What's new
What's new

Feed trip disassembly, well actually hand wheel clutch removal first.

MikeMM

Plastic
Joined
Feb 10, 2018
I just purchased my first Bridgeport J head mill real cheap from an R&D facility that was being shuttered, so I'm expecting some minor (hopefully) repairs are due. It's an older machine from the 60's with zirks so the morons have always greased instead of oiled and now the knee, table, and saddle barely move due to old hard grease, so I'll be busy cleaning out the oil paths and ways surfaces.

First thing I noticed after I got the machine into my garage and started to go through it was the retaining ring on the threaded shaft with the micro nuts was detached. Sure enough, the micro feed trip lever was also bent and not engaging the trip plunger. I straightened the lever temporarily until I see what other parts I need to order and proceeded to adjust the trip assembly.

During the adjustment, I noticed the cam rod sleeve assembly was not fully retracting to the left after the trip release. It was hanging up on something and I would need to manually pull the clutch trip lever by hand for it to fully disengage. I flushed the entire area with solvent while working it back and forth just hoping it was caked up swarf and it would move freely. No luck, I need to remove it from the head so I can examine behind it and all contact surfaces to figure out what is going on.

Here is where I am stuck. To remove the feed trip bracket, I first need to remove the handwheel clutch stop assembly. I removed the cap and spring to exposes the detent ball but the ball will not come out. I magnetized a small piece of drill rod and it sticks nicely to the ball but the ball will not extract. I feel the ball moving as I push and pull the plunger through the 3 positions so the ball is not frozen in place.

I was thinking about possibly using some epoxy on the drill rod and letting it fuse to the ball and trying to extract that way. I could see that going bad and digging a deeper hole than I am already in.

Any methods or tricks I can try?

Thanks,

MikeMM
 
Obviously, this was moved from another area. So, welcome to the BP section.

How long have you screwed with the ball? 1-2 hours. I can tell you I've worked on one that long. What I've had the best luck with is air. This is the trick, to blow compressed air around the ball and not have it shoot 36 foot across the shop unless you have another.

If you have a numbered set of drills, run a dril (using your fingers) into the hole to clean up any burrs. You don't want to remove material. Then just keep working at it. IMO, epoxy would be a bad move. It proably won't stick to anything but the threads and then you've really got a mess.

Just make sure the hole is clean and burr free and the ball will come out.
JR
 
Some images that might help.
Ball #173 ?
It can be a bugger. Tube sprayer like from WD-40 type can. Light spray oil or such to flush.
Ask your Dentist for used dental cleaning tools.
BP Feed 3.JPGFeed 4~.JPGFeed 1.JPGFeed 2.JPGFeed 3.JPG
Verify on assembly that the feed will kick out in both directions, feed down and feed up. This can be tripped manually with the machine off.
Sometimes the trip pin at the top (not the dog bone) is not drilled on center, the 4th image. Install with the longer length down else there may not be enough overhang to trigger the feed trip. If the circlip is damaged replace it. the new one should fit tight and snug.
John
 
Last edited:
Hey JRlowa, thanks for the welcome, I don't know where the post was moved from as I thought I originally posted in the BP section. It took almost 24 hrs to show up in the forum.

Well anyway there are no chips or burrs in the hole and I've been blasting it with air but getting nowhere. It looks very clean and no obvious deformation of the bore that seems to have a death grip on the ball. I have plenty of drill bits to spin in the hole but what am I looking to clear at this point? Is there a way I can remove the shaft together with the bracket as a complete assembly?
 
Some images that might help.
Ball #173 ?
It can be a bugger. Tube sprayer like from WD-40 type can. Light spray oil or such to flush.
Ask your Dentist for used dental cleaning tools.
View attachment 220491View attachment 220492View attachment 220493View attachment 220494View attachment 220495
Verify on assembly that the feed will kick out in both directions, feed down and feed up. This can be tripped manually with the machine off.
Sometimes the trip pin at the top (not the dog bone) is not drilled on center, the 4th image. Install with the longer length down else there may not be enough overhang to trigger the feed trip. If the circlip is damaged replace it. the new one should fit tight and snug.
John

Yes its ball 173. I've been using wd40 with straw, gumout with straw, blow gun with shop air... nothing doing.

The feed kicks out in both directions up and down. All the linkage is good exept the bent feed trip lever on the bottom which I am replacing. I am reusing the original clip, Not damaged and has snug fit. What I think I see but can't confirm without disassembly is the trip plunger bushing #123 has a groove or step worn into it and the trip plunger #121 is hangin up in this groove or step during its travel.

Funny you mention about asking my dentist for cleaning tools. I am the lead service technician at IQ Dental Supply and I have more of these probes, explorers and curetts than you can imagine. There is just no wat to get any of them behind the ball to pry it out.

I even have on my service bench a selection of surgical drills with spindle speeds of 400,000 rpm spinning 1/32 carbide end mills which will annihilate the ball and any other piece of metal I touch with it whether its hardened or not. But as a service tech, I follow the same Hippocratic oath as a Dr. and first, do no harm.
 

Attachments

  • 20180212_194513.jpg
    20180212_194513.jpg
    85.2 KB · Views: 109
  • 20180212_194204.jpg
    20180212_194204.jpg
    89 KB · Views: 113
  • 20180212_194013.jpg
    20180212_194013.jpg
    82.1 KB · Views: 109
MikeMM
Nice tight photos. I used to get that close with film but not yet with digital.

How I got the ball out since there is no way to get at it with the reverse pin in place.
The reverse pin 111 with it's detent positions will smack the ball thru the hole if the pin is
moved quickly back and forth. Thread something into the front of the pin to do this.
The handwheel clutch 113, thought that will rotate so the ball will drop vertically towards the floor.
Use the plastic straw to hold it up against the reverse pin so it takes a hit. Flush debris as needed
and get lucky :)

The assembly 119 to 123. The pin 119 is there to hold 121 in place. 121 has a slot that limits travel.
Feed kick-out occurs when 121 does not fully engage with bushing 122-123. This is a housekeeping problem
caused by debris. Suggest holding off on removing ball 173 and spray out this assembly that is loaded into 118. Remove feed trip plunger 124
and insert a long rod in it's place. Apply upward pressure and oscillate to loosen debris while spray cleaning. Also engage the feed lever
that moves 117 into position. When the debris is clear there should be an audible click when 121 drops into place. Use the long rod
in place of 124 to disengage feed.

There are two screws that hold the quill scale in place. The length of engagement is critical for the lower hole. If the length of the screw is too long it will contact the feed trip plunger 124 and cause a feed trip-out problem.
Parts List L.jpg
John
 
You can remove the whole assembly, then instead of pulling the ball out, you push it in, and it will roll out the backside of the shaft. 5 minutes to pull assembly out, and 30 seconds to push ball. I got a video of it if I can find it.
After fighting it for hours, trying every trick. I stated at the manual and figured out how to get the whole assembly out without taking it apart, since the ball was stopping progress. With everything out just hit me to push it in
 
MikeMM
Nice tight photos. I used to get that close with film but not yet with digital.

How I got the ball out since there is no way to get at it with the reverse pin in place.
The reverse pin 111 with it's detent positions will smack the ball thru the hole if the pin is
moved quickly back and forth. Thread something into the front of the pin to do this.
The handwheel clutch 113, thought that will rotate so the ball will drop vertically towards the floor.
Use the plastic straw to hold it up against the reverse pin so it takes a hit. Flush debris as needed
and get lucky :)

The assembly 119 to 123. The pin 119 is there to hold 121 in place. 121 has a slot that limits travel.
Feed kick-out occurs when 121 does not fully engage with bushing 122-123. This is a housekeeping problem
caused by debris. Suggest holding off on removing ball 173 and spray out this assembly that is loaded into 118. Remove feed trip plunger 124
and insert a long rod in it's place. Apply upward pressure and oscillate to loosen debris while spray cleaning. Also engage the feed lever
that moves 117 into position. When the debris is clear there should be an audible click when 121 drops into place. Use the long rod
in place of 124 to disengage feed.

There are two screws that hold the quill scale in place. The length of engagement is critical for the lower hole. If the length of the screw is too long it will contact the feed trip plunger 124 and cause a feed trip-out problem.
View attachment 220590
John

Pictures are with Samsung galaxy phone. Haven't pulled out my Nikon digital in years. lol


Free at last. Pulling the pin back and forth rapidly "smacking the ball from behind" while using solvent spray can straw to apply pressure on ball while flushing solvent and slowly releasing straw pressure on ball finally did the trick. It must have rotated the ball and flushed out any leftover swarf that was still in there. Thanks for the tip John.



As it turns out, the drag on the release lever was caused by a deformation in the bushing. someone obviously didn't know how to assemble / adjust trip plunger stop. a quick touch with a stone and back to a flat surface. i quickly reassembled to test and its working fine, but letting the whole trip latch mechanism sit in naptha to really clean it out.
quill scale screws are no problem. they are original, correct length and pristine as well as threads in casting. Got lucky there too
 

Attachments

  • 20180215_125119.jpg
    20180215_125119.jpg
    93 KB · Views: 113
Last edited:
You can remove the whole assembly, then instead of pulling the ball out, you push it in, and it will roll out the backside of the shaft. 5 minutes to pull assembly out, and 30 seconds to push ball. I got a video of it if I can find it.
After fighting it for hours, trying every trick. I stated at the manual and figured out how to get the whole assembly out without taking it apart, since the ball was stopping progress. With everything out just hit me to push it in

Sam, if you can find that video, I would love to see it. I was afraid to start to disassemble it not knowing what to expect. I know its after the fact but good to know in case...
 
Congrats on the successful "extraction" Mike :)
Had to scrape the bottom of my brain to remember those details.

Dental picks are handy for popping out the seal on some bearings so they can be repacked with grease.
Used to get some from my dentist years ago.
Not this guy!
Marathon Man.jpg
John
 
Ball came FLYING out!

I was successful (eventually) in extracting that pesky lil ball yesterday by blowing air in BEHIND the ball forcing it out. I got air in there by placing a piece of tubing over the feed knob shaft #110 allowing air to be channeled in between 110 and 111. 1/2" id tubing fit the stud perfectly. I first removed the reverse feed knob itself but I don't think that is necessary. You can just make out the socket head cap screw i threaded on to the shaft for my unsuccessful efforts to 'smack' the ball out. Here's a pic:
IMG_0302.jpg
 
Now you've done it! H&W will probably have that listed now as a dis-assembly tool. Probably $39.95, but it will come with a tactical flashlight and a cheap pair of safety glasses. :D

Good job!
JR
 








 
Back
Top