Gunner...Is the outside edge of your table on your mill higher than the
inside part of the table where the T-slots are? I assume that the table
should be completely flat from edge to edge and end to end. I guess it
is likely that the the inside of the table has "sunk" over the years
because of things being clamped to it. It looks to be from .002-.005
low in places. My plan was to completely check the table end to end and
then draw file it back into shape. Any suggestions? Thanks, Steve

In article .com,
wrote:
Gunner...Is the outside edge of your table on your mill higher than the
inside part of the table where the T-slots are? I assume that the table
should be completely flat from edge to edge and end to end. I guess it
is likely that the the inside of the table has "sunk" over the years
because of things being clamped to it. It looks to be from .002-.005
low in places. My plan was to completely check the table end to end and
then draw file it back into shape. Any suggestions? Thanks, Steve

That does not sound right. I can think of at a few other
possible causes of this observable problem. (I'm presuming that you
have swung an indicator mounted on an arm in the spindle over the table
to discover this problem.)

1) It could be that the head is out of tram. At least, most Bridgeports
have provisions for adjusting the orientation of the head to the
table -- both front to back ("nodding" the head) and from end to
end (tilting it to one side or the other). Until this is known
to be right, don't trust measurements made by swinging an
indicator in the spindle.

2) Wear in the Y-axis slide. This may be more worn in the middle
or at the back, depending on usage patterns over the years.
This will take a lot of work to fix, if that is the problem.

3) Wear in the Gibs of the vertical slide, allowing the knee to tilt.

Of course -- you might actually be talking about the borders of
the table, which define the troughs to control coolant flow.

If it is this, I would suggest that unless you need to mount
something on the table with a footprint bigger than the flat area of the
table, you leave it alone.

I guess that this could come from someone using the machine
itself to grind the table flat, and not able to reach the border fully,
so they left it all untouched.

You could make a riser plate for the vise, if that covers more
than the flat area.

Good Luck,
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 ---

"DoN. Nichols" wrote in message
...
In article .com,
wrote:
Gunner...Is the outside edge of your table on your mill higher than the
inside part of the table where the T-slots are? I assume that the table
should be completely flat from edge to edge and end to end. I guess it
is likely that the the inside of the table has "sunk" over the years
because of things being clamped to it. It looks to be from .002-.005
low in places. My plan was to completely check the table end to end and
then draw file it back into shape. Any suggestions? Thanks, Steve

That does not sound right. I can think of at a few other
possible causes of this observable problem. (I'm presuming that you
have swung an indicator mounted on an arm in the spindle over the table
to discover this problem.)

1) It could be that the head is out of tram. At least, most Bridgeports
have provisions for adjusting the orientation of the head to the
table -- both front to back ("nodding" the head) and from end to
end (tilting it to one side or the other). Until this is known
to be right, don't trust measurements made by swinging an
indicator in the spindle.

The 8540 is a horizontal mill so swinging an indicator in the spindle won't
tell you much :-). So far as I can tell there is no provision for adjusting
alignment of the column, other than shimming where the column is bolted to
the base. The table itself is something like 26" long x 6-3/4" wide x
2-3/4" deep so it seems unlikely that it would "sink".


2) Wear in the Y-axis slide. This may be more worn in the middle
or at the back, depending on usage patterns over the years.
This will take a lot of work to fix, if that is the problem.

3) Wear in the Gibs of the vertical slide, allowing the knee to tilt.

Of course -- you might actually be talking about the borders of
the table, which define the troughs to control coolant flow.

The 8540 table has two troughs along the X-axis ends about 1/2" in from the
outer edges of the table. On the two examples I have, the tables are flat
to within 0.001" or so all the way across as inspected along the Y-axis with
a knife-edfge type straight edge. I didn't try feeler gauges but couldn't
see any light along the straight edge where it met either table.

If it is this, I would suggest that unless you need to mount
something on the table with a footprint bigger than the flat area of the
table, you leave it alone.

I guess that this could come from someone using the machine
itself to grind the table flat, and not able to reach the border fully,
so they left it all untouched.

Unlikely as it's a horizontal mill (see above). Maybe the table was surface
ground, although any grinder capable of grinding the table length would
probably be capable of grinding the full width as well (6-3/4 x 26).

You could make a riser plate for the vise, if that covers more
than the flat area.

That sounds like a good fix and it could be slotted so that the vise
alignment keys could still mate with the T-slots, assuming the vise is so
equipped and the T-slots aren't totally munged.

Maybe the OP could post a picture to www.metalworking .com - that might
provide some missing info.


Good Luck,
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 ---

wrote:

Gunner...Is the outside edge of your table on your mill higher than the
inside part of the table where the T-slots are? I assume that the table
should be completely flat from edge to edge and end to end. I guess it
is likely that the the inside of the table has "sunk" over the years
because of things being clamped to it. It looks to be from .002-.005
low in places. My plan was to completely check the table end to end and
then draw file it back into shape. Any suggestions? Thanks, Steve




Use a big flycutter and take a skin cut over the whole thing. You need
a big one so you can reach the edges. Make sure you tram it in so it
cuts a flat surface. The only problem is if your ways are worn. If
they are worn the top of the table will have a crown in the middle and
cutting it will only make matters worse. You can check the ways with a
straight edge and a dial indicator mounted on the table and the straight
edge on the knee.


John

On 2 Jan 2005 11:55:31 -0800, wrote:

Gunner...Is the outside edge of your table on your mill higher than the
inside part of the table where the T-slots are? I assume that the table
should be completely flat from edge to edge and end to end. I guess it
is likely that the the inside of the table has "sunk" over the years
because of things being clamped to it. It looks to be from .002-.005
low in places. My plan was to completely check the table end to end and
then draw file it back into shape. Any suggestions? Thanks, Steve

Nope..mine is dead flat all the way across. It has fairly low hours.

Sounds like yours has some wear as you say. Draw filing or having it
ground flat again may be in order. Its relatively easy to remove and
it could be easily blanchard ground, and probably for not to much
money, depending on your area.

Mine is going to need a new y axis nut before long, or an adjustment
if it has a splt nut, Ive never looked (making a note)

Gunner

"War is an ugly thing, but not the ugliest of things. The decayed and degraded state of moral and patriotic feeling
which thinks that nothing is worth war is much worse. The person who has nothing for which he is willing to fight,
nothing which is more important than his own personal safety, is a miserable creature and has no chance of being
free unless made and kept so by the exertions of better men than himself."
- John Stewart Mill

On 2 Jan 2005 22:00:44 -0500, (DoN. Nichols)
wrote:

In article .com,
wrote:
Gunner...Is the outside edge of your table on your mill higher than the
inside part of the table where the T-slots are? I assume that the table
should be completely flat from edge to edge and end to end. I guess it
is likely that the the inside of the table has "sunk" over the years
because of things being clamped to it. It looks to be from .002-.005
low in places. My plan was to completely check the table end to end and
then draw file it back into shape. Any suggestions? Thanks, Steve

That does not sound right. I can think of at a few other
possible causes of this observable problem. (I'm presuming that you
have swung an indicator mounted on an arm in the spindle over the table
to discover this problem.)

1) It could be that the head is out of tram. At least, most Bridgeports
have provisions for adjusting the orientation of the head to the
table -- both front to back ("nodding" the head) and from end to
end (tilting it to one side or the other). Until this is known
to be right, don't trust measurements made by swinging an
indicator in the spindle.

2) Wear in the Y-axis slide. This may be more worn in the middle
or at the back, depending on usage patterns over the years.
This will take a lot of work to fix, if that is the problem.

3) Wear in the Gibs of the vertical slide, allowing the knee to tilt.

Of course -- you might actually be talking about the borders of
the table, which define the troughs to control coolant flow.

If it is this, I would suggest that unless you need to mount
something on the table with a footprint bigger than the flat area of the
table, you leave it alone.

I guess that this could come from someone using the machine
itself to grind the table flat, and not able to reach the border fully,
so they left it all untouched.

You could make a riser plate for the vise, if that covers more
than the flat area.

Good Luck,
DoN.

If they used the mill itself, a 3" or so area on either end would be
proud as the table will not go all the way right and left.

On reflection, I think you have the best Idea with a thin spacer
unless the OP wishes to spend some time and money.

Gunner

"War is an ugly thing, but not the ugliest of things. The decayed and degraded state of moral and patriotic feeling
which thinks that nothing is worth war is much worse. The person who has nothing for which he is willing to fight,
nothing which is more important than his own personal safety, is a miserable creature and has no chance of being
free unless made and kept so by the exertions of better men than himself."
- John Stewart Mill

On Mon, 03 Jan 2005 00:25:21 -0500, john
wrote:



wrote:

Gunner...Is the outside edge of your table on your mill higher than the
inside part of the table where the T-slots are? I assume that the table
should be completely flat from edge to edge and end to end. I guess it
is likely that the the inside of the table has "sunk" over the years
because of things being clamped to it. It looks to be from .002-.005
low in places. My plan was to completely check the table end to end and
then draw file it back into shape. Any suggestions? Thanks, Steve




Use a big flycutter and take a skin cut over the whole thing. You need
a big one so you can reach the edges. Make sure you tram it in so it
cuts a flat surface. The only problem is if your ways are worn. If
they are worn the top of the table will have a crown in the middle and
cutting it will only make matters worse. You can check the ways with a
straight edge and a dial indicator mounted on the table and the straight
edge on the knee.


John

Fly cutters dont work very well on a horizontal mill when trying to do
the table G

Gunner

"War is an ugly thing, but not the ugliest of things. The decayed and degraded state of moral and patriotic feeling
which thinks that nothing is worth war is much worse. The person who has nothing for which he is willing to fight,
nothing which is more important than his own personal safety, is a miserable creature and has no chance of being
free unless made and kept so by the exertions of better men than himself."
- John Stewart Mill

Any suggestions?

If it is indeed not quite flat, correcting that would be a nice little
scraping project.

"Gunner" wrote in message
...
On 2 Jan 2005 11:55:31 -0800, wrote:

Gunner...Is the outside edge of your table on your mill higher than the
inside part of the table where the T-slots are? I assume that the table
should be completely flat from edge to edge and end to end. I guess it
is likely that the the inside of the table has "sunk" over the years
because of things being clamped to it. It looks to be from .002-.005
low in places. My plan was to completely check the table end to end and
then draw file it back into shape. Any suggestions? Thanks, Steve

Nope..mine is dead flat all the way across. It has fairly low hours.

Sounds like yours has some wear as you say. Draw filing or having it
ground flat again may be in order. Its relatively easy to remove and
it could be easily blanchard ground, and probably for not to much
money, depending on your area.

Mine is going to need a new y axis nut before long, or an adjustment
if it has a splt nut, Ive never looked (making a note)

I just removed the table and saddle on an 8550 (same as 8540 but without the
power feed) and both nuts are one piece.

On Mon, 3 Jan 2005 10:04:45 -0600, "Mike Henry"
wrote:


"Gunner" wrote in message
.. .
On 2 Jan 2005 11:55:31 -0800, wrote:

Gunner...Is the outside edge of your table on your mill higher than the
inside part of the table where the T-slots are? I assume that the table
should be completely flat from edge to edge and end to end. I guess it
is likely that the the inside of the table has "sunk" over the years
because of things being clamped to it. It looks to be from .002-.005
low in places. My plan was to completely check the table end to end and
then draw file it back into shape. Any suggestions? Thanks, Steve

Nope..mine is dead flat all the way across. It has fairly low hours.

Sounds like yours has some wear as you say. Draw filing or having it
ground flat again may be in order. Its relatively easy to remove and
it could be easily blanchard ground, and probably for not to much
money, depending on your area.

Mine is going to need a new y axis nut before long, or an adjustment
if it has a splt nut, Ive never looked (making a note)

I just removed the table and saddle on an 8550 (same as 8540 but without the
power feed) and both nuts are one piece.


sigh..I was afraid of that....

Gunner

"War is an ugly thing, but not the ugliest of things. The decayed and degraded state of moral and patriotic feeling
which thinks that nothing is worth war is much worse. The person who has nothing for which he is willing to fight,
nothing which is more important than his own personal safety, is a miserable creature and has no chance of being
free unless made and kept so by the exertions of better men than himself."
- John Stewart Mill

Ir anyone is looking for a very clean 8540 call me at (949) 645-7601. That's
in SoCal. I have a very nice one for sale. Leigh@MarMachine