Calibrating 9" Model A With Tailstock Alignment Bar - Page 4
Close
Login to Your Account
Page 4 of 7 FirstFirst ... 23456 ... LastLast
Results 61 to 80 of 127
  1. #61
    Join Date
    Nov 2007
    Country
    UNITED STATES
    State/Province
    Texas
    Posts
    286
    Post Thanks / Like
    Likes (Given)
    76
    Likes (Received)
    55

    Cool Progress Report Part Deaux

    Quote Originally Posted by jim rozen View Post
    How's your new level - have you got the machine dialed in yet?
    Thank you for asking Jim! Actually, I was getting ready to send a PM instead of posting again on this thread,
    but since you asked...

    I want to first level the entire bed on both axis (planar) before attempting or even thinking about any test bar measurements.
    First thing I had to do was make some alum plates to put between the lathe feet and the wooden pillars that
    the lathe was initially sitting on. Inserting spacers between the foot and soft wood would have been useless
    for obvious reasons. I had some quarter inch stock plate, but my band saw blades were toast. Had to wait a couple days
    for delivery. Anyway, those are cut and ready for installation.

    As you can see in the photos, it's going to be a bit cramped getting to the left foot under the QCGB. I am honestly
    thinking of just taking it off altogether, and even unbolting the HS and moving it forward by about 6 inches just to
    have a clear work space. I expect that once I do the HS level, then the TS, that I'll have to go back and tweak the HS
    again. Will prob have to go back and forth several times until everything is perfect. (Not only do I have the TS twist
    to straighten out, but also the left to right level [slope]).

    I bought a box of body panel shims, but those are really just a rough start. (Prob a waste of money actually)
    Rather, I will use feeler gauges front and back (of each foot) to arrive at a precise level (I have several sets).
    When I get to precise numbers for all four points, I'll make appropriate
    shims from stainless or brass shim stock...kinda depends on how far off everything is.

    There is also the part of me that just wants to take EVERYTHING off and level the bed as if from the very start as I should have done.

    As you probably know, assembling the components of a 9" is really a snap....and I've got time on my hands.
    But I'm wondering if the weight of the HS, TS, QCGB and carriage is going to significantly change the overall level
    of the bed? I don't want to have to visit this again if I can help it.

    The precision level arrived and it looks to be in perfect calibration (the printed instructions are awful).
    I've been using a scissor jack to lift the ends.
    (As you can see in the photo, I have not yet inserted the plate under the headstock foot).

    Advice/opinions would be great; thanks.

    PMc

    precision-level.jpg alum-plate.jpg alum-plate-ts.jpg space-under-hs.jpg

  2. Likes texasgunsmith liked this post
  3. #62
    Join Date
    Feb 2015
    Country
    UNITED STATES
    State/Province
    Florida
    Posts
    713
    Post Thanks / Like
    Likes (Given)
    0
    Likes (Received)
    193

    Default

    Quote Originally Posted by mcload View Post
    I want to first level the entire bed on both axis (planar) before attempting or even thinking about any test bar measurements.
    First thing I had to do was make some alum plates to put between the lathe feet and the wooden pillars that the lathe was initially sitting on. Inserting spacers between the foot and soft wood would have been useless for obvious reasons. I had some quarter inch stock plate, but my band saw blades were toast. Had to wait a couple days for delivery. Anyway, those are cut and ready for installation.
    You didn't have to do the Al plate thing, but it might just make it a little more stable. SB 9" lathes were leveled with shims under the appropriate foot edge between the cast iron and the wood.


    Quote Originally Posted by mcload View Post
    As you can see in the photos, it's going to be a bit cramped getting to the left foot under the QCGB. I am honestly thinking of just taking it off altogether, and even unbolting the HS and moving it forward by about 6 inches just to have a clear work space. I expect that once I do the HS level, then the TS, that I'll have to go back and tweak the HS again. Will prob have to go back and forth several times until everything is perfect. (Not only do I have the TS twist to straighten out, but also the left to right level [slope]).
    The HS doesn't slide. It has an indexing pin that it fits in, so you won't be moving the HS forward.

    How much twist and slope do you have? Make doubly sure that your level isn't sitting on a burr on the pyramids - stone the burrs flat if you have to.


    Quote Originally Posted by mcload View Post
    I bought a box of body panel shims, but those are really just a rough start. (Prob a waste of money actually).
    Unless they are in the range of 0.001" to 0.010", they are too coarse.

    Quote Originally Posted by mcload View Post
    IAs you probably know, assembling the components of a 9" is really a snap....and I've got time on my hands. But I'm wondering if the weight of the HS, TS, QCGB and carriage is going to significantly change the overall level of the bed? I don't want to have to visit this again if I can help it.
    This is one of the drawbacks of having a wood stand - wood moves. Once properly leveled, the HS, TS and QCGB will no longer change the level of the bed. However, the carriage will, as it moves along the bed (not significantly, but detectable).

    Because your stand is wood, expect to check level 3 or more times a year.

  4. #63
    Join Date
    Nov 2007
    Country
    UNITED STATES
    State/Province
    Texas
    Posts
    286
    Post Thanks / Like
    Likes (Given)
    76
    Likes (Received)
    55

    Default

    Jim, many thanks for the comprehensive response and suggestions.

    I agree with the wood bench issues, but its what I've got. Having air conditioning in my shop helps, but yeah, wood will move ever so slightly. I'd be okay with tweaking a few times a year. I may have to rethink the wood bench for the Model-B 9" waiting in the wings.

    Unless you built a metal bench like a tank, it's going to flex as well if it's ever moved. Pinning it to a concrete floor is about the only way to insure rigidity. But for me, wood is easy to work with and materials readily available. Getting some thick angled rectangular tubing, cutting, and welding is just something I'm not set up to do very easily...most of all welding. I'll have to consider finding a good metal stand like those made by SB for 10K lathes. Problem is, the cost of the stand will have to be included with the lathe when I sell it.

    In regards to the indexing pins in the headstock...there are no pins either on the '46 nor the '59 9" lathes I have. I would remember something like that. Perhaps they are on heavier/larger models. Might be nice to have, but then again, just one more thing to get bunged up that needs replacing. I've included some photos below of the lathe bed and bottom of the HS on my '59 model below....still dirty as I've done nothing with them yet. So yes, I could possibly move the HS forward just a bit...but frankly, after removing the QCGB and side gears, there's really not much more left to take off.

    Unfortunately (or maybe fortunately), the precision level is not digital, and therefore, cannot be zeroed. This means that I'll be leveling to mother Earth despite the level of my floor and/or bench. But no big deal one way or the other. As of this writing, I haven't played around with the level yet, so I don't yet know how sensitive it is in showing a .001 change (or even if I can see that on the bubble). Nor do I know how far out of level I am on each end. I assume that in theory, feeler gauges under the level will closely approximate what will be needed under each foot.

    Hopefully I'll get to that today, unless I get lazy or diverted. Yes, I'll make sure I'm not sitting on a burr on the ways; thanks for reminder.

    Best Regards,

    PMc

    img_0955.jpg img_0956.jpg

  5. #64
    Join Date
    Feb 2004
    Location
    peekskill, NY
    Posts
    25,312
    Post Thanks / Like
    Likes (Given)
    0
    Likes (Received)
    5159

    Default

    Quote Originally Posted by SLK001 View Post
    Make doubly sure that your level isn't sitting on a burr on the pyramids....
    I would point out for the sake of accuracy, the level is not sitting on anything important. The carriage does not ride
    on the peaks of the triangular ways. It would be better if it were sitting on the worn, sides of the ways. The issue
    of having a solid bench that does not move over time, is extremely important.

  6. #65
    Join Date
    Nov 2007
    Country
    UNITED STATES
    State/Province
    Texas
    Posts
    286
    Post Thanks / Like
    Likes (Given)
    76
    Likes (Received)
    55

    Default

    Quote Originally Posted by jim rozen View Post
    I would point out for the sake of accuracy, the level is not sitting on anything important. The carriage does not ride on the peaks of the triangular ways. It would be better if it were sitting on the worn, sides of the ways.
    Well I'm not quite sure how to accomplish that. If you want me to level the worn part of the ways, then I should remove the compound rest and set the level on the machined flat (where it normally sits), with the carriage at both ends of the bed. Correct?
    Or should i just leave the carriage where the ways are most likely worn the worst?

    PMc

  7. #66
    Join Date
    Feb 2004
    Location
    peekskill, NY
    Posts
    25,312
    Post Thanks / Like
    Likes (Given)
    0
    Likes (Received)
    5159

    Default

    Quote Originally Posted by mcload View Post
    ... level the worn part of the ways, ...
    PMc
    Just saying. Take the wipers off and see the square groove cut in the underside of the saddle, so it does not
    bear on the tops of the V-ways. They don't do anything, except make a nice-looking place to rest a level.
    You can adjust the machine so the level reads something that way. But it has nothing to do with how the
    carriage behaves.

    Maybe at one time they did, look at your photo of the ways, where the headstock was resting. Notice there's no
    wear, all the scraping is there. Now compare with the previous photo where the carriage actually rides, no scraping
    left there. Metal has gone away over the years, normal to see this.

    Imagine making a thing called a sled, that rides on the Vs the same way the carriage does, and putting the level on top
    of that. Then when you slide it back and forth from one end of the bed to the other, the bubble will move back and
    forth, inside the vial, as the sled moves from a very worn area (near the headstock) to a less worn area, near the right
    side of the bed.

    Imagine you did those things, and that is the result you see. What do you do next?

  8. #67
    Join Date
    Nov 2007
    Country
    UNITED STATES
    State/Province
    Texas
    Posts
    286
    Post Thanks / Like
    Likes (Given)
    76
    Likes (Received)
    55

    Cool Still On The Bus!

    Okay, I see what you are proposing, aka a sled that bears only on the used position of V ways.
    Yes, I understand that the very top of the V's are free from wear.
    And I understand that the wear is brought about by the carriage that rides on these ways.
    So in real terms, I already have a sled that bears on the V ways and not on the top.

    So even if I could, why would I manufacture a special sled for the precision level?
    You DO understand that this is a 70+ year old hobby lathe, right? Quite frankly, and
    with all due respect, I am lucky just to be able to lay a precision level across the V ways
    in the first place. I seriously doubt this lathe has ever been leveled to such a great degree.

    I got on this bus and I'm riding it as far as I can and as far as practical. Most of all, I'm
    learning a lot. So yeah, she's worn and I will just have to live with it. In "old" days, the
    owners would simply buy a new bed and not go to the expense of machining an old bed flat again.
    They were never meant to last forever. (Reminds me of some of these old cars like a 34 Ford that are
    restored to new condition, with owners paying well over 75 thousand for the work).

    When you ask "what do you do next", I'm not sure what you are asking. (Is this a quiz?! :-)
    The only answer would be to scrape the whole damn thing flat. I would like to think these little machines
    could command the kind of money to make perfect, but they don't, and I'm not really interested in that kind of labor-intensive commitment.

    I don't think I've got that many years left in me anyway!:-) We can continue to split hairs and chase theoretical physics and
    trigonometry is it relates to the wear of a 70 year old vintage machine, but I just can't go there with you.
    But I DO appreciate your interest and advice, and I hope you won't quit. Indeed, this IS an outstanding thread
    and I appreciate the input from everyone who has posted. I hope I haven't been a PITA!

    I will continue to level the bench and the machine the best I can...I don't mind the tweaking every now and then.
    But in the end, I'm really very proud to go out to my garage and see such a fine-looking little SB lathe...a true
    family survivor. And with patience and sharp tools, she will do as fine a precision cut as anyone else's
    (within reason).

    Will be back in touch when I have an update.

    PMc

    img_0883.jpg

    I've been looking at this beauty too; gives me inspiration!
    And I like that stand!

    lathe.jpg

  9. #68
    Join Date
    Feb 2015
    Country
    UNITED STATES
    State/Province
    Florida
    Posts
    713
    Post Thanks / Like
    Likes (Given)
    0
    Likes (Received)
    193

    Default

    The tops of the ways are precision surfaces. THAT is what you are leveling and WHERE you put your level. It's true that because of wear, the carriage will go in and out of being level as it travels. However, there is NO WAY to compensate for that uneven wear, EXCEPT to know your machine and make the needed compensations on the fly. Unless you are planning on machining a production run of precision shafts that need ±0.0005 tolerances along the entire length, don't worry about the leveling of your lathe. In fact, most hobby lathes are never leveled at all - and they still do good work!

    I am seeing what maybe can be called an obsession with leveling your lathe. Get it as close as you can, then forget about it! People have put their lathes on wheels, which means that their lathes are NEVER level and they make acceptable parts for their projects and still enjoy their lathes to the fullest.

    So:

    1) Get as much twist out of your bed as you can with your shims,
    2) Set your tailstock on the headstock centerline using the test bar method,
    3) Start enjoying your lathe.

  10. #69
    Join Date
    Feb 2004
    Location
    peekskill, NY
    Posts
    25,312
    Post Thanks / Like
    Likes (Given)
    0
    Likes (Received)
    5159

    Default

    [QUOTE=SLK001;3560705]The tops of the ways are precision surfaces.

    Nope. Take off the way wipers and *look* with your own eyes. The carriage does not touch those surfaces.

  11. #70
    Join Date
    Feb 2016
    Country
    UNITED STATES
    State/Province
    Texas
    Posts
    863
    Post Thanks / Like
    Likes (Given)
    436
    Likes (Received)
    272

    Default

    Quote Originally Posted by jim rozen View Post

    Nope. Take off the way wipers and *look* with your own eyes. The carriage does not touch those surfaces.
    The saddle not touching them is his point. That the top edge, being unworn, would be as close to what bed should have been new. Where what the carriage does touch is probably worn. That leveling will straighten a twist, but not circumvent wear.

    But I figure you gathered that already when you mentioned running the carriage back and forth, a few posts ago and posed a question to Mcload on what he'd do next.

    I think there's a few options: Do nothing, live with it, adjust operating habits. Scrape bed. Shim chuck side of head stock to get spindle closer to parallel with wear.

    I can't imagine bending bed at head stock to pull bed wear more true to spindle, but I guess anything is possible.

  12. #71
    Join Date
    Feb 2015
    Country
    UNITED STATES
    State/Province
    Florida
    Posts
    713
    Post Thanks / Like
    Likes (Given)
    0
    Likes (Received)
    193

    Default

    Quote Originally Posted by jim rozen View Post
    Nope. Take off the way wipers and *look* with your own eyes. The carriage does not touch those surfaces.
    Sorry, but the tops of the ways are precision surfaces. Just because they don't get worn down doesn't mean that they aren't precision. If you referenced the actual wearing parts of the ways, there is no way you could ever pretzel the lathe bed level after significant wear had occurred.

    Here's a pic of a South Bend technician setting the level of a lathe using the tops of the ways:


  13. #72
    Join Date
    Feb 2004
    Location
    peekskill, NY
    Posts
    25,312
    Post Thanks / Like
    Likes (Given)
    0
    Likes (Received)
    5159

    Default

    Quote Originally Posted by SLK001 View Post
    Sorry, but the tops of the ways are precision surfaces. Just because they don't get worn down doesn't mean that they aren't precision. If you referenced the actual wearing parts of the ways, there is no way you could ever pretzel the lathe bed level after significant wear had occurred.
    Ah, correct. They *used* be surfaces that were originally closely related to the actual precision surface, the prismatic ways. Now they are basically junk in this regard.
    No improvement in a used machine can happen by referencing to a bogus feature like this.

    Pretzel. Interesting word. Does the bed adjustment screw on larger SB lathes pretzel anything? Is the bed of a 9" model A made of nobendium?

    Imagine the following thought experiment. A ten inch long piece of aluminum stock is chucked in the headstock. A dead sharp tool is used to turn a few
    thousanths off the OD along the entire length of the stock. A micrometer then measures the machined surface in several places along the length of the
    stock. The numbers are not the same.

    Imagine several cases for the mclods machine, the numbers agree by:

    a) 0.0001 inch

    b) 0.001 inch

    c) 0.003 inch

    d) 0.005 inch

    e) 0.010 inch

    He is presented with each case. In which case does he say "This worn lathe works well enough to do the class of work I need it to do.'

    Now for the record, we do not even know *which* one of the cases is present here.
    But even for (c) or (d) above, the amount of bed adjustment needed is pretty mild. He cannot determine which case he
    has with a bubble level. But he can determine it, by simply cutting a piece of stock.

  14. #73
    Join Date
    Nov 2007
    Country
    UNITED STATES
    State/Province
    Texas
    Posts
    286
    Post Thanks / Like
    Likes (Given)
    76
    Likes (Received)
    55

    Default

    Quote Originally Posted by SLK001 View Post
    The tops of the ways are precision surfaces. THAT is what you are leveling and WHERE you put your level. It's true that because of wear, the carriage will go in and out of being level as it travels. However, there is NO WAY to compensate for that uneven wear, EXCEPT to know your machine and make the needed compensations on the fly. Unless you are planning on machining a production run of precision shafts that need ±0.0005 tolerances along the entire length, don't worry about the leveling of your lathe. In fact, most hobby lathes are never leveled at all - and they still do good work!

    I am seeing what maybe can be called an obsession with leveling your lathe. Get it as close as you can, then forget about it! People have put their lathes on wheels, which means that their lathes are NEVER level and they make acceptable parts for their projects and still enjoy their lathes to the fullest.
    So:
    1) Get as much twist out of your bed as you can with your shims,
    2) Set your tailstock on the headstock centerline using the test bar method,
    3) Start enjoying your lathe.
    I tend to agree that the best bed alignment (for me, anyway) is going to be by using the unworn top ridges of
    the V ways as recommended by factory. To try to calibrate for the worn portions seems to be an exercise in futility
    since there will be a slight downward slope where the wear begins and an upward slope where it ends, meaning a non-linear
    situation that will always be changing depending on where the carriage is being used. So you either try to eliminate the wear
    best you can, or align via factory methods. If you are outside of the worn portion, then you are out of alignment.
    Damed if you do, damned if you don't.

    I think I will pretty much follow SLK's 3-step process; seems like a doable target to shoot for.

    But I have to say that I'm having a blast with that precision level....I've never used one before, and I'm very
    impressed with its sensitivity!

    And it's true about wheels...almost every piece of machinery in my shop/garage is on wheels with exception to the lathe and tall drill press. There are occasions when I need to slide one end of the lathe out for cleaning or whatnot, but I have small brackets painted on the floor for re-alignment. It's the price you pay for having a small work space. I'm not sure where I'm
    going to fit the other 9" either.

    Thanks for the input! The best I can do is the best I can do.

    PMc

  15. #74
    Join Date
    Feb 2016
    Country
    UNITED STATES
    State/Province
    Texas
    Posts
    863
    Post Thanks / Like
    Likes (Given)
    436
    Likes (Received)
    272

    Default

    Anybody got pics,or links of pics that show the bed twisting screws ? Its my understanding they're at TS end, if equipped, but in the reading I've done, ive not seen them.

  16. #75
    Join Date
    Feb 2011
    Country
    UNITED STATES
    State/Province
    Texas
    Posts
    2,480
    Post Thanks / Like
    Likes (Given)
    1971
    Likes (Received)
    1098

    Default

    Quote Originally Posted by texasgunsmith View Post
    Anybody got pics,or links of pics that show the bed twisting screws ? Its my understanding they're at TS end, if equipped, but in the reading I've done, ive not seen them.
    20181108_174351.jpg The adjusting screw is in the middle of the round red tag on the face of the foot.

  17. Likes texasgunsmith liked this post
  18. #76
    Join Date
    Feb 2015
    Country
    UNITED STATES
    State/Province
    Florida
    Posts
    713
    Post Thanks / Like
    Likes (Given)
    0
    Likes (Received)
    193

    Default

    Quote Originally Posted by jim rozen View Post
    Pretzel. Interesting word. Does the bed adjustment screw on larger SB lathes pretzel anything? Is the bed of a 9" model A made of nobendium?
    No, the bed of a 9" isn't made of nobendium (although a little is thrown into the melt, just to make things interesting).

    By "pretzel", I mean that the bed would require a non-linear adjustment with only a linear adjuster in order to correct for bed wear.

    Let's look at what really is happening.

    1) At the HS, the prismatic ways have virtually zero wear.
    2) At 4" from the HS, the faces of the ways have 0.001" of wear.
    3) At 8" from the HS, the faces of the ways have 0.005" of wear.
    4) At 12" from the HS, the faces of the ways have 0.008" of wear.
    5) At 16" from the HS, the faces of the ways have 0.001" of wear.
    6) At 20" from the HS, the faces of the ways have virtually zero wear.

    Now the lathe only has one adjustment "knob" to apply in order to level the lathe, or remove any twist. Any one of the above conditions can be chosen to "correct" for, but ALL of them are incorrect starting points for leveling - period. This is because he effects from the wear on the diameter of the work is trivial compared to the effects of bed twisting. For example, the effects of a bed way face wear of 0.010" on a 0.500" diameter bar is less than 0.0004" (0.5004" actual vs 0.5000" desired). On a 1" diameter bar, the effect is even more trivial (1.00005" actual vs 1.00000" desired). THAT is why leveling from the TOPS of the ways is so important.

    So, set level from the TOPS of the ways and don't worry about the wear, because the wear is trivial to achieving the desired precision.

  19. #77
    Join Date
    Feb 2015
    Country
    UNITED STATES
    State/Province
    Florida
    Posts
    713
    Post Thanks / Like
    Likes (Given)
    0
    Likes (Received)
    193

    Default

    Quote Originally Posted by M.B. Naegle View Post
    20181108_174351.jpg The adjusting screw is in the middle of the round red tag on the face of the foot.
    Also, I don't believe that the 9" lathe has them.

  20. #78
    Join Date
    Feb 2011
    Country
    UNITED STATES
    State/Province
    Texas
    Posts
    2,480
    Post Thanks / Like
    Likes (Given)
    1971
    Likes (Received)
    1098

    Default

    Quote Originally Posted by SLK001 View Post
    Also, I don't believe that the 9" lathe has them.
    The OP's and mine don't (The picture is of our heavy 10), but the principal's the same in that you slightly twist the bed into plain. On the 9" you would just shim up the right foot under the front or back hole.

  21. #79
    Join Date
    Nov 2007
    Country
    UNITED STATES
    State/Province
    Texas
    Posts
    286
    Post Thanks / Like
    Likes (Given)
    76
    Likes (Received)
    55

    Default

    Quote Originally Posted by jim rozen View Post
    Now for the record, we do not even know *which* one of the cases is present here.
    But even for (c) or (d) above, the amount of bed adjustment needed is pretty mild. He cannot determine which case he
    has with a bubble level. But he can determine it, by simply cutting a piece of stock.
    That will be among the first things I will do after I get it lined up the best I can.

    Thanks.

    PMc

  22. #80
    Join Date
    Feb 2004
    Location
    peekskill, NY
    Posts
    25,312
    Post Thanks / Like
    Likes (Given)
    0
    Likes (Received)
    5159

    Default

    Quote Originally Posted by SLK001 View Post
    Also, I don't believe that the 9" lathe has them.
    Nope, they don't. As mentioned, one slips a few shims under the front, or rear mounting pad at the tailstock end with the 9A machines.

    The 10L beds (bench model) have a cool suspension, the bed is secured via a pin to the upper foot so it can pivot. There's a tab that
    exends down into the lower foot, with a screw that bears on the front of the tab, and one that bears on the rear of the tab. To
    adjust one first slacks one screw a bit, and brings the other one up to push the tab. The tab is locked between the two opposed
    screw, and won't move once set.


Tags for this Thread

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •