Do Model Trains Really Need Bearings?
Вставка
- Опубліковано 8 сер 2024
- Here's a further experiment that tests the kinetic friction of bearings vs no bearings: • Bearings vs. No Bearin...
An experiment to prove whether or not separate bearings actually improve our locomotives!
Become a Sam'sTrains engineer here: / @samstrains
Get your Sam'sTrains merch: teespring.com/stores/bullmane...
Thanks for watching!
Email: samstrains@outlook.com
Instagram: / samstrainsofficial
Facebook: / samstrains
Twitter: / samstrains
0:00 Intro
4:10 The Experiment
8:56 Theory: Why Bearings are Best
12:39 Square Bearings
16:41 Conclusion - Авто та транспорт
![ЛЕБЕДЕВ у ДУДЯ: муху не обманешь 😁 [Пародия]](http://i.ytimg.com/vi/E74h5fvVrqs/mqdefault.jpg)
Here's a further experiment that tests the kinetic friction of bearings vs no bearings: ua-cam.com/video/wnWOx54oFNk/v-deo.html
Thanks Sam
This one does not appear on the YT list of videos for some reason which I am sure others understand.
Is there a way to reduce the friction of wagons and coaches or are pin point bearings still the best?
@@mkaustralia7136 Yes, I Just found it tonight.
I'm a Mechanical Engineer. That assumption with explanation was absolutely spot on Sam. Could do worse than use your video to explain the advantages of Plain Bearings at an engineering college. And doesn't CAD make drawing 3D model examples easy to visualise. Top video mate 👍
I am a graduate of two science degrees and I agree completely with the above comment.
@@robertsparks3685 Cheers for your endorsement
Spot on. Agreed.
I completely agree, as someone with an engineering degree also. Only things I would do to improve this would be to test more locos (like the bachmann and hornby Halls and 9Fs), and use a pulley as a bearing for the string instead of the book.
Technically these bearings are called journal bearings and a lot of research has gone into them since the early 1800s.
Most important to note is hydrodynamic effect of the oil film between the bearing surface and the shaft - this is similar to the effect of a skater's blades on ice though that is hydrostatic rather than hydrodynamic but both produce extremely low friction - effectively the shaft is floating on a very thin oil film
The other important thing about this type of journal bearing is they are made from an alloy that is softer than the rotating shaft or axle but the reasons for this are super text booky.
My guess is the bearings on model locos are actually phosphor bronze rather than brass though brass would work
I don't think people realize how much work goes into produce a video like this. Thank you Sam for your effort and diligence. I have dozens of trains and I can confirm those with bearings do run smoother in general.
Excellent question ! Correct me if I'm wrong, but, as the bearings are made with brass, we can consider that this metal has low friction properties besides it's elasticity (I've spend one hour replacing a brass spring of a Kadee coupler this afternoon, "fiddly" is an understatement here...).
So, first, I applause your ingeniosity : top level variable killing and highly smart test setting :simple, straightforward and relevant ! then, rigorous execution of the experiment, great !
For the results : yeah, confirms with reliable figures what we already have seen "on the ground". Half the resistance, twice the energy to the wheels, the mass is done.
For the mechanical engineering part, nice explanations. We understand now what are the physical mechanisms at play, and the motivation to put bearings in model engines.
Thanks for the good job done Sam, that settles the debate on the rational points you've made here.
This is a well constructed and thoughtful experiment, you kept it simple so anyone can understand. Well done.👍
Your best and most thought-provoking video to date, proving what engineers have known for centuries regarding not only the superiority of bearings over bearingless, but also the importance of fine clearances and having two different high quality metals (in the case of our models, steel axles and brass plain bearings). One should never have a chassis without bearings, for reasons which your excellent presentation made clear, and certainly not raw chassis castings with no attempt to machine the bearing surface.
When scratchbuilding, the only time I have omitted bearings has been in N gauge, where I choose brass for the chassis sideframes, precision drilled to a tight interference fit for the axles, then hand reamed to give the minimal running clearance needed to prevent bearing chatter. All bearings need lubrication but very sparingly at regular intervals.
great video. Whilst the bearings will improve the performance a little bit, I'd suggest the significance of their addition is providing good evidence of overall good engineering and quality; Its unlikely a model will be designed with bearings and then shoddy other parts if that makes sense.
Excellent video, I like the scientific approach to the bearing issue! Here's the multi million dollar question are you going to do a 'how to' video on how to convert a non bearing chassis?
Oh my god yes please 🙏
Very interesting seeing brass bearing versus no bearing stiction (the friction that had to be overcome before rotation will occur) values being quantified like that. Big problem is our train dc motors torque varies sinusoidally and the variation is significant (unlike industrial motors that are constructed differently) This becomes really important if you try starting the motor when it last stopped when the shaft was aligned at one of the low torque points. Then you often have to crank up the volts to get more armature current flowing to get enough torque to overcome the stiction; in a dc motor torque is proportional to field flux times armature current. Three pole motors are the worst case (3 commutator slots with 3 armature windings one winding between each comm slot). Going 5 pole reduces the torque low to high range variation I.e. appearing as smoother torque generation and thus more repeatable starting results etc. As a motor ages not only does the stiction go up as the bearing wears (and or dries out - ditto any gear trains) but also the magnet loses its magnetism (field flux) so reducing the motors available torque which compounds the problem. So yes good quality engines should have both decent bearings and field magnets for smooth consistent low speed starting as well , 5 pole better than 3 pole (fly wheels actually go against smooth starting but help smooth out any torque pulsations once the motor is turning which helps low speed operation and covers you a bit for dirty track etc). That is my perspective, hope helps, all the best Stephen
Mechanical Test Engineer here... Great job Sam!! Sound testing procedure/execution. Definitely could do with some fine tuning of the testing, but all in all you nailed most of what you did. Well done! Your theory on why separate bearings are better is spot on. Your explanation on square bearing surfaces is also excellent.
I've been scratchbuilding chassis' for over 25yrs and have used separate bearings (brass, bronze or ball) from almost day one. Definitely better than solid/integrated bearings, at least when they are metal on metal. Metal axles running in an engineering plastic (nylon, Delrin, etc...) bearing are also pretty decent, but not as long lasting. Nylon/Delrin axle "muffs" running in Nylon/Delrin "bearings" run extremely well too, but I wouldn't consider that for larger (HO/OO or bigger) scales.
Fantastic work on the CAD to explain the matter. This channels is becoming a thing for engineers ;)
Axles in any slot with play around have another detrimental effect, they doesn't run straight, they end in banging around at an angle regarding the chassis and thus the track. You keep all square in your CAD explanation for the sake of easy understanding, but imagine that the axles can completely goes sideways too in their slots and have binding points that increase friction the more speed and/or torque is applied!
Whereas a bearing keeps everything straight of course
"I went straight for the nuts." 🤣🤣🤣 Priceless gold Sam.
This video is long over due! Thank god we have you in the MR community to explain, using facts, the simplest things to all the sheeple out there. 😂 speaking of sheeple…. I personally have no issue you with you investigating the mechanism before you run a loco…. But for those who say “ooo eeer you shood not mess with your locomotives. It is… it is becoz of you cos you had broken them”….. how about change the order in your videos that shows the performance before the mechanism? I service dozens of locos daily for a model shop and everything you have said in all of your videos is correct! I can’t understand how some sheeple think square slots with no bearings is fine! 😅 machines don’t least forever! That’s why we service our cars and have the oil changed! To prolong the life of the moving parts in the engine!!!! Same thing applies micro machines like locomotives and watches! It’s good to service them! It’s not good to never take them apart and have them cause more and more wear and tear because a few sheeple say “it is because of you that you had broken them”
Imagine if our cars and real locos didn’t have bearings 🤣
Blimey, very helpful and insightful this Sam. Thanks a bunch for going to town to this premier level of testing. You really have nailed it here we thought 😃
Back in the early 1940s, Lima Locomotive Works ( USA) introduced new concept Timken Roller Bearings to one of its new design 2-8-4 Steam Locomotive. To show how Rolling friction was reduced with Roller Bearings they had several ( female) office staff haul the locomotive over a short Distance ( photo in publication and advertising). Of course, they had (hidden) behind the loco and tender, some men to overcome the static resistance and getting loco moving...
None the less, once the Loco was moving, the Ladies were able to keep it Moving along.
Demonstration of Roller Bearing reducing Rolling Friction of the Locomotives compared with traditional Babbit-filled Brass/ Bronze Bearings.
This increased the Energy Efficiency of the Locomotive, as less was lost in Friction compared with older bearing designs.
Roller bearings were also used the Running Gear and Drive links.
At the same time Roller Bearings began to be used on Bogie Truck Axle Journals, reducing the incidence of " hot boxes" and fire and Journal fracture due to lack of oil in bearing box.
Very well done, Sam. I hope you will produce similar videos in the future. One of the great strengths of model railroading as a hobby is that there are so many different aspects to it, technical and artistic. So there are many avenues that can be explored using your excellent skills in presentation and explanation. Cheers from Wisconsin!
Loved this video, very interesting. Maybe you could make a list of key features that would make the perfect loco, then measure all manufacturers against it!
Like I have said in comments in the past I learn a lot from watching Sam’s videos. They are informative and easy to understand. To all the critics who don’t have anything nice to say they should just watch and listen. I have had problems with old engines with no or square openings were the axles sit and have so many problems of metal fillings and excess axle problems. Sam keep these informative videos coming .
Excellent video, Sam. Clear and informative.
At 07:35, though, the phrase:
"...go straight for the nuts...", made me spit my tea out with laughter. Sorry.
You've updated the coaches in your intro sequence, I notice. 👍👍👍
Well done Sam . As allways great presentation. stay safe.
Bill from Western Australia were this experimet works the same but upside down where we all have velcro on our feet!
Fantastic video! What a huge amount of work to make it. Much appreciated.
Thank you.
Good video, very informative. FYI When model locomotives started getting bearings 100 years ago it was to reduce wear, and examples I have definitely bear this out. In fact literature didn't mention free running at all, just longevity and the ease of replacement. The massive weight and huge motors in use at the time caused a lot of wear in higher mileage models, even through the very substantial sheet steel frames.
With brass bearings on the axles and gearing this was of course measurably reduced. A supermotor has 3 separate brass bearings just on the armature.
Good viewing chap :)
Sam, I wish you'd do more of this kind of video. You are very thorough and your insights help me enormously on my own railroad.
Excellent video. Definitely need bearings!
Thank you!! Yep absolutely :D
Thanks for watching - Sam :)
Well done. You seem to have been very thorough.
Excellent demonstration. I like your channel a lot because you do explain a lot of technical topics that are rarely covered in the hobby. Thank you.
Probably one of your best “investigation” or more educational videos on the channel, maybe even the best.
I have an old loco from the 60's that to my shock has actual, very tiny ball bearings. The detailing is very basic, and the (all metal) chassis is robust, but even the gears are made of brass, and even with all my modern locos this old-timer is still in my top 5 with the lowest current draw, when it runs "solo" (even has a flywheel sort of)!
Yes ultimately precision bearing show an extra level of design in a product. And yes you are correct in calling the "brass" bits bearings and not bushes. I won't bother going into the difference, suffice to say they are indeed bearings.
However as an Engineer I can spot several things you didn't perhaps realise.
A product is generally designed to a minimum specification. The choice of be axle location system will be calculated on multiple factors, not least of which is price. But it goes deeper than that, the gearing, the size of motor used, the weight of the item, its expected life span ect ect ect all play a part on the design process. Ultimately if something performs within specification with a cast Zamak bearing then it works as intended.
For your experiment to be conducted properly you would have to know the exact dimensions of any of these parts, the specifications of the surface finish, the precise specification of the materials and any lubrication that's used.
Bronze, brass, phosphor bronze, Zamak ect all have different properties. These properties can change as they are used in their application.
High precision industrial machinery use multiple different material for bearing surfaces depending on what they do and which part of the machine it is.
All bearings have recognised tolerances. These tolerances can be easily found in places like the Zeus book. Knowing what is intended by the designer of the item gives a clearer indication of the quality of the part.
In short though I do agree that precision bearings are preferable it is a far more complex thing than you may realise.
In the days of Triang and Hornby Dublo they fitted a large motor, so the bearings were inconsequential. When a manufacturer is producing 1000s of locos, then fitting a smaller motor means more profit. Your experiment proves that better bearings allow a smaller motor to be used. Thanks for doing all that work in Sketchup to illustrate this video.
You're logic and process was spot on. Any external force, such as friction from air, friction of the rails, the string etc, was exactly the same between both chasis, and therefore creating a controlled testing environment.
Having bushings definitely improves friction forces, but the ultimate performance of a chasis is a combination of bushings, design of the gears and the motor itself.
It seems that the non bearing chassis accelerates more once it starts moving which would suggest that there is a certain amount of 'stiction' that needs to be overcome to get the chassis rolling in the first instance. I don't remember you mentioning lubrication in the video, as this might be a variable that could have some effect on the results.
Yeah you’re absolutely right, I noticed that! We see this in performance of locos too - they seem to struggle to crawl more without bearings!
Really enjoyable video - more like this please!
I think your presentation is bang on accurate, great vid. 👌
Excellent video.
I'm particularly intrigued by the square slots producing less running friction than half-round raw surfaces, but creating increased inertia. This definitely tallies with my experience of Hornby Dublo and Wrenn locos, as some of the latter are re-engineered versions of the earlier chassis with square form bearing surfaces.
A well thought out experiment, and a well done experiment. As for not testing in a vacuum, which made me smile, the fact is we don't operate our trains in a vaccuum! Terrific video!!! Thanks for the information! Now, to go look at my engines.....
Excellent video explaining a subject I had always wondered why for the money that some manufacturers charge they didn’t or don’t fit bearings
Sam, considering that you're carrying out home brewed testing, your methodology is excellent, particularly carrying out several tests in order to obtain an average. Sampling more than one type of wheel arrangement in order to get some idea of possible variations caused by valve gear friction is also noteworthy. The only thing I would add is that as the friction of your string over the book is likely to be much the same no matter which chassis you're testing, the true percentage difference between the bearing types will be even greater, though by how much would require further work to determine. However, I'm not sure that "going straight for the nuts" is all that scientific!
Thank you for this; a very valid, useful and cogently presented offering. Congratulations, excellent job, a lot of effort on your part, which has paid dividends. MW.
A very educational and informative video Sam. I learnt a lot. I hope the manufacturers are watching. 😀
Great and very clear video with a perfectly accurate result. Nice work Sam 👍
Great idea for a post Sam! I hope we can look forward to more of these takes on construction/maintenance as an 'occasional series'. Idea: explain about pole motors - you often mention the number of poles and I've picked up that more is better, but have no clue why! Thanks.
Real world example, last year I did two turns on the Talyllyn Railway, my loco for the day was Tom Rolt. In the morning my train was made up of the original coaching stock plus the Corris coach. The original coaches are on packed greased axle block bearings. In the afternoon my train was bogie coaches running on roller bearings. Despite the TR being mostly downhill on the return journey I found I needed to open the regulator more to keep speed and counter the friction of the drag of the morning train, in the afternoon it was more about gentle brake applications to keep the train under control.
Excellent point well made in an easy to understand way. Makes perfect sense to me 😊👍
Bronze, from which this bushings are made, a much harder and wear-resistant, than pot-metal, from which chassis are made. I have some Roco diesels, which don't have bronze bushings, just axles in cast bogie gearbox, and after little use I have scoring on all axles in friction area (dirt and abrasive particles get embedded in soft bearing surface of pot-metal and began grind the axle). However on locos with bronze bushings everything looks like new.
The main point of this bronze bushings - decrease wear and increase longevity.
Brilliant investigation! It's this type of content that makes your channel so good. I wonder if the slot and axels on the non-bearing locos become hot during use (they would if it was a real loco!). It would be interesting to run bearing and non-bearing locos for extended durations and then view the slots or bearings with a heat camera. I also wonder if coaches should have bearings rather than pinholes in the plastic moldings?
Well explained Sam. I find that even on wagons and coaches, adding pinpoint bearings makes them roll more freely.
As for those square holes, I had an old Mainline/Bachmann with a lot of wear to the chassis in that area.
I ended up cutting half circles of brass tube and epoxying them in place - It's never run better :)
Super well done Sam! Clear and concise and proves your point very well.❤️🤓
A bushing used with a rotating shaft (the axle) is known as a Plain Bearing. That's definitive.
EXCELLENT VIDEO Sam , I'm a big fan and love your channel keep up the good work. Best wishes to you mate 👍
I very much enjoy these little experiments.
Hello Sam. I was given some information about the real railroads that dealt with mountain grades. In the beginning, rolling stock were built with friction or "Solid Bearing" axles. Good for not much. And, eventually roller bearing axles on locomotives came into building, followed by passenger, and then freight cars/wagons. This was a major point in pulling uphill. But, it was the downhill experience that was to be relearned... No friction to hold back and MORE brake shoes burned up, shortening their use, because, now you have got an entire train with "Free-Rolling" axles! That required a new skill.
John BC, Canada
A fascinating investigation. Thanks for sharing this.
A very good video overall as usual. One point I do feel that is worth bringing up though is that not all bearing are made of the same materials though so the logic that bearings are better can't be applied universally. For instance a loco with bearings made of poor quality metals might be worse off than if say it had no bearings and the axles just sat in the chassis made of high quality metals. It's also worth noting even though you probably already know this that bearings don't make or break the performance of a loco a good motor, competent gearing, good weight balancing, etc. I do agree with your overall point that good quality bearings certainly do make a difference.
I'm just about to build an 0-8-0 Hunslet shunter - a brass kit. The kit expects solid brass bushes, I was going to upgrade that with sprung brass ones on the inner axles. Having seen your vid, I've bought some top hat 6mm oilite bushings, which I'll ream out to 1/8". These will be sprung.
I've made quite a few brass kits and properly aligned, accurate and chunky bushings definitely make a difference. Limited travel with springs on 0-6-0 and especially 0-8-0 to make sure each wheel touches the track. It's easy in 'O' gauge. 'OO' is a bit fiddly, but worth it 🙂
Sam, you do some very interesting experiments - keep it up
Thanks for an informative video. Like you I am strongly in favour of bearings. I will have to take my Hornby 4F to pieces to see if they have bearings. Certainly they draw far less current than my older ones. The same has occurred with the 2P 4-4-0. I had put it down to being loco driven rather than the tender driven ringfield motor.
Well put together video - I agree totally! A lack of bearings also can result in wear to the plastic base keeper plate from the axles. I have often encountered this on old split chassis locos and it accentuates wheel movement and can affect gear meshing consistency. I have successfully 'filled' this wear with plastic repair but it is further evidence of a very poor design.
This is very interesting Sam you should do more like this ;)
Cheers Jasper & Willow
Thank you! I really enjoyed it!! :D
Thanks for watching - Sam :)
I always learn something new from Sam’s videos.
Great video again thank you Sam. I think bearings also play a big part in reducing the noise of a loco.
What about "Starting Friction" ?:
Stiction has been a part of the English language since at least 1946, when it appeared in a journal of aeronautics. While stiction refers to the force needed to get an object to move from a position at rest, it is not related to the verb stick. The word is a blend word formed from the st- of static ("of or relating to bodies at rest") and the -iction of friction ("the force that resists relative motion between two bodies in contact"). So, basically, it means "static friction" (or to put it another way, "stationary friction").
My German Trix generally only have bearings on the axles directly driven by cogs. In one instance that's all 5 axles in others only 1. Other axles are set in circular grooves in the zinc alloy and the interior axles are sprung with large amounts of articulation for curves and turnouts.
Hi Sam.
1) What's a 'fizzitist'? 😂
2) Did you oil the axles first?
3) Excellent demonstration for the scientifically uneducated. I'd have thought the majority of modellers were aware of the reason behind the fitting of bushes/bearings, but what most of us probably didn't know was how much of a difference these bushes make with regards to the resistance of the free running of axles.
May I be so bold as to suggest you continue with your scientific experiments, even though, as you said, you're not a 'fizzitist'! 😀
Paul. 👍
brilliant experiment. Very convincing
hi sam. a back to school video. anyone with a bit of common sense should know that when a shaft is fitted with bearings provide less friction when rotating which equals less force needed to turn and less wear and tear. as you explained well. a chassis will be grinded away in time be it over a long period of time in such a small size but never the less it gets eaten away thereby causing more strain on the motor until it eventually burns out or becomes to weak to power the model which incidently is what manufacturers want to keep their spare parts division busy or sales of new models up.
An important point to make is that the bearings themselves should never! ever touch a part directly at all. It's the thin oil film created in between the parts that prevents them from touching. This is what a glide bearing does, it separates the moving parts from each other by producing a microscopically thin film of oil between them. Now with these bushings the same is achieved by the material itself. It is very porous. If you look at it under a microscope it's not smooth at all, rather resembles a gouda cheese. So what the car industry have been using in starter engines (the top bearing) is a little brass washer that gets put into an oil container for it to absorb the oil in it's pores. This oil warms up when friction between the moving parts occurs and viscosity ensures the tiniest bit of oil gets released causing the film between parts to appear.
Now, you mentioned the bearings are to be oiled every now and again and replaced when worn, but here is the thing. When servicing your loco's, take the bearings out and let them soak overnight in oil so the pores can fill up with it again. Do this at regular intervals and you'll never have to worry about friction anymore, nor will you ever have to replace the bearings. Remember, it's the oil film that does the heavy lifting, the bearing is just there so the film can form.
Hi Sam!
Back in the day when I was driving RC cars one of the first upgrades on the list was swapping out the stock bronze bushings for a set of ball bearings. It made such a difference that trains having bushings as the premium option has always felt pretty rubbish.
What would a train built using ball bearing everywhere perform like? I imagine like a swiss watch compared to what is available now but theories need testing!
When the models get to a certain size ball bearings would be almost impossible and expensive to produce in a commensurate size which is why quality watches use 'jewels' as bearing surfaces.
Being in O Gauge (3-rail) I'm only aware of the top-end locomotives in that scale being equipped with ball bearings. The US passenger cars produced by Golden Gate Depot are equipped with ball bearing trucks, and their sister operation 3rd Rail, is incorporating ball-bearing trucks into their newest O scale locomotives.
Excellent! I now clearly understand the importance of bearing.
Lovely video sam
This was quite interesting to see! Thank you for putting the time in to do this
Question: have you ever had the experience of testing one of the Bachmann starter set Steam Locos? (I think Yard master was the name of the set)
hi Sam, bearings are a great idea,back in the day Triang locos did not have this,as i have Triang locos regular lube inspections are important, hope the new hornby jinties will have bearings,
My degree is in physics and there is an important gap in the experiment. You are measuring static friction, but not kinetic friction. Static friction is the high knudge needed to get something moving. Kinetic is the drag after some starts moving. To measure kinetic friction the best method would be the most difficult. Push each train at a known speed, and measure the distance each travels. Given the challenge of moving at a knoe speed you could put a higher weight, say 25g, and measure time needed for the weight to hit the floor. The second method would be effected by friction in the string mechanism as well as the static friction, but I would argue that while these shortcomings would effect the absolute numbers they would not effect the test of your hypothesis, that bears have less friction.
Thanks for the awesome feedback Andy - yes you're right this only tests static friction. I know exactly how I could test kinetic friction, so I might give that a try in another mini experiment,
Thanks again,
Sam :)
@@SamsTrains One idea for kinetic friction : you can manufacture an hammer-like pusher that strikes the rear end of a test vehicle motionless on a flat piece of track, and measure how far it goes. The hammer had to have a 1/4 circle downwards motion to strike the idle vehicle, and have a calculated mass to give consistent results.
[Sarcasm:] In Yellowstone, the bears exhibit a great deal of friction, especially if the subject does not remain in his car. And don't even think of "going straight for the nuts."
Really interesting and relevant video there Sam. One question - how does this relate to curves? Is there a risk that bearings hold the wheels too rigidly and result in greater resistance when running round trainset curves? Could no bearings allow greater movement to allow wheels to move more to the shape of the curve - with less resistance?
Hi Sam. Even though we intuitively knew that bearings are better than no bearings, it's nice to see some proof. I'm not so sure how negligible the effect of air resistance caused by the added weights to the chassis is; I would have liked to have seen some card (or other material) added to the heavier chassis to compensate.
SMT is obviously on your watch list. 🙂 Great content as always Sam
Great Video Sam. Thanx for all your efforts and Testing and re Testing to get an Average was just Brilliant.
Well Done Young Sir..!
All that's needed now is the Model Makers to get on Board.
If Charging Big or Megga
$$$ or £, €, or ¥ for your Product, stop Scrimping on Quality, if you want a Happy Customer..!!
I will Not mention names. But pull your Socks up Guys..!! You know who you are, and so do the Buyers..!!
Thanx again Sam. Well done for Pointing out the Shoddy Practice..!!
Cheers All.
Also by removing that slop it must have a greatly beneficial effect on the noise produced by the loco
Sold my bachmann 9f cos it sounded like a box of metal bolts clanking. My new Hornby one sounds like butter on a warm pan. 😊
EXCELLENT Video Sam
Brilliant👏🏻. Very interesting. Cheers. Oh, and good science 👍🏻👍🏻
Hi Sam, great video. Your testing shows how bearings affect how much force is needed to get the chassis moving. In reality it is the axles turning that get the chassis moving. The conclusion is the same bearing make a big improvement to performance. The difference may be where the wear occurs.
The brass bearings retain oil better by filling the clearance so there is always a wedge of oil at the load bearing point of the bearing to give the thin film required.
You did not appear to mention lubricant for the respective bearings mukka. How did you measure the amount of lubricant on a bearing or mere frame notch?
You should have used a locomotive in Reaearch Livery!
Good work chum. Regards from Oz.
Gaz
I think some manufacturers need to see this Sam.
Cheers Jasper & Willow
Yeah!! Hopefully - though most of them use bearings already!
Thanks for watching - Sam :)
Awesome video again there Sam ,, I have often wondered why the manufacturers made these axles with no bearings but it's pretty obvious.
Planned obsolescence ,, like they did in the mid to ealry 60's where the quicker something wears out the quicker they will be replaced. Its All about the dollar too I suppose.
Cheers from John in Australia
Interesting. Thank you 👍
Hi Sam, very good video, have you thought of using graphite in a pencil instead of oil for a lubericant, might be interesting?
The other factor that is worth considering is the friction between different materials. The cast chassis material, even if machined to fine tolerances, which is possible to do, will have a higher friction than would the bronze bearings that you and other manufacturers are using.
I find this video very interesting, I do have a Question and that question is this its about lubrication on the bearings what would happen if you have to much and what would happen if you had not enough would of been interesting to see the out come of it, because you were deal with bearings and the fixture and fitting.
Conventional knowledge is that too little lubricant increases friction and wear. Anything beyond the correct amount encounters rapidly diminishing returns, accompanied by making a mess and attracting contaminants like dust/dirt.
Thankyou I really enjoyed watching these instructions. No I'm not going to do a treardown of my locos thankyou very much; too old to start that.
Turned brass bearings do give smoother running BUT issues I have experienced starting with Hornby large Prairie, 72xx. Intermittently stalling on points there needs to be some movement in one axle at least up and down to keep wheels picking up power.... I ended up fitting stay alive on DCC. Hornby had the Prairie back 3 times as main drivers did not all sit on plate glass without wobbling.
That's interesting! But even without bearings that issue could still occur - many manufacturers do fit a sprung axle to their steamers, and they don't have to sacrifice the bearings to do it!
Thanks for watching, Sam :)
A great video well done, it would be interesting to see if you are able to 3d print some semicircular bushes/bearings to fit the squared chassis blocks (like in the bachmann Robinson 04) and see if it made a noticeable difference in performance? Nylon bushes are used in many other applications so could it work for this?
Its a trade off between friction and wear. A greater area will increase friction but reduce wear. You see that in wagons with pin-point bearings which at first have minimal contact area and are very free running. However due to the small surface area they wear out quicker. I have this with an ex-Lima PCA cement wagon set.
Bearing area is not related to friction. Pin point bearings have lower rolling resistance because the bearing diameter is smaller compared to parallel bearings.
@@terryflynn8830 Haven't you contradicted yourself? If Bearing area is not related to friction then why would it matter that bearing diameter is smaller compared to parallel bearings?
@@alanrobertson9790 The difference in rolling resistance you are seeing relates to the basic reason why the wheel works. The larger the ratio of the wheel diameter to axle diameter, the greater the mechanical advantage. Think of the wheel as a vertical lever just before you give it a push with the centre of the axle and wheel as the fulcrum.
@@terryflynn8830 Levers etc perfectly true but off topic. The lever principle applies to any wheel whether low resistance pin point bearing or not. Do bearings with a large area offer more ROLLING resistance - yes they do. Think your original statement about area not being relevant only applies to sliding resistance. No need to tie yourself in knots there are plenty of information on the internet.
Good experiments Sam, which got me wondering if any manufacturer produces ceramic bearings/journals? I come from the cycling world where some moving parts have ceramic bearings, mainly, I think, balls and races or needle bearings on derailleur and crankset and wheel axles
Hi Sam
I assume you did not try just letting the roll down Gordon’s Hill to see how far they got. If the initial impediment to moving (the technical term is in other posts) means they, or one, cannot start, you could give an equal impulse push to each.
The points about the oiling of the bearings or cut outs possibly being a difference may be valid, but it is hard to see that it would be the whole of the difference.
An outstanding video, and great to see those with appropriate professional expertise confirming your thesis and proof. The University of Life course is often very good!
Great video. ☺️
Thank you!! :D
Very interesting video today Sam
My thought was that the brass is a softer metal than the iron or steel chassis and that perhaps there was a small bit of rotational freedom to allow the axle easier spinning properties.
Great video! I own four Bachmann American locomotives and sadly, none have bearings. It makes servicing a pain as I have to oil them constantly in order to keep them running smoothly. By the way, does your Baldwin 4-6-0 produce a lot of motor noise? Mine does and I was wondering if I just got a bad example. Thanks!
First Class Video, is this the first model train paper to be peer reviewed on line?