Thread: Bridgeport Way Wear

I have a line on an early 60's Bridgeport mill. I went to have a look at it and the horizontal (y-axis) ways seem to me to have quite a bit of wear. I am new at this, so hoping some experienced members here can provide some guidance.

One photo shows one of the ways (left side) at the front , the other shows the other (right side) way at the rear. Sorry they are at 90 degrees to each other, they should be parallel. The latter picture is more clear, but it is the same on both ways and the same at the front and the rear. The scrape marks are completely worn away towards the centre where the table tends to travel more frequently, the ends of the ways the scrape marks are still visible.

How many thou of wear would you expect this kind of pattern to represent? I shudder to think how much it would cost to get the ways rescraped.

Dan

Dan - it seems like there is definitely wear there. Of you read through my post on my "restoration, rebuild, redo, whatever-you call it" youll see I'm up against the same thing. I have Steve Brooks' book and by your pictures and mine, he would deem that "normal-moderate" wear. I spoke to John at J & L scraping and got quoted at $3k+ for all the ways. However, John did tell me that for hobby use you might not need to have it done.

So my theory was to complete the rebuild process, put it all back together and check to see how bad the wear affected the work. Worse case scenario is that I use it to make (earn) the $3 and get it scraped. But something tells me that it'll be ok for my needs. Time will tell though.

You have a really good machinist machine rebuilder up there you can consult with. I taught him to scrape and he has way grinders, planer and a complete rebuild shop. Brad is right about your use vs need, but leaving it that way will snowball into more and more scoring. A few simple steps could be done to help eliminate some of the problems and stop the spread of more. Some of the deep dings (looks like someone dropped a tool on the way causing a deep pit) would have to be left in unless you plug them or cut the way down. You can see the ways are pretty low as the center covers show wear too. If you scrape the ways you might want to put Turcite or Rulon wearstrips under the saddle to raise it back up and it will move really smooth. Give Shane Carr a call and see what he says. If you can buy the machine for $1000.00 or so, it might be worth while spending a few bucks fixing it up. There are several machine Rebuilders all over who can scrape Bridgeport's, one of the simplest machines to rebuild. You can also call me and I would be happy to help.

Carr's Machining Ltd.
1638 Industrial Avenue
Port Coquitlam,
British Columbia, V3C 6N3
Phone: 604-464-6098

IMO, if the ways look like that, what does the rest of the machine look like. The price that they are asking should reflect the condition.
JR

Thanks for all the good info in the replies. This is my first post even though I joined PM over 4 years ago. I guess I have been waiting for the 'right' machine to come along! Will let you know how it turns out.

Dan

All depends on what your going to do on it, its still going to be a lot better machine than a cheap import bench mill though! My based on the pick is worn half that, the scraping is noticeably thinner in the middle but still present. Yesterday i was making a punch tool (die shoe, die + profiled Punch) for 2mm aluminium, That worked fine today during testing, a few months back i made some punches + dies for 1mm bright steel, i had no difficulty holding tolerance on them either.

Ruff guess is you might have had to fight it a little but probably could do the same with ways like that. Much worse than that and i would start to defiantly consider rescrapeing it. Gotta remember the whole saddle arrangment on a bridgeport is not realy big enough for the longer table versions, too much weight - leverage and often infrequent - broken lube systems results in what your seeing there.

Equally bare in mind a slightly rusty beat up old car that smokes a bit is just as capable of going out to get the groceries as a brand new showroom fresh model. Hence if you get it power it up and make some stuff, if its immediately obvious its a issue then rebuild it, or just get on and use it if it will do for now. Remember its a tool to do a job, don't get carried away thinking its gotta be kept spotless and in mint factory condition to do anything, it has not! Its a tool to cut metal, a messy nasty hard process :-)

Mine has that same wear pattern on it. its a 72. it still holds tolerance quite well...so far

Mine BP also looks similar. When I bought it for $1000, I was thinking it might be a problem. However, I have seen no problems in my work, so I won't worry until I do. To help slow further wear I installed homemade way covers made of a treadmill tread. Works perfect. Took 30 min.

That mill looks fine for home shop work. If you are going to be earning a living with a milling machine you would not even be asking these questions you would be buying a new mill. I had a BP with 20 thou worth of wear across the knee the shop that it came from never oiled it and used it outside where it got rusty. I made ok parts with that mill for years the only time it was a problem was flycutting big plates. Small parts wont see the error. Get it and use it, if you need a better mill sell it and upgrade.

I agree with kpotter. I have a 1958 J-head machine and I've done a lot of work on it for my company doing prototyping and modifications, and the only real issue I've seen is my memory in remembering to cinch up the knee when doing something where I need really accurate holes at some depth. The relative size of the way bearing surface areas compared to most "normal size" parts means that it takes a hell of a lot of swayback to start seeing it in your work. The point about large plates is correct, though, and that is where you may see mismatches in the cutterpaths.

A way to eliminate some of the wear, or at least to spread it around, is to get in the habit of placing the vise, or smaller work pieces in positions closer to the ends of the table to even the wear. It will also help to move the ram in and out a bit, for the same benefit.
Regards,
Bob

I decided to let this one go. For a variety of personal reasons, as well as the fact that it got bid up to nearly $2600. It also seemed surprisingly worn for something that had been in a university physics department since 1962, never mind the expected 50 years of student abuse on the table.

It came with a decent number of goodies, so I don't think the price was really out of line, just not a screaming deal.

Thanks to everyone who shared their thoughts.

Dan

i pumped the Bridgeport oiler at least once a day. i once took a mill apart and saw all the items being oiled and sometimes plastic tubing was so brittle it broke where it went to slide screws. sometimes oil is not getting to all spots.
.
after i repaired a Bridgeport i pump oiler 6 times in the morning and 3 times in the afternoon. worse that happens is a little oil on the floor. the oiler pump only pumps maybe 0.1 to 0.2 cubic inches of oil each pump. it is not much. too many machinist never oil their machines every and wear occurs at a faster rate.

i pumped the Bridgeport oiler at least once a day. i once took a mill apart and saw all the items being oiled and sometimes plastic tubing was so brittle it broke where it went to slide screws. sometimes oil is not getting to all spots.
.
after i repaired a Bridgeport i pump oiler 6 times in the morning and 3 times in the afternoon. worse that happens is a little oil on the floor. the oiler pump only pumps maybe 0.1 to 0.2 cubic inches of oil each pump. it is not much. too many machinist never oil their machines every and wear occurs at a faster rate.

i pump the Bridgeport oiler at least once a day. i once took a mill apart and saw all the items being oiled and sometimes plastic tubing was so brittle it broke where it went to slide screws. sometimes oil is not getting to all spots.
.
after i repaired a Bridgeport i pump oiler 6 times in the morning and 3 times in the afternoon. worse that happens is a little oil on the floor. the oiler pump only pumps maybe 0.1 to 0.2 cubic inches of oil each pump. it is not much. too many machinist never oil their machines ever and wear occurs at a faster rate.