What and Where to add lube to Cincinnati #3 vertical mill....

Hey guys, i'm new to the forum here but not to machining. I just recently purchased a Cincinnati #3 vertical milling machine, early 1950's era, and am running it through it's paces to confirm everything works on it. All the power feeds work fine and speeds and feeds change with no problems or noises. No noises with the spindle either. My concern is the sight glasses that are about eye level on both sides of the machine. They don't indicate any lube circulating through them. There is a cast inspection cover on the back of the machine about the size of a large softball, also about eye level that I removed and looked into. All the gears and bearings seem to be getting a good oil bath, but I don't see any fluid level inside this deep cavity to know if it's just low and needs some added or has another issue. I see a copper drainback line from one of the sight glasses inside this area, so i'm assuming the source of the fluid that flows thru the sight glasses originates from inside this area. My question is, can someone tell me the recommended fluids/lubes to put in all of the spots around the machine. It has the typical spring loaded flip top fill cups(what lube is best for these locations), it also has at least 3 threaded aluminum fill caps that says "Oil" on them, they also are on the table area and knee with sight glasses also(what lube is best for these), and then the various grease fittings around the spindle area and along the upper side of the frame.

Sorry for so many questions, but this machine seems to be in great shape and I just want to preserve its condition so it can serve me for many years to come. Thanks!

First, say serial so we will know WHICH #3 vertical. You will find that on a tag attached to machine outlining lube areas

If High Speed Dial type, serial may start with 4A

Number is 4AC7L34-75.

A little earlier, might be a help since it talks about lube

http://vintagemachinery.org/pubs/2097/15146.pdf

Thanks, it still doesn't specifically mention the lube that reaches the high level where the sight glasses are. We have an older Cincinnati centerless grinder at work that uses 3 different lubes in it. One is a gear oil, another is a bearing and circulating oil and then a spindle oil. We have modern Mobil brand oils for it, and I am thinking the oil I need for this particular area is the bearing and circulating oil. For the centerless grinder we use Mobil DTE. It smells close to the same as the oil that is covering the gears and parts in my machine and has near the same thickness feel to it, I was just hoping someone could confirm. The man I bought the machine from keeps saying to put hydraulic oil in it, but I think he is using that in a generic way and needs to be more specific. Or does it really matter between a "gear oil" and "bearing oil"?

Should only be two high (eye level) sight glasses on the machine. The one on the left side (if you are standing in front in operator's position) near the spindle and feed shifter, clutch and dials, is the flow indicator. Only time you see the constant drip or stream is when the machine is running and maybe even just when the spindle is turning, can't remember right this second.

Other one is on the opposite side on the head feed mechanism. That is indeed a level indicator and should be kept at the halfway mark. Gobs of oilers on the vertical ways, on the head ways up on top (need a step ladder to even see them, unless you are a 7ft4in pro basketball player), the elbows with OIL on them are to be filled to where oil is visible in the cup, unless there is a glass or other level indicator of some type.

There should be, as John says, a lubrication chart right above the serial number plate that shows all the lube points and tells what lube to use.

Mike C. said:

There should be, as John says, a lubrication chart right above the serial number plate that shows all the lube points and tells what lube to use.

Click to expand...

Thanks! Unfortunately the chart you are mentioning is no longer on the machine. It does have a rebuilder tag on it from Hoffaker in Rhode Island from sometime in its history along with an ugly green paint job. So maybe they remove them as part of their protocol or it was removed prior to or after that.

I can't fine that number in the serial number book.

cmike said:

I can't fine that number in the serial number book.

Click to expand...

Same here. Maybe a second look on machine?

Seems more likely it would start with 4A3V

Try the right front top face of the table. May need to clean it off.

These are from my 1953 manual. Hopefully they will help. I am going to try to leave them full sized so you can zoom in. Not sure the website will let me do that. For what it is worth as you can see in the sticky on the cross reference chart from the previous owner I run 46HYD in everything but the knee screw. Table, gearbox, knee, everything 46HYD.





Paul B.

EDIT: not sure the full size thing worked. The files are like 4000x2000 size. I can PM them to you if you can't download them in a way that's readable.

Thank you Paul B., those 2 pages are just what I needed. Thanks everyone else also for your help. More questions will come i'm sure.