Bridgeport Mill problems
RSS | Subscribe | Contact Us | Advertise | About Us
Results 1 to 11 of 11
  1. #1
    Join Date
    Feb 2008
    Location
    Nebraska
    Posts
    167

    Bridgeport Mill problems

    I have an old series 1 J head bridgeport mill in the shop. We use it all the time. Well today, we went from high gear to slow gear or back gear, and the damn thing makes this horrible grinding noise.
    I have looked at everything, can't figure out what the hell has happened. Sounds like gears aren't matching up right in the head somewhere. You put it in high gear and the machine runs like new. You go to put it in the back gear or slow gear and the mill is screaming at you.


    Any ideas??

    Thanks

  2. #2
    Join Date
    Jun 2008
    Location
    Central California
    Posts
    3,769

    Re: Bridgeport Mill problems

    I haven't looked at a breakdown of one or had one apart in a long time so don't remember if the back gears are fully disengaged or just idling in high range, but I'd guess the former and that a bearing in the low range section has frozen up. Sounds like time to pull it all apart; best way to find out and the only way to fix it.

  3. #3
    Join Date
    Jan 2006
    Location
    In A Nice Comfy Chair
    Posts
    15,802

    Re: Bridgeport Mill problems

    We have one that does the same thing..

    What we do..NO laughing...is take a piece of wood and band saw it on an angle say 30 degrees and where the lever is on the top of the head that engages the back gears slide the wood under the lever and push the wood and move the lever up the ramp..
    Sometimes it takes a couple of whacks with a rubber hammer but the gears will engage and stay engaged..

    This machine has been like this for years..

    Yes it works.

    ...zap!


    I am not completely insane..
    Some parts are missing

    Professional Driver on a closed course....
    Do not attempt.

  4. #4
    Join Date
    Jun 2010
    Location
    Louisville, KY
    Posts
    407

    Re: Bridgeport Mill problems

    When you switch gears in mine, the order goes like this:
    -Press stop
    -Engage brake
    -
    -Switch to low gear
    -Rotate spindle by hand until the gear engages, it is quite obvious
    -Turn on spindle.

    Of course, you could have broken a tooth on one of the gears, too, but mine doesn't change between high and low on the fly and makes a horrible grinding noise if you don't spin the spindle by hand to make sure it engages.

  5. #5
    Join Date
    May 2010
    Posts
    92

    Re: Bridgeport Mill problems

    You may want to check to see if the High/Low lever hasn't slipped on the shaft that it turns... Had that happen to one in the shop once.......

  6. #6
    Join Date
    Feb 2012
    Location
    Cape Breton, Can.
    Posts
    142

    Re: Bridgeport Mill problems

    Have a close look at the two pins that ride on the ramps for the hi/low lever mentioned. The pins can work loose in the inner sleeve causing the gears to be partially engaged while direct is still connected.
    I rebuilt a basket case mill a few years ago, that needed some major rework to this mechanism. Think i had to make new pins and locate a new set of holes 180 from the original.
    Briggs weldnpower 225/210/cv
    Ln-25 suitcase
    Millermatic 130

  7. #7
    Join Date
    Oct 2010
    Location
    western kentucky
    Posts
    4,408

    Re: Bridgeport Mill problems

    go with what winmac has stated, check the pins, and also replace the compression springs.. its about a 2 hour job..

    the pins will pull out of the tapped holes after time... If the topend of the mill hasnt been pulled off before there will be an extra set of tapped holes, get a new pair of cam ring pins and 4 compression springs. if the belt looks bad or getting tired, now would be the time for a new timing belt and vbelt..

    It would also be a good time to fix the brake if the brake isnt functioning properly.. I just ran a small bead down both sides sides of the brake lock stud with my tig welder..

    I've ordered from this place in the past, they are quick, inexpensive, and have excellent quality parts..
    http://www.machinerypartsdepot.com/s...57/page/552090
    4pcs part#1108 (compression springs, # 9 below)
    2 pcs part#1109 (cam ring pin, #31 below)


    step pulley pictured below
    Attached Images Attached Images  
    Last edited by brucer; 02-22-2012 at 02:43 AM.

  8. #8
    Join Date
    Oct 2010
    Location
    western kentucky
    Posts
    4,408

    Re: Bridgeport Mill problems

    to add,
    there are 2 small set screws in the top of the spindle pulley bearing sleeve that lock the cam pins in place.. think they are 8-32 set screws (#10 on the picture above), they will more than likely be full of crud.


    and if the holes for the cam pins are wallowed out, you need to check and see if you have an extra set of tapped holes in the spindle pulley bearing sleeve, if not you might as well order a tap, If I remember correct the tapped holes for the cam pins are 1/4-32..
    Last edited by brucer; 02-22-2012 at 02:52 AM.

  9. #9
    Join Date
    Jul 2013
    Location
    Bay Area, California
    Posts
    27

    Re: Bridgeport Mill problems

    I had the exact same problem with the back gear noise. I took Winmac's advice and tighten the cam ring pin (#32 in the figure above), about half a turn.

    The noise when using the back gear was completely gone (and believe me it sounded really nasty). I was so happy it was not something more complicated or expensive.

    THANK YOU.

  10. #10
    Join Date
    Jul 2013
    Location
    Bay Area, California
    Posts
    27

    Re: Bridgeport Mill problems

    Whoops.

    Correction: cam ring pin #31 above; it was #32 in my manual.

  11. #11
    Join Date
    Oct 2008
    Location
    Minnesota
    Posts
    313

    Re: Bridgeport Mill problems

    We always turn it by hand or ours will make a heck of a grinding noise and everybody will look at you like you should know better and shake their head. Opps.

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  
RSS | Home | Penton Media | Contact Us | Subscribe | For Advertisers | Terms of Use | Privacy Statement