Getting crowded in the garage and still need a decent lathe. So off goes my
Bridgeport, you can see pics here.
http://www.professorwiz.com/sales.htm
Works alright, downfeed needs something, has readouts I never hooked up,
some tooling included.
Russ
www.professorwiz.com

SN says 1955

Awesomewiz wrote:
Getting crowded in the garage and still need a decent lathe. So off goes my
Bridgeport, you can see pics here.
http://www.professorwiz.com/sales.htm
Works alright, downfeed needs something, has readouts I never hooked up,
some tooling included.
Russ
www.professorwiz.com

Thanks, I didn't even see where the serial number was.
I know it's abit old, doesn't even have the chrome ways.
Russ


"RoyJ" wrote in message
ink.net...
SN says 1955

Awesomewiz wrote:
Getting crowded in the garage and still need a decent lathe. So off goes
my Bridgeport, you can see pics here.
http://www.professorwiz.com/sales.htm
Works alright, downfeed needs something, has readouts I never hooked up,
some tooling included.
Russ
www.professorwiz.com

I think Roy is referencing the number on the "J" head. It's been a
long time but maybe someone can tell us if it was dovetail or round ram
in the mid 50's. There should be another number stamped, I think, on
the lower vertical way surface. BTW the chrome ways were probably an
option at the time your machine was built and for some reason this
feature was slow to catch-on (at least around Chicago from '63 till
around '76).

A buddy got the round ram one from his uncle man is that a pain to find
parts for, and the collets are abit small, but hey it works. This one takes
the standard r-8 collets. Do you think the price is fair? I bought it for
$1500, with the motor burnt and hooked it up this way but that was before
the 9/11 attack and it seems like prices dropped because of all the places
going out of the business.
Russ


"rigger" wrote in message
ups.com...
I think Roy is referencing the number on the "J" head. It's been a
long time but maybe someone can tell us if it was dovetail or round ram
in the mid 50's. There should be another number stamped, I think, on
the lower vertical way surface. BTW the chrome ways were probably an
option at the time your machine was built and for some reason this
feature was slow to catch-on (at least around Chicago from '63 till
around '76).

The pic of the horizonal ways at
http://www.professorwiz.com/bridgepo...03850.JPG.html
shows a serial number of BR29414
corresponds to 1955 at
http://www.machinetoolclearinghouse.com/bridge.htm

rigger wrote:
I think Roy is referencing the number on the "J" head. It's been a
long time but maybe someone can tell us if it was dovetail or round ram
in the mid 50's. There should be another number stamped, I think, on
the lower vertical way surface. BTW the chrome ways were probably an
option at the time your machine was built and for some reason this
feature was slow to catch-on (at least around Chicago from '63 till
around '76).

RoyJ writes:

The pic of the horizonal ways at
http://www.professorwiz.com/bridgepo...03850.JPG.html

The knee ways are badly worn. It will take months of scraping work or many
$1000s to get this machine back to anything but a glorified drill press.

Right you are Roy. These pix were loading so slowly I skipped a few.

dennis in nca


From: RoyJ

The pic of the horizonal ways at
http://www.professorwiz.com/bridgepo...03850.JPG.html
shows a serial number of BR29414
corresponds to 1955 at
http://www.machinetoolclearinghouse.com/bridge.htm

Makes you wonder if some people have heard of way covers. This could
make an interesting project.
I doubt if "months" is the correct term to use here though. An
"experienced" scraper hand could easily do the horizontal knee surfaces
in less than a day (after the vertical surfaces of course) ,with the
proper tools. On the other hand, if there is enough wear, you might
want to send that knee out to be ground first.

dennis in nca

Richard J. Jinch said:
The knee ways are badly worn. It will take months of scraping work or
many
$1000s to get this machine back to anything but a glorified drill press.

rigger writes:

An
"experienced" scraper hand could easily do the horizontal knee surfaces
in less than a day (after the vertical surfaces of course) ,with the
proper tools.

Ten, count em, 10 surfaces to be scraped on that one axis alone. Flat,
bearing quality, aligned up/down, tilt fore/aft, tilt left/right, all to
better than 0.001", with the concave wear something like 0.010 in the
extreme.

Assuming you disassembled, cleaned and shipped (both ways) out to an
expensive grind job, the hand scraping would still be days of work. If
you're removing the meat by scraping alone, then it is easily weeks of
backbreaking labor.

What were you picking up from the pix to indicate wear? I'm in the
market for a brigeport, always ready to get tips to spot the dogs.

Richard J Kinch wrote:
RoyJ writes:


The pic of the horizonal ways at
http://www.professorwiz.com/bridgepo...03850.JPG.html


The knee ways are badly worn. It will take months of scraping work or many
$1000s to get this machine back to anything but a glorified drill press.

Paid $1,100 for a round ram of 1962 vintage with 2 axis DRO.

Clean with little wear with 1J head.

From a major shop closing down 100 miles North of St. Louis.

Hugh



"Awesomewiz" wrote in message
.. .
A buddy got the round ram one from his uncle man is that a pain to find
parts for, and the collets are abit small, but hey it works. This one
takes
the standard r-8 collets. Do you think the price is fair? I bought it
for
$1500, with the motor burnt and hooked it up this way but that was before
the 9/11 attack and it seems like prices dropped because of all the places
going out of the business.
Russ


"rigger" wrote in message
ups.com...
I think Roy is referencing the number on the "J" head. It's been a
long time but maybe someone can tell us if it was dovetail or round ram
in the mid 50's. There should be another number stamped, I think, on
the lower vertical way surface. BTW the chrome ways were probably an
option at the time your machine was built and for some reason this
feature was slow to catch-on (at least around Chicago from '63 till
around '76).

RoyJ writes:

What were you picking up from the pix to indicate wear? I'm in the
market for a brigeport, always ready to get tips to spot the dogs.

Those knee ways are *the* major wear point for the Bridgeport machine.
The very ends do not experience wear since they're near to (or past) the
range of travel. Most of the wear is in a swayback pattern around 1/3
and 2/3 up the knee ways where the saddle rests on two bearing areas.
You can always see the crescent-moon scraping marks, testifying to the
original precision surface, at the ends, but depending on the degree of
wear, these marks are more or less worn off towards the middle. On this
particular machine, the photo shows they are completely obliterated
except at the very ends of the ways, indicating extreme wear, concave
where it should be flat. The mating surface on the saddle will have a
somewhat conjugate wear shape, convex where it should be flat.

If you remove the table and saddle, you can place a machinist's ruler
(the kind that has a precision straight edge good to a few tenths of
thousandths) on edge along the ways, and measure the deviation. On an
old machine like this, you will find concavity of several thousandths or
more.

With this degree of wear, if you adjust the gib with the table
positioned at the center of travel, the dovetail ways will bind up and
not move after a few inches. If you loosen the gib to allow more
travel, the table will be loose in the worn areas. Thus, the machine
has either lost its rigidity, or its table travel, take your pick, and
since you need both to do most machining tasks, the machine is broken.
It is not merely that you lose dimensional precision or squareness; you
either have motion but no rigidity and thus can't cut, or you have
rigidity but no motion and thus can't cut.

There's a similar process with the wearing of the table ways, but since
the table is much longer than the knee, and is protected from chips and
dirt, the wear tends to be slower and spread out more and thus is not
the limiting wear factor compared to the knee ways.

The usage pattern over the years can alter the process. If you run the
table left and right with a power feed all day, while the cross feed is
locked, then the proportions may be different. But typically the knee
ways are well worn before the table ways are.

The leadscrews likely have corresponding severe wear, and these are not
reconditionable.

The scoring shown in the photo is also extensive. A few dings, scores,
chips, and even oops-drill-holes do not ruin ways, but if they're
covered in scores, then the surface is way past being a bearing surface
any more, and can't maintain lubrication, so you have runaway wear.

I bought my Bridgeport machine cheap, realizing it was well worn and in
need of reconditioning by a laborious scraping process. On
disassembling the cross-travel gib, I discovered that the wear was worse
than appearances: The gib, long past its adjustment range for wear, had
a shim, consisting of some steel pallet strapping, shoved alongside it
by the previous owner. The mating dovetail was ruined.

With scraping, and epoxying on Teflon bearing surfaces, and $$$$ for
some new ballscrews, my machine now works better than when it was
factory new.

Note that the photo of the OP's machine was very clear and in high
resolution to show the state of wear. Most snapshots would not give you
enough to diagnose the degree of wear on the ways.

Hugh Prescott writes:

Paid $1,100 for a round ram of 1962 vintage with 2 axis DRO.

Round ram from 1962? Didn't they end in the mid-50s? What's the S/N?

Hi Richard,
Have you done much hand scraping? I've done a little myself when
working for others. I wouldn't call myself a journeyman but have
worked with many and through training and observation have , at least,
begun to develop a technique. Some get good rather quickly (not I) and
for others it takes a while. When someone first begins to learn
scraping it goes slowly because of the technique involved in the
sharpening component, the actual scraping and the extra care in
measurement. But an experienced scraping hand (which you become after
a while) goes through these small items very rapidly. Has your
experience been with a hand or power scraper?
When scraping a Bridgeport knee you don't move it much. You bring your
flats and straight edges to the piece which saves a lot of time.

dennis in nca.

Richard J Kinch Aug 1, 12:17 pm writes
rigger writes:
An
"experienced" scraper hand could easily do the horizontal knee surfaces
in less than a day (after the vertical surfaces of course) ,with the
proper tools.


Ten, count em, 10 surfaces to be scraped on that one axis alone. Flat,

bearing quality, aligned up/down, tilt fore/aft, tilt left/right, all
to
better than 0.001", with the concave wear something like 0.010 in the
extreme.

Assuming you disassembled, cleaned and shipped (both ways) out to an
expensive grind job, the hand scraping would still be days of work. If

you're removing the meat by scraping alone, then it is easily weeks of
backbreaking labor.

Just an FYI:

The crescent shaped marks on the way surfaces are standard on a new
Bridgeport (and many other machines as well) but are not necessary
according to many. The sliding surfaces are first precision scraped
using a method which leaves very little distinctive markings. After
the surface is as close as you need it, some apply a oil holding
pattern composed of marks (not always crescent shaped).
The idea here is to let people know that not seeing the usual pattern
on a way surface is not conclusive evidence of wear especially if the
machine has been rebuilt previously.

dennis in nca

On Aug. 1 Richard says:

You can always see the crescent-moon scraping marks, testifying to the
original precision surface, at the ends, but depending on the degree of

wear, these marks are more or less worn off towards the middle. On
this
particular machine, the photo shows they are completely obliterated
except at the very ends of the ways, indicating extreme wear, concave
where it should be flat.

rigger writes:

But an experienced scraping hand (which you become after
a while) goes through these small items very rapidly. Has your
experience been with a hand or power scraper?
When scraping a Bridgeport knee you don't move it much. You bring
your flats and straight edges to the piece which saves a lot of time.

My scraping experience (per se) is limited to hand scraping, for
flatness and for bearing quality. However, when I reconditioned the
Bridgeport, I used a combination of milling and grinding to get the bulk
off of the knee.

I don't know about "very rapidly". Just the cross-travel ways alone on
a Bridgeport consist of 14 precision surfaces as large as 2 x 18 (being
2 flat knee ways, 2 knee dovetails, 4 saddle flats, 4 saddle dovetails,
2 sides of a gib). Each of these surfaces must be scraped to alignment
with the others in 3 degrees of freedom (height/pitch/roll), then to
flatness (2 more degrees of freedom), and finally to bearing quality.
So you essentially have a task of 14 times 6 = 84 specific goals. Each
goal must be proved by at least two independent measurement techniques
or instruments. So you're at 168 indication tasks. Each such task must
be achieved by a significant number of scraping cycles. Unless you're a
scraping god, errors will happen and re-do's will be needed, and some
re-do's require re-doing not just the original error but a number of
dependent surfaces.

The upshot being, you have literally thousands of steps involved, each
taking from minutes to hours, if you are genuinely reconditioning the
machine to factory quality, not just touching things up.

Supposing you get all this aligned and finished, then you have the new
problem that the old leadscrews and yoke do not fit the new alignment.

If you have the luxury of starting with a precision reconditioned
surface from a regrind that is already aligned and just needs scraping
for the final degrees of flatness and bearing qualities, then I suppose
it can go "rapidly". That is, after all, how the factory can make them
at the economical price of $13K. But that requires tooling that most of
us don't even have available in our locale.

One of the tools I made was an 18 inch long by 3/4 wide flat to mark the
dovetails, starting will run-of-the-mill steel angle. This one tool
took me an entire day of laborious scraping to get to a precision
flatness. I'm sure that time would improve with experience, but it is
inevitably a significant task.

I spent weeks just buying and/or making tools for the Bridgeport
reconditioning job--granite surface plates, height gages, straightedges,
gage blocks, levels, indicators, squares, etc. I suppose you shouldn't
count that overhead but once.