Lathe Setup - Page 5
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Thread: Lathe Setup

  1. #101
    Join Date
    Dec 2018
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    1,329

    Re: Lathe Setup

    Rear bearing journal 1.9686 (50.0024mm)

    Rear bearing bore 1.9684>1.9685 (49.9973>49.9999)

    Bear in mind that my stuff isn't calibrated to any good standard. All we're looking at is measured differences. And...….the bore measurement is an indirect measurement with telescoping gage.

    But clearly there's a problem. This should be a transitional fit, not an interference fit. It's why it was so difficult to drive the spindle out of the headstock.

  2. #102
    Join Date
    Mar 2009
    Location
    MN
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    5,145

    Re: Lathe Setup

    If you're measurements are accurate (and that's a big if. I certainly don't trust my measuring abilities down to a tenth) then it looks like it's too tight.

    So, I'd try to track down some decent bearings and have them in hand before making any corrections.

    Is your old lathe still hanging around?
    My name's not Jim....

  3. #103
    Join Date
    Mar 2010
    Location
    Morton, Washington
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    4,892

    Re: Lathe Setup

    Sorry I'm late to the party. I haven't read the entire thread.

    What is the lubrication method on this machine? I would normally expect splash oiled on this size of machine. I certainly wouldn't expect greased bearings in a headstock but I don't have any imports. Was the bearing dry when you pulled it? I'm with the others on excessive pre-load and/or a lubrication issue. Did you check all the galleries? Make sure they are clear. Also make sure all the wicks are installed as per the manual diagram. I'm rebuilding a lathe right now that was missing one and the bearing was starved and trash as a result.

    I recently had an issue with an oil leak on one of the lathes at the school. Turned out the labyrinth ring was installed wrong and the bearing couldn't drain. At high rpm the bearing would then pump the oil out of the headstock faster than I could add it. Pulled it apart, turned the ring about 15 degrees and it's all good. I will tell you that the front race had to be frozen and then hydraulically pressed in. It was tight. The rear race tapped in.

  4. #104
    Join Date
    Dec 2016
    Posts
    152

    Re: Lathe Setup

    the races and rollers don't show any heat blueing or sign of seizing.the pitting/slight fretting on the outer race could be from too much preload and impacts and vibrations on shaft while stationary ,not from lack of oil.
    i still don't see anything that would prevent this shaft from spinning though,unless as mentioned before,the belts were not tight enough.

  5. #105
    Join Date
    Dec 2018
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    1,329

    Re: Lathe Setup

    I think belts sound reasonable. Checked them, and they have about 3/4" deflection. Hell...…...I dunno

    The endplay was pretty hefty. Before disassembly, it took 1/2 turn of the nut to take the play out. M 1.5 thread. That's some kind of distance at 1/2 turn. If my math's correct...…..that's somewhere in the vicinity of .029 on half a turn.

    Even the oil seal (grooved collar) had to be pried off the shaft, while tapping it with a brass hammer, it's so tight. Driving the shaft thru the bearing took a hefty hammer, and block of wood. THAT might be where the Brinelling came from.

    New bearings might just yield the same results. Their tolerances are azz backwards compared to Imperial bearings.

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    Dam things have a tolerance that deviates on THE NEGATIVE SIDE. More of that stinkin' Metric ISO crap. Holy Crap!!!!!!!! Bore tolerance possibly -10 on a P5

    Good ol' American Class 2...………… (Class 3 has same bore tolerance)

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    Deviation is on the + side. At least it goves you room for a shaft that's possibly outsized.

    Anyways, the new bearings on on their way. FAG's new old stock

  6. #106
    Join Date
    Dec 2018
    Posts
    1,329

    Re: Lathe Setup

    Quote Originally Posted by forhire View Post
    Sorry I'm late to the party. I haven't read the entire thread.

    What is the lubrication method on this machine? I would normally expect splash oiled on this size of machine. I certainly wouldn't expect greased bearings in a headstock but I don't have any imports. Was the bearing dry when you pulled it? I'm with the others on excessive pre-load and/or a lubrication issue. Did you check all the galleries? Make sure they are clear. Also make sure all the wicks are installed as per the manual diagram. I'm rebuilding a lathe right now that was missing one and the bearing was starved and trash as a result.

    I recently had an issue with an oil leak on one of the lathes at the school. Turned out the labyrinth ring was installed wrong and the bearing couldn't drain. At high rpm the bearing would then pump the oil out of the headstock faster than I could add it. Pulled it apart, turned the ring about 15 degrees and it's all good. I will tell you that the front race had to be frozen and then hydraulically pressed in. It was tight. The rear race tapped in.
    All the galleries were clear at first oil change before first startup. I ran oil thru them to verify they were feeding the bearings after I refilled the headstock.

    Rear "seal" is a slinger on the inboard side, and a grooved collar on the outboard side. Bearing cover has a pocket that drains back to the headstock thru a lower gallery. All galleries were clear on disassembly.

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    Front bearing is open, and drains directly back into the headstock
    Last edited by farmersammm; 03-03-2019 at 03:21 AM. Reason: added last sentence

  7. #107
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    Dec 2018
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    1,329

    Re: Lathe Setup

    Da chop is back open for bizness.

    Got bearings comin' in, figured I ought to pull the last spindle bearing.

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Size:  107.6 KB The cage was removed to access the outer lip on the roller race. I didn't want to use the bearing cover as the base plate to press the bearing off. It's made of cast iron, and most likely very brittle. A bearing splitter was used to grab the lip, and wood used to protect the spindle. It pressed out very smoothly, Thank God.

    This fine machine is like a surprise birthday party

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Size:  117.8 KB A little present between the bearing cover, and the bearing.

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Size:  130.2 KB Not claiming to be a master machine rebuilder, but I have a sneaking feeling that this doesn't belong where I found it. Judging by the pressed in pattern on the metal, does ELIPTICAL WEAR PATTERN come to mind If that was between the bearing shoulder, and the shaft shoulder, it had to **** the bearing a smidge I'm a-thinkin'.

  8. #108
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    Dec 2018
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    1,329

    Re: Lathe Setup

    " **** " : C O C K Gotta PC algorithm goin' on when it comes to censoring "bad" language 'Cept this ain't a bad word

  9. #109
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    Dec 2018
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    1,329

    Re: Lathe Setup

    Anyways......back to it.

    Gotta truck bearing on the front of the spindle.

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    And a Gen-U-Wine Little People knockoff/fake/questionable P5 in the back.

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    Go figger.

    Musta run out of the "good" stuff on second shift Parts list calls out P5's for both bearings.

    This brings to mind my favorite argument/conspiracy theory.

    I still think the line production bearings, given today's production equipment, are probably very high tolerance to begin with. They slap a P5 stamp on 'em, and ask ya to bend over. Just sayin'...………………………………… (remember that this thing, before it crapped out, was running .0005ish runout at the spindle). I'll eat my words if the new bearings bring the runout down by a considerable amount Of course, I'll be happy with the meal if it brings it into better numbers.

  10. #110
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    Dec 2018
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    1,329

    Re: Lathe Setup

    EDIT

    " (remember that this thing, before it crapped out, was running .0005ish runout at the spindle). ) "

    If you look back earlier, the runout was measured at the end of an 8" turned bar, not the spindle face. So I correct myself. Runout was very good at that distance from the spindle.

  11. #111
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    Dec 2018
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    1,329

    Re: Lathe Setup

    I also had some thoughts on the trash in the assembly.

    It could not have come from cutting the cage on the bearing. It's a piece of YELLOW metal. Probably Bronze.

  12. #112
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    Dec 2018
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    Re: Lathe Setup

    At this point, I'm also assessing the other bearings. The intermediate shaft in particular. Squirted some oil on it, and gave it a spin.



    I'd like to hear less noise when the shaft is spinning without a load. Prior to the teardown, there was quite a bit of noise in this area, but couldn't trace it down just by listening to it run.

    The motor bearing is also pretty doggone loud too. But it's a separate discernable sound when the lathe is running.

    Stinkin' bearings

  13. #113
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    Dec 2018
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    Re: Lathe Setup

    Cleaned the mystery piece of metal. It appeared yellow because it still had oil on it. Also removed all the grinder grit from cutting the cage on the bearing. AND IT IS ATTRACTED TO A MAGNET...….so it's steel.

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    It's on the order of around maybe 5+ thousands thick, and has obviously been under a great deal of pressure. I don't believe it ran underneath a roller bearing, but who knows Looks more like it was squeezed between castings or something

    At this juncture, I'm thinking of taking a peak inside the apron. God Only Knows what's floatin' around in there.

    I didn't buy a lathe...……..I BOUGHT A STINKIN' KIT

  14. #114
    Join Date
    Aug 2006
    Location
    St. Paul Park MN
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    864

    Re: Lathe Setup

    No you are wrong! when you buy a kit it only has to be put together not tore apart, buy new parts then assemble.

  15. #115
    Join Date
    Dec 2013
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    1,351

    Re: Lathe Setup

    Might try one of these to track down noise locations. NAPA probably has them if you don't already.
    https://www.amazon.com/HARDK-Automot...-1-spons&psc=1
    ---Meltedmetal

  16. #116
    Join Date
    Dec 2008
    Location
    Lockhart,Tx (BBQ capitol of the world)
    Posts
    965

    Re: Lathe Setup

    Quote Originally Posted by farmersammm View Post
    Cleaned the mystery piece of metal. It appeared yellow because it still had oil on it. Also removed all the grinder grit from cutting the cage on the bearing. AND IT IS ATTRACTED TO A MAGNET...….so it's steel.

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    It's on the order of around maybe 5+ thousands thick, and has obviously been under a great deal of pressure. I don't believe it ran underneath a roller bearing, but who knows Looks more like it was squeezed between castings or something

    At this juncture, I'm thinking of taking a peak inside the apron. God Only Knows what's floatin' around in there.

    I didn't buy a lathe...……..I BOUGHT A STINKIN' KIT
    Looks like swarf that has been pressed flat!

  17. #117
    Join Date
    May 2015
    Location
    Kansas
    Posts
    75

    Re: Lathe Setup

    "This fine machine is like a surprise birthday party "

    You sir, deserve sucker of the decade for buying a boat anchor.

    You say you bought it new and before you ever set it up on its pedestals that you decide that they needed re welded and run it?

    Then you have to dismantle the headstock and screw with everything
    in it having not ever turned a chip,OMG.

    Talk about putting LIPSTICK ON PIG!

    You sir in my opinion have dickeyitest OCD.

  18. #118
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    Dec 2018
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    1,329

    Re: Lathe Setup

    Quote Originally Posted by Meltedmetal View Post
    Might try one of these to track down noise locations. NAPA probably has them if you don't already.
    https://www.amazon.com/HARDK-Automot...-1-spons&psc=1
    I forgot I even had one of these Name:  erniefp.png
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  19. #119
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    Dec 2018
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    Re: Lathe Setup

    One of the new bearings came today, and it confirmed a suspicion I had.

    When removing the old bearing, and trying to see why it was so difficult to remove, I felt a ridge where the thread meets the ground journal. And, on the other side, it was a smooth transition.

    Anyways......the new bearing doesn't wanna fit either.

    So, I get out a fairly decent straightedge.

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    The GD threads are not concentric with the shaft

    This accounts for the labyrinth seal not fitting right. Has to be fought on/off. And it accounts for the difficulty removing the bearing.

    Ordered a bigger set of V blocks last week, and still waiting on them to arrive. Tracking info showed THEY WERE SENT TO HONOLULU Need the bigger blocks to be able to spin this thing with an indicator on it. Probably gonna see just where the problem is when I spin it.

    At this point, I'm anticipating having to press fit the bearing onto the shaft in order to set preload, WITHOUT WHACKING ON IT TO DRIVE IT. Also need to be able to press the shaft itself, in order to back off the preload if it goes too far. Should be fun...……..But!! If you can get it right, it's a doggone sure bet that the bearing bore will never move on the shaft, and wear it. Time to get out the welder, and make a fixture I guess

  20. #120
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    Mar 2009
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    MN
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    5,145

    Re: Lathe Setup

    Id do some light hand filing on the threads and go after the rear journal with some fine Emery long before I considered pressing for pre-load.
    My name's not Jim....

  21. #121
    Join Date
    Dec 2018
    Posts
    1,329

    Re: Lathe Setup

    Quote Originally Posted by kioti View Post
    "This fine machine is like a surprise birthday party "

    You sir, deserve sucker of the decade for buying a boat anchor.

    You say you bought it new and before you ever set it up on its pedestals that you decide that they needed re welded and run it?

    Then you have to dismantle the headstock and screw with everything
    in it having not ever turned a chip,OMG.

    Talk about putting LIPSTICK ON PIG!

    You sir in my opinion have dickeyitest OCD.
    Smile when you say that!

  22. #122
    Join Date
    Dec 2018
    Posts
    1,329

    Re: Lathe Setup

    Quote Originally Posted by Boostinjdm View Post
    Id do some light hand filing on the threads and go after the rear journal with some fine Emery long before I considered pressing for pre-load.
    What I'd figured on, was to mount an indicator on the nose. Move the bearing in to get it to 0, then back off. Measure endplay, and run it back in with the threads...…..using the threads as a micrometer to reach 0 again. Before disassembly, I was able to move the bearing inward with the adjusting nut if I used a bit of torque. The thread is approximately 17TPI, so I can segment the radius to achieve a pretty close run-in distance with the assistance of the dial indicator.

    I'm thinking it shouldn't do any damage to the bearing. You'd press against the rear cone inside race when seating the rear bearing, and when moving the shaft rearward...it's pressing on the inside race of the front bearing where it seats on the shaft shoulder. If a guy's careful, he wouldn't be applying any kind of real force to the rollers at any time other than initial seating.

    Once I clear the thread, then I'm just working against the slight interference fit on the ground portion of the shaft.

    The new bearing clears the thread fine, up till it contacts the ground journal. It's possible the thread is also angled in relation to the shaft, and tilting the bearing, preventing it from starting true to the shaft. It rocks very slightly when it contacts the beginning of the journal. I'll know for sure when I indicate it.

    Far as your comment on metal removal...………….I see no problem with removing material from the thread, as long as I know the portion of the radius to remove. You can remove quite a bit of thread in a small area without affecting the clamping force of the nut, or running the risk of the nut stripping the thread. But I don't want to just remove material blindly...….just in the canted area if need be.

  23. #123
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    Dec 2018
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    Re: Lathe Setup

    I have a feeling that this whole deal started when the dood came back from lunch (fish head soup), found the hangup I'm running into...………..and just took a mallet, and slammed the bearing onto the shaft till it stopped moving. Then poor ol' ignorant Sammy gets ahold of it on this side of the ocean, and promptly burns up the bearing in the first few hours of run time.

  24. #124
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    Dec 2018
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    Re: Lathe Setup

    And...……..if it doesn't work out...……..I'll ship it to Lars...……….COLLECT Name:  mutley.gif
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  25. #125
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    Aug 2006
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    St. Paul Park MN
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    864

    Re: Lathe Setup

    Quote Originally Posted by farmersammm View Post
    And...……..if it doesn't work out...……..I'll ship it to Lars...……….COLLECT Name:  mutley.gif
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Size:  9.3 KB
    Oh No. I have enough projects here on Cockle Burr hill. Just out along the freeway getting a dump trailer rigged up so he could make it to the shop. The trailer either has a bent spindle or axel... burned a new tire off in a few miles from tire rub.

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