Heavier Sockets Make More Power? Stumps Physicist

[@eddie4453]

Mechanical engineer here, the goal of these attachments is to achieve better dynamic frequency responses out of the tool. The resonant frequencies are difficult to pinpoint and just about every condition influences if you can perform at a resonant frequency. If your attachment makes the tool perform at a natural, resonant frequency, you will see force multiplication on the output. I think there’s a MythBusters episode about this.

[@kco1270]

And it would make sense that the tools are tuned for the larger, heavier sockets that you would use with larger, higher strength bolts.

[@eddie4453]

@@kco1270 ideally yes. Unfortunately, a poorly chosen socket/extension could easily suppress and dampen the output torque of the tool. You saw some of this in the video. Dynamic systems and controls are a really interesting field of study.

[@blackcat31w]

Good line of thinking! Any time you hit something with a hammer there is some oscillation. If you hit the object again when the oscillation is in the same direction as the hammer blow you get an additive effect. Keep hitting the object and the oscillations of all the previous hammer blows add up and if you strike the object at the sweet spot where all the oscillations add up in your favor you get more effect.

[@bjmcculloch]

@Eddie To make this a testable hypothesis, can you propose a way to tune the resonant frequency of the system in a fairly continuous, reversible, and repeatable way? I’m thinking of a socket with a concentric outer sleeve (like the hollow design from the video) that has dozens of tapped holes for removable set screws to change the mass / rotational inertia. I guess they’d need to be blind holes so that you could set them to the same depth every time.

[@aviphysics]

Physics education myself, but thinking the same thing. Some kind of resonance seems important.

[@richardjones38]

What matters is moment of inertia, which is mass x radius squared. This is why your hollow socket performed well - it probably had the same moment of inertia of some of the far 'less heavy' solid versions you tried. The mass at the larger radius has a very big effect on moment of inertia, where the mass you saver by making it hollow has a relatively small effect. It's also why the IR one performed less well with it's flywheel cut off. You probably didn't reduce it's mass by much (30%?), but enormously reduced it's moment of inertia. You only have a limited amount of energy from each impact from the wrench to accelerate the socket. This is why 'heavier' (i.e.a higher moment of inertia) isn't always better. Imagine a socket with an insanely high moment of inertia. The impacts from the wrench will be so small relative t o it that it'll not move at all. This is why the whole front wheel doesn't turn when trying to undo a stuck wheel nut with an impact wrench - the energy from each wrench impact is almost totally insignificant because the moment of inertia of the whole wheel is enormously high relative to what the wrench is designed to turn. There will be an optimum moment of inertia of the socket for each impact wrench running at a particular pressure, where the energy it has from each impact to accelerate the socket is transferred most efficiently to the socket (and then 'dumped' into the nut or bolt. The highest readings you for will be where the moment of inertia of your socket most closely matched this optimum value for that wrench and air pressure (mechanical impedance matching).

[@adaycj]

By definition inertia is the resistance to motion or changing motion. Momentum is your friend here if you want a moving socket to move a bolt.

[@th3b0yg]

You make a good point. Moment of inertia is the relevant figure of merit, rather than mass.

[@davidmcgee2126]

Just reading the title not watching the video. I thought not much of a physicist. You are absolutely correct

[@adampetten1009]

I don't think this is happening, a heavier flywheel on a motorcycle works in this sence but the socket has no velocity so very little momentum.

[@ErwinHolland.]

@@adampetten1009 An engine isn't a impact drive. (well, it kind of is, but not like that) If I understand it correctly, it's basically moving the mass of the flywheel, and keeping it moving with the impacts of the tool. If that is balanced correctly, it will improve the torque. If it's not balanced correctly, it won't do anything, or even make it worse.

[@kellhound7227]

Lmao got a physics professor to Ghost you after making an interesting observation! That's why I love this channel, and also the straight forward approach to letting people know what tools actually do, vs their advertised specs! Thank you for your Content!

[@SvdSinner]

Remember: Half the physics professors out there are below average.

[@h8GW]

@Greg Wilson Physics is just applied math, after all.

[@chocolatethunder3218]

@@SvdSinner Below average *Physics professors*

[@tessierrr]

Inb4 he didnt ghost but making a thesis on how it works 🤣

[@Logan-dk8of]

@@tessierrr if he was a good physics professor he would have ghosted him to go conduct his own experiments on the subject for the next 2 months

[@allupro]

From the results it would seem like that the more outwards the mass is, the better it is. So maybe you could try to weld together a souped up flywheel design and give it a go? Also, perhaps a good way to test the effects of rigidity vs. outboard mass would be to use pipes of same weight but differing sizes and wall diameters.

[@KACPER050599]

distance in moment of inertia calculation is squared, so 2x distance means 4x inertia with the same mass. Would be interesting to see something like IR flywheel but with more mass at greater distance

[@nicksz8909]

I believe the best results would be maximizing angular momentum (which is moment of inertia x angular velocity), and having a hollow section increases angular momentum without increasing weight as much as a solid heavy socket. We know from your basic I=MR^2 equation that inertia scales with the square of radius. As the socket gets heaver, your inertia increases, but your velocity goes down and it trades off. if you plot angular momentum (nut busting power) on the y axis of a graph weight on the x axis you should see a bell curve where more weight helps and then starts to inhibit. i imagine this is different with all different tools and the engineers tune the weights of the impact mechanism to with best with the average weight of common used sockets. For the practical application in the video here, i bet both the IR and the cheaper socket may both be on the left side of this bell curve because of how much power this air impact may have. whereas the makita knockoff you are already so far to the right on the bell curve that you actually lost power. IR may have designed this socket to work best with the average homeowners impact (whatever that may be) and adding weight may make it work better for bigger impact wrenches and reducing weight may make it work with smaller impact wrenches. if the combo between your chosen impact and the IR socket happens to fall at the top of the bell curve, then ANY change you make will reduce overall beans. anything is a tradeoff and they may have done a ton of engineering to maximize this socket's performance with a specific type of impact.

[@ericbuilt269]

How about a super short impact extension that is a flywheel style? Every socket in your drawer becomes special. Would the design outweigh the inherent losses associated with adding the extension?

[@joshrakestraw5580]

I think these two are on to something. Increase the moment arm and you should be able to increase the torque. Now the force being put into the moment arm would be determined on how fast the tool could accelerate the mass, so there would be a sweet spot for weight. Or at least that’s my armchair analysis. I think it would explain the weights not making a big difference because the moment arms are pretty close to the same and once you get to a certain weight it hinders the process instead of helping because the acceleration is slowed down with the higher weight.

[@joshrakestraw5580]

I’m thinking the largest diameter possible with a weight that the tool can handle would be the most effective option. Also have to take into account how rigid the new tool is, too much flex and distance from the center and I’m thinking there might be some sort of harmonics canceling out the effort put out by the tool. Spitballing here

[@JimGriffOne]

06:23 - The welds along the washers will be flexing, reducing torque transmission and losing energy to heat in the flexing motion. The other designs use a single body which massively reduces flexing. The flywheel one may be using resonance to store energy and release it in between hammer blows. It may perform differently on different impact wrenches, providing little gain on one but more gain on another. Total guess.

[@Wiedy99]

Torsion from the small welding spots were my guess as well. they could add a few more and wider beads on the outside and test it again. I'm sure the results will be much better. (Of course only if it has been welded properly on the inside as well)

[@randomname930]

@@Wiedy99 From the look of those welds they weren't done very well either. Looked like someone was doing the "overlapping spot tacks" with MIG, or at least that would explain the weld craters you can see at kzbin.info/www/bejne/lZXKopxtnd1rnJo The other unknown being filler wire. I'd imagine you want something with a very high yield strength as welded for an application like that. Of course then you'll run the risk of it being too brittle but if that weld can yield it'll just be more wasted energy.

[@hazza2247]

i definitely agree with your theory about the washers, the resonance thing would be interesting to see tested on other impacts as u said

[@paulgolff4996]

Jim, you and Eddie (a couple of hours later) are on the right track. The complete system of the driver, the socket, the bolt, and everything else involved will have complex resonances. While they're all held closely together as far as human perception is concerned, there is some play at every connection. All of these objects are subject to very high angular accelerations, and each one is made of some distinct material manufactured in a distinct shape. The professor was wrong to suggest, if he did, that more mass wastes energy somehow. Extra mass can't dissipate energy this way. Instead, it will give each individual rotary pulse more time to deliver energy from the driver into the socket before that energy is dumped into the bolt. (One could possibly measure this with an oscilloscope connected to the strain gauge in the torque sensor.) Sockets with a larger moment of inertia further increase this time by giving less rotary velocity, and therefore a longer time period per pulse, for the same energy input. But again, even if the increased pulse duration isn't enough to explain the increased torque, there could still be an explanation in the resonance effects, and measuring those would require very expensive test equipment such as a high-bandwidth laser interferometer. Or maybe, ultimately, several of them to simultaneously measure the motion of the driver shaft, chuck, socket, and bolt.

[@car0lm1k3]

pretty much exactly. based on the IPM/BPM of the tool it is designed for.

[@Keirathi]

Something I noticed from your graphs: The super heavy lead socket seemed to not hit its peak in your short duration tests. It started out slow, which makes sense. It's a lot of mass to get spinning. But it also never hit that plateau that you see from all the other sockets. It's slow to get spinning, but that also means that once it is spinning, it's also carrying more momentum and slower to STOP spinning as well. I'm curious what it would do in a longer test.

[@saturnmedia1]

100% noticed that too, it was only just ramping up!

[@flyingmonkeyofus69]

noticed this as well. would love to see super extended ultra best case scenario testing for these

[@evancathey3968]

Problem is that it doesn't actually spin. Once it is that tight it is actually stopping completely and rotating fractions of degrees.

[@aaadamt964]

I'm curious if the lead absorbs energy instead of transferring it because it's more malleable.

[@tomo-zb2tk]

@@evancathey3968 And maybe it tunes itself to right own frequency with each smaller step?

[@majorpipe]

Every time I watch a video on this channel, I have the same thought: between your obvious intellect, the creative and entertaining ways in which you test various products and theories, and the ease with which you articulate the results, Astro hit a grand slam when they hired you. I sincerely hope they realize that.

[@jozsefizsak]

For sure! Thank you for expressing it better than I could.

[@jozsefizsak]

@@indyginc Exactly.

[@BrianClem]

Right on. I agree

[@davidhori4899]

This channel is informative, uses clear communication, and delivers it with a humorous, entertaining voice-over. Well done!

[@TsunauticusIV]

It’s an awesome channel, for sure. I found them when they were still very young. Fell in love with the channel, even before they started using the “live/moving graphs”. Those graphs are the bees knees tho. Absolutely love them. Thank you for supporting the channel and saying kind words. 🙏

[@rawstewage1122]

A couple of thoughts: -Firstly I think it’s most useful to think about this problem in terms of angular inertia. E.g a weight put further out contributes more to inertia to the socket than the same weight close to the center line. - In those terms it looks possible that all of the sockets that perform well kind of cluster in the same region. Either having little weight far away from the body like the hollow socket or a fair bit of weight concentrated close the the center like the Lyle. -This suggests that there’s an optimum amount of angular inertia for a socket to have -If this is the case then we can explain the lead and heavy washer sockets low performance by them being further from this optimum amount. -But then why does this optimum exist? -I can only hazard a guess but we already know that increasing the hammer mass of an impact improves its performance. -But we’re not increasing the mass of the hammer you say. True but the socket is the hammer from the perspective of the bolt. -That would explain why increasing the weight of the socket improves performance. But we also need to explain why there’s an upper limit where performance drops off. - If we again think of the socket-anvil-hammer system as the hammer from the bolts perspective perhaps the super heavy socket prevents the system from reaching its maximum speed during the split second that it’s being accelerated by the impact before it in turn impacts the socket. This all suggests a couple more experiments. - Does relocating the weight of the socket to further from the centre also improve performance as my tiny knowledge of physics suggests? -Does my guess that it’s the weight of the entire socket anvil hammer system hold up. If we move an oz from the hammer to to socket what happens? -If we force the issue and remove all slop from the socket anvil joint by say welding the socket on does the impact perform the same? Awesome video as always

[@jasonspudtomsett9089]

Great video! Sometimes when I'm having difficulty getting a fastener in or out, i turn the whole impact driver in the opposite direction until all of the slop is taken up in the wrong direction... giving it a maximum slop condition. When i pull the trigger the motor has a brief moment of more free-wheel spin while it takes up the slop in the system. Kind of like trying to give the motor a soft start without any pre load. So, going of that , I wonder if the flywheel like designs optimize slop spring back to couple the most angular momentum into the system. Kind of like adding a secondary hammer to the impact driver.

[@bjmcculloch]

@@jasonspudtomsett9089 Yes, I’m wondering how much the variability in the slop for different sockets influences the outcome - both in terms of the driver-to-socket slop and socket-to-bolt slop.

[@dustinroberson1865]

Perhaps the maximum socket weight is somewhere below the weight of the hammer in the gun. If the hammer weighs more than the socket, it's going to be exerting too much of it's inertia just to move the socket?!? just a guess, but your thinking was on par with mine

[@simonkolar5478]

I think the flywheel acts as a resonating element (constructive interference). If so, then it only works well on some tools where the forces, masses and spring constants are in harmony.

[@tigo01]

I think this is the correct explanation as well. If you could modulate the speed of the impacts, I think you will be able to find the correct speed that will maximize the torque for each of the weighted sockets.

[@toyorover1313]

I would like to see a test where they keep some tension or preload on the socket in the correct (tightening) direction, to minimize the socket 'bouncing' back and forth. Similar to this resonance question in a way.

[@sinsilius]

Yup, just like this very channel explained in a video half a year ago with slo motion video of cut open impact wrenches. Harmony of all the systems (motor, spring, hammer, anvil and now + socket modifications)

[@TheSengga]

Yes, this was my initial thought. Resonance can extremely powerful. Think of how if you sing the right note you can shatter a wine glass.

[@c0nct3d]

@@tigo01 It makes me wonder if you could design a tool that could automaticly adjust its rpm to be the closest to the resonant frequency (or a multiple) of the system.

[@ureviews]

The way to solve this (I think...), is to make a hollow socket with different diameters but same weights (or at least very close). I wonder if at some point there would be diminishing returns as you go wider, or maybe not if you can keep the same weight somehow.

[@justinjones5288]

My thoughts as well

[@hitnovak]

Torque is the rate of change of angular momentum, so the goal of maximising the torque is to maximise the change of the angular momentum of a socket. Energy of a rotating body is I*ω*0.5ω, while the angular momentum is I*ω (I is the moment of inertia, and ω is angular velocity). Therefore an object with higher moment of inertia will achieve a more rapid change in angular momentum for the same amount of energy, which means higher torque. However, the "useful" energy you get for each impact decreases as the mass of the socket increases. Since the moment of inertia is mass times the radius squared, the best way to increase the moment of inertia without decreasing the "useful" energy is to put the extra mass as far from the center as possible, which is why IR socket works so well despite being lighter than most other sockets you've tried.

[@cynic777]

Love the curiosity here and the determination to confirm things and not just accept manufacturer’s claims! Love the experiment with molten lead socket and “modifying” the IR socket!

[@fantasticsound2085]

I would love to see you test a homebrew socket with and even wider flywheel design. A ridiculously wide, yet similar mass experiment to see if equal or even less mass at a further distance from center increases the moment of inertia.

[@JackdeDuCoeur]

Very nice start. Gotta identify all the variables to the extent you can. Fitment to anvil, fitment to bolt, eccentricity of mass, internal rigidity, thermal properties during stress; those occur to me but there are surely more.

[@alexmills1329]

Excellent video presentation, you were able to lead us to the conclusion without spelling it out and confirming what your findings suggested with a reputable source. It’s interesting that these impacts are so powerful that you are actually losing power from the sockets flexing as this video shows, and also might explain why the effect could be lesser with larger sockets, because they are larger and more rigid and aren’t being delivered the same power per volume of steel, so there is less lost energy in vibration.

[@lousassole6969]

Have you considered making a "flywheel extension" (a short anvil extention with a flywheel welded on it) so the weighted flywheel could be added and removed using any socket? Would be a handy tool to have if it worked the same

[@rope_bunney7927]

generally having an extension on your impact reduces it peak because of the slop between impact > extesnion > socket opposed to just impact > socket. you would think the losses couldnt be that much but as a mechanic i promise the extension just ruins it :(

[@DISOPtv]

@@rope_bunney7927 Yeah, probably two or more things happening, rigidity and inertia. As humans have found, not everything has one simple explanation, but a combination of variables that can send a person into a crazy deep dive or wild goose chase.

[@bobbyhaskell2048]

A extension does reduce the tq value from the impact but perhaps a flywheel design could mitigate some of that. I think that's an interesting idea.

[@ledetdillan55]

I had to get a weighted 17mm for my honda crankshaft. It wouldn't budge with a normal impact socket but as soon as I put the weighted socket on it and gave it the beans, came right off. Super useful socket.

[@josbanse]

There is a logical solution from physics standpoint. The stiffness of the socket increases the capability as it flexes less as you might think about torsion reducing sticks that only goes so far and start flexing. The mass might improve things but as for why the heavy spacer stack and lead version did not succeed is based on the fact that those have a low torsional rigidity. On the lead the lead is so soft that it flexes itself and the spacers were only strip welded which gives flex also. This is why the hollow large diameter pipe was a good one as the pipe is very rigid. The flywheel one shoud be very hard steel and delivers impact very well.

[@Highstranger951]

I completely agree. IR pulled the old smoke and mirrors trick.

[@GrimResistance]

So a tungsten socket might actually be good as long as it's not too brittle

[@robertwar7814]

So if IR used the smoke and mirror trick, then cutting the flywheel off would have increased or matched previous performances. I agree that torsional energy delivered is correct in regards to Flexibility x Mass x Velocity. The key I believe is finding the correct combination of the three to increase torsional force applied.

[@nickrider5220]

Thanks for doing this - exploring why some things work and some don't 👍 The only sockets that conformed to what I thought were the lead socket and ultra heavy ones. Great channel !

[@jimhaines8370]

I have every Lisle socket they sell and use them many places were you can fit them on chassis and suspension bolts when you need them they are cheap and work great

[@0RayJones]

I appreciate how the questions you bring up are the exact questions that pop into my head while viewing your video. Those same questions are answered as best as possible a few seconds later or in a future video. Alot of diy's, professional, scientific, etc...youtubers, just gloss over or completely ignore obvious questions their results bring up. Amazing video. U da best.

[@JosephArata]

Spring tension might be a factor. Metal used in bolts and tool steel isn't 100% rigid, if it was, it would sheer off or fracture under torsional load. The flywheel design might be using that spring tension to keep the socket from "flexing" as much when the impact hammer releases it's energy into the socket.The metal wants to spin the opposite way that you twisted it because of spring tension in the metal. Theoretically, you could reduce that from happening with a flywheel.

[@jonathancorbett5917]

Yeah maybe like the TTC rope-hammer analogy. Maybe the flywheel is holding the rope (the spring in the socket) at the top twisted while the hammer pulls back to hit again

[@JosephArata]

@@jonathancorbett5917 Yes. A flywheel is an inertial torsional lever with a fixed position. That's why larger engines need larger flywheels to prevent the engine compression from trying to reverse the engine direction when there's no power stroke happening.

[@HyperF1]

I, the ghost physicist👻, am back to make some points here: 1. Rigidity: Each strike creates tiny deformations in the contact surfaces, which is converted into heat in the metal. Softer metal absorbs more of the striking energy, even if you cast it inside. 2. Inertia: More precisely, the moment of inertia or rotational mass. The surfaces of the socket and nut do not fit perfectly, but an in-between gap is designed to facilitate insertion. A socket with heavier rotational mass will gain more angular momentum during this "flywheel interval" before collision with the nut, given a fixed rotational speed of the driver. A heavier rotational mass means that it's literally heavy or that its mass is distributed over a farther radius. 3. Resonance: Every time the socket and nut collide, they both rebound. They'd better stay in-phase next time for a better momentum transfer, otherwise there will be an increased damping loss of energy. The resonance frequency is related to rigidity, mass and shape of the material.

[@thee_ging5315]

In a way the heavier sockets help facilitate a form mechanical impedance matching, similar to how a horn amplifies sound. Mark Rober had an excellent demonstration of mechanical impedance matching in his video on the worlds largest horn where he demonstrates the effect on a block of jello. Also the drum might be more efficient due to the moment on inertia for a ring/tube being greater than a disk/cylinder, allowing for a more efficient use of a given mass. You could test it by having to sockets of the same weight but make one hollow.

[@Timestamp_Guy]

I suspect that the maximum efficiency occurs when the anvil (and connected stuff) have about equal inertia to the hammer. Similar to a Newton's cradle, where you get perfect energy transfer between ball only if they are of equal mass. any more or less, and it will start to degrade performance. It would be a pretty straightforward thing to test, though.

[@AngDavies]

In collisions, the most energy is transferred from mass one to mass two when they are both of equal mass, maybe something similar is happening here- when the hammer/anvil is of equal moment of inertia to to the socket, energy is most efficiently transferred.? There's at least 4 bodies at play, so it might no be quite so elegant.

[@Agouti]

Engineer here, my guess is that the free play between socket and nut is critical here - after each impact, the socket is bouncing back and getting a "run up" for the next impact. If so, the extra rotational inertia lets you build up more kinetic energy during this tiny run up window, much like a heavier hammer does inside drive. There could also be a natural frequency tubing element here, getting the socket to bounce back and forth in time with the impacts to help amplify. The high speed footage will hopefully show this. I'd like to see some tests between sockets that have very snug fits vs ones with some slip to see if this helps or hinders.

[@TheUncleRuckus]

The one with washers didn't work well bc it's not a solid mass, the welds holding the washers together were flexing which didnt transfer the mass into the fastener. The hollow one is acting like a flywheel and that increased sockets inertia which is why it worked so well. This also the reason why the Ingersoll Rand sockets performance dropped so much by removing "flywheel", it lessened the sockets moment of inertia. Think of it this way, that flywheel thing is acting like a "Cheater Bar" would on the end of a wrench, so it would stand to reason that removing it would decrease the amount of force you can put into the socket. 👍👍

[@davidb6576]

Great video concept and execution! Don't be too fussed about the prof ghosting you, but it would be nice to get some other views from physicists on the matter.

[@makingmistakeswithgreg]

The high speed camera footage will be very telling. The ability for the socket to not flex would be the key ingredient. I have a feeling the flywheel on the IR socket helps keep the socket from twisting has more to do with performance than the added mass helping it. You guys should take the output drive on a impact gun and tig weld it directly to a bolt. By eliminating the slop in the socket fit (on both the socket to bolt head and drive to socket) and 100% of any loss due to twist, the numbers it posts should be the best of all of them. I am a really good tig welder and would be happy to do this for free. Just chuck the bolt in a lathe and turn the face of the bolt flat and the same on the impact drive face. I can have it set out the day after I receive it 👍

[@douglasmayherjr.5733]

It would be interesting to see the weighted sockets on the high speed camera. The heavy mass ones, might not show much. I would think the Ingersoll Rand Flywheel design and hollow design might show some interesting things. I would think the flywheel would whip helping the internal weights. I would also think the weight of the socket would be limited by the hammer mechanism of the impact. I’m just a HVACR Tech and ex Farmer, that’s my non engineer opinion. Really appreciate your channel and testing.

[@thewoomelanghotel8756]

Top Stuff. I blame simple centrifugal force myself.

[@HomoKieran]

It makes some sense to me. While it does take more energy to get a heavier socket moving, as long as you have that energy to get it moving it then has more momentum and will apply a higher torque before coming to a stop. Hence why the more powerful wrenches benefit more from the weighted sockets, and why going too heavy is detrimental when you don't have the energy to get it moving at a decent pace. I would imagine that the lead lined socket with something like a 1" impact behind it would perform even better. Things get complicated when you're dealing with impact forces and not continuous ones. Also the reason why the hollow socket performed well despite being light, like the IR socket it places that weight further from the axis of rotation which increases the torque and momentum that it was.

[@h8GW]

I presume the less rigid flywheel designs allow for the metal's elasticity to spring the flywheel's mass forward and add force to the next blow.

[@ErwinHolland.]

Yeah, exactly what I was thinking. As long as the power of the hammer can "overcome" the mass of the socket, it will impact harder because it's now kind of working like a bigger hammer. If you make it too heavy, the hammer doesn't have the power to overcome the mass, so it just dampens it. I have the feeling the scientist doesn't really know how these tools work.

[@dustinroberson1865]

Makes you wish they had just put a bigger hammer in it to begin with

[@Thinkingaway]

The reason the lead socket didn't work is because lead is a damper material and doesn't transfer impact force effectively. There has to be a balance of torsion and rebound speed along with mass. Those are the physics behind the IR socket, the bigger the diameter, the faster the rotational inertia resulting in more force with a smaller mass. Lisle uses the heavier mass at a smaller diameter approach. I have several variations of these sockets myself both retail and shop made and can confirm they do work. Great video as always 👍

[@dangerrangerlstc]

Maybe some sort harmonic thing happening? Everything is a spring after all. Those webs in the IR socket may be flexing under impact and the rebound is imparting more energy into the blow.

[@wim0104]

it's totally about the combined resonance of a series of springs, yes. one of the springs is how tight your hand holds and twists the powertool.

[@ferrumignis]

I was thinking the same, if the impact rate is somewhat close to the resonant frequency of the socket mass and impact drivetrain stiffness then peak torque could be increased quite a bit. This would mean that the ideal mass would be somewhat dependant on the impact wrench used, but I guess they are mostly in the same ballpark.

[@paulg.6222]

I feel the hollow socket is near a sweet spot in which the weight (and placement of said weight) allows the socket to reach optimal momentum (therefore delivering more kinetic energy) while simultaneously optimizing the centrifugal force applied to the socket and therefore the torque applied to the bolt. Here's a link to how to calculate it. (I posted this like 2 hours ago with the link but my comment keeps getting taken down? Maybe because of the link? You can find the calculator at omincalculator. Im sure you'll find it) I'll continue researching it more as well! Also, thank you for all your great content. Your clarity, humor, and rigor is more IMPACTFUL than you realize.

[@sheerwillsurvival2064]

I bought the OEM 6 piece set of crank sockets. They work great, would like for you to test them they are only $99 set. My opinion it rigid because it’s thicker and won’t stretch or flex and adds a little weight which helps up to a point

[@AtlasJotun]

I've used the Lisle and was blown away at how well it worked on those stubborn F-series Honda crank bolts. I figured it was partly the increased mass, but also some increased rigidity allowing better torque transmission. Absolutely bitchin' that Astro's making a hollow socket, good work! Now find somebody to manufacture your gas-powered impact!

[@evil_me]

I think the harmonics of the socket might be a really big influence, I'm wondering if the test results would be different with a different impact that has a different hammer mass and/or different BPM?

[@andrewmquintero]

I was thinking the exact same thing. Geometry, material, and mass would need to be tuned to reach optimized harmonics per impact gun and use case, which is why we see different results from one gun to another.

[@Fellafoe69]

I had a problem getting off a honda crank pulley today with my Ryobi impact, all i did to get it loose was weld a rod to the side of the socket wrap a rag around it and add preload with my hand. works a charm

[@70stastic]

I'd love to see one of those hollow sockets filled with lead shot. I'd be curious to see if the dampening effect would hold the socket against the hex more consistently. Most of the power loss I've seen from impact sockets is from the socket bouncing backwards and the impact impulse being partially lost from the air gap created by that bouncing.

[@ferrumignis]

Steel shot would be better, lead deforms easily which absorbs energy.

[@eugenehall390]

I've found through hands on experience using many designs of those sockets on many stubborn crank bolts that it has something to do with the sockets ability to not bounce back between impact blows. Heavy alone helps keep it from counter rotation. Flywheel designs move the helpful weight from the center to act as leverage. Making that small weight be more useful than being on the socket wall. Your hollow design multiplied that by being light and even bigger in diameter (leverage). More power is transferred because it's not having to overcome extreme weight but the amount of weight used to hold pressure on the fastener between impact blows has leverage. I suggest a video with a deep socket with a bolt head welded to it. See how far it get. Then add a wrench to it with incremental notches to add weight to. Impact to limit Then add the wrench. Then weight to the first notch to limit. Move out till you run out of wrench.

[@lukebryant5025]

I would be curious to see how precise the fit of the socket on the anvil and the bolt would affect it, I feel like I have noticed a difference between different brands before I wonder if it's because one brand fits better

[@lukek8032]

Definitely need to check this out. I’ve had sockets that were real snug on bolts not hit as hard as sockets that were looser on the bolts head.

[@chang.stanley]

The professor is correct on all points. Your last question has to do with the springiness of the long bolt on your test set up(and crankshafts)where the additional mass is able to counteract the lower force of a weighted socket in overcoming the bolt bouncing back on every hit. It's explained in the Ingersoll weighted socket patent.

[@CheapHomeTech]

Perhaps the lead absorbed the energy? Maybe a hollow with a heavy flywheel made of strong stiff metal would be ideal?

[@strayling1]

Measiuring the temperature rise in the different sockets might shed some light.

[@SvdSinner]

The answer comes not from a static analysis like the Physics prof did, but by a harmonic analysis of the tool. It is the flexible/spring characteristics combining with the outer mass that do several things. In the first stage, the flywheel resists the blow, but stores the energy. In the second stage, the socket hits the bolt head and the flywheel returns the energy to increase the overall torque. In the next stage the flywheel actually stores some energy at the end of the impact. Next stage, that energy anti-rotates the socket between blows. This backwards rotation makes it easier during the next cycle to store energy in the flywheel because the socket gets a tiny bit of free turning before it hits the bolt and experiences resistance from that. Ultimately, the ideal design would have far away mass combined with a golden amount of flexibility connecting it to the socket.

[@SvdSinner]

This also gives the added benefit of extending the blow to the bolt head. This allows it to counter more of the twist the bolt does between the head and the threads. (In other words, makes it slightly more like a breaker bar that can remove headbolts when impacts cannot.)

[@1kreature]

Wonder if the tightness of fit between the wrench and the socket (and extensions) as well as the socket to nut have just as big of an impact as the weight.

[@JackdeDuCoeur]

Me too!

[@JayFude]

Learning about tuned mass and such. High speed cameras and impact wrenches are a great combo.

[@alfonsmarklen1345]

I would really want to se a continuum of this tests since the lead socket did have a pretty steep slope at the end of the test so might overtake the other sockets in a 30s test or something

[@pkenny2077]

Do you think the lead socket struggles though being a softer material and not being able to transfer the blows as effectively, maybe acting more like a dampener

[@sixtyfiveford]

Great demonstration!

[@TorqueTestChannel]

Thanks! As you well know plenty we havent even touched on yet here

[@nismomike3182]

Do you think a heavier battery transfers more rotational force to the fastener as well. We usually attribute all the gains of a larger battery to the added pixies. Would be interesting if you added weight to a Powerstack.

[@ALAPINO]

These are not new (weighted sockets and bits), but your data collection and testing is! I don't wrench every day, but when I do it's helping with 5,000 lb dies with hex bolts with millions of injection cycles on them. Usually, just in an attempt to restore a moulding surface or to replace components. I find AirCats don't do it sometimes without significant heating (which is foul as all heck) so a torque assistive device such as these would likely help. As for the IR (I am not an enginerd but I play one at work) the toroid was attached with 3 spokes. The spokes could act as a delay or offset disconnecting the input torque from the output. Applying the spinning mass outward from the centre of applied rotation might be a torque "run up" with each impulse. The IR socket body just acts as a normal socket without the ring on spokes. I don't know. The hollow socket seems, to my mind, doing the same thing in a round about way. The mass is lower but applied further away from the axis of rotation. Man, this is all so much fun and interesting! (The stacked washers appear to be end welded with a few beads, so one would assume a lot of energy loss is happening there between the lack of connection of the washer's masses) l have to make one of these on Monday. Thanks TTC!

[@mtraven23]

love that you did the practically test at the end! To play armchair physicist for a moment....I think the professor my be under estimating the power of these guns. Given sufficient power, the difference in resulting angular velocity is likely quite small, within the reasonable weight ranges you tested. You could try to find what is "sufficient", rather simply, by restricting the pressure/flow to your gun. really enjoy your videos, well organized and packed with data...and just the right volume on the impact noise!

[@themotobarn702]

Got home from work and was super happy to see a new video from you guys, especially since I've been waiting for a test like this and plan on buying the Lisle 19mm. Also, I just bought at 4am a Ridgid R86012 with charger and battery for $150 (black Friday deal) due to your amazing videos and still might have to pickup the R86211 HT used at some point. Thanks for all the amazing content!

[@djr11472]

Haha, I can't say what is happening, but as soon as you summarized the prof, my immediate thought was "No, he's wrong, cut the flywheel off the IR and prove him wrong!" I was very gratified to see that almost immediately.

[@lolipoable]

Not about providing something is wrong. All about understanding the mechanics and physics

[@scuderianorreno]

My stab at this is harmonics/resonance. The inners of that impact gun revolves with a certain speed under a certain load. The speed in combination with the weight of the anvil and rigidity of these parts will ideally translate into the impacts that is relayed from the gun to the nut without delay and energy loss. In most cases the natural frequency of the main components (determined by mass, stiffness, shape etc) mismatch, and there will be a lot of rattling around and wasting of oomph. In ideal cases their frequencies will match (could be first, second or third order and so on ) and the impacts will travel from the gun to the screw head in a cleaner way. There are also several unknown factors as play between the parts that could affect the result.

[@Xoars]

Like @allupro said in a previous comment, I believe the further out the weight acting on the pivot point (bolt head), acts as a lever applying torque in the forced direction. They all start out similar to the regular deep socket, but once directional momentum is achieved and the outward most mass is accelerated to the nominal force that the gun can apply, the weight (with its momentum) is applying more torque as a lever effect. The hollow socket reduces mass to achieve the momentum required for the torque, but also has the majority of its mass further from the fulcrum.

[@azy6868]

As the Ingersoll Rand PowerSocket is struck by the hammer tool, it is caused to oscillate at an ultrasonic/sonic frequency, which is briefly transferred to the bolt/nut, inducing a ultrasonic/sonic hammering effect at the interface of the thread/friction surface, thus overcoming the static resistance points. This effect is similar to the Ultrasonic/Sonic Jackhammer Researched, developed and produced by NASA (NPO-20856). An ultrasonic/sonic jackhammer (USJ) is the latest in a series of related devices, the first of which were reported in “Ultrasonic/Sonic Drill/Corers With Integrated Sensors” (NPO-20856), NASA Tech Briefs, Vol. 25, No. 1 (January 2003), page 38. Each of these devices cuts into a brittle material by means of hammering and chiselling actions of a tool bit excited with a combination of ultrasonic and sonic vibrations. A small-scale prototype of the USJ has been demonstrated. A fully developed, full-scale version of the USJ would be used for cutting through concrete, rocks, hard asphalt, and other materials to which conventional pneumatic jackhammers are applied, but the USJ would offer several advantages over conventional pneumatic jackhammers. Search for NASA (NPO-20856) for more information and white papers.

[@mwcolton11]

This makes the most sense of all the other guesses. The main impact is a low freq impulse that does create some higher freq harmonics, but those harmonics die out at the higher freqs. The resonant freq of the flywheel (tuned by the size of the spokes) will add energy at a much higher freq to more effectively decrease the friction of the threads (restating what you just said).

[@KenFullman]

It's all about angular momentum. Your driver is not pushing the nut around. Instead it is driving the socket. The socket is not a perfect fit on the bolt ( or nut) so as the anvil in your impact driver hits, it propels the socket, which (in that split second) merely takes up the slack. The socket then hits the nut. The angular momentum of the socket therefore has a massive effect on the resultant force applied to bolt. Angular momentum is increased with diameter and mass. But lead is rather soft, so although it has a large angular momentum, it's also a great shock absorber. So it will absorb a lot of the energy. You should have repeated the test using a socket cast from depleted uranium. That would have had the perfect combination of rigidity and density. You could perhaps add some Vanadium carbide into the mix to make it a bit more wear resistant.

[@robertcarpenter1615]

God bless you for your merit. I loved all of this. Your questioning intrigue and plain spokeness without being high & mighty. Just seeking an answer. And your willingness to question those answers you received. In real world examples. This was a great video. I thank you so much for sharing.

[@kylefowler5082]

I had to watch this video twice to soak in all the info, good stuff! I think the professor left the chat because you proved that extra mass on the socket up to a point does improve performance. In my mind I equate you guys tightening a bolt to a carpenter driving a nail. A heavier framing hammer drives a nail in with less blows versus using a dollar store claw hammer as long as you have a big, burly carpenter using both hammers. But give him a sledge hammer and suddenly a bigger hammer is a hindrance. I believe there is a point where a heavier socket is like the carpenter with a bigger framing hammer but there is also a point where too heavy of a socket is the carpenter is swinging a sledge hammer. Too heavy of a socket becomes too much enertia to overcome for the impact.

[@zedwolf5556]

The shot tword the end of the guy using the socket on a lug nut gave me an idea, try making a flywheel type mass out of a short 1 inch extension. I know there would be losses because reasons, but it would be usable on many different sockets. You could also play with weight diameters and see the difference.

[@SpatialDragon]

If you melted the lead out of your test socket it would work better. You had it before you "fixed" it. I was with you though. Then after seeing the results I saw the flaw in the weighted socket. IR socket is the best. You could make a ring of heavy iron, weld it on with stand offs and make a better socket, but your welds better be top notch. This was a great test. Well done. Really makes you think about what you think you know.

[@DIRTYHARRYBALLISTICS]

This is genuinely perplexing. As an armchair physicist myself, im as stumped as the professor who ghosted you. Not that its any great surprise to most, but i'm a problem solver at heart, and ive spent many hours since your first episode about weighted sockets trying to sort the why, and i had come to a similar idea that it had to do with efficiency of transfer due to rigidness, but when you cut the flywheel off the IR and debunked that, i'm back to square one as well. Perhaps a channel like Smarter Every Day might have some ideas.

[@benjamin8981]

because the bolt isn’t rigid and it flexes. more mass (especially further from the center) soaks up the spring forces

[@xnewguyx2738]

I wonder if the cut socket being slightly unbalanced could have anything to do with it.

[@benjamin8981]

@@xnewguyx2738 not when the socket itself is moving less than 1rpm

[@johnfavrin3583]

I had a similar theory about air hammer bits too; a heavier, denser tool will stay more deformed and almost spring loaded between hammer blows of the tool

[@vampirejesus8170]

@Torque Test Channel I might be thinking of this the wrong way but here we go. The flywheel socket has its mass farther out from the center. So it is easier to move when the impact happens. Theoretically then the same weight even farther out from the center would hit even harder. Your hollow socket had more mass that the flywheel but it was about the same distance from the center. If you had too much weight closer to the center then it is harder to get moving i.e. the two heavier sockets you used. The amount of force the impact has when hitting was less. An object at rest has the tendency to stay at rest and vice versa. There would be a spot where the flywheel will be too far out/too much weight and you would see diminishing return on the action. But it would be neat to see where the sweet spot is on weight vs. distance.

[@messybench]

I broke 2 HF 1/2" impact extentions, removing Honda crank bolts. I have the Lysle weighted socket and then bought a new Earthquake impact gun. In the end, I built a long socket by cutting a deep impact socket in half and welding pipe in between. So it's one piece long enough to get past the fender, set on a jackstand, and use a breaker bar with my jack handle as a cheater. I bought 2 HF breaker bars, thinking one might fail. In the end, it worked. I later tested tightening a bolt with an estimated 500 ft/lbs (my 230lbs and a 30" cheater). My Earthquake could not remove it. So I bought the Hercules mid torque. It was just barely able to remove it. If I added a pipe wrench on the socket and leaned on it while using the gun, it was removed easily. My shop made pipe socket wasn't better at delivering torque except that I did not break like the extension. I may make an extension with a hex on it and try a large wrench combined with my impact. ps. Why are Honda bolts so tight?

[@fleksimir]

Mechanical engineer here. You don't tune a rotating object by just adding mass, you tune it by adding rotational inertia, which is a combination of mass and distance from the axis of rotation. Adding the same amount of mass, but further from the axis of rotation, adds more rotational inertia (while adding the same mass). Hollow fesign (and the flywheel design) maximise rotational onertia to mass ratio. It may also be a case of tuning for vibration effects, but someone already commented on that nicely.

[@aidanhamilton9859]

I have weighted lisle sockets, they work great. Never had a crank bolt not come off using it.

[@Timestamp_Guy]

You know, a Newton's cradle, where the swinging balls smack into each other, and one goes flying while the rest stay completely put? I suspect that's analogous to what's happening here, and why heavier isn't just better. There's probably a "sweet spot" where the added weight is about equal to the weight of the hammer (really, rotational inertia, not weight, but it's an analogous property). Once you go heavier, it adds no more benefit, and will start to decay.

[@davidfarmer]

As many others have stated, the mass isnt as important as the moment of intertia. My theory is that the moment of inertia needs to be tuned to the impact mechanism. You might gain some more info by attaching scales to your impact sockets and watching them in high speed video, plot the rotational position, velocity, acceleration etc. I wonder if permanantly attaching the socket to the anvil would help too. Last thing, if you want maximum mass tungstem is the material to use. You can buy tungsten wire on mcmaster, which you can then wrap around your outer tube. Then braze it in place. maximum mass concentrated far out. also a good way to increment the mass.

[@sasjadevries]

One useful thing to test is how much the rigidity of the connection between the wrench and the socket affects the applied impact. I.e. if the socket is shrunk-fit onto the torque wrench, then they essentially act like one piece and you only have impact transfer from the socket into the bolt. But if the square drive is loose, then you have to transfer the impact from wrench to socket, and then from socket to bolt; so that means you have to impedance match the "moment of Inertia" twice, and you have two occasions to lose energy. The looser the connection - the more slack it has to take out before it acts like one piece. Now I reckon, that with a really tight socket (welded, shrink-fit), you wouldn't need any extra weights on the socket, and the extra weights should only hurt. (I'm using simplified phraseology here, obviously it's about dynamic moment of inertia and not weights)

[@johnharder5618]

Nice video I help my brother work on his tractors One of the bolts on the Allis Chalmers is supposed to be torqued to 600 Foot Pounds But after crud build up and corrosion the air impact sometimes had problems So I took a 5" dia piece of 3/4" plate steel and welded a flywheel type add on to a 1 1/4" deep impact socket That made a world of difference breaking those nuts loose So I bet that idea should work also on a 19 mm socket

[@mercMADCommando]

If you want to add further data, machine a bolt with a square drive in the end. I know this removes one of the joints and that will improve torque. The IR socket is likely creating resonant frequencies that works with the hammers. It's also possible the vibrations are helping the "shuffle" the threads lowering the torque needed to tighten. I have seen that make a difference when loosening bolts using a Hytorc and hitting the socket with a hammer (I do not recommend this, simply relaying information).

[@cheatinggravity173]

What is at work here are several factors combining to work together. #1 is a combination of flex and flywheel momentum causing a 'double whammy', especially with the IR flywheel socket. It is the opposite of what happens with a harmonic damper on the front of an engine, because instead of the flywheel being connected by rubber, it is connected with semi-flexible spokes of steel. When the impact from the gun hits, it sends both a shockwave and rotary kintetic energy through the steel. Some of that energy is also potential energy being stored by the flexing of the steel in the socket, then as the flex hits the flywheel, it sends the energy on through the socket and eventually hits the end of the socket which turns into kinetic energy at the lug nut. The timing of the potential energy release hits in a way that magnifies the blow rather than dampen it. This also explains why the I.R socket doesnt work as good on hammers with faster bpm or lighter blows, because the timing of the flexing of the material doesnt match the bpm of the gun. It is similar to using resonant frequencies to multiply forces and why anything large made out of metal has to have its resonant frequencies either dampened or mitigated in some way. Bridges, cars, etc. In automotive, cars are so quiet now and dont crack sheet metal as much because much effort has been given to address NVH (Noise, vibration, and harshness). Your lead filled socket didnt work because lead has a vibration dampening property to it- instead of transferring energy to the other side of the socket, it flexes and converts that vibrational energy into heat. Simply having flywheel mass doesnt work without the spring of proper steel. The large diameter, lighter weight socket work well because they transfer the impact torque more efficiently than a heavy skinny socket. It is the opposite effect of using a torque limiting extension. The futher from the axis of rotaion you get, the less force is applied to the steel socket wall, therefore less flex and more direct impact hit. There may be some harmonics helping the equation as well, as there is more surface area to resonate a shock wave.

[@alanjackson4397]

I love this channel seems to always touch home with me my son and I just got the Lile socket getting ready to remove damper on his daughters Honda hope it works

[@rpavlik1]

Fascinating. My best guess is that the ring was actually adding rigidity.

[@benjamin8981]

the socket is rigid but the fastener is not. the weighted sockets work best on longer bolts or longer lugnuts but don’t make a difference on acorns and shorties. the flywheel and weight resists spring force from hammering on a bolt. think of a long bolt as a torque stick. it just keeps rebounding over and over but add a flywheel to soak up those rebounds and somethings gonna give.

[@benjamin8981]

try this test with longer bolts if possible. i know it wasn’t easy to come by the tool you’re using in this video. putting less weight but further out should also help

[@nicknasser713]

I bought the lisle socket and it was an absolute game changer for Honda crank pulley bolts. We used to use Hondas oe pulley tool and a breaker bar and it would take at least two guys to do it the way honda suggested. Now with this socket it's like taking off any other bolt.

[@Tom89194]

In my 400 level FEA class in engineering one of the effects we looked at is the multiplication of force caused by the fact that forces applied to a part travel through the part and can reflect back(think pressure waves). So if you manage to set up a reflected wave properly it can multiply the final output force at least on occasion, and you end up landing some heavier blows even if it isn't on every blow from the impact. The lead socket was probably VERY good at dampening vibrations in itself, the best performing sockets probably ring the longest when struck (good luck holding the solid boy from lisle in a way that allows it to ring though) The design of the IR might be based on trying to get vibrations to reliably reflect around to and from the mass ring through the spokes.

[@cameroncrush9591]

I feel like this would make an awesome collaboration with Smarter Every Day. He always searches for the best most conclusive answers!

[@orangetruckman]

Great testing! It’s super interesting. I’d recommend for you to get a lathe and make the diameter of the sockets you need 😇

[@nickcampbell3075]

Im no physicist but i reckon all the factors come into play - Ridgity transfers the blow efficiently (big factor with extensions and swivels) - Mass, bigger the sledge, bigger the blow until you can't even pick the thing up (via makes less difference on smaller impacts) - Flywheel counteracts the recoil like a dead blow hammer

[@drewrinker2071]

I think it's all about finding the right resonant frequency that most closely matches the tool itself , and this subject is touchy for most physicist because everything is frequency even matter and throws just of everything you've learned in high school text books out the window. But if you think of the ir socket with the flywheel before you cut it, I'd be willing to bet if you hit it just right you get a certain amount of ding much like a tunning fork and same with the hollow socket. Maybe those two are closest to the actual resonant frequency of the tool itself. To test my hypothesis one could actually use the blows per minute to come up with a hz value, whatever that may be, then in turn create a socket that will resonate well with that hz value. Think of energy much like a tunning fork. I think Mr Tesla was right when he think in terms of energy, frequency and vibration.

[@jacksonkyle9671]

The thing about professors is that they mainly operate in the theoretical. I'm just a lowly mechanical engineer but I think you have a couple things going on here. The point about rigidity is definitely true but most likely negligable. As long as a large amount of energy isn't being lost to deformation (i.e., the whole thing is made of steel and not, say, lead...) then it probably isn't a factor in these tests. I imagine the flanks of the nut are deforming more than the sockets typically do. As far as your observations, you are probably seeing a mix of flywheel effect optimization, and what I guess I might call good harmonic matching. The hollow socket cleans up because it has the right amount of mass and puts it in the right place. The heavier sockets probably don't work well because the impact can't accelerate them to top speed in the small space that they rotate in (the fixed impulse from the hammer doesn't deliver enough energy). The lighter hollow socket is being rotated to a higher speed, and the energy is being put into mass located farther from it's axis. Given two sockets of equivalent mass, one with a much higher moment of inertia around it's axis is going to be able to deliver more impulse to the nut. This kind of ties into my other theory about the harmonic matching. I imagine at some point the mass is optimal for the hammer speed and force which allows it to sort of bounce off the hammer with perfect timing and absorb the energy more efficiently. I would put this firmly in the speculative category because I simply don't know enough to be confident, but it seems right in my head. Anyways, big fan of where you're taking this channel and I would love to see more of this type of testing.

[@kaidwyer]

I would say that the springiness of the structure plays a role, and that these flywheel/hollow designs are achieving some kind of resonance with the impact driver, while a solid design with a higher Young’s modulus will have a higher resonant frequency and won’t scavenge energy with subsequent impacts. Try tapping a flat steel bar on its wide side, and then on its thin side, and you’ll notice a difference in the tone it gives. My guess is that optimizing for low mass, high resonance, and low resonant frequency is what gives a good result.

[@thereloadingcraft]

Wheel weights are a reloader’s friend! Loved that lead casting ASMR 👌🏻

[@Dogpool]

Have never had a problem getting those Honda bolts off with a bit of heat. Really doesn’t take a whole lot of torch time on the end of the nut. Below the amount that would melt the seal or belt cover. Done many times with no problem at all. I did get one of those flywheel style socket though for lug nuts that won’t come out. In this way the other fat socket won’t fit most lug nuts. So it is the superior product.

[@skyd0g157]

This needs a smarter everyday collab for sure!

[@petrwowra4097]

Awesome video, thanks. I have the same experience. I made weighted socket for my fake makita, just big nut welded over the 17 mm deep socket, similar to IR. But it's worse than cheap noticeably lighter 17 mm socket. Looks like more weight just eats energy from weak impact wrench and don't transfer it to the bolt.

[@lgunderso2117]

As an engineer with a practical understanding of sockets/metal components I think there’s a good bit of resonance in the designs. If the impact shockwave starts at the drive end of the socket it can store energy into the flywheel, the bolt end of the socket starts to apply force, and at the same time the shockwave stored in the flywheel travels down the socket and hits the bolt at the right time to deliver more force. Too much weight and dampening, as is the case with the heavy, soft lead socket, would back this theory up, as would the high spring rate of the large hollow tube welded to the socket.

[@canative2468]

I want to compliment you on a very good video and you have a very analytical mind allows you to test things in a way much like the great scientists did it in the past I am an electrical engineer for the last 40 years and it appears to me that the problem is a little more complex than what everybody is realizing So I'll try to put it in terms of electronics which makes it a little easier to understand The rep of an impact tool is actually the base frequency and when it impacts it generates lots of harmonics in the high frequency range for a very short time. It is much the same as a pulse generator with a rep rate that's rather slow and the pluse width is small. If you do an FFT analysis, you will find all power is in the upper harmonics. The mass of the socket must be tuned to these harmonics. A thin wall socket will just flex every impact absorbing most of the torque, and a heavy socket will absolve the torque in inertia. I believe your test confirms this. Great job, you should of been a engineer!

[@williamwampler7742]

It seems that heavier sockets effect the rebound of the impact. I’d like to see some tests with the good old trick of using your hand on the socket and turning in the direction of motion. This also helps reduce rebound and I’ve found it very helpful with new battery impact wrenches because they are higher frequency impact rates.

[@LukeA_55]

I've never heard of that trick but that goes along with what I was thinking. Some way to keep the socket from rebounding so that all the hammer's force is transfered to the bolt rather than back through the tool

[@michaelransom5841]

This all makes perfect sense from the perspective of the physics. If the Prof ghosted you, he probably just got busy. This is all about efficiency... basically, you are trying to convert kinetic energy to force to do work. The TLDR version, the mix of extra rigidity, additional mass, and importantly, the additional mass that is placed far out from the point of rotation, all culminate to make the tool more efficient as it isn't losing energy bouncing around and can conserve its angular momentum better, but since the distance over which your socket is being accelerated is so short, too much mass will cost you too much momentum to be beneficial. The total amount of kinetic energy available is determined by the motor in the impact wrench. The job of the hammers and the gearing in the impact wrench is to convert that kinetic energy into force with which you can do work. There are a LOT of factors determining how efficient this process is, but we can break down what's going on here by looking at the equation for work, and conservation of angular momentum. W=F*D, and given that force=mass x acceleration, we can re-write that as W=M*A*D Conservation of angular momentum is a physical property of a spinning system such that its spin remains constant unless it is acted upon by an external torque. Angular momentum is determined by an object's mass, its velocity, and how far the mass extends out from the point of rotation. Lol.. ok I planned on explaining this in detail, but I am totally procrastinating my actual work in the process, so I'm going to cut this short. By having more mass farther out on the socket you reduce the amount of negative acceleration and loss of momentum the socket experiences when it impacts the bolt (the bolt is applying a negative torque to the socket). the net result is a smoother conversion of the kinetic energy to motion in the direction of the drive.. (think what happens when a mosquito hits a windshield.. you apply equal force to each other, but he feels a ridiculous amount of acceleration, and you feel practically none so your velocity and therefore your momentum is conserved). so ya.. more mass further out helps conserve angular momentum and reduces the degree of negative acceleration felt by the socket so less energy is wasted by the socket bouncing off the bolt with each impact. But remember, as with everything, there will be a sweet spot... KE=1/2*M*V^2, and P=M*V, so velocity is important, and if you have too much mass you won't be able to provide enough acceleration with a given amount of force to impart sufficient momentum over the tiny distances you have to work with in this situation. that's the condensed version.. hope it makes sense. cost you too much momentum to be beneficial. l mean

[@violinmiata]

The extra mass further away from the center of the shaft acts like the flywheel that it is. The extra weight does slow the response of the impact twisting. But, the force in motion wants to continue in motion. This would explain the sweet spot of weight and the distance of the weight from the center of the tool. It’s like putting a wrench on a stuck bolt and hitting the wrench with a hammer, the farther away from the bolt that you hit the wrench with a hammer, the more torque is applied at the same hammer speed.

[@twisted2291]

I have the 4 popular size Lisle brand sockets. I use them a lot on rusty suspension bolts. I got mine for $20 each. As I was told. The thickness of the socket kills the deflection and allows more of the impact torque to be applied to the head of the bolt. I don't question the magic behind them. I just know if I need to break these sockets out. It means I am done messing around. Both the 19 & 21 one sizes I have used on lug nut the would come off, and in about 3 blows. It is needing a stud replaced cause it just cranks it right off.

[@bgracey7225]

Lead is soft and serves only to convert more of the kinetic energy to heat. Higher rigidity offers lower transmission loss. Lower mass is similar, hence the hollow tube performing better. And of course a force applied further from centre equates to higher torque, so the rigid flywheel and hollow tube both have merit based on that. But if you want to get at the nitty gritty of the energy transfer I suspect you're going to have to run tests with a high speed camera to watch where things flex and resonate. What you're up to with those varying tool designs is impedance tuning. If you can perfectly match the impedance between tool and fastener you'll transmit the greatest amount of torque. Changing either will change the required impedance value and you'll have to start tuning again. So it's fun to get close, but I wouldn't spend too much time looking for perfection!

[@lexi-conby]

The extra mass on the socket is actually helping extend the mass of thehammer and anvil but in a way not obvious. However, due to the small amount of play between the socket and the bolt, the extra mass acts like a rubber band. That extra mass has a delay tug on the bolt after the strike. Reason why it works within reason is because the tool needs to have enough power to not be bogged down by the extra mass. The rubberband tug effects are more pronounced not just with mass but mass as far away from the center because thst mass is traveling at a higher velocity. The anvil now needs more force to stop and that force is transferred to the bolt. Once the socket hits the bolt, there is also an additional recoil and that recoil helps reduce the tool’s energy needs. It’s sort of like using the energy from the recoil of a machine gun to load and fire the next bullet. I would think that if you can match the recoil to the amount of play between the socket to the bolt, you might be able to get higher torque numbers ~ like shave off 1/100 mm off each side of the bolt or the socket to find the optimal recoil. I’m not a physicist but just thinking out loud lol

[@chrispoirier384]

Just a thought. Impacting longer gives higher numbers and maybe smoothing (longer duration) out the impact energy also yields higher numbers by reducing the amount of time where there is no torque in between impacts. So if you look at each impact the spokes can deflect and the inner socket rotates ahead of the flywheel shape (outer ring). The spokes act like springs and eventually un-flex and transmit the stored energy. I am willing to bet the inertia and the spoke stiffness can be tuned to work best at some number of impacts per second. Cool videos. Yes I'm up at 2am watching this. Lol

[@charlescamen5225]

A great experiment with sound practical field data. I believe the physicist was correct but overlooked considering the resonance of the system. The resonance would change between tools, particularly between different types of tools. There are various factors in play: 1. increase overall mass does absorb more energy, hence less overall torque 2. increased rigidity increase the transmission of torque. 3. Increased rotational moment of inertia increases the peak torque on impact 4. the harmonics of the system that occur due to the three properties above and the speed of rotation will result in a system resonance that peaks for different systems. The hollow tube(pipe) is efficient at forming a rigid tool and has minimal weight for a given rotational moment of inertia, more so than the flywheel tool. I cannot speak of the system harmonics as this will need to be assessed using various laboratory equipment. As seen in your experiment when the flywheel band was cut off the flywheel tool, the peak torque reduced proving that the rotational moment of inertia does assist in transferring more torque. It just so happens that the hollow pipe is an optimum mix of the competing factors to transmit torque. It would be interesting to experiment on fine tuning the wall thickness of the outer tube to see how sensitive the tube wall thickness is o the overall effect. thanks