New to me Bridgeport mill, this beginner has questions.

[jason867]

Hey guys. I originally posted this in the New Members Introductions sub-forum, and I later realized maybe I should've posted here.

I'd been wanting a vertical mill for some time, and finally brought home this Bridgeport yesterday!



Details:
Serial # on the base indicates 1965 manufacture.
220v single phase GE motor, it looks like it says 3/4hp but i haven't looked close yet.
9x42 table.
No-name 6" vise.
X-axis power feed.
Pneumatic power drawbar (3/8" impact gun with bracket)
Very simple Mitutoyo 2-axis DRO
Could use info on this.


The ways appear to have most of their scraping intact. There's a patina on most everything, but no nasty rust. The X Y screws appear to have minimal backlash, although i haven't measured it yet. Table moves pretty smoothly to ends of travel. Everything seems to work correctly.

There is one issue. To pull the trailer inside my polebarn, we considered spinning the head around upside down. Before i loosened the four front face bolts, i tested the spin screw, and it spins freely, no feeling of stripped threads or anything. We left the head where it was and instead tipped it as far forward as it would go, which was enough.

Got a bunch of free tooling too: chucks, collets, set of titanium nitride endmills, small face cutter, indexer and tail-stock with it's own set of collets, some indicators & stands (unsure if they work well though), right angle plate, extra vice jaws, big work fixturing kit, etc.

It's all got surface rust, so I'm gonna get some evapo rust to bathe it all in.

Still gotta wire up a 220 socket, and get everything situated.

It's got grease zerks instead of a one-shot oiler. I know it's supposed to be oil, not grease. What type of oil should i be using? Would straight 30 non-detergent motor oil be okay? What about head lubing? It's got those tiny cups with spring loaded caps.

I need to get it wired first, clean up some, figure out proper lubrication, then i can get the table trammed in and get milling!

Any recommendations for this n00b machinist?

 

[CJ5Dave]

Way lube, like for lathe ways, is correct I think for the fittings. Hard to get there. You can get it by the gallon from H and W machine. Also the plunger applicator at left but they don’t hold up well. These little grease guns work well if you gut the plunger and seal the tube. I used the cap off brake cleaner and sealed it in the bottom with RTV. Turn it upside down and it works well with way oil.

 

[CJ5Dave]

This might help.m

http://www.vintagemachinery.org/pubs/2099/26353.pdf

 

[IHinIN]

Congrats on the Bridgeport.
Way oil in the zerks and spindle oil in the cups on the head.

 

[Jake M]

It's got grease zerks instead of a one-shot oiler. I know it's supposed to be oil, not grease.

Depending when it was made, it might have called for grease. It would NOT have been "dollar a tube chassis lube", that'll gum up and plug channels everywhere as the oil goes away but the binders stay in place and plug stuff up. There's actually way grease (and similar for other applications) that would have been used, and aren't afflicted by this.

If you're not sure what's been done in the past, you might be well served to investigate deep enough to determine if it is full of old dried out grease binder.

What type of oil should i be using? Would straight 30 non-detergent motor oil be okay? What about head lubing? It's got those tiny cups with spring loaded caps.

Any lubrication is better than no lubrication, but atuomotive products are not your best way out. There's too much going on in even the simplest "flavors" of them, and you'll find that they don't sit well when used for intermediate or long term storage. Such as a machine that isn't used for a whole shift or more every day. Automotive engine oils and automotive oriented gear oils, they all have a reliance on a LOT of SUSTAINED heat, very heavily forced curculation (even if it's splash, it's violent compared to the use in a machine tool...). Their oxidation protecteion, boundry layer librication, their moisture handling, it ALL relies on a LOT of heat and a LOT of circulation.

Again, some oil is better than no oil, but I wouldn't start there for anything machine tool related unless it was desperate.

The simple cheat substitute is hydraulic oil. Plain old hydraulic oil, NOT tractor fluids, not hydrostatic fluids, although it will be in that section if you buy locally. Basically not anything at all with a particular use case. Plain, minimally ammended oil is what you want. Either R&O or AW of an appropriate weight. That's a very plain oil, R&O is rust and oxidation inhibition, while AW is Anti Wear (high pressure) ammended. You'll never see enough "abuse" of the oil to make use of the high pressure feature, but as strong (but not infallable) rule of thumb, like for like, the AW is gonna be built out of a stronger base stock blend, just due to it's typical applications. But that's splitting hairs. Both are light years ahead of what was available twenty, forty, sixty years ago.

The "right" answer comes in specialized stuff that's exactly for this. I suspect the "right" answer for machine that would have been way oil. Probably Vactra 2 or equivalent for this stuff, and Velocite 10 or equivalent for the spindle.

As I have been studying these manuals and factory documentation, reminding myself why I have not bought and probably will not buy any of the remaining specimens that live here in this machine tool desert... I have learned one thing beyond any doubt. The recommendations DID change over the years, and it did not correlate to changes in the main components. It was updated because of "real world performance" issues, or due to changing lubrication standards (since oil was invented, you can't compare like for like from ten years apart), and possibly some for wartime availability. Or ten thousand other reasons that did not have to do with changing the construction of the machines. Although the machines DID change some over the years... I don't think I'd go backwards, as in, I don't think I'd consider putting way grease in a machine that's too new to have been recommended for grease... But I would not hold the project up over technical perfection here. Although it would drive me nutz until I sorted out what "needed" to be there, you've got some room. "No" oil in there is going to hold you up. "Some" oil in there will keep the project moving.

Edit-
I forgot to throw in there with the "plain" hydraulic oils- The AW type oil automatically, by definition, does include an R&O package.

 

[jason867]

Just got 220v wired up and was eager to make my first cuts!

 

[ttabbal]

I know the way oil feels expensive, and for oil, it kind of is. But it is good stuff and lasts a long time. Mine was similar vintage and the previous owner put grease in it. Might have been the "right" grease, but I wasn't 100% sure, so I cleaned it thoroughly and switched to oil. I use Vactra 2 on both lathe and mill and have no trouble with it. I'm using a modified grease gun, it works well, but can be tedious to lube everything. It would be nice to get a one-shot or similar set up, but I'm not willing to pay for one right now.

Looks like the machine is working well overall from the video. The DRO looks like it might have an incremental mode, but not much else. Nothing wrong with that, but modern units can do circle patterns and similar. Still, it's nice not to have to use the dials. They aren't bad once you get used to it, but it's nice to just "know" where the cutter is. And if it works well, no reason to swap it really.

 

[jason867]

After reading and watching several videos, hoping for generally acceptable way oil alternatives, that's the conclusion I'm coming to realize.

I'm looking to modify a grease gun as well.

Got the dro reinstalled last night and played around with it. It appears to be very simple. The plastic dials on the right can be advanced by hand, then you press the load button and it copies the value to the digital display.

On the back of the dro, for each axis, there are three toggle switches, Direction, inch/millimeter, and RAD/DIA.

The other two switches are obvious, but I'm not sure of the purpose for the rad/dia switch. I assume it means radius/diameter, but I'm not sure how the dro would do anything related to circles with such limited controls...

 

[jason867]

The guy I bought this mill from was a reseller. But he does work at Cummins as a machinist or CNC operator of some sort, so he appeared knowledgable.

He supposedly bought the machine from an older guy he knew, who appeared to be a knowledgeable machinist himself. I don't believe any grease was pumped into this thing.

 

[jason867]

I'm thinking of buying these guy's way and spindle oils, since they're Hoosiers too:

Oil

machinerypartsdepot.com