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  • Addendum- Please accept my apology, I get running my mind and mouth and writing to cover all the important stuff that I usually forget something and I omitted an important piece you mentioned.

    “New style” and “heavy duty”- First, those claims mean whatever they mean and are wholly worthless in most cases because they are advertising terms and not engineering functions. In bearings specifically I can answer that and I consider it truly “need to know” because in many cases “new and improved” and “heavy duty” can be the single fastest way to get the WORST possible solution and create more problems than they solve.

    A bearing is locked into several constants that cannot be changed. ( normally the ID,OD and width because it still has to fit in whatever it has to fit without substantial re machining)

    A bearing only does one thing- it rolls. The only 2 other considerations ( which affect it) are does it roll fast or roll under a lateral load. Go back to the simple ( and not fully complete because there are hundreds of potential considerations) specification list above. In most cases “heavy duty” simply means they reduced the inner/outer race and installed beefier rolling media. That may or may not help you ( and can work against you) depending on the specific reason YOUR bearing in YOUR application failed.

    It can also mean other things like different heat/cold treatment, finer finish for vibration reduction or specialty lubrication, has a different race design to accommodate some kind of load and so forth.

    See, these “new improvements” are rarely anything new or improved. ( or heavy duty because the APPLICATION, not the bearing, defines the “duty” and whether its “heavy” or “light” and since bearings are broad based and fit many radically different machines and because they are fitted by dimension any given manufacturers bearing such as a 6205 may or may not meet all the other criteria you need for “your” application depending on the rest of those numbers)

    You get these “improvements’ ( for lack of a better term) because all end users work with component manufacturers and give them all kinds of failure data, customer complaints and conduct testing ( again against that list earlier for bearings) so they conduct or revise their design FMECA (failure mode effect and criticality analysis)and find out the failure mode for that application ( greater load capability, increased heat tolerances, greater misalignment capability and so forth) and as a result they go back and address whatever is in the baseline design and “augment” it.

    The specifics are really infinite so just be careful when you are retrofitting anything or considering stuff like “new and improved, “heavy duty” and whatnot because UNLESS you specifically why YOUR bearing is failing and then you know EXACTLY what property(s) were changed from the baseline design- you may wind up in a worse predicament with anything “new and improved” or “heavy duty” because they have strengthened a different parameter ( and as a result weakened the one that is causing your specific failure) so despite all good intentions you can make your particular situation worse.

    Just friendly advice from one who deals with this every day.

    Comment


    • Originally posted by Beeman View Post
      I was under the impression that chain was pretty good at energy transfer. (http://www.gates.com/facts/documents/Gf000202.pdf).
      I’m sorry- I must have overlooked your post due to focusing on other things and if I had seen it would have addressed your points much earlier. I address this issue all the time and it’s a long discussion so I’m going to cut it down and hit just the high points. I hope you find it beneficial and useful.

      Yeah, they all tell you that and they are all correct- and they are all incorrect. (or to be “PC” they are selectively picking the data to tell you the side of the story they want you to know and kinda disregarding the rest of the story)

      You see this everyday especially in politics and advertising. It gets even worse when companies sell both products or have strategic alliances with those who do- or even fear damage to their reputation by being viewed by the world as “aggressive” or demeaning to another company or product. (or for liability reasons).
      Gee it looks like I contradicted myself because they cant be telling you the whole story and not at the same time can they?
      I’ll give you all sides of that argument and you can decide for yourself.

      If you ever saw the movie “My Cousin Vinny”- remember his brick discussion with the playing card. Allow me to show you the “thin” side to those claims on chains.
      You see this everywhere. Product claims are basically useless unless the testing data and criteria for the claim is released along with it to qualify and quantify whatever claim they give. Even then you have to be careful because the question then becomes: “Does their test and performance claim match the application I’m thinking about using”- if it doesn’t then you still have nothing.

      Guns use undercut barrels and specialty loads to publish weapons ballistics.

      Batteries use cold cranking amps/cranking amps/marine amps ( all with different meanings defined by BCI) .

      Some oils advertise themselves as “synthetic” ( when in reality they are just grade III mineral oils highly refined and do NOT deliver the results of a true synthetic but that can advertise that way because of a SCOTUS decision that said if they met the baseline characteristics of a synthetic they could call themselves such) to promote their products and so forth.

      Ask the question- If chains were so effective and efficient, not to mention have a 150 odd year proven history and relatively cheap compared to other systems, why is almost every manufacturer who uses them in their widget trying to replace them? ( belts and drive shafts on motorcycles, timing belts on cars and the list goes on to almost infinity)

      The standard talking points are weight, size, maintenance, lifespan, in some cases strength and so forth. They are all true and the chain loses to the belt in most applications in all of those areas with increasing frequency- but theres more.

      There are also applications where a chain because they are metal and almost impervious to everything will never be replaced. Attachments, extreme environmental or thermal hazards, applications where there is a high risk of debris and many “run-to-fail” applications are some examples of these.

      But, lets focus on efficiency and energy transfer since that the parameter being discussed.

      Before we go any further there has to be an alignment on a few things so there is no misunderstanding, misleading and we are on the same page. (critically important if you or any other reader doesn’t do R&D or controlled experiments in laboratory conditions)

      Parameters like torque, energy transfer are very broad terms and have to be defined with strict definitions when talking in terms of applications of the methods to determine them and interpolate data get skewed.

      When you build the DOE (design of experiments) you have to not only define what you are measuring but how and also note what is EXCLUDED from the experiment. (untested or unevaluated which could also have an influence on the result)

      Controlled testing almost always has an objective they are testing for (or against) so most tests are focused rather than broad ranged or open ended. ( for example testing a machine for performance under arctic conditions and the results may have no bearing whatsoever on that same machine in use in a desert)

      Testing criteria- that has to be detailed with all methodology and exclusions and how the test is falsified ( or if it is- many are not)

      Combination testing- in most every case, one single test or parameter never tells the whole story and many just conduct one so the results may be “true” but misleading.
      Component testing- (one of the things I have done) Component testing must be qualified by the application it is tested on or the results are wholly useless because I could take a #50 chain and test it on a motorcycle and get one set of data and put it on a 1000hp motor pulling a mile long conveyor and get another.

      Comparison testing- This is the “mother” of all tests to be wary of because it takes custom metrics and numerous correlation factors to establish accurate criteria to test multiple dissimilar items to and has more booby-traps in it than a desert road in Iraq. Its one thing to test one dishwashing liquid against another but its another thing to test apples against alternators in terms of miles-per-gallon. (with chains V. belts that’s almost what you are doing)

      Secret testing ( the best one of them all)- this is where companies contract people like me to test their products in real world or specific applications so they know the “truth”. These type tests are used for litigation or for honest 3rd party evaluation and are almost always TOP SECRET because they often reveal things a product manufacturer doesn’t want people to know. FEW companies will ever release these but they all have them and do them routinely.

      Sorry for the long list but to see and understand where I’m coming from you need to know that I know how companies do things and for what I’m going to say to make sense.

      Motivations

      Chain companies sell chains which are a tangible product and promote their strengths (only natural) and the product has a well known history.

      I sell “reliability” and “performance” which can be a tangible (when measured against reduced downtime/maintenance cost in real dollars) or intangible when measured against concepts like “safety” when we reduce safety costs because the machine doesn’t break down as often so the risk by exposure is reduced or “performance” when we often only focus on a piece of a machine like upgrading from a chain drive to a belt drive but you cannot isolate that from the aggregate machine output and we have an established history too.

      The difference is that we often have to “prove” ourselves against entrenched ideas and products and as an industry we are very good at it.

      Now to the chains and their claims ( and for purposes of correlation we are ONLY comparing a cogged belt and not a V belt or other design- yes, that makes a difference)

      Energy transfer- Chains publish the high range( around 98%ish depending on which manufacturer you look at and the specific type of chain) and that’s true but misleading. These measurements are derived from point to point on the sine as a chain is at TDC on the sprockets under full stretch. These measurements are the delta between a calibrated electric motor ( usually a DC but can be AC) and a calibrated dyno or other braking device. I promise you those readings are 100% true and correct- it just doesn’t tell the whole story. The funny thing is that I could nail a broom handle to 2 wheels and get you 99.99% with the same test.

      Heres what they didnt tell you- That’s all done with a virgin chain and when a “seasoned” chain is tested it drops substantially because of the resistance between the chain and sprockets. They also don’t do a “spin test” where the load is removed and the train coasts to see the transfer weight when backlash is introduced and adjust their load figures accordingly. Belts tend to even out where chains “clack” back and forth.

      Torque- on chains they publish the starting torque at the moment of full load. That’s not the full cycle. What they didn’t tell you was the ramp up losses and the ‘lock” when it closed all clearances and subtracted it from that figure. Cogged belts are almost immune to this effect. Its easy to measure a rope when its tight at the moment of tension but try it when its all curled up.

      Heres what they didn’t tell you- Everybody loves to quote “start up” torque but that’s only part of the story. They didn’t mention the weight factor for running torque. Somewhere in the equation it was not mentioned the losses when RPM changes and chains slap around eating up that wheel energy.

      Motive properties- Chains ( and V belts) have this torque eating property too. (V belts have it but to a lesser extent because they do flex and grab- chains don’t) Chains engage power like gears do ( about 3 teeth doing all the pulling) and have a “slack” side that does virtually nothing. This has to do with continuous torque over a circle and load dispensation. What is created is the “pendulum” effect where an object is running “out of balance” rather than distributing true motive forces through all arc seconds in motion. This robs you of energy transfer because energy is expended in the wave in a spike every time the pendulum crosses the line of zero potential then contributes little to the wave because it “coasts” the rest of the way hoping inertia sees it through the process. ( not to mention the additional strains on the rest of the drive train) Thermal imaging and vibration ( normally 2 plane) studies show this clearly.

      Cogged belts are different because they are “timed” by the cogs and at proper tension they “push” as well as “pull” the load.( about a 70:30 relationship) This is probably best described here in terms people can relate to as a winch with a straight pull V. a winch with a snatch block. Chains and V belts are linear pull and cogged belts are more snatch block. ( completely discounting uniform loading and taking full advantage of the circle of the sprocket/pulley)

      I could go on for hundreds of hours and tens of thousands of words going into every detail so I’ll cut it off here and just to sum it up.

      Advertising claims are nothing more that variations on the “unsinkable” Titanic theme and mean nothing if you don’t dig deeper into the physics. They can be true/false and right/wrong at the same time or not even apply to the subject on the table.

      If you don’t know the facts/data/specific parameters of the tests these claims are addressing and then further know how that affects your specific application you actually know less than nothing.

      Theres an old Vulcan proverb: Be wary of Romulans bearing gifts. Salesmen ( and women) as well as product marketing are absolute experts and masters of their domain when they are selling but at the end of the day they are closer to “serpents in the garden” and only tell you the broad side of that playing card ( which is in their best interest to make a sale) and not tell you the rest. They play all these games and millions more.

      Again, let me reiterate that there are always plusses and minuses for chains V. belts and which is “best” because there are multiple considerations but in this conversation the subject was specifically and only torque/direct energy transfer and the losses associated with it and nothing else. With all things being equal, chains lose almost every category repeatedly- that’s why they are being replaced over every industry they can except in applications where their unique qualities reign supreme. I also need to state than in NO WAY am I “anti chain” but in most applications its simply not the best choice when all things are considered.

      To falsify my post- get your local chain vendor ( who does not sell belts) and your local belt vendor (who does not sell chains) so we don’t have a conflict of interests together in your office for a net conference and presentation.

      When I’m don’t putting the inalienable industry proven facts on the table for all to see( they already probably know them anyway)- watch which one experiences whatever their respective sex does for “excitement” and then observe who is trying to find the closest way to the door. The truth will be self-evident then.

      Comment


      • Holy CR@P my attention span will not even allow me to begin to read the novel that was just posted.
        l like to buy stuff and no I don't do payments!

        Comment


        • Originally posted by amphibious drew View Post
          Holy CR@P my attention span will not even allow me to begin to read the novel that was just posted.
          Well, now you see why engineers are always kept in their locked rooms and fed with sling shots. If we get started conversing on a subject we will bore you to tears and melt your mind. The only reason they keep us around is because every once in a while someone may need us.

          Comment


          • Originally posted by amphibious drew View Post
            Holy CR@P my attention span will not even allow me to begin to read the novel that was just posted.
            .

            Comment


            • Thanks M&M you have gave me lots to thinks about,all things being equal I now believe that this bearing setup is superior to the long existing argo set upto a point, and a real world test in the conditions I use the vehicle in will tell the tale.N.C.T

              Comment


              • Wow..

                If I could have written letters like that, I probably wouldn't have gone though so many GF's in the past.

                All points noted. Thanks for the run down.

                *Edit - letters that are the same in length, not content. :P "Dear honey, Did you know that ANSI 50 HD chain is....."
                Last edited by Beeman; 03-30-2012, 08:56 PM.

                Comment


                • Originally posted by Beeman View Post
                  Wow..

                  If I could have written letters like that, I probably wouldn't have gone though so many GF's in the past.

                  All points noted. Thanks for the run down.

                  *Edit - letters that are the same in length, not content. :P "Dear honey, Did you know that ANSI 50 HD chain is....."
                  Let me tell you a quickie short story about what drove me to eventually wind up digging into all these details. You may find it entertaining. Its obviously dated by the information but the facts and physics applied then too. (unknown to me at the time this focus was a “set up” by the staff to teach us that everything that glitters was not gold)

                  When I was in school one of the biggest theoretical “dreams” was the infamous “100mpg” carburetor. ( everybody was talking about the Fish and Pogue) Granted this was when catalytic converters were relatively new new things, radial tires were rare and things like emission controls, fuel injection and computers were mostly still on drawing boards somewhere and gasoline chemistry was radically different than it is today.

                  After examining those carbs in detail of their theory the classes produced some models that as far as carbs go looked like they might deliver performance pretty close to that mileage on paper on bench tests. Everybody got pretty excited.

                  Well, then came the part about putting them on vehicles for testing. (somewhat of the proverbial “cold shower” but that was the ultimate teaching point of the exercise and our young bright minds fell for it hook, line and sinker)

                  In short, we proved that there was no such animal possible because the properties of the gasoline did not have the stored energy potential to accomplish the task even if such a mythical beast could be built. (one of those outside parameters nobody even thought about until we did the failure analysis) Well that showed us in no uncertain terms that all those then claims of people designing and building them then the big “oil companies” swooping down and buying them up were all BS because they couldn’t be built in the first place. ( we were not sophisticated to use such modern terms like “urban legends” and back then it wouldn’t have endured to “legend” status because in theory and in the backs of all the magazines of the day it was allegedly happening in real time- for those here who remember the early and mid 70’s)

                  The final straw was the realization that even if you had some kind of “miracle carb” you STILL couldn’t get that legendary gas mileage unless you had the 100mpg car with the 100mgp vehicle weight, custom designed engine to maximize that carb, custom drive train, tires and vehicle aerodynamics.

                  That particular lesson was one of the few that really stuck with me and shaped me to this day when dealing with all these “claims”. It directly effects me now even because salesmen and various marketing types are free to use all these terms and sell their “snake oil” but my world is solidly grounded in the laws of physics and math. I find myself often being in the undesirable position of them writing a check with their mouth that they expect me to cash with my @$$ so I have to push back.

                  Comment


                  • Originally posted by North Country Tough View Post
                    Thanks M&M you have gave me lots to thinks about,all things being equal I now believe that this bearing setup is superior to the long existing argo set upto a point, and a real world test in the conditions I use the vehicle in will tell the tale.N.C.T
                    If you could and would and its not too difficult since you have all the parts- could you slip the bearings on the shaft and take a pic of what it would like installed? (maybe with the housing too)

                    I see lots of pics here but they have all kinds of other stuff in them obstructing the full view

                    Comment


                    • I know its a long shot but is there any potential material out there that would be strong enough for tracks but have buoyancy characteristics.

                      Comment


                      • Originally posted by azz7772 View Post
                        I know its a long shot but is there any potential material out there that would be strong enough for tracks but have buoyancy characteristics.
                        I seriously doubt any such animal exists or could be manufactured hypothetically. I’m hardly a plastics expert but I understand the concept of buoyancy pretty good and know that all plastics have about the same level of buoyance regardless of their base or density.

                        Buoyancy isn’t just about whether something floats or not but how much upward force it can exert when displacing water.

                        When one looks at it from that perspective I would think any plastic strong enough to be a track with enough buoyancy from dimension and enclosed air/foam to matter ( with only about 50% of it in and under the water pushing up) would almost have to be the size of a pallet on either side of the vehicle.

                        Comment


                        • ok I am just thinking out loud it may be stupid or ridiculous sounding but that's how new things are invented. On that note what do you all think about a track that is designed like a tire tube but thicker with a tread design molded right in and the vehicles tires get eliminated totally. maybe this track design could ride inside the rims some how with a cog design? And all you do is mount it over the rims and inflate it to a set pressure then you have floatation.,traction,some suspension, and maybe good swimming characteristics. I don't know just a crazy thought I had today.

                          Comment


                          • Originally posted by azz7772 View Post
                            ok I am just thinking out loud it may be stupid or ridiculous sounding but that's how new things are invented. On that note what do you all think about a track that is designed like a tire tube but thicker with a tread design molded right in and the vehicles tires get eliminated totally. maybe this track design could ride inside the rims some how with a cog design? And all you do is mount it over the rims and inflate it to a set pressure then you have floatation.,traction,some suspension, and maybe good swimming characteristics. I don't know just a crazy thought I had today.
                            Well, its been my experience that in the engineering world the only “stupid and ridiculous” ideas are the ones you didn’t spec out and properly test before you put them into production.

                            Your “operational” concept (rims, rollers and cogs) will most certainly work because its been proven in tanks and heavy equipment for over a century.

                            Your “functional” concept- I can see no reason off the top of my head it would not work. We blow up things and fit them over other things all the time. You would obviously have some functional restraints but so does every other device. Nothing does “everything” well.

                            Materials and construction- Here is where I personally see the problem. Using rubber in a tire/rim configuration is one thing- having a rubber compound that could handle all that load, stress, torque and durability on its own is another. I don’t see putting any kind of aggressive track pattern on them as a big deal because tires do it every day.
                            I’m not sure such a material that would meet the application requirements exists but it would be an interesting study.

                            I would suggest you find someone in that field or maybe in the tire industry and pass your idea to them and develop it. Who knows what kind of new materials they have on the drawing board. That’s going to be the hard part because the function and operation are already known to be possible.

                            Comment


                            • I’m having a beer and brain storming session today myself after a week of mind numbing drivel and meetings. I would like to throw some shafting ideas out and invite everyone to shred them to pieces because I see that issue come up in numerous threads and that’s obviously a critical part of the machine.

                              Since I have never had an AATV or measured one- I’m assuming an overall shaft length of 24” for discussion purposes. ( the length really doesn’t matter from a mass production perspective because the differences are only a few dollars)

                              It also makes no difference whether you are in the sprocket, pulley or coupling opinion because the shaft is not going to care whats on it.
                              Just going from experience in designing shafts and estimating a HP from about 50 down and a weight of 1500 lbs overall-I know I can make a shaft that for all intent and purpose would be “indestructible” for anything short of a nuclear detonation in these vehicles in the 1.250 to 1.500 diameter range for about $50-60 a shaft. ( that price is probably on the high side)

                              Forgetting metallurgy because that’s pretty much a constant, I would:

                              Cryo and heat treat them out the gate ( done in batches this would add maybe $5 to each shaft) That would get the maximum capability out of the base stock.
                              I would harden all wear surfaces such as bearings, seals and sprockets/hubs/pulleys and that would pretty much end shaft damage from those things.

                              Splines et al- from a CNC perspective, once there is a CAD/CAM print to load in the machine and teach the robot- this is almost insignificant because it can have anything on it. It would have shoulders and so forth for proper component placement for alignment and what not.

                              One thing I would do is have everything keyed with about a zero to .002 interference (shrink) fit. This would be the best possible fit in every category. This would be for hubs, bearings, sprockets/pulleys and everything else. Granted this would require pullers for removal and heating capability ( and putting the shaft in a freezer overnight) for installation but anyone with a shop has this capability and this alone would eliminate a lot of issues currently encountered.

                              Thoughts?

                              Comment


                              • Originally posted by mudNmallards View Post
                                If you could and would and its not too difficult since you have all the parts- could you slip the bearings on the shaft and take a pic of what it would like installed? (maybe with the housing too)

                                I see lots of pics here but they have all kinds of other stuff in them obstructing the full view
                                Gonna shoot some pic,s tomorrow and post them up.NCT

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