'54 Square dial w/ threader gearbox issues. Any guess on downtime?
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    Default '54 Square dial w/ threader gearbox issues. Any guess on downtime?

    HI Guys,

    I've got a '54 square dial with issues with the threading gearbox. Sounds like a rock crusher when you try to thread.
    I've never actually *tried* to thread anything with it like that. 5 seconds of listening to it convinced me to shut it down and switch back over to feed. So I don't know if it's cutting accurately or not. The feed side works great, and as that's 99% of what I do, it hasn't been a huge issue. But it would be nice to be able to single point if I needed to.
    This is (or was) Oldster's machine. He passed away a few years back, and I bought out the company, so now it's my problem.
    Other than the problem with the threader, it works fine. 10-4K RPM smooth as you please.

    I learned on a round dial, so yes, I've got it all set up right, that's not the issue. (so far as I know...)

    My question is this: I don't have time to fuss with it. We do have a couple of machine mechanics local to me who I'd trust to dig into her guts. But none of them is a EE specialist, so none of them has any real guesses on how long it'd take to diagnose/fix the issue, and whether or not it'd take the whole machine down while they were digging around in the gearbox.

    So, anybody got any guesses on (A) what the problem might be, (B) whether or not it'd take the entire machine down to work on it?
    I do need the thing from time to time, and when I actually do need it, I *really* need it. Right now. So being down for weeks with no firm schedule isn't going to happen for a non-critical problem.


    Thoughts?
    Regards,
    Brian

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    The gearbox comes out like a cassette. Yes you will have to remove the drive rod, threading leadscrew, etc. and belt on the back of the headstock, and maybe some other small stuff that I can't remember. A competant ? machine mechanic should have no problem doing this. Remove the small plate at the bottom front of the gearbox and you will see some bolts, remove the curved front top of the gearbox after you remove the tombstone selector on the headstock. There will be some socket screws accessible that bolt into the headstock. The whole gearbox then slides out, then you can take it or they can pick it up without moving or removing anything else. Actually with the curved top off of the gearbox, you can look down into the box and probably diagnose without removing the box. I found on mine that over the years, coolant had made its way past the non-seals on the driving/threading leadscrews and made a witches brew of rancid goop that certainly didn't help in the smooth operation of the gearbox.

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    Remember that the difference between the threading input to the gearbox and the feed input starts above the gearbox at the gearing on the end of the headstock. I'd start isolating the problem there - take off the intermediate gear, or disengage it from the input and output and see how much noise things give you. A lot of it could be in those gears, or the threading input to the gearbox. Once you get into the pinecone things are together, then they split on the output selection. There are ways of splitting the input from the ouput using the controls, so you should be able to isolate the ends (pro tip: don't do this under power! some selections lock up the gearbox!)

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    I disassembled my 10EE down completely. For non-stop work, a day to disassemble and a day to put back together *assuming* no issues along the way, like bell mouthing a taper pin, cussing a lot, and then drilling it out to remove and now have boogered up parts. Mine is a 56 square dial.

    The gear box comes apart quickly, once you realize the trick that took me about a week to figure out. You do ruin the bearings tapping each shaft out. lots of 6204's and 1 6303. Two angular contact pairs on the feed and threading output, but those two pairs do not need to be disturbed in disassembly.

    Easier if you do not have the ELSR.

    edit: a few more thoughts:

    You can use the lathe while the gearbox is out, you just don't have power feed.

    You do have to turn a couple of aluminum bearing pushers, installers, to deal with the various shafts.

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    To the OP: There is just too little known from your description of the problem to have ANY chance at a 'guess' of the time needed for repair:
    Lets say ONE ball bearing is bad, the race holding and spacing the balls rusted and broke due to water based coolant contamination. So the ball bearing is seizing binding popping etc.. And lets say it's an easily pulled and replaced bearing?
    You might take the box out, have the bearing in stock and pull it, replace it, and return the gear box to the lathe and be back in business in 12 hours..
    Lets take the same scenario: The same bearing bad, but is seized enough that it spun on the shaft, and also spun in the gear box case.. Both are badly galled, and just replacing the bearing is not an option. So the shaft has to be either replaced, made from new, hard chromed and ground. The gear case has to be replaced, or bored and bushed.
    And this is still just one bearing causing the problem..

    So your request is really like the automobile owner taking their car to a repair shop and saying: My car is making funny noises. 'what is wrong? and how long will it take to fix it? Not questions that can be answered with the current lack of information.

    So find someone to take the cover off the gearbox, and look at it.. SEE what is causing the noise..
    Check on EBay: there are often whole threading gearboxes for sale. Having a separate gearbox on the bench to inspect and have ready to swap in, will make the return of service of your lathe a one-day affair.

    DualValve

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    Quote Originally Posted by Alberic View Post
    HI Guys,
    I learned on a round dial, so yes, I've got it all set up right, that's not the issue. (so far as I know).
    Brian, round dial and square dial lathe gearboxes are different in design. It is possible to have timing problems on a square dial that don’t exist in a round dial, due to incorrect arrangement of the knobs. So before you go a lot further, make sure all three knobs are correctly set and the upper lever is Fully engaged. I don’t have a running square dial machine right now or i would provide more info.

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    Quote Originally Posted by rimcanyon View Post
    Brian, round dial and square dial lathe gearboxes are different in design. It is possible to have timing problems on a square dial that don’t exist in a round dial, due to incorrect arrangement of the knobs. So before you go a lot further, make sure all three knobs are correctly set and the upper lever is Fully engaged. I don’t have a running square dial machine right now or i would provide more info.
    Salinas? I'm in Santa Cruz, and live in Watsonville. We should get together sometime.
    Good point about the differences between the round and square machines. I'll re-read the manual and make sure, but I did read it the first time, so as far as I know, I got them all in the right spot.

    I was playing around with the selector yesterday, and shifting the feed rate around was very stiff, and took some jiggering. (Normally, I just leave it set hard left, and fuss around with the ABCD dial to change the feed if I need to. (Rarely)
    Since it works so well for everything *except* threading, I rarely mess with that end of it. Or need to.

    Yeah, I know the 'makes noise' description wasn't tremendously useful, but it's the best I've got until I start pulling things apart in time I don't have. After fussing with the selector, I begin to suspect it may be in the pinecone somewhere.
    The suggestion about buying a pullout gearbox is well taken. I'll start hunting one. I've already got a full, brand new, just re-wound MG set, hiding out under a table as hot spares, just in case. (Oldster was a big believer in having hot spares, and I've thanked his ghost for that, more than once, as they've saved our tails many more times than once.) A tradition I follow.

    I'll lay in some 6204s and a 6203, just on general principles. It doesn't *sound* like bearing rattle, it's definitely gear teeth sounding unhappy, but having the bearings on hand is cheap insurance against the great Murphy in the sky.

    Thanks for the help guys,
    Brian

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    Hi Brian, sorry if the 'tone' of my 'not enough information' post was a bit 'snarky' or whatever. I did re-write it a few times to try to get the point across without being too much of a jerk.

    I have both a round dial and a square dial. and I have to whole-heartedly agree with RimCanyon.
    On my Square dial, I have to hand rotate the spindle slowly and carefully select the right gears, and then make sure the other selectors are 'in' the right spot. I once bumped a selector with my hip walking past the lathe, when it was running, with the threading screw turning, and I thought I had destroyed the gearbox.. it sounded like I had dumped a handful of 1/4" ball bearings into the turning gears !!

    So slowly move the selectors, if they have not been moved much over the last decade or two, the spring-loaded detent-check balls might be stuck in their bores and are not holding the selectors in the correct locations.

    Watsonville? I knew and know several antique car collectors there. I don't get to the west coast as much as I used to, so it's been a few years.

    DualValve

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    I'll second dual valve's post about rotating the spindle when you set the knobs. I've been fooled more than once when I think a knob has been turned fully home, but in reality it has another ⅛" to go. In addition to turning the spindle, sometimes I hand rotate the feed rod or the lead screw until that knob clicks into place.

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    DualValve: don't worry about it. I'm not any kind of bent. It *was* a pretty vague description. I'm sorry if my reply sounded like I was. Wasn't intentional.
    I'll go futz with the selectors again tomorrow, and hand-spin the spindle to make sure everything seats properly. If I'm *very* lucky, that may be it....

    Thanks,
    Brian

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    Just to check and compare 'noise' from threading gearboxes, I fired up my ' 11/1941' round dial, [ex-Eastman Kodak] and ran the lead screw at several different threading pitches. It runs pretty quiet, there is some obvious 'gear-meshing-sounds' but not alarming.

    Then I fired up my oh-so-worn '4/1942' parts-10ee. I ran the threading gearbox in it.. wow.. no: WOW! That tired lathe has done a lot of threading in it's past, or maybe never had the lubrication topped up.
    It really sounds nasty, and has a lot of gear-lash [free-play] between leading and trailing drag on the lead screw. So it definitely has some issues.. and I did follow my own advice and made sure the selectors actually were in proper notches and the box was not trying to come out of one meshing gear-set and into another ratio while turning..

    I wish I had a good square dial gearbox here, I'd ship it to you to have as a 'user' while you tore into your own for repairs.. But this is a round dial and I'd not waste the time to even remove it from the lathe, unless there was some obscure part in it I needed..

    Hopefully you will find a 'sweet-spot' with the levers/selectors that quiets it down...

    Thinking on a gear box making noise: it either has to have bad bearings that are not keeping the gear teeth in proper mesh, or there might, maybe, be a broken tooth on a gear set, [pretty difficult in my thinking] or a selector that slides out of correct location and tries to engage/dis-engage under load or rotation. Not really much else to make noise? or am I forgetting something?

    I've been surprised several times by having noises in an automotive transmission turn out to be caused by the oddest/weird problem that I really had to scratch my head over. But that type of transmission usually has synchronizers and a lot of wear in shifting rails and shift lever-selectors. Out lathe threading gearboxes are not abused by people who don't know how to shift, or double-clutch, or even 'THINK' what they are doing when pushing in a clutch pedal and moving a gear-shift lever. It's amazing what abuse a car's transmission can be subjected to.

    And I did not think your response to my 'not enough info' comment in any way read like I had been a bit too harsh. Actually it was a great response to a potentially abrasive comment I had written.. Writing on an internet board/forum a person has to be very careful, it is so easy to NOT get the correct message as intended into words.. Glad my comment was well taken..

    I just thought of one 'noisy' car transmission that I would have bet a payroll check was caused by a bad bearing in the countershaft gear. But it turned out to be a 'clump' of congealed gear-oil that was much more like road-tar than anything poured or pumped into a transmission case.. The hard lump was in the bottom valley of two adjacent gear teeth, and it was so hard that it was about as hard as the gear teeth. So with every rotation of the countershaft, these teeth would put a significant side load on the two gear-trains in the trans.. Turning the input shaft by hand it was a noticeable 'bind'... I thought for sure it was a bad roller bearing inside the countershaft gear. I slid the shaft out, and removed all the roller bearings and they were all perfect as was the inside of the gear. It was only afterwards I looked for a bent or broken tooth on any of the gears, and finding none, looked closer and found the hard as steel 'gunk' in the bottom of two adjacent teeth.. I broke two dental-pics digging the gunk out.. eventually found a needle file that was the right shape/profile and cleaned the petrified gunk out..

    Sorry for the long 'story' but my point [I'm finally getting to it] is that your noise could be some swarf/chips/old lube that have migrated to and have taken up homesteading in a gear tooth or two, resulting in some serious binding of the gears as they rotate..

    Take care, hope you find something 'easy' to remedy.

    DualValve.

    Watsonville: I think the home of Jack Passey: a prominent teens-through-thirties' Classic car collector and dealer. He died several years back. I purchased quite a lot of spare parts from the estate.

    DualValve

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    Another possibility is that the controls are out of time with the gears. Someone cowboy'd my 10EE and the timing was off on the A-B and C-D-E levers. I reset it by working the controls to find the center and reinserted the controls there so I would have the right throw to either side. I still have a little noise on the A-B that's taken care of by a little control movement - I should get in there and see why.

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    HI guys,

    New data.
    I futzed with the selectors a bit, and still got the same noise. The shop was running full out with the big CNC's rolling along, so I couldn't really hear crap, but from what I could tell, it sounded like the noise was coming from sort-of behind the back gear selector. (It's not the back gear selector: it's dead silent in backgear+feed. It only grumbles in thread mode.) And now that I really listen to it, it could be a shaft rattling around in a blown bearing. It's not the whine or rattle of a dead high speed bearing, but none of those are actually running that fast.
    One oddball data point: I set for 16TPI, running in back gears down around 100 RPM. It ran, grumbling, but it ran. So I moved to the apron to test the half nuts. No joy. Then I looked at the lead screw and it'd stopped. As soon as I moved the selector to a different speed, it kicked back in, still grumbling. And it ran just fine when I switched back to 16TPI to check. No idea what happened, but it looks like something somewhere slipped out of engagement.
    So...
    Looks like I spend a Sunday with a wrench in hand pulling the thing as far apart as I can, to see if there's anything obviously blown in there, and proceed from that point.

    Another question: I remember (dimly) from my days with the round dial, many moons ago, that there was some sort of interlock on the apron so the half nut lever wouldn't engage unless everything else on the apron was set properly for threading. My half nut lever wouldn't throw, and I couldn't find anything obvious on the apron to be that looked to be the interlock. Any other square dial folks know what's going on?
    (Both of my feed levers were in neutral, and I tried it with the reverse knob both in and out. No joy.)

    Thanks,
    Brian

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    More data:
    Now I'm really in the soup.
    I went back to it after the shop shut down for the day, and I could actually hear.
    Put it into thread mode, and got it spinning. Suspiciously quietly.
    Why? Because the leadscrew wasn't turning at all. In any pinecone setting.
    So I flipped everything back to feed, and then tried to re-set for threading. Now the tombstone won't rotate into either thread setting, no matter how you jiggle the spindle.
    The feed still works just fine, so I quit while I was ahead, but yeah, something in there was clearly on its last legs.
    There wasn't any bang or crunch to indicate a catastrophic failure, it just....quit.

    I sense wrenches, allen keys, and swearing in my future....

    Regards,
    Brian

    PS--> Anybody got any clue what the apron's twigging on to engage the 'no half nuts' interlock? It *should* have been able to engage, from all that I know. And yet..

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    Maybe like the round dial poster from NC, your shift fork in the headstock is broken or simply had the bolts vibrate loose and separated. That would explain the threading gears not engaging. It is pretty simple in there. If the shift fork is not shifting the reasons are few.

    I realized I should clarify my earlier post. Having taken everything apart and put back together. *I* could remove, disassemble and reinstall the gearbox in one day each. The first time one does it, as DV stated, the newness of the procedure combined with problems along the way, could stretch the job out longer. However, as I mentioned, the lathe is useable without the gearbox so the extra time could be absorbed. If you do decide to disassemble the entire gearbox email me your phone number and I'll tell you the tricks you need.

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    Hi Brian, you have to have the push-pull fwd/reverse knob in the middle or neutral position. There is a mechanical interlock to prevent the half nuts from engaging the screw with the potential of the feed rod being engaged.

    I think you need to giggle, wiggle, and curse at the treading box controls some, I think there is a specific order to engage everything.. I rarely thread so I can't remember just what. But I too have found the 'tombstone' knob unable to move, until I moved some other knobs or levers..
    And I seem to remember that the knob will only engage in ONE spot in the engaging gear, so put light pressure on the knob and slowly turn the spindle a full 360*, you will find the spot it will engage in..
    I took the top cover off the headstock and looked inside, it is easy to see the shift-fork and see the notch the 'dog' was to slide into. It then might still take a curse or two. :-)

    DualValve

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    To go from feed to thread move the right shift lever to thread, the tombstone knob to LH or RH, then the left hand lever to thread. It's helpful to pull the spindle over lightly when chifting a lever or knob to find the right spot in the gearbox, and to have the backgear out so that things are easy to move. There's an interlock between the right hand lever and the tombstone - the RH lever must be in thread for the tombstone to be in either thread.

    To move to feed reverse the order.

    To the OP: you can remove the 1/4 round panel and get a top view of a lot of the gearing. IIRC you remove the tombstone knob/housing (I think the shaft can stay) then the A-B knob (and shaft?) and the screws holding the 1/4 round and it (maybe) pulls off? I'm a floor and a couple hundred feed from my lathe and can't verify things.

    To me it sounds like the A-B knob isn't sliding the gears it's supposed to anymore.

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    HI guys,

    New day, new data.
    A) thanks for reminding me that the reverse knob on the apron has to be in neutral too. The detent ball isn't real energetic, so I'd just blown through the 'middle' setting on my way to the ends. Once I got it in the middle, the half nut lever throws just fine. Solved.

    B) You're right, there is only one spot on the spindle where the tombstone knob will engage. A bit of hand rotation later, I got her back into thread mode, grumbling along just like yesterday. Which led to..... New data!

    C) So I got the lead screw rolling. With the half nuts active, finally. The instant I threw the half nuts, the lead screw stopped dead.
    Put any load on it at all, and it stops. No crunching or grinding, it just stops, and then you have to switch all the way back to feed and back into thread to get it rolling again. And it'll stop as soon as it's under load. So that's clearly an indicator.
    The CDE knob feels....less positive than I think it should, so I'm thinking that may be part of it.
    Clearly, an expedition into the wilds of the gearbox is called for. The drawback is that this particular machine has a DRO mount that holds a flat plate right over the top of the headstock. Which is normally really handy, as a place to put calipers, prints, and other misc. crap. But it does make getting into the headstock more of a project than I'd like it to be just now.

    So, anybody got a clue on what'd have to fail for the lead screw to just stop dead at the first sign of a load?

    Regards,
    Brian

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    A sheared taper pin on the lead screw.

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    Further data:

    So I got to wondering: With the machine set to 'feed' I can hand spin the lead screw with no real drag on it at all. It just spins freely.
    In 'thread', it doesn't move at all. By hand.
    I put it back in thread, and ran it a bit. It stopped dead every time I closed the half nuts, but did keep rolling with a slightly lesser load on it. So it's not running on a totally sheared pin, and just spinning by friction with the drive gear. It's got a bit more connection than that.

    I'm coming to the belief that some bozo crashed her hard while cutting a thread, and pretty much blew up the threading side of the gearbox. Or at least sheared the pins. (ah, mechanical fuses. How do I love thee...)
    Which moves it firmly onto the 'fuss with it *much* later' list. I've been meaning to take the thing down for a serious rebuild at some point in the next few years. It's looking like that may be the time to deal with it. Or, if I can find a pullout gearbox somewhere...

    Thanks for all the help.
    Brian


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