Bridgeport.. oil or grease..???

I have a Bridgeport M head milling machine noticed that the lead screws for the X and Y axis has grease on them and assumed That somebody not knowing what they were doing pump to Grease through the fittings and lubricated it that way .. then I talk to an old-school machinist who told me that back then those first machines didn’t use oil that the oil fitting You see was actually a grease fitting and that’s how things were done back then,,, i’m not quite sure whether I believe that or not ... I can’t understand why they would use a fitting that looks exactly like what you hook your grease gun up to Wytchwood miss lead anyone who doesn’t really know what’s going on as far as lubricating there machine ..
Can anyone tell me whether or not this is true for a 1938M head ... I can just imagine what a pain in the ass it’s going to be too have to take that all apart and clean out all that grease that’s impacted into those groups they cut for oil to go through if that’s not the case ... any help with this matter is greatly appreciated thank you...

This has been discusse on here at length.

"Grease fittings" are dominantly used for grease, but not exclusively. They use them in oiling applications where you want to pump oil into the system and not just rely on gravity to trickle it in. You need a modified or purpose-built lub gun to do it.
OR
Add a one-shot system to the machine. Does the same job a lot faster.

Problem with grease in a manually applied system is that on ways's it only stays "pressurized" keeping swarf out for a little while, before it's just a sticky lub keeping the swarf in.

If you religiously pump actual way grease in on a daily basis (not Tractor Supply axle grease!), you might be ok, but oil is so much more forgiving if you laps. The new CNC mills that use grease are using timed dispensers with very thin specialized grease, and the ways are all covered.

I'll add too, if the wrong grease has been used, you'll probably need to tear it down anyway to clear all the passages and get the right lub a chance to actually lubricate the ways. I added lub pumps to 4 of our previously greased mills 7 or 8 years ago. Annoying but necessary.

Bellaru433 said:

I have a Bridgeport M head milling machine noticed that the lead screws for the X and Y axis has grease on them and assumed That somebody not knowing what they were doing pump to Grease through the fittings and lubricated it that way .. then I talk to an old-school machinist who told me that back then those first machines didn’t use oil that the oil fitting You see was actually a grease fitting and that’s how things were done back then,,, i’m not quite sure whether I believe that or not ... I can’t understand why they would use a fitting that looks exactly like what you hook your grease gun up to Wytchwood miss lead anyone who doesn’t really know what’s going on as far as lubricating there machine ..
Can anyone tell me whether or not this is true for a 1938M head ... I can just imagine what a pain in the ass it’s going to be too have to take that all apart and clean out all that grease that’s impacted into those groups they cut for oil to go through if that’s not the case ... any help with this matter is greatly appreciated thank you...

Click to expand...

In my 55 years as a machinest I've used both oil and grease, mostly grease.The only time I would hate to use grease is cutting cast iron.
I have had special oil guns and they would always wind up leaking so we would have to store in a plastic pail.
As long as it gets lubed I don't think that the machine cares what type oil or grease it is.
I have a couple of bridgeports that i paid $2000 ea and use them everyday for the last 35 years on a production job making $60 hr holding .005 tolerances.I use grease in them with no problems.

mc3608 said:

In my 55 years as a machinest
{basically saying, trust me}

As long as it gets lubed I don't think that the machine cares what type oil or grease it is.
{an opinion}

I have a couple of bridgeports that i paid $2000 ea
{mmmm ok}

and use them everyday for the last 35 years
{mmmmm ok}

on a production job making $60 hr holding .005 tolerances.
{mmmmmm ok}

I use grease in them with no problems.
{that you are aware of}

Click to expand...

I am not picking, really I am not,
but this is the kind of unscientific
feel good, in denial type of mentality
that can breed misinformation and
does not help people trying to learn
the proper way to care for their machine.
There are thousands of Bridgeport factory
manuals out there. It would seem to me
as a good place to start to find proper
information. I can assure you, Bridgeport
does not recommend greasing the slideways.

--Doozer

Doozer said:

I am not picking, really I am not,
but this is the kind of unscientific
feel good, in denial type of mentality
that can breed misinformation and
does not help people trying to learn
the proper way to care for their machine.
There are thousands of Bridgeport factory
manuals out there. It would seem to me
as a good place to start to find proper
information.


--Doozer

Click to expand...

I can assure you, Bridgeport
does not recommend greasing the slideways.
(MMMMMMMM An Opinion)


MMMMMMMMMM FYI PG 8
http://vintagemachinery.org/pubs/2099/17104.pdf

Holy crap! You are right!
Bridgeport was recommending #2 grease.
Knock me over with a feather!
I still don't think it is a good idea
as the grease would hold grit and make
a lapping compound leading to a worn
out ways. I was wrong about the factory
manual recommending grease. I just don't
know of any other machine manufacturer
that recommends grease for the slideways.
From a design point of view, grease on
ways just seems like a very bad idea.
Thanks for the manual link.

-Doozer

"Everything you know is WRONG!"
Credit to Firesign Theatre

Bridgeport recommendations evolved over the decades, as I'm sure everyone realizes. The M-105 manual from 60's era recommends waylube for both ways and screws. Obviously, a one-shot oiler wouldn't be a very good avenue for grease application in the context. The choice of grease or oil as a recommended lubricant stems from the design/maintenance philosophy of low speed/sliding = grease, high speed/rotating = oil in the early part of the 20th century, I think. Maybe doesn't explain wheel bearing grease, but we all have our inconsistencies...

Oil or grease?

Reminds me of the back gear lube question. The manual (pg 8) says a few squirts of oil in the cup on the head and oil for the ways. So I would use oil in both locations.

IMO, even if grease in an OLD manual, it's not the best way to lub the machine. NEWER manuals say to use oil which to me says Bridgeport decided it was better. It's common for manufacturers to change and update their maintenance routines for machinery as technology and resources improve.

I can say that personally using a clapped out Bridgeport with grease, and then using oil on the same machine was night-and-day. The ways moved a lot smoother and it was easier to find the sweet spot adjusting the gibs (by feel since the ways were worn).

We all have our opinions though.

The OP says "lead screws", does not mention ways.
Perhaps different if separate lube points.
Bob

My 56 Bridgeport had tons of dried grease clogging up the passageways.. its oil for me