Thread: Bridgeport Lubrication Modifications.

Bridgeport Lubrication Modifications.

I had been told by several rebuilders that the Bridgeport oiling system left something to be desired so I decided to make some modifications after receiving my rebuilt quill assembly with instructions to keep the oil off the sealed bearings as it seeps into them and ruins them. In addition, I was told that the lubrication system did not adequately distribute the oil. So, I decided to make a few modifications. Here is the before picture.


I modified the end of the quill to keep oil out of the sleeve and quill bearings. I turned an old nylon gear (blue) down to fit and made am insert (white) on my lathe and attached it to the end of the sleeve sealing it with silicone.


It is shown here inserted into the quill body.


Finally, I shortened the tube on the lubrication cup.


The job was still not finished because oil could run down the splined shaft so I added an oil slinger (see black washer)


So, to this point I should have eliminated most of the oil going down into the quill bearings. I wanted to provide some point lubrication for the feed gears and bearings so I drilled and tapped a 1/8" NPT thread where I could insert an oil tube to the right length (I recorded these for the future).


I will write myself a letter of lubrication instructions since all of this will be enclosed and hope I can keep everything well lubricated in the future.

Jim

Jim, is yours a J- head or an M- head?

I thought it was an M-head but it turns out to be a J-head. Someone thought it was an M-machine with a J-head. It doesn't have the head nodding mount. It has a J serial number on the head.

Originally Posted by modela

...after receiving my rebuilt quill assembly with instructions to keep the oil off the sealed bearings as it seeps into them and ruins them.

Oil ruins sealed bearings?
How?

--Doozer

Originally Posted by Doozer

Oil ruins sealed bearings?
How?

--Doozer

According to the spindle professionals the lighter weight oil leaks in and degrades the bearing grease. I probably would have doubted it but I heard it in too many sources not to have credence. My advice from C&M was to keep it out.

Jim

"....oil leaks in and degrades the bearing grease."

I will have to think about that one.
Grease is oil and a soap thickener,
so I could see adding extra oil to grease
lowers its viscosity and makes it thinner,
but the old bearings were oil lubed to begin with.
Oil is a better lube for bearings than grease.
Grease is only used where places that oil can
not be contained (in a housing or gearbox or such).
So oil "contaminating" greased bearings?
Sounds like ketchup contaminating a hamburger.

--Doozer

BPs (and other machines) were designed to be a total loss system for lube. IMHO, the best thing that you can see is clean oil on the vise or table and on the base. That means the lube system is working and flushing out all of the crude. The biggest reason bearings fail is not enough oil. The second is the wrong oil.

Doing what you did is OK for you. If that's what you want, that's fine. IMHO, a total waste of time. Like putting chrome valve covers on a dump truck.
JR

I don't get it... why would you put sealed bearings in a BP? What problem does that solve?

Originally Posted by 310 Guy

I don't get it... why would you put sealed bearings in a BP? What problem does that solve?

The bearings in the spindle were rough and I had it rebuilt. Rebuilders use sealed bearings.

My advice came from a rebuilder that specializes in spindle rebuilding. He suggested keeping the lighter oil away from the sealed bearings. Others I have talked with that rebuild Bridgeports say the same. All the unsealed bearings in this machine were in rough shape. Tearing it down I noticed that the oiling system did look kind of crude. My Bridgeport is a 1950's version.

Other parts of the machine were in good shape but seemed like a bit oil starved. Regarding this being a waste of time, perhaps, but I had this thing apart so I might as well fix it. I grew up working on machinery like this. The machinery was rugged but some of it was under-engineered. A few changes can improve things.

Jim

I work with porous materials, e.g., wood and dielectrics, where oil can potentially spoil the intended use. It cannot be completely removed from the matrix of the composite material. This is why sealed bearings are interesting *to me*.

Originally Posted by modela

Rebuilders use sealed bearings.

No rebuilder that we use!

H&W doesn't offer sealed bearings. Neither does BP or High quality.
JR

I worked for 13 years for the factory as a service rep. Sealed bearings were only used by special order. I would not use that spindle rebuilder again. The engineers at Bridgeport did one heck of a fine job designing that head and knew what they were doing. Almost all the spindle replacements I did was because of total lack of lube. I,m with JR 100% on his statements. Sometimes I get bearings with seals, I just pop em out.
Bill

Originally Posted by Mr Bridgeport

I worked for 13 years for the factory as a service rep. Sealed bearings were only used by special order. I would not use that spindle rebuilder again. The engineers at Bridgeport did one heck of a fine job designing that head and knew what they were doing. Almost all the spindle replacements I did was because of total lack of lube. I,m with JR 100% on his statements. Sometimes I get bearings with seals, I just pop em out.
Bill

.
too many machinist forget to oil their machines. I know for a fact many machines in many shops often went months without anybody using the oiler and or adding oil to the head. After I had a Bridgeport apart and saw all the places the oiler was suppose to oil and seeing where plastic tubing was suppose to oil screws but had dried up and cracked so not getting oil where needed.
...... after replacing the sliding metal way covers that protect the Z axis screw in the knee, I used oiler 6 times in the morning and 3 in the afternoon. In my opinion most mills are not getting anywhere near the oil they should be getting.
....... grease bearings are normally rated for 5-10 years with normal usage. After all most power tools with sealed grease bearings last usually at least 5-10 years. Oiled bearings in theory can last longer as long as their are no oiling interruptions. Some greased bearings undersized for the load will loose oil from the grease (soap & oil mix) over time and the dried grease will suffer from lack of lubrication too but it takes many years to occur normally. But I have seen heat exposure (hot bearings) and chemical exposure accelerate the oil from grease loss so sealed bearings went dry in months. No system is perfect.
........ But their are plenty of electric motors with sealed bearings or are open on one side so grease can reach bearing from grease fitting that last for 5-10 years easily.

Originally Posted by JRIowa

No rebuilder that we use!

H&W doesn't offer sealed bearings. Neither does BP or High quality.
JR

I just bought a head rebuild kit from H&W. All the bearings were sealed.

Jim

Originally Posted by JRIowa

That means the lube system is working and flushing out all of the crude. The biggest reason bearings fail is not enough oil.
JR

According to skf 15% of failures are due to the crud that is being flushed thru, another 15% due to improper or lack of lube.
Sealed bearings seem like a no brainer when you read the engineering data.
http://www.skf.com/files/191342.pdf

(This is interesting...)

I would heed Mr. Bridgeport's advise he is very well versed on machine repair, especially B.Ps. Plus he is a heck of nice guy.

Wait a second.... You have to oil the head? BRB...

im enjoing this thread, lots of great info and insight for people that dont know. it's nice to see what works and what might not before a repair is needed..

My Webb 4VH Mill has bearings that are to be oiled on a periodic basis. I notice that when I put oil in the cups, usually once a week, the next morning, oil will be dripping onto the table from the spindle. I think that's a good sign. It's a 1987 model and the spindle is still in good condition.

Also, it has a one shot oiler for Way oil on the side of the knee. When I use that, the oil will drip out of the knee ways the next day. I guess it works.