1. Home
  2. ⏣ General Metalworking
  3. Bridgeport question
  4. Page 2

Bridgeport question

There are only 3 of these bolts. You have access to the nuts, the bolts are in a round T-slot in the belt housing. If you have a way to lift it straight up, like an engine hoist, you can pull it motor and all. You have to lift carefully straight up so as not to bend the upper part of the spindle.

Once the belt housing is removed, (and do it completely so you don't risk bumping something and bending the spindle) then remove the skirt with 2 screws in the top of the quill. Block up the spindle to prevent it from falling, and remove the two screws next to the feed handle on the right side. The counterspring is in this, and it will unwind as soon as you take the screws out. Then, you should be able to remove the cover and pinion as one piece out the right side of the head. The quill can now be dropped out the bottom of the main housing. (Oh, you have to get the stop ring off the front, too.)

You want to remove the belt housing entirely, so as not to have it hanging by the spindle. I'm not sure if there is a reason you can't lift the spindle out the top, but maybe it will bind going that way. I have always dropped them out the bottom, the normal direction they extend. Maybe that is because the feed gear is in the way. If I go too far and it pops out of the bore am I

As I say above, you can't get the quill out the top without disassembling stuff you don't want to mess with. I am not sure whether the rack teeth go all the way to the top of the quill, maybe they do. If so, you don't have to pull the pinion, but you probably do have to unscrew the plate around the feed handle so you don't break the counterspring. You would be winding it down well past where it normally goes.

You still have to pull the belt housing to remove the quill skirt. Maybe when factory fresh this will just slip through the bore, but not after the machine has been used a lot.

Jon

Reply to
Jon Elson
Loading thread data ...

Thanks Jon, I totally see a disaster in my future doing this myself. I'm going to find a repair service in the Chicago area and bite the bullet on this one. I'll watch and see what he does but I'm going to totally screw this up if I try it. I might as well replace the timing belt, drive belt, springs, and any other p/m parts they recommend. This is too big of an investment to play super-hero on. Thanks a lot for the detailed explanation. I'm noticing .040 runout on the spindle up top when the quill is fully seated upwards so I'm going to replace that as well.

Respects,

Rob

Reply to
Rob Fraser

Oh, hell, this stuff isn't rocket science (where you get blown up if anything goes wrong). The Bridgeport J head is really pretty simple, easy to disassemble and work on, and if you just take your time and are careful with the heavy pieces, you are not likely to get in trouble.

.040" runout? Hmm, that could be related, hope you don't have a bent spindle. Yes, when you have it open, definitely wise to replace all the wear parts. My head sounded pretty OK, but looked a bit rough, so I opened it all up anyway. I'm REAL glad I did, several of the small bearings in the back gear train had exploded, the ball spacers had broken up and been creamed by the balls, and there were chunks of the spacers and shields just laying in the gear train! The plastic bushings in the vari-speed pulleys should be checked, most likely they will need to be replaced if the head has a lot of time on it.

There are pins that ride in a cam ring that lifts the driven pulley assembly to release the direct-drive clutch. (It is different on the 1J and 2J, but I think they all have this problem that the pins wallow out the threads in the bearing housing that goes up and down. So, you want to check if those pins are wobbly.

You want to check the pipe cleaner-like oil wicks to make sure they are dripping oil where it is needed.

If the spindle has to come out, your service person will get that evil gleam in their eye and try to sell you a new spindle bearing set. Just be sitting on something soft and secure when he tells you the price! I totally lucked out on the 1J head I bought to retrofit my round-ram Bridgeport. The bearings had been changed just before it was packed away for storage. Or, at least I think that must be the story, as it had that run-in lube jelly stuff in the bearings. Hopefully these bearings will outlast me.

Jon

Reply to
Jon Elson

The quill has to come out the bottom. The rack isnt full length on the quill.

I did this Wed morning. Used a fork lift with sling to pull the head (after removing the 3 nuts).

The rest of your post is accurate enough.

Found 3 tiny chips binding up the quill.

The Russian machinist refuses to stop using the (full house pressure) air nozzle to clean chips off the machine.

What with replacing the motor pulley (A belt..trying to run a B belt doesnt work...)on a thread roller, the Bridgeport and fixing a Clausing drill press.....took me 4 hours

Gunner

"[L]iberals are afraid to state what they truly believe in, for to do so would result in even less votes than they currently receive. Their methodology is to lie about their real agenda in the hopes of regaining power, at which point they will do whatever they damn well please. The problem is they have concealed and obfuscated for so long that, as a group, they themselves are no longer sure of their goals. They are a collection of wild-eyed splinter groups, all holding a grab-bag of dreams and wishes. Some want a Socialist, secular-humanist state, others the repeal of the Second Amendment. Some want same sex/different species marriage, others want voting rights for trees, fish, coal and bugs. Some want cradle to grave care and complete subservience to the government nanny state, others want a culture that walks in lockstep and speaks only with intonations of political correctness. I view the American liberals in much the same way I view the competing factions of Islamic fundamentalists. The latter hate each other to the core, and only join forces to attack the US or Israel. The former hate themselves to the core, and only join forces to attack George Bush and conservatives." --Ron Marr

Reply to
Gunner Asch

PolyTech Forum website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.