'm going to be able to scrape ways, will
just have to live with the known error, I can keep it under .001" by
staying away from the outermost table position.

Bill

On 04/03/2011 05:31 PM, Ed Huntress wrote:
"Bill wrote in message
...
On 04/03/2011 04:38 PM, Ed Huntress wrote:
"Bill wrote in message
...
On 04/03/2011 11:51 AM, Ed Huntress wrote:
"Bill wrote in message
...
Hi Group,

Want to know if anyone in the San Diego area has a surface grinder big
enough to handle a 24x8 inch machine table. I've been searching for
how
come I can't seem to make flat surfaces that are actually parallel to
the
other side...and measuring about .0015" in variation as I run the mill
table in/out on the Y axis. Wierd thing is it seems backwards, the
table
gets closer to the spindle as I move out away from the machine base.
So
I
want to know the table top is flat...have already tried fiddling with
the
bolts on the vertical slide of the table, no joy there. Can anyone
suggest
where I might get this done, without breaking the social security
bank?

Thanks,
Bill

You can measure flatness of the table first, Bill, without grinding it.
But
knee-type milling machines are subject to several types of inherent,
geometrical traverse errors, so it's more likely that your problem lies
there. Somewhere there is a good, illustrated explanation of this.
Maybe
someone knows where it could be found online.

Do you have a precision straightedge and a dial indicator?


I have a dial indicator that does .0001", which is what I measured with
earlier today. No precision straightedge, but what made me suspect the
table surface is this: I have an optical flat disc salvaged from an old
instrument for I know not what purpose, but sliding the disc across the
table in "Y" direction, there seem to be some height changes at the edge
of the table slots. I can more feel it than see it, so maybe not enough
to
worry about? This is a pretty old machine, a Gorton O16-A, built in 1954
it looks. Could indeed be just wear everywhere! Any pointers to
measurement "how to" info would be appreciated!

Bill

I wish I could help with the measurement, and I have two books on the
subject of rebuilding and tuning machine tools, but they're in my storage
and I haven't looked at them in 20 years.

I'm hoping someone will have a link to a very nicely illustrated
explanation
of such errors -- I remember seeing it in print a few decades ago.

An optical flat might be hard to read, as sensitive as they are. And a
little rounding at the edges of the T-slots is no surprise in an old
machine.

By the time they had the sag errors all figured out, sometime in the
1930s,
builders were building-in some correction factors. Sometimes they
overcorrected. It's not completely obvious, and you can really chase your
tail trying to figure out where the problem is.

A good straightedge would really help -- either the kind used by machine
tool rebuilders or just a knife-edge precision blade. I have one made by
Starrett, 18" long.

If you're ambitious, you can get any old straightedge quite close to
straight by laying it on a piece of craft paper, tracing the edge with a
razor-trimmed chisel-edge pencil, and then carefully flopping the tool
over
its own edge, and tracing again. File or stone the high spots. When you
get
too close for the pencil marks to be clear, use a razor to cut a fine
line
in the paper, in place of the pencil. You can get surprisingly close if
you
have patience and you're careful.


Ok, you gave me motivation...I checked out my 12" Mitutoyo metal ruler on
a small surface plate, and it seems pretty decent for straightness. So I
put it across the mill table, with a light behind it, and do NOT see light
leaking under the edge of the ruler. So sounds like the table is flat
enough for most purposes, certainly mine. All of the ways on this machine,
old as it is, still show a lot of scrape marks. Could be I just need to
make allowances for how it is... not a big problem for most things I might
attempt.

Bill

That's the way it often goes with old machines, particularly knee mills.
It's not generally much of a hardship. In the really old days, no one
considered a mill to be a precision machine, anyway.

Yes, I'm not overly concerned, just was wanting to understand what I was
seeing.

Bill

On 04/03/2011 05:37 PM, anorton wrote:

SNIP
In place of a straight edge and indicator, you can also use an optical
technique. Mount a mirror on the side of a flat-bottomed block, and look
at the change in vertical angle of reflected light as it is moved down
the table. This is the technique used to calibrate granite surface
plates. Usually an autocollimator is used to measure the angle, but a
poor man's substitute is to look at the height of a reflected laser
pointer on a far wall. Of course this method measures change in tilt
versus position which then requires a little math to convert to change
in height of the table. The goverment has a publication on how do do this:
http://www.osti.gov/bridge/product.b...osti_id=650156

Wow. That is some little bit of math.

Bill

On Sun, 03 Apr 2011 17:14:42 -0700, Bill Martin
wrote:

On 04/03/2011 04:38 PM, Ed Huntress wrote:
"Bill wrote in message
...
On 04/03/2011 11:51 AM, Ed Huntress wrote:
"Bill wrote in message
...
Hi Group,

Want to know if anyone in the San Diego area has a surface grinder big
enough to handle a 24x8 inch machine table. I've been searching for how
come I can't seem to make flat surfaces that are actually parallel to
the
other side...and measuring about .0015" in variation as I run the mill
table in/out on the Y axis. Wierd thing is it seems backwards, the table
gets closer to the spindle as I move out away from the machine base. So
I
want to know the table top is flat...have already tried fiddling with
the
bolts on the vertical slide of the table, no joy there. Can anyone
suggest
where I might get this done, without breaking the social security bank?

Thanks,
Bill

You can measure flatness of the table first, Bill, without grinding it.
But
knee-type milling machines are subject to several types of inherent,
geometrical traverse errors, so it's more likely that your problem lies
there. Somewhere there is a good, illustrated explanation of this. Maybe
someone knows where it could be found online.

Do you have a precision straightedge and a dial indicator?


I have a dial indicator that does .0001", which is what I measured with
earlier today. No precision straightedge, but what made me suspect the
table surface is this: I have an optical flat disc salvaged from an old
instrument for I know not what purpose, but sliding the disc across the
table in "Y" direction, there seem to be some height changes at the edge
of the table slots. I can more feel it than see it, so maybe not enough to
worry about? This is a pretty old machine, a Gorton O16-A, built in 1954
it looks. Could indeed be just wear everywhere! Any pointers to
measurement "how to" info would be appreciated!

Bill

I wish I could help with the measurement, and I have two books on the
subject of rebuilding and tuning machine tools, but they're in my storage
and I haven't looked at them in 20 years.

I'm hoping someone will have a link to a very nicely illustrated explanation
of such errors -- I remember seeing it in print a few decades ago.

An optical flat might be hard to read, as sensitive as they are. And a
little rounding at the edges of the T-slots is no surprise in an old
machine.

By the time they had the sag errors all figured out, sometime in the 1930s,
builders were building-in some correction factors. Sometimes they
overcorrected. It's not completely obvious, and you can really chase your
tail trying to figure out where the problem is.

A good straightedge would really help -- either the kind used by machine
tool rebuilders or just a knife-edge precision blade. I have one made by
Starrett, 18" long.

If you're ambitious, you can get any old straightedge quite close to
straight by laying it on a piece of craft paper, tracing the edge with a
razor-trimmed chisel-edge pencil, and then carefully flopping the tool over
its own edge, and tracing again. File or stone the high spots. When you get
too close for the pencil marks to be clear, use a razor to cut a fine line
in the paper, in place of the pencil. You can get surprisingly close if you
have patience and you're careful.


Ok, you gave me motivation...I checked out my 12" Mitutoyo metal ruler
on a small surface plate, and it seems pretty decent for straightness.
So I put it across the mill table, with a light behind it, and do NOT
see light leaking under the edge of the ruler. So sounds like the table
is flat enough for most purposes, certainly mine. All of the ways on
this machine, old as it is, still show a lot of scrape marks. Could be I
just need to make allowances for how it is... not a big problem for most
things I might attempt.

Bill

Which 016A do you have?

Here is the one I own.

http://home.lightspeed.net/~gunner/myshop/016a_1.jpg

Need a second one?

Its in very good shape.

G

Gunner, near Bakersfield, California


--

"You can have peace. Or you can have freedom. Don't ever count on having both at once."
Robert A. Heinlein

Bill Martin wrote:


That's the way it often goes with old machines, particularly knee mills.
It's not generally much of a hardship. In the really old days, no one
considered a mill to be a precision machine, anyway.

Yes, I'm not overly concerned, just was wanting to understand what I was
seeing.


I didn't see what kind of mill this is but it sounded like the problem
you have might possibly be corrected by shimming the base or adjusting
the feet (if so equipped) or adjusting the knee lock (if it is a knee
mill) . You could easily induce (or remove) a .0015" bend or tilt in the
Y axis by how the casting components are stressed under load.




Bill

On 04/03/2011 08:28 PM, Gunner Asch wrote:
On Sun, 03 Apr 2011 17:14:42 -0700, Bill
wrote:

SNIP

Which 016A do you have?

Here is the one I own.

http://home.lightspeed.net/~gunner/myshop/016a_1.jpg

Need a second one?

Its in very good shape.

G

Gunner, near Bakersfield, California


--

"You can have peace. Or you can have freedom. Don't ever count on having both at once."
Robert A. Heinlein

It's very nearly the same, mine does not have the arm on the left side
(facing) for downfeed, but has a power downfeed box. The main electrical
cabinet is a little different, it has switches on the front,
it had a dual speed motor originally. I took off the 460V motor,
replaced with a DC motor & speed controller for the time being.
Don't think I can stand two of them...:-)

Bill

On 04/04/2011 05:48 AM, jim wrote:


Bill Martin wrote:


That's the way it often goes with old machines, particularly knee mills.
It's not generally much of a hardship. In the really old days, no one
considered a mill to be a precision machine, anyway.

Yes, I'm not overly concerned, just was wanting to understand what I was
seeing.


I didn't see what kind of mill this is but it sounded like the problem
you have might possibly be corrected by shimming the base or adjusting
the feet (if so equipped) or adjusting the knee lock (if it is a knee
mill) . You could easily induce (or remove) a .0015" bend or tilt in the
Y axis by how the casting components are stressed under load.




Bill

I did attempt to adjust the knee lock, only made it worse. Induced an
even bigger change going from unlocked to locked. I just set it back to
mildly snug top and bottom, and now there is almost zero change from
unlocked to locked. That never was the issue though, so I didn't really
fix anything there.

Bill

On Mon, 04 Apr 2011 10:35:03 -0700, Bill Martin
wrote:

On 04/03/2011 08:28 PM, Gunner Asch wrote:
On Sun, 03 Apr 2011 17:14:42 -0700, Bill
wrote:

SNIP

Which 016A do you have?

Here is the one I own.

http://home.lightspeed.net/~gunner/myshop/016a_1.jpg

Need a second one?

Its in very good shape.

G

Gunner, near Bakersfield, California


--

"You can have peace. Or you can have freedom. Don't ever count on having both at once."
Robert A. Heinlein

It's very nearly the same, mine does not have the arm on the left side
(facing) for downfeed, but has a power downfeed box. The main electrical
cabinet is a little different, it has switches on the front,
it had a dual speed motor originally. I took off the 460V motor,
replaced with a DC motor & speed controller for the time being.
Don't think I can stand two of them...:-)

Bill

Its available G

I loaned it to a "friend" a few years ago, along with a lathe, welder
etc etc. In return..he was supposed to rebuild the tranny for my
motorhome. Nothing major or expensive.

Its been hummm 5 yrs now..still no tranny and little contact.

So Ill be driving my forklift down there and doing a little repo work in
the very near future.

Shrug....I spent a fair amount of money just getting him those machines
and making sure they were in good operating condition, and providing a
3ph RPC...and he screwed me around. I think Id have been better off
simply paying AMMCO to rebuild the tranny.

Gunner

--

"You can have peace. Or you can have freedom. Don't ever count on having both at once."
Robert A. Heinlein