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What can't be restored on an older Bridgeport mill?

crtten

Aluminum
Joined
May 10, 2017
Hello all,

I'm a novice looking to buy my first milling machine. I have read a lot about what to look for when buying a used mill but I'm not very confident that I'll catch all of the issues when I go to actually buy one.

My question is, with old Bridgeport type mills, what typical wear can and can't be easily fixed or restored? Table wear, ways, gibs, quill? If I buy a mill and get it home to realize I have worn ways am I just totally hosed or can they be rescraped etc? My goal being to eventually have a mill that functions like new.

Thank you for the input.
 
Anything can be repaired given enough time and money.

Every used Bridgeport on this planet has some wear in the ways. It's just a question of how much you can live with. We probably can't answer that for you. If you just want to drill holes and mill weld chamfers, the thing can be pretty well clapped out and you'll never notice.

Ways can be ground and scraped, but that's expensive.

Quills can be ground/plated/lapped. Again, money.

Spindle splines can get pretty badly worn. Not much you can do there except replace the parts.

All parts of the belts drive can be repaired or replaced.
 
Hello all,

I'm a novice looking to buy my first milling machine. I have read a lot about what to look for when buying a used mill but I'm not very confident that I'll catch all of the issues when I go to actually buy one.

My question is, with old Bridgeport type mills, what typical wear can and can't be easily fixed or restored? Table wear, ways, gibs, quill? If I buy a mill and get it home to realize I have worn ways am I just totally hosed or can they be rescraped etc? My goal being to eventually have a mill that functions like new.

Thank you for the input.

There $ is $ nothing $ that $ can $ not $ be $ repaired $ on $ a Bridgeport! Try to find a good one, it's cheaper to start with a good one than to rebuild a worn out one.
 
What's your budget?

Around here (So Cal) machinery has been going for rediculosly cheap prices at auction, if you aren't in too much of a hurry I'd hit a few auctions, you could get a very good BP in the $2500 range I wouldn't comtemplate getting a BP that needed any work it terms of grinding and scraping the ways.
 
What's your budget?

Around here (So Cal) machinery has been going for rediculosly cheap prices at auction, if you aren't in too much of a hurry I'd hit a few auctions, you could get a very good BP in the $2500 range I wouldn't comtemplate getting a BP that needed any work it terms of grinding and scraping the ways.

I'm in Washington state, everything on Craigslist here seems really expensive. My budget is likely a max of $4000 but I'd rather spend less if possible. How do you find auctions?
 
I'm in Washington state, everything on Craigslist here seems really expensive. My budget is likely a max of $4000 but I'd rather spend less if possible. How do you find auctions?

Find the auctions on line.

$4000 should get you a very nice BP with ways in good condition and a DRO, at least down here.
 
Be very critical of the ways and precision surfaces. Yes they can be returned to like new condition but it will cost money or a lot of your time and money.

Just to have the table ground costs 1600.00 at a good shop in Texas. Then you have to have it, or learn to, scrape in the surfaces for final fit. Cost to grind a whole Bridgeport was right at 3600.00.

That cost is the sole reason THIS ended up taking 1/4 of my new shop addition :(


Now if you have the time and would like to enrich your skill set refurbishing old machines is a good way.
 
I think, aside from the $$$$ aspect everyone is bringing up, the location is big as well. @Swatkins brought up a shop in Texas, my shop (H&W Machine Repair and Rebuild) is in Indiana... so you would need to verify there is a capable rebuilder in your area who can grind and scrape like you might need. I dont know how many customers we talk to who get a "rebuilt" machine or get their machine back from a repair shop and they didnt do anything but clean it. Otherwise, you are looking at having to ship out the machine (or knee, saddle, and table) to get ground and scraped, which obviously is more $$$.

For us, to grind and scrape the ways, you are looking at about $1,800 per axis so about $3,600.

@Moonlight, love $ your $ response $ so $ much. $$ ahahah

Jon
H&W Machine Repair
 
..... My goal being to eventually have a mill that functions like new.
.....

If your time is worth more than $2.10 per hour you can not do this for less than the price of a new machine.
Besides the ways there are screws and nuts, bearings, quill fitting and taper grinding.
Functions decently is different from functions like new.
Bob
 
If your time is worth more than $2.10 per hour you can not do this for less than the price of a new machine.

Are you talking about a new Bridgeport, or a new "Bridgeport shaped Chinese paper hold-down"?

If he wants the genuine article, he's got 7,620 hours to figure it out. All the things you mention can be fixed for about the cost of a Communist import.
 
All the things you mention can be fixed for about the cost of a Communist import.
The Commie ones are fluoridated but he could get one from Taiwan, that bastion of Freedom and Democracy :)

I've seen a few Gortons up in Washington on Craigslist. They are a better mill than a Bridgeport and they go for less money because fewer people know about them. If'n I wuz buyin, that's what I'd look for. This is heresy but I even like the older model with the belt drive head. Faster to change speeds and less to go wrong. Model is Mastermil 1-22 or if you want to play with the big dogs, get a 2-30.

Gorton made good stuff.

I would avoid the Cincinnati Toolmaster, aka the "lightning mill" - never strikes twice in the same place. I'll probaly catch some flack for that :eek:
 
Those Gortons are about twice the weight of a Series I. But don't they have a weird spindle taper?

Sometimes you find a nice Wells-Index or Lagun/Kondia for less than a real Bridgeport.
 
Those Gortons are about twice the weight of a Series I. But don't they have a weird spindle taper?
Yes, you're right, some have 30 nmtb but a lot of them have a Brown & Sharpe #9. I just put Enco quick-change adapters on mine, either fleabay or there are other brands.

Sometimes you find a nice Wells-Index or Lagun/Kondia for less than a real Bridgeport.
Dui ! *(that's commie-talk for "right ! Like a stupid shit I forgot to mention those !") Those are also good. In fact, Bridgeport is maybe the worst bargain of the bunch. Until you go to sell it, anyhow.

Oh wait, don't forget Tree. Those are the bee's knees (except I don't like them, the stupid tool change thing is awful. But the mill is real nice.)

And if you are doing little stuff, there are other, better choices, too. Bridgeport is okay if you come across one you like but if yer lookin', there's other machines just as good.
 
I think, aside from the $$$$ aspect everyone is bringing up, the location is big as well. @Swatkins brought up a shop in Texas, my shop (H&W Machine Repair and Rebuild) is in Indiana... so you would need to verify there is a capable rebuilder in your area who can grind and scrape like you might need. I dont know how many customers we talk to who get a "rebuilt" machine or get their machine back from a repair shop and they didnt do anything but clean it. Otherwise, you are looking at having to ship out the machine (or knee, saddle, and table) to get ground and scraped, which obviously is more $$$.

For us, to grind and scrape the ways, you are looking at about $1,800 per axis so about $3,600.

@Moonlight, love $ your $ response $ so $ much. $$ ahahah

Jon
H&W Machine Repair

Well, some time in the next year or so you are going to get the Bridgeport I have owned since 1980 to do a full rebuild on!
 
keep an eye on school auctions, machines tend to be 30 years old with little wear but stupid stuff like broken handles that can be easily fixed. school administrators see a 30 year old machine with a broken handle and figure its junk.
 
..... Lots of info here on what to check out; some obvious visual things are chrome ways with flaking still intact, spindle taper smooth and undamaged, original paint, table in good visible condition, reasonable backlash in dials, quill not worn/scored. ......

Easy to say these things once you know your way around but I remember buying my 1st used at a auction in the 70s.
Had this same type advice and still knew nothing about what I was bidding on. Got lucky sometimes, not so lucky others.
It's easier to judge condition once you have owned a dozen, hard to describe "good" in words to someone who has not.
Bob
 
Hello all,

Thank you for your replies. I went to checkout a Series 1 J head today. The owner has owned it for 20 years, used it seldomly, and knew very little about it. I'm a novice, and I was teaching him how to use it toward the end of my visit. He used it mainly, from what I could gather, as a drill press. He is selling it because he's moving out of state and does not want to move it.

From the serial number I found the mill to be made in 1969. It is a 3 phase, step pulley J head, It's seen a lot of use and wear in it's life. I stayed for 3 hours to test all of the things I could think to test. My initial reaction is to pass on the machine, but I wanted a second (and third) opinion to make sure I'm making the right decision here. This is literally the first mill I've ever gone to buy.

The owner wanted $4000 for the mill, vise, and some tooling. At the end of my visit I told him it's worth more like $1.5K w/o tooling and maybe $2k w/ tooling. I think it's really worth more like $1K all things considered, but again, I'm a novice and I'll defer to your guys' expertise. He agreed on the $2K price, but I'm confident I could get him lower, because he now sees the issues the machine has.

What I found:

1. The machine was covered in oil/grease/dirt/chips, even though he was trying to sell it.

2. The table had a big chunk milled out of the middle, which was covered initially by the vise. Is this fixable?

3. Powerfeed motor was missing.

4. DRO X axis was not accurate, Y axis was fine. (likely fixable, but I'd probably replace the DRO as it was very old)

5. 45 thousandths of backlash in X and Y axes. (likely adjustable)

6. Turret, ram and head moved in all directions (yay!)

7. The X axis had 3 thousandths deflection toward each end and 1 thousandth in the middle.

8. The Y axis had .5 thousandths deflection toward the end nearest the column and 8.5 thousandths toward the opposite end.

9. The Z axis had 5 thousandths deflection.

10. The quill had 2 thousandths deflection from side to side, and also scoring on the right side from the quill lock.

11. The spindle itself had .5 thousandths runout when running not under load.

12. The ways on the Z axis looked good, still plenty of flaking/frosting (not sure the correct term for that)

13. The ways on the X axis were not visible because the mill was in a small room and the X axis couldn't be fully transversed.

14. The ways on the Y axis looked highly worn, Flaking visible on the extreme ends but the middle was smooth as glass.

The Y axis was by far the worst of the 3 axes, so I took off the guard and the wipers to adjust the gibb. The gibb was bottomed out already (a previous owner must have done this, since the current owner didn't even know what the gibbs were, what they did, or where to find them)...

So like I said, my initial reaction is to pass on it, it seems like a worn out machine that's been misused. But if the wear to the ways can be fixed in a reasonable fashion, then it'd be a decent machine.

My questions:

1. can the slop in the Y axis (8 thousandths difference from one end to the other) be fixed either by scraping, shimming, etc, in my own shop, or is that too far worn?

2. can a milled/damaged bed be fixed by filling with weld and remilling it flat using the mill itself?

3. Should I just make a hard pass on this mill and keep looking like my gut is telling me to do?

I've attached images, hopefully they work.

Thank you for your replies.

IMG_7166.jpgIMG_7167.jpgIMG_7158.jpgIMG_7159.jpgIMG_7160.jpg
 
Before we can tell you to pass on the machine you need to tell us what you are going to use it for. It may be perfectly acceptable for your intended use. Not everybody needs a machine accurate to .001. Sometimes it's a ok machine if the motors good and it will run every time you push the start button.

All my life I've had to use used worn out machines to build things with. Because I work in so many disciplines I can't afford to fill the shop with brand new machines of every type, I have to buy used. That is one of the reasons I have taken three scraping classes (soon to be 4 :D ) and have a big ass planer in the shop. I buy the best machines I can afford and then fix them up as best I can. I used to pour over the machine tool catalogs lusting after a new lathe. I always thought I would be in heaven If I could turn the crossfeed dial .003 and actually take off .003 everytime :)

I amaze myself sometimes with the level of precision I can get out of some of the more worn machines. You can do good work on a worn machine, it's just a lot harder.

Please tell us what you're going to use the machine for and the level of precision you need. The machine you're looking at might, or might not be a good fit.

To answer your question on the bed.... You could build up the hole with liquid metal, bondo, other hard filler or even cut a piece of cast iron and fasten it in place for a repair. Welding is going to mess up the table. You can use the mill to level off the repairs even but be advised the table is probably bannana shaped with the ends down at least .010". Machines that have a hard life usually suffer from over enthusiastic tightening of hold down bolts. Excessive tightening of the hold down bolts deforms the metal lips of the T slots, stretching the metal in that area and causing the table ends to bow down. A repaired table might not look as nice but can function just as well as a pristine one...
 








 
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