Bridgeport 2J Maintenance

Hi Folks,

I have finally got around to starting on a bit of renovation of my Bridgeport 2J milling machine. I picked it up a while ago, but it has a few issues so have started pulling it down for an inspection and a good clean. One of the issues as I have found is that the one shot lube for the ways was clogged pretty badly and the ways on the x-axis are not in great condition and the y-axis is not much better. Now I knew when I brought this that it was in poor condition, but for my use I have not had a problem with it, and I seem to be able to product parts that are accurate enough for my needs anyway.

..but, given that I am pulling the whole thing down for a very good clean and paint and fixing a few issues here and there, I thought it was worth seeing what could be done for the ways. I have not been able to find anyone who seems to repair these machines, I suppose what I am looking for is the x and y axis ways to be re-scraped and the table. Does anyone knows who, if anyone does this in Melbourne? For a reasonable price I would consider it. I am guessing it would be too expensive, but the questions is worth asking while I am at it. The table is 48 inches long, and it seems to have a high spot in the middle of the saddle and wear on the outside edges which is not uncommon for these milling machines with the longer table as they don't seem to have enough with in the saddle to support the entire length of the table. As I said, I can live with it, but if there was someone out there who fixes these things up then I would be interested in getting into contact with them.

Anyone have any ideas? (looking on the USA forums they would say to dump the machine and buy a good second hand/new one blah blah blah, but they seem to have millions of milling machines going for $500 over there. Sadly it is not the same here) By the way this is for hobby use, fixing old piston pumps, the odd model steam engine etc.

Below you can see the scraping/flaking marks on the saddle in the middle. Would seem to me the explanation for this is that the table is sagging in the middle over the ends. It is possible the table was rarely if ever moved, but if that was the case, the scraping marks wouldn't have worn away... If the table is bowed (a straight edge along its length would suggest it is but only very very lightly) would fixing it would be difficult (?)

Attachment 278192

Y axis is nice and worn along its length. Light scoring.

Attachment 278185

Ugly green flaking off paint, most of the filler underneath is coming off. Will remove and re-paint. Not that interested in it being pretty, but it is pretty hard to keep clean with the current state of the surface.
Attachment 278186

Hi Bennet,
I'm sure there would be one or two guys in melbourne that could do it, Phil "Machtool" would be one, but the cost would be fairly prohibitive i would think. You could just get the table ways and top ground but that would only be a half a5ed fix. Best way to do it would be to learn to scrape yourself, get the table ground and do the rest, that way you wouldn't need a big surface plate.

Cheers,
Ew

Why there are still scraping marks in the middle is because you would find that area has been relieved by a small amount... it is done to make machine life greater before reconditioning is possible...

There would be many people in Melbourne capable to reconditioning the ways.... But it would not be feasible, it would cost more then buying a new turret mill..

The ways are but one portion to consider.... Are the feed screws worn out along with the nuts? What condition is the head in? Is the quill worn?

It is possible to do a lot of the reconditioning work yourself, but not many people would have the patience to do it in the first place plus setting up the required tools required would not be cheap...

Hi,

Thanks for the replies. The quill and the head are in good condition, there is a DRO on it, so backlash is not such a big issue anyway. The backlash is not too bad, but I am considering splitting the feed nuts to improve it a bit. I think I will just clean it up, make sure all everything else is in order and get on with using it.

Thanks.

One thing I like about the BP is there is a lot of information available on repairing and rebuilding them. Here are a couple of resources that may interest you and aren't too expensive in the grand scheme of things.
Rebuild Manual for Bridgeport 2J Variable Speed Mill | eBay

I have a couple of Steve's manuals and they're simply the best there is out there, end of story. He's a very nice guy too, so good luck to him.

There's also a DVD called Scraping for Alignment.
Scraping for Alignment Two Disc DVD | eBay

Their donor is a Bridgeport so you can follow along with what they're doing, though it's not really a BP instructional DVD, and it also glosses over some things. Badly at times in my opinion. You'd probably want to have a reasonable knowledge of scraping and machine geometry before cutting loose with an angle grinder, but you may be able to scrape some of the bearing surfaces to at least improve them. There's no rule that says a machine needs to be completely rebuilt and every surface scraped to sub-atomic level for the job to be considered viable, but you'll obviously need access to specialist tools in order to tackle any scraping at all.

Good luck.

Pete

Hi Bennett,

I think you have a reasonable machine. I picked up a BP 18 months ago that looks identical to yours except is was MUCH dirtier.
The lube system fitted refused to work untill I soaked the metering fittings in MEK for a few days. I pulled one apart and found that there was not much to them. I made a fitting that I plugged into compressed air and would allow me to force MEK through them under pressure untill they started working.
Now works a treat.

Having said that, I cannot be sure your metering fittings are all metal construction. MEK eats plastic.

Paul M

Hi Paul,

Some metal, some plastic. Plastic ones are not in good shape and I think I will re-do them. Have got all the x, y, z screws and handles off now, going to give them a good clean, split the feed nuts and put it back to gether
and see how it goes. Having a milling machine in parts is not much fun, I keep needing to use it. Next time will take the motor and head off first so I stop smashing my head into them every time I am working on the knee.

Found about 2kgs of swarf inside the knee. At least it will be lighter from now on :). I have the rebuild manual for the 2J and it is great. Most is quite straight forward, but there are a couple of things that I have found that would have caught me out... And I had to make a pin wrench to pull the z axis collar off. Someone has been here before me and had a tendancy to use a hammer a bit. Why are there hammer marks all over the axis handles????

Need a parts washer...

Quote:

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Originally Posted by Bennett

Need a parts washer...

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I have a really nice one here, your welcome to use it.

As for the hammer marks mine is similar. I don't think the steel is particularly hard.

Do you have the chrome ways?

Have had a few bridgeports over the years starting with a new one my dad bought in 1971 or 72?

48" bed is the optional longer table and before they chromed the knees they did wear considerably. They were never the flattest travelling table even when new so I would have measured drop and considered what you are going to do before worrying. Now apart use a straight edge, sander and scraper and tidy up the high spots. The aim is to get the bed firm on the gibb without tight spots. Good luck a good mill have fun.