The Science Of Roundness

[@bluejack644]

Fun fact: The red tip on the end of the probe (in the thumbnail photo) is actually a precious Ruby gem. I was a machinist for several years and worked in the CMM room occasionally where precision parts were measured in x, y, and z axis. They use a Ruby tip on the probe because it can touch objects many thousands of times without wearing out or becoming disfigured or flattened on the end, from repeated long term use. It maintains a perfect surface tip for touching and measuring with precise accuracy for repeated regular use over extended periods of time, as an accurate precise measuring device. Once the probe touches a part in many points, in all axises the computer gets a picture of exactly what the part looks like, in order to maintain continuity of accuracy in the production process of the parts being machined.)

[@hazza2247]

very interesting fact, any reason they don’t use diamond? is ruby better somehow or is ruby simply just ‘good enough’ and cheaper?

[@theondono]

@@hazza2247 diamond coated tips are used in some very specific applications, but cutting a diamond into a sphere with tight tolerance would be hard.

[@hazza2247]

@@theondono makes sense, thankyou

[@Metal27928]

Same reason rubies are used as bearings and pivot points in mechanical watches.

[@volbla]

@@Metal27928 I was just about to ask! Watches are so cool. They're like a miniature engineering exhibit.

[@lewzero]

Wow, that "125 feet" comparison made me realize how incredibly well made ball bearings actually are. Amazing video, thank you.

[@HelloKittyFanMan.]

Bearing balls, actually.

[@harryharrison4876]

Well, as long as they’re not Chinese...

[@h3xagon0001]

@@HelloKittyFanMan. Balling bears you mean

[@HelloKittyFanMan.]

@@h3xagon0001: I _do?_ So you think you're a mind reader?

[@jeron9272]

@@h3xagon0001 Nonono, its bear balls

[@ai4px]

This and the History Guy are what needs to be on Discovery Channel instead of all that reality TV programming.

[@octane613]

This is what it used to be like. It's what I grew up watching, and it truly expanded my way of thinking of how things are made, designed, etc.

[@pvic6959]

discover USED to be that. i used to spend so much time on it as i grew up in the early 2000s. its what turned on me onto science in the first place

[@frontiervirtcharter]

But advertisers are willing to pay more for the audience that follows reality TV, and the stockholders listen to the beancounters.

[@trackie1957]

I’m a retired mechanical engineer and I’m just loving your descriptions. Stuff that I’ve intuited you have expressed wonderfully.

[@erikjohnsen807]

I’m planning on studying mechanical engineering this fall, and these videos are getting me even more pumped for it.

[@matito_67]

oh boy just wait until finite elements, jokes aparts the best career in the word

[@theghostmachine]

By the time you finish your degree, I doubt you'll remember roundness measurements, unless you do a project in this subject.

[@VadersAprentice2000]

Wait until materials science. Hard as fuck but incredibly interesting.

[@dizzywow]

Patience. You've got a year of calculus and physics, first.

[@mrwess1927]

How is it going, don’t give up

[@kirara4953]

"The wheel is a bunch levers organized in a circle." Whoever invented the wheel got discredited so hard

[@firefox5926]

i think youre thinking of gears :P

[@fomalhaut_the_great]

@@firefox5926 watch the video before commenting

[@firefox5926]

@@fomalhaut_the_great in a brave heart-esque yell "NEVEEEEER" but on a more serious note i prefer to do a running commentary as a watch :)

[@the_hanged_clown]

too bad so sad wakanda

[@tensevo]

The wheel: I invented myself

[@ijuvatar]

as a former specialist in the field of measurement technology i approve this video

[@alligatormonday6365]

Metrology is so interesting and important.

[@BillAnt]

@Steven Cone < You're right, especially for guys who like to measure certain parts of their body... if you know what I mean, ;D

[@shankarnarayan3118]

Your no one to approve the video

[@felixschrodinger7533]

Only thing I disapprove is the use of the imperial system. Especially when talking how accurate machine tools should be and the machines use metric.

[@AndreAnyone]

#$600OrWAR ! give us our fvcking money! “every society is just 3 meals away from revolution” March on Washington! surround senators homes 24/7 "the french aristocracy didn't see it coming either!" they have unlimited money for wallstreet and the banksters and wars but only crumbs for us ? time to rise up! DEATH TO TYRANTS ! protest with GUNS so what do you think is gonna happen when 50 million people start to get evicted ? you think they just gonna lay down and die?? lol they are going to burn Washington to the fvcking ground !!! jfj

[@ringlord13]

Got here from the Flatness video, this one is well done as well for a high level introduction. A great follow-up to this one would be a GD&T specific video on the differences between circularity (roundness), cylindricity, run-out, and total run-out. You may find your word choice in this video isn't quite as precise as it needs to be if you dive into that rabbit hole. Well done nonetheless.

[@samp-w7439]

Same here. I preferred the flatness video.

[@earthenscience]

around 5:00 they go on about "constant diameter" then go on some long winded explanation about circumscribed circles, instead of just saying to use constant radius. i quit watching the vid after that lol

[@lucasng4712]

@@earthenscience no

[@Factory400]

Roundness is directly proportional to the volume of beer I consume in a given period of time. I am now perfectly round as I have optimized my consumption of beer.

[@the_original_Bilb_Ono]

I would like to apply to be a test subject to further your theory, Professor Ale.

[@alphabravo8850]

Lol

[@jamesbra4410]

Im surprised you can finish typing your comment. I would have probably rolled down the street.

[@Kev376]

Now to find out why my girl looks this way in... The Science Of Flatness

[@mal2ksc]

That's one sure way to get in shape. Round is a shape!

[@tylercgarrison]

came here from the "science of flatness" video. This was just as good. Keep up the great videos my friend.

[@joemathew7284]

Me too lol

[@barthooghwerff1682]

I love your approach to these videos how you start at the fundamentals and end with the limit. Very thorough!

[@jmchez]

This was great! I love details of precision machinery, the science of metrology and ideas of quantum mechanics. You combined them all. Very well done. This channel and "Machine Thinking" go very well together.

[@LaGuerre19]

The roundness of those silicon spheres at the end is mindboggling. Another great video; thank you!

[@NC-oy8hq]

I used to have to change tools in a horizontal mill and tram them in to less than 50 millionths TIR , the set the front of the insert to 6-9 microns above the guide pads and about 15 microns below at the back ... I would say this is a very truthful and informative video

[@redpilled3569]

What type of indicators did you use and who was the work for, nasa?

[@NC-oy8hq]

Red Pilled mititoyo , and basic production machine shop. When your shoving a one shot boring bar ( no rougher ) that’s 4 fluted , pcd tipped , and 385 mm long down an aluminum part in 3.2 seconds holding plus or minus .015 microns on diameter , shit has to be straight.

[@RainBoxRed]

Was doing some reading and it seems the ways of manufacturing machines often use moore scraping to get them very flat. The techniques are amazing really when you get to that level where holding a part and heating it will give you measurable deviations.

[@snaproll94e]

I felt like I was watching the fundamentals of a GD&T class. Good stuff with great illustrations of principles.

[@DougDingus]

These are well produced, concise, informative, and inclusive. Well done!

[@zvisger]

This channel makes the best content. He makes it feel as prolific as it is.

[@motonol_409]

this is pure gold. bestexplanation of the mechanical engineering basics ever!!! keep up the good work

[@thelunchbox420x]

I just found you in my suggestions after watching a bunch of space videos and I'm glad you did. I love the information and how in-depth you go. Thank you for making all these videos, they are really interesting. You earned a new subscriber.

[@klazzera]

when you try to drill a thin sheet of metal, most of the time the drill hole is a reuleaux triangle. i never realized that this shape has a constant diameter, it all makes sense now since the drill bits are almost a line in their cross section.

[@klazzera]

follow up: i meant the regular twist drill bits. there are also special stepped drill bits for thin sheets that drill a nice round hole.

[@GenoLoma]

@@klazzera Also, use a vise to hold the part, oil for lube, and go slow on the drill press handle.. assuming of course that the roundness of the required hole is important.. ;)

[@klazzera]

@@GenoLoma yeah also you can use a piece of oiled fabric between the part and the drill, not sure why it works but i saw it on youtube, better for big sheet metal structures when you cant use the press

[@dustinjames1268]

For drilling thin sheets I always put hardwood underneath and slowly drill through into the wood below The pressure from underneath keeps it flat and the slow steady follow thru keeps things round

[@klazzera]

@@dustinjames1268 that would also keep a steady center resulting in a circle hole

[@kerryh8er04]

Your metrology video's are great. Really clear and concise.

[@sasquatchhadarock968]

Got a job as a machinist a couple years ago and they made us watch these cringe-ass corporate training videos from the 70s/80s. They ought to be using these videos. 👍

[@SonOfAntalis]

I am late to the party. Your videos are amazing. Great quality, narration, information distribution, and length.

[@captainkiddoregon]

Interesting timing on this video. I was just sitting here trying to figure out what roundness callout to be measured on a SLA pattern we just built. Not that the video gave me that number but it was still educational. Thank you.

[@aahillakhani399]

It's crazy how the intro could be a short video on its own. My new favorite channel

[@peteroleary9447]

Great video! I'm glad these are showing up in my recommended. These videos make a great compliment to the Machine Thinking channel. FIM (full indicator movement) is slowly replacing TIR on engineering drawings. I would've liked to see discussion of roundness vs cylindricity vs sphericity. Roundness has a somewhat transcendent quality because it only exists in 2 dimensions and doesn't exist in a 3D world.

[@jmchez]

The "Machine Thinking" channel is the first thing that came to my mind. They both, do indeed, go well together.

[@janvanruth3485]

3d roundness= a ball

[@ttiff97]

More GD&T videos please!! As a recent MechE grad these are super helpful in improving my understanding of GD&T

[@blabby102]

Really nice video. But if you are talking about metrology at such a high level, why on earth don't you use metric?

[@ajinprakash9763]

True though!!!!! Anyways great video.

[@RainBoxRed]

Although I agree, it isn't really an issue as the conversions are all exact and this video is more about the techniques rather than the units of measure. And I hope they use metric on the ISS.

[@GenoLoma]

@@RainBoxRed dude, of course they do.. EVERYONE uses metric, except most of those stubborn buggers on the other side of the Pacific, and half their northern counterparts.. ;)

[@AirCrash1]

Good point and the USC is not a true measurement system as it has no references other than to the Metric system. The USC is a trade barrier employed by axis of evil countries like the USA and North Korea.

[@adoatero5129]

I'm just a layman, but in the middle of the video I too begun to feel that something is not quite right. At first I couldn't put a finger on what it is, but a little later I realized that it's the words "science" and "inches" used together. It doesn't ruin the video at all (I think the video is very good). It just feels a little off. On the other hand it's easy for me to notice, as I live in a "metric country". I have a great sympathy towards those people who don't learn to use the metric system as children, and for some reason have to learn it when they are older. The metric system is of course easier than the imperial system, but you still have to "grow" to it to feel comfortable using it. I'm glad that I don't have to learn the imperial system - that would be torture. Well, I know that one mile is about 1,6 km, and an inch is about 2,5 cm, but that's about it :-). And of course the actual torture aren't the units themselves, but counting and converting between them.

[@ezzywill7467]

I like your use of terminology with explanation. Many of my colleagues including myself in the manufacturing industry refer to these different types of measurement incorrectly and resulting in confusion regarding this very subject. Thank you

[@satyris410]

My life is complete, a video that uses "datums" as the plural of "datum" and "data" as singular. I'm just playing, I love this creator, one of the absolute best on YT

[@bentonrp]

Your no nonsense approach is refreshing indeed.

[@PPYTAO]

My new fav channel! Keep up the amazing content, you’ll blow up in no time.

[@gambero972]

Master piece! You just made a summary of 2 semesters of my engineering course.

[@Aufenthalt]

These are videos which make KZbin a better place.

[@AlexLopez-gn8qc]

I took metrology on my first semester of college, was the best class. Something so natural as measurements can be so unique

[@BrianHoff04]

I measure this stuff everyday and believe this is a terrific video to explain to the production folks exactly what we are measuring and how that measurement is being made. Thank you.

[@FortisNome]

A few videos later, you have convinced me to subscribe! Keep up the great work!

[@ahndeux]

Congratulations! This video was better than Melatonin in putting me to sleep. 5 minutes into it, and it was lights out!

[@ItsJarred260]

You give people such a good understanding of what I used to never be able to understand

[@ag135i]

This is a different and unique video video from the regular mainstream videos in a good way I mean, thanks for the informative video.

[@qutaara3454]

Why this channel has only 300k ! Explanations are astonishing! Luv it

[@Glenn.Cooper]

Really enjoy your channel! A great look at aspects of engineering and related topics that I haven't really seen covered - at least not so well.

[@truevision1463]

The reason why the wheel reduces friction is because when a wheel is rotating, without any force being applied on it, the point of contact is at rest when compared to the ground. This is because the point of contact has two components to its velocity, one the linear motion of the wheel, and two the rotational component, which are equal and opposite to each other, when the wheel is perfect rolling. And since there is no relative motion between the wheel and the ground, there is no friction. Also the frictional force between two surfaces only depends on the normal force between them, and the materials they are made from. It is independent of the surface area of the contact

[@peetiegonzalez1845]

The friction remains at the axle but is easily overcome thanks to the leverage offered by the wheel.

[@HotelPapa100]

What you say about friction is a theoretical concept laid down in Coulomb's law of friction. It does not hold up to close scrutiny in practice; the coefficient of friction is NOT constant. Both speed an pressure have an influence. As for no friction between wheel and surface: again, this is an assumption of perfection. The touching surfaces are not infinitesimally hard; they deform on contact. As there is hysteresis between compression and release, the center of force of the contact area is shifted from the point exactly under the axle of the wheel, resulting in a small distance that acts as a lever. Rolling friction thus is sometimes expressed in terms of that "friction radius"; this concept explains why larger wheels roll more lightly, (that, and the fact that they re less disturbed by imperfections in flatness on the surface they roll on.

[@peetiegonzalez1845]

@@HotelPapa100 That's totally irrelevant to the point in the video about leverage. If your wheel was the same diameter as your axle you'd have a hard time overcoming the friction. With a large wheel on a small axle you have leverage making it much easier to overcome the friction, because there's less distance for the rubbing surfaces to travel against each other, and more force (torque).

[@HotelPapa100]

@@peetiegonzalez1845 I was replying to Sankar Manoj. That the lever in a wheel is hidden in the ratio outer diameter to bearing diameter is kinda obvious if you analyze the problem a little more in detail.

[@ericpatterson3887]

Not sure why 374 people (at time of typing) chose to give a thumbs down. Must be competitor video content makers, or some incredibly snobbish scientists who where looking to criticize this video. Very well done video,and well thought out. Thank You for your effort, it was quite informative and entertaining. Good editing, good audio, all around good production values. Keep'em coming!! When I was watching this video, I couldn't help but think of all those people who believe in evolution (yes, creation evolves, but that is obviously by design!). If you can't see design in the things around you and call the designers' works "mother nature", then you are being blinded by man's ignorance. I can't see how you could miss the glaring evidence of a creator in the simple things, much less the complex things!!

[@WildmanTech]

Excellent treatise! I wanted to do this on my channel, but I like your's so much I'll just send people here!

[@RacingTIR0]

TIR0 I came up with this user name some 20 years ago. Over time I found out dozens of meanings of the word which always fit me. And you just unraveled another one, the biggest meaning so far. And it fits me again perfectly since I’m a notorious perfectionist.

[@mad-cyantist3159]

Great video. Such a simple thing runs our world.

[@paul_fredrick]

Great job explaining stuff. Feynman would be proud.

[@MichalL_77]

Great video ! Could you include metric measurements as well ?

[@dr.blauerkraut]

L+Ratio lmao Get 360NoseFucked N00b gg

[@mraxilus]

Full agreement, I'm surprised that more people aren't upset about this.

[@edwincloudusa]

He already got me mesmerized in the first 4 minutes when I realized it was just the intro!

[@ralphdoggie]

2:33, this double's the torque at wheel A's axle, not B's. 2:59, the reason a wheel reduces the effective coefficient of friction is NOT because only a small area of the wheel makes contact with the road. It IS because the vertical force on the axle bearing is (essentially -- see below) the same as the force between the wheel and the road. If the wheel is rolling, the sliding friction force acts on a lever length equal to the radius of the axle bearing, whereas if the wheel is sliding, the sliding friction force acts on a lever length equal to the radius of the wheel. The friction is reduced by the ratio of the two radii. Note that the above is for the simple case of same coefficient of sliding friction in the bearing and between the wheel and road, a simple sliding bearing (versus roller or ball bearing), and uses an ideal wheel (as mentioned in the video) that doesn't deform under load, and has zero weight (even real wheels weight much less than the loads on them).

[@Penguin_of_Death]

The word 'doubles' does not need an apostrophe

[@trackie1957]

Fascinating video. Runout is not necessarily caused by out of roundness. At 8’22” a shaft with a smaller journal is shown. If both cylinders are ‘perfectly round ‘ but their axes are not concentric, non-parallel, or both, runout will be present. In this demonstration, the runout decreases as the indicator was lowered. Either the journal was less round at the shoulder than its tip or its axis was not aligned with the body of the shaft (or the specimen was not held properly in the fixture...).

[@RichardBaran]

Wow I can't believe you don't have more subs. Excellent content!

[@FilterYT]

I'm new to this series, thanks for sharing such great content!

[@jennyanngarcia1031]

This video is informative and helpful.. ..been looking and searching for some information that i can learn to solve my problem about unsble rondness ... many mechanical set up and replacement of machine parts and toolings were done , leveling of machine and runout checking of spindle were conducted.. yet same problem still occur most frequently.. i just hope, this channel.can give.an additional advice and solutions.. thank you..

[@aculasabacca]

Great job, Best I've seen in a while, on any subject.

[@sean..L]

This is so interesting, I would have never even wondered about this stuff.

[@markswishereatsstuff2500]

Every once in awhile, YT's algorithm sends something that blows me away. Today was it.

[@spicylegato6024]

Bro nice! It’s so round!

[@theders311]

Why do I enjoy watching these videos AFTER I've spent too much time on my GD&T homework.

[@carterredfearn4249]

I just started my career as a CNC machinist. This video was absolutely entertaining and incredibly informative. Thank you for producing such a wonderful video!

[@philzail2532]

FNG

[@ConceptHut]

Very well done videos. This is probably my fourth. Next up, The Evolution of CPU Processing.

[@danieljakubik3428]

Impressive ending and throughly educational!

[@landenevans4938]

That was a well Rounded video!

[@groupchat2554]

Seriously amazing work.

[@SaiVihtooMyint]

Left the field of engineering but did really well in college Metrology, I always appreciated metrology and the precision of things we can make

[@yoddlegcoin]

Awesome channel, so glad it got recommended to me. Keep up the good work!

[@mikefelber5129]

Finding not only a fulcrum that could be strong enough to life the rock in the initial example & a force that could reach the height of such a long fulcrum are major considerations. Love these videos- Roundness, flatness- I didn’t even know ovality was a word! Soundly like an arthritis medication lol. #RockOn #KeepLearning

[@VoidHalo]

Wow, I watched 2 videos on curves,solids of constant width like rouleaux triangles yesterday. I didn't expect to see them again in this video. I just came across it while binge watching other videos on this channel. I wasn't actively looking for anything about rouleaux polygons.

[@tensevo]

Great video mate, it would be good to see you cover more mechanical engineering topics.

[@quosswimblik4489]

You can use circles to measure more in depth thermal and electrical properties of circuit layouts and place/manage the devices and required logic better.

[@TheAlison1456]

This channel is one year old and already has such quality videos. It's like the new Vsauce but without too drastic tangents. Though, it'd be good if you cited sources and additional reading in the description alongside the transcript. Possibly through another URL such as google docs.

[@EdgedPixie]

It's amazing that some chill music made me sit through a lecture on metrology. ...I'm a computer science student.

[@09NXN06]

I welcome this with exceptional insight!

[@rabarber9610]

With 292k followers honestly this channel is way underrated

[@justinberdell7517]

Great videos! I just subscribed!

[@philhawtin5269]

I really appreciate you doing these videos. Thanks

[@_Solaris]

Such basic concepts go so deep.

[@EchoDafunk]

Thanks for the info. I feel a little smarter. 💪😎

[@zachcrawford5]

A constant diameter doesn't constitute roundness but a constant radius does.

[@pork_cake]

True, but as he mentioned in the video an axis or point of rotation is not always available or useful in metrology, which is why the circumscribed/inscribed circle method is the preferred fundamental principle.

[@zachcrawford5]

@@pork_cake I didn't quite understand how you find those circles with out a physical center.

[@SlyNine]

@@pork_cake but how do you know you created a circle to measure if it's a circle?

[@jadesmith6823]

Brilliant 🙏❤️🙌

[@ndyce]

@ 9:05 I experienced an endorphin kick when seeing the dial gauge shape up to 5 to 1. Having spent the last six months dialing in bicycle disk rotors seeing something go from 5 to 1 on a dial gauge makes happy. ROUNDNESS!

[@nbaua3454]

This video can be a semester project highlight.. nice

[@recklesflam1ngo968]

loving this channel

[@jameswiblishauser9745]

this is so cool. subscribed.

[@DEtchells]

Really fascinating (as always)! I’m curious how they get to “first principles” roundness (for lack of a better term). For example, the metrology setup used a probe and a rotating stage. How do they know that the rotation of the stage is perfectly circular? I guess that’d be when it has zero TIR, but what if deviations in roundness of the stage just happen to correlate with opposing deviations in the bearing supporting it? The info on bearings was eye-opening, I had no idea they could be so perfectly spherical(!)

[@TheChrisey]

You can also measure roundness by measuring the radius of the circle at every given angle. The more samples you measure the more precise it gets.

[@trudyandgeorge]

Just a great channel. Keep it up mate.

[@akuhafiz1128]

VERY VERY EXTREMELY CRAZY GENIUS BRO

[@tamasmihaly1]

Beautiful stuff.

[@thelaw2174]

The lineup consisted simply of six hydrocoptic marzel veins, so fitted to the ambifaciant lunar wane shaft that side fumbling was effectively prevented. It's produced by the modial interaction of the magneto reluctance and capacitive directance. The original machine had a base-plate of pre-formulated amulite surmounted by a malleable logarithmic casing, in such a way that the two spurving bearings were in a direct line with the panometric fan. The main widing was of the normal lotus deltoid type placed in panodermic semi-boloid slots of the stator. Every seventh conductor being connected by a non-reversible tremi pipe to the differential girdle spring on the up end of the gram meter.

[@realitygaming7982]

Yet another amazing video

[@LeoStaley]

goodness I love your videos so much

[@dominicjose1116]

6:07 wow, you just explained the concept of circularity tolerance so easily...

[@brownmatthewn]

Man, this is my new favorite channel. Great work on these videos. Don't listen to the unit of measure trolls. The concepts you explain are of the fundamental nature of things, and valid regardless of units systems.

[@aledirksen01]

So I was watching the vid and thought it had a lot of interesting concepts in it and it all in that 4 mins. Nice vid and then I notice, that was just the INTO. Holy I will keep looking and will probably get my mind blown!

[@OutbackCatgirl]

i definitely wish there was metric in this video as well, i have literally no reference point for what all these numbers mean without a calculator :c i guess it is for an American audience so that's just how it is...

[@joelsterling3735]

Nice presentation, dude. I want you on my team for sure.

[@kaylor87]

Watched the flatness video a couple weeks ago, so of course, YT has been suggesting this one ever since. Can finally say, I'm glad I watched it! Sub'd after this one as well, thanks for the content!

[@irisartin385]

Runout isn't a measure of roundness the way you have it depicted in the video. If a component is in a fixed-axis rotational setup (as depicted in the video), then it could be perfectly round and still have non-zero runout if it's axis of roundness is not aligned with its axis of rotation. In other words, runout of a part rotating around a fixed axis is a measure of roundness and concentricity, and non-zero runout doesn't tell you whether roundness or concentricity is off. In order for runout to be a measure of roundness only, it has to be measured using a V-block, as depicted earlier in your video.