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Thread: Benchtop Slip Roll

  1. #26
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    Re: Benchtop Slip Roll

    Quote Originally Posted by djd775 View Post
    On the bushing vs bearing debate, you need to consider that different principles are at play.

    Bushings are the equivalent of sliding a big box across a floor.

    Bearings are the equivalent of rolling that same box across the floor on dowels or rods.

    Bushings have friction as a part of their design; in an ideal world, bearings would come very close to zero friction on the rolling elements.


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    This isn’t actually true because as stated a bushing is intended to maintain a film of oil, which if properly applied results in no contact between mating surfaces

    So that box on the floor would be hydroplaning across the floor.
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  3. #27
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    Re: Benchtop Slip Roll

    Here's an explanation of the two different types of bearings. Which has to be right, because it ain't comin' from Farmersammm





    So, if a perky young fella, with winning ways,, tells ya the same.......................

  4. #28
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    Re: Benchtop Slip Roll

    Quote Originally Posted by farmersammm View Post
    Absolutely.

    It's an apples vs. oranges thing. I'm talking about reducing operator effort, others are talking about load capacity.

    Nobody ever listens to me, which is ok Perhaps, coming from a "valid" source, it's more palatable https://www.bearingtips.com/bearing-...basics-primer/

    Another consideration, not mentioned yet................................shaft wear.

    A bronze bushing will eventually eat a shaft. A needle bearing will also eventually eat a shaft. Even a pressure lubed babbitt bearing eventually ruins a shaft when it wears (gas/diesel crankshaft bearings). You can bank on shaft wear with any bushing.

    Roller, and ball, bearings operate in a contained system. Rolling elements caged inside an inner and outer race. The shaft never comes into play (unless there's a catastrophic failure, and the inner race spins on the shaft).
    Sure because a hand operated roller will ultimately see millions and millions of rotations 🤣.

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  6. #29
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    Re: Benchtop Slip Roll

    Now, if you want less filling, more taste..........................



    Not entirely accurate in the minute details, but definitely more entertaining.

  7. #30
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    Re: Benchtop Slip Roll

    Quote Originally Posted by M J D View Post
    Sure because a hand operated roller will ultimately see millions and millions of rotations 🤣.
    What about friction do you not understand

  8. #31
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    Re: Benchtop Slip Roll

    Quote Originally Posted by BrooklynBravest View Post
    This isn’t actually true because as stated a bushing is intended to maintain a film of oil, which if properly applied results in no contact between mating surfaces

    So that box on the floor would be hydroplaning across the floor.
    That film of oil, or any film for that matter, including a cushion of air,, will generate friction. I believe that's what he was trying to illustrate.

  9. #32
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    Re: Benchtop Slip Roll

    And, of course................friction negates torque, or in other words.............requires more torque to overcome. If the torque comes from your puny body, torque matters. Unless you're a fatazz, and simply leaning on something can make it move.

  10. #33
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    Re: Benchtop Slip Roll

    Quote Originally Posted by farmersammm View Post
    That film of oil, or any film for that matter, including a cushion of air,, will generate friction. I believe that's what he was trying to illustrate.
    Yes, that was a big part of my point for sure. Also, the point was made that a bearing needs to have enough pressure to cut through the lubrication film (displace the lube) which is fair … but needs to be kept in context ie: there are different principles at play in bushings vs. rolling element bearings.

    In the case of galling mentioned above, I wonder if low shaft load may have been as much to blame as low speed. Low shaft load could be insufficient to overcome the sticky grease and force the balls/rollers/etc to actually turn. Then they’d be just plowing through the lube and galling would likely happen.

    As many have pointed out, there are tons of considerations when choosing bushings vs bearings … kingpins are a good example, where bearings could easily have enough load capacity, but the rolling elements would put wear points on the races as the truck bounces down the road with the kingpins stationary - then you no longer have a smooth race to work with. Same reason an empty concrete truck still lets the drum turn slowly while driving down the road.

    Sorry to contribute to the rabbit trail … IMHO, bearings will not cause you any trouble on this slip roll project. They are a low effort solution for operation, and are practical in the sense that they come with all the mounting provisions (flange/pillow block) so it’s easy to just bolt them in place. The availability of a spherical outer race to compensate for misalignment is just another bonus.


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  11. #34
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    Re: Benchtop Slip Roll

    Quote Originally Posted by djd775 View Post
    Yes, that was a big part of my point for sure. Also, the point was made that a bearing needs to have enough pressure to cut through the lubrication film (displace the lube) which is fair … but needs to be kept in context ie: there are different principles at play in bushings vs. rolling element bearings.

    In the case of galling mentioned above, I wonder if low shaft load may have been as much to blame as low speed. Low shaft load could be insufficient to overcome the sticky grease and force the balls/rollers/etc to actually turn. Then they’d be just plowing through the lube and galling would likely happen.

    As many have pointed out, there are tons of considerations when choosing bushings vs bearings … kingpins are a good example, where bearings could easily have enough load capacity, but the rolling elements would put wear points on the races as the truck bounces down the road with the kingpins stationary - then you no longer have a smooth race to work with. Same reason an empty concrete truck still lets the drum turn slowly while driving down the road.

    Sorry to contribute to the rabbit trail … IMHO, bearings will not cause you any trouble on this slip roll project. They are a low effort solution for operation, and are practical in the sense that they come with all the mounting provisions (flange/pillow block) so it’s easy to just bolt them in place. The availability of a spherical outer race to compensate for misalignment is just another bonus.


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    I read an article concerning wind turbines that covered the failure problems they're experiencing. Mainly bearing "skid". Lightly loaded shafts that cause the elements to skid, instead of roll.

  12. #35
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    Re: Benchtop Slip Roll

    Quote Originally Posted by farmersammm View Post
    What about friction do you not understand
    Deflection of the shaft is way more of an issue than friction in this application. Everything does not need to be " engineered" to some ridiculous standard. This is a simple hand crank pyramid roller not a nuclear turbine. This I'm sure YOU will never understand. I've worked on lots of poured in place babbit equiped log decks and old machinery that had loads of weight and torque to contend with. Those loads would utterly destroy ball bearings .

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  14. #36
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    Re: Benchtop Slip Roll

    Quote Originally Posted by farmersammm View Post
    Here's an explanation of the two different types of bearings. Which has to be right, because it ain't comin' from Farmersammm


    So, if a perky young fella, with winning ways,, tells ya the same.......................
    Well, when a guy makes a basic statement that is incorrect, you instantly question the rest of his statements.

    In the antifriction bearing video, he starts off by stating the bearing is made up of an inner, and outer race that is "alloy steel" that is case hardened.
    According to him, the race is tough inside, but, case hardened only on the outside.

    My personal experience shows the bearing race is actually through hardened.

    The way I know this is that there was a junkyard near where I lived as a child.
    We would go get these bearings, BIG bearings, the balls were about an inch in diameter.

    Well we wanted the balls, simply to play with, shoot with a sling shot, play marbles, all sorts of things.
    Removing the stamped metal cage was one way to get at the balls,, but was VERY labor intensive.

    I soon found that you could stand the bearing up on the concrete sidewalk, and hit it with a 10 pound sledge hammer.
    The race was through hardened, and little more than a tap, and the bearing race would break like glass,,
    ( I was only 10 years old, I could not "swing" the sledge, I basically could only drop it,,)

    THAT was the easy way to get at those balls.

    So, the guy is totally wrong about material that the race is made out of,,, what else does he have wrong??

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  16. #37
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    Re: Benchtop Slip Roll

    Quote Originally Posted by M J D View Post
    Deflection of the shaft is way more of an issue than friction in this application. Everything does not need to be " engineered" to some ridiculous standard. This is a simple hand crank pyramid roller not a nuclear turbine. This I'm sure YOU will never understand. I've worked on lots of poured in place babbit equiped log decks and old machinery that had loads of weight and torque to contend with. Those loads would utterly destroy ball bearings .
    I work on a lot of chain bottom trailers that use bronze bushings on the sprocket shafts, grease them once a day and they will last forever unloading 45,000 lb loads 20 times per day, the front idler sprockets are cast iron running on steel shaft with nothing but grease, again greased once a day and very little wear. When the sprockets wear out the entire assembly gets replaced as a unit because its all welded at the factory.

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  18. #38
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    Re: Benchtop Slip Roll

    Quote Originally Posted by 12V71 View Post
    I work on a lot of chain bottom trailers that use bronze bushings on the sprocket shafts, grease them once a day and they will last forever unloading 45,000 lb loads 20 times per day, the front idler sprockets are cast iron running on steel shaft with nothing but grease, again greased once a day and very little wear. When the sprockets wear out the entire assembly gets replaced as a unit because its all welded at the factory.
    For sure. Even UHMW idler sprockets last a long time provided the operater doesn't routinely reverse the deck. I've yet to see any bearing with a small ID to OD relationship hold up well . In a chain bottom or a log deck friction on a bearing surface is the least concern, as is a slip roll as dragging large amounts of weight or resistance of metal forming is a main concern. Of course some can't be bothered with simple yet effective 🤣.

  19. #39
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    Re: Benchtop Slip Roll

    Quote Originally Posted by SweetMK View Post
    Well, when a guy makes a basic statement that is incorrect, you instantly question the rest of his statements.

    In the antifriction bearing video, he starts off by stating the bearing is made up of an inner, and outer race that is "alloy steel" that is case hardened.
    According to him, the race is tough inside, but, case hardened only on the outside.

    My personal experience shows the bearing race is actually through hardened.

    The way I know this is that there was a junkyard near where I lived as a child.
    We would go get these bearings, BIG bearings, the balls were about an inch in diameter.

    Well we wanted the balls, simply to play with, shoot with a sling shot, play marbles, all sorts of things.
    Removing the stamped metal cage was one way to get at the balls,, but was VERY labor intensive.

    I soon found that you could stand the bearing up on the concrete sidewalk, and hit it with a 10 pound sledge hammer.
    The race was through hardened, and little more than a tap, and the bearing race would break like glass,,
    ( I was only 10 years old, I could not "swing" the sledge, I basically could only drop it,,)

    THAT was the easy way to get at those balls.

    So, the guy is totally wrong about material that the race is made out of,,, what else does he have wrong??
    https://www.fleetequipmentmag.com/tr...ning-bearings/

    https://www.knowyourparts.com/techni...ent-hardening/

    https://nesbearings.com/through-hard...case-hardened/

    I guess the process varies by manufacturer, and apparently by global region.

    It seems that through hardened steel would have to be tempered, or it would be so brittle that it would break very easily. Apparently Nachi tempers their steel used for bearings.


  20. #40
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    Re: Benchtop Slip Roll

    Quote Originally Posted by M J D View Post
    For sure. Even UHMW idler sprockets last a long time provided the operater doesn't routinely reverse the deck. I've yet to see any bearing with a small ID to OD relationship hold up well . In a chain bottom or a log deck friction on a bearing surface is the least concern, as is a slip roll as dragging large amounts of weight or resistance of metal forming is a main concern. Of course some can't be bothered with simple yet effective ��.
    I remember using the old school Pexto slip rolls that used nothing but a steel shaft in a cast iron housing with grease lube. Those things lasted forever.

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  22. #41
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    Re: Benchtop Slip Roll

    Quote Originally Posted by farmersammm View Post
    Here's an explanation of the two different types of bearings. Which has to be right, because it ain't comin' from Farmersammm





    So, if a perky young fella, with winning ways,, tells ya the same.......................
    Your "perky young fella" is an idiot.

  23. #42
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    Re: Benchtop Slip Roll

    How so?

  24. #43
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    Re: Benchtop Slip Roll

    Quote Originally Posted by farmersammm View Post
    How so?
    The whole thing about "case hardened" races. I will agree with the guy about "hydrodynamic" bearings in the second vid. I have worked with brass bearings on railroad locomotives. A well designed brass can make 400PSI oil pressure from the axle rotation picking up oil from the cotton waste wick in the journal box. Most railcars have roller bearings now but it's amazing how little force it takes to move a car with the old "friction" bearings.

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    Re: Benchtop Slip Roll

    From my description of the guy, you gotta know I don't like these kind of people. Smart, hip, trendy. But I have to admit he's nailed it, as far as modern bearings go.

    I hope you read the links I posted. I had absolutely no idea how these things were made, until I did some looking around. I posted some stuff from reliable resources. Bower, and the other company. I figure it's good info.

    The whole thing started out as a question about what would be the easiest thing to rotate...........bushing, or ball bearing. That's it, nothing more. It's not a challenge.

    Name:  capstans-railcar-movers-740x516.jpg
Views: 255
Size:  61.9 KB Back in the day, when I was still young..............I used to do container hook and drop, and pool car distribution. I know that a car is easy to move with a Johnson Bar. So, that's nothing new.

    I mean, Hell............whole advantage of a rail car is the steel on steel footprint. No resistance to moving. I'm not trying to bust anybody's chops. You, and the other half of the Dynamic Duo need to take it down a notch. When I say it's Day, y'all gotta quit sayin' it's Night just to make it into a big argument. It doesn't do anybody any good. Don't like me, that's cool.............but don't fight the facts. Just sayin'

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  27. #45
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    Re: Benchtop Slip Roll



    This whole thing was about ease of rotation, not much else. I've been down this road. I actually work with this stuff, and can give an opinion that's not total crap.

    This was a deal that hit the scrap pile. It wasn't workable. The turning effort was too much. Bronze, steel, plastic............it's all the same. Bushings rotate hard when it comes to cranking something by hand. I think that was the premise of the whole discussion.
    Last edited by farmersammm; 12-07-2021 at 02:42 AM.

  28. #46
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    Re: Benchtop Slip Roll

    Bearings and bushings both have their proper applications. I would use bushings in the described application. Partly to allow mounting the bottom pair of rollers closer together. The further apart they are the longer the unbent flats at the joint will be. Further I think it is easier to design a drop end for the top roller, with bushings, so you don't have to spring the rolled part over the top roller to get it off the roller. As for the difficulty of turning the crank/wheel, I'd probably use gears or reduction drive sprockets or a gearbox to get the required force to where I wanted it and if I went that far the next addition would be a motor. All of this is what I would do and is entirely dependent on my personal resources. Fortunately for me I already have a set of rolls probably commercially built pre-WW II. And they are on bushings and are motorized. Just my 2 cents, worth less than what you paid for it.
    ---Meltedmetal

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  30. #47
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    Re: Benchtop Slip Roll

    Quote Originally Posted by Meltedmetal View Post
    Bearings and bushings both have their proper applications. I would use bushings in the described application. Partly to allow mounting the bottom pair of rollers closer together. The further apart they are the longer the unbent flats at the joint will be. Further I think it is easier to design a drop end for the top roller, with bushings, so you don't have to spring the rolled part over the top roller to get it off the roller. As for the difficulty of turning the crank/wheel, I'd probably use gears or reduction drive sprockets or a gearbox to get the required force to where I wanted it and if I went that far the next addition would be a motor. All of this is what I would do and is entirely dependent on my personal resources. Fortunately for me I already have a set of rolls probably commercially built pre-WW II. And they are on bushings and are motorized. Just my 2 cents, worth less than what you paid for it.
    The distance of the rollers from one another is the main reason I designed it with bushings.

    it was a matter of space over function.
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  32. #48
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    Re: Benchtop Slip Roll

    So now that we've solved all the problems of the bearing world, how is the build going?
    The harder you fall, the higher you bounce...

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  34. #49
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    Re: Benchtop Slip Roll

    Quote Originally Posted by whtbaron View Post
    So now that we've solved all the problems of the bearing world, how is the build going?
    Honestly I’ve been too busy with other work for personal projects. (Not a complaint)

    I need to find the time to work on it.
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