Hi all Engineers, if you can, please help Finding Flywheel suppliers on the Marble Machine Engineering Server: discord.com/invite/7aSFJA6bkH You will find all the Help Request Forms there thanks!

@dchubad

3 ай бұрын

There is also the crankshaft type, not just cogs and belts

@thomasbecker9676

3 ай бұрын

I thought you were gong to make your own, because you knew better and it would be cheaper?

@jankusmierski

3 ай бұрын

Do You think about bicykle type of gearbox. It easy to change gears and it’s tested ;) NuVinci gearbox is stepless. Maybe You can even seat like on the saddle and have bike type pedals to drive a marble machine :)

@strenter

3 ай бұрын

Instead planetary, maybe cycloid gear might be an option. Those can be built smaller than planetary gear boxes and - as James Bruton showed with his robot dog creation (I think v3, maybe v2 as well, lots of it 3D printed) it is easily backdriven (springy legs). Edit: You could ask Sumitomo, they are building cycloid gear boxes.

@Mentholox

3 ай бұрын

Have you tried looking at the old engine community? All big flywheels ive seen came on those type of things. I expect a quite tight community with contacts everywhere and alot of random/spare parts.

Martin, here's my only feedback: when looking at survey results, probably don't use pie charts... They're only good if it's few slices, and you really want to know the composition of the whole. Humans are bad at comparing the sizes of slices, and you have to look back and forth between slice and legend to get the full picture. If you use bar charts instead, you'll get better comparisons and your brain will be able to recognize values quicker and easier.

@bassenji5565

3 ай бұрын

This is exactly what professors told us during my master of data Science :)

@jhalanddesign

3 ай бұрын

Second this. Pie charts are more or less useless in communication

@WebmediArt

3 ай бұрын

True, but that visualisation is just the default by the tool he used, right? 👀 IMHO the right choice, as he did not waste additional time for post processing.

@salocinnicolin5113

3 ай бұрын

In my uninformed opinion, I think he just used the Google forums charts. For unknown reasons Google really like to use those pie charts (or ar least a few years ago, I hope they've grown out of it)

@brennon_

3 ай бұрын

Pie is fine for 2 data points.

The greatest answer in engineering "it depends..."

@-Devy-

3 ай бұрын

I mean this is very often the case regardless of the subject matter.

@SciPunk215

3 ай бұрын

That's why they get paid the big bucks. 😄

@Scanlaid

3 ай бұрын

"Hey smarty pants, what does this big adult diaper making machine do?"

@victor-oh

3 ай бұрын

​@@Scanlaidit depends

@bringerod5141

3 ай бұрын

My proffessor in uni used to ask questions and if someone started an answer with "It depends" he would say "Exactly! Correct!"

One thing to keep in mind is the noise level of each solution too. You don't want it to be a noisy machine. You want your instruments to shine. A less optimal but quieter solution for a problem may be the best overall.

@sandy_knight

3 ай бұрын

I was thinking the exact same thing. It might also be worth considering how each solution contributes to the resonance of the overall instrument.

@tedferkin

3 ай бұрын

@@sandy_knight Same here. I was thinking straight cut gears are notoriously noisy, which is why meshed gears got used in motor gearboxes. However, precision is a problem for them. The same could happen with the belt drives, Martin is going to have to check none of the lengths of belt end up in resonance with any of the speeds he does or end up with the belt as a musical string. Also the weight of each solution should be a consideration for both transport and any inertial resistances. Lastly the idea of swapping out gears, mid performance, really sounds like a bad idea, what if you don't want a pause from one song to the next..... A multi-ratio gearbox sounds like the best option, even if it does require more engineering. I wonder when Martin gets his course in synchromesh design

@albratgaming2348

3 ай бұрын

@@tedferkin Rebuilding the machine in any way while out on location.. is a bad idea in general. I have been part of a machine building project on a few occasions for industrial applications. When it came to how to drive a machine.. anything that requires changing parts.. Any production environment says "No" immediately. If you can have a variable motor or quick change pulleys/ gearboxes that can switch speeds with a lever.. Sure, no problem. But stop the machine and spend 15 minutes changing a pulley or even moving a belt.. They would rather avoid it as even moving a belt can result in damage / downtime. Also I had to change pulleys on the machines in my workplace and the job is such a pain in the rear.. it might only take 10 minutes to do.. but you have to align / tension and reset positions of pulleys and 1 misaligned pulley and resistance / noise / resonance.. things you don't want on a hand powered music machine. :P

@howterson

3 ай бұрын

The balls are the problem

I love this series! Students often complain that they are too bogged down in theoretical stuff and need more practical knowledge and Martin is going in the opposite direction. We are approaching a point where Martin enrolling and completing an engineering degree is the fastest way to finish the marble machine and I am enjoying every minute of it.

@esmeralda150498

3 ай бұрын

I was thinking the same thing at this point it might be better to enrole in a mechanical engineering degree. Or by the end of this series he will go from music to mechanical engineering.

@KazeKitsune

3 ай бұрын

Theory feeds practice... You can do a lot with trial-and-error, but you can do it faster (and with fewer iterations) when you start at the theory.

@Kandralla

3 ай бұрын

@@KazeKitsune I concur. Theory lets you build models, math models will reveal to you what what you can change and how effective those changes will be. There's nothing better than building something and having it work right the first time because you took the time to understand what governs the problem you're solving.

@aronseptianto8142

3 ай бұрын

as a student that has kind of gone both way, i think the problem with school is that we're doing theoretical stuff without a practical goal in mind. Because obviously not all subject can end with a practical project, that would be wildly expensive and time consuming.

@br52685

3 ай бұрын

Could you imagine being in a classroom with this narcissist? Many of us have had classes with "that person," and it was a truly miserable experience.

Planetary gearboxes are the best for back-driving. That is why wind turbines use them. Straight cut gears also put less stress on the bearings. So if you use bushings then use straight cut gears.

@Zadster

3 ай бұрын

Planetary gearboxes can also be stacked very neatly, as they are inside automatic car gearboxes.

@transportationaddict2888

3 ай бұрын

Agreed, planetary gearboxes, especially the ones u buy online have been very nice for my used.

@aronseptianto8142

3 ай бұрын

this is from a very amateur engineer but given that you want to offset the location of the flywheel anyway, you may as well have the belt have some amount of ratio right? Unless having 1:1 ratio belt is somehow more efficient/easier to build

@xxportalxx.

3 ай бұрын

​@@aronseptianto8142yeah, the only downsides are the size of the pulleys, and potential stretching of the belt (but this is on the power end, so I don't think stretching matters at all). I think he's getting hung up on the efficiency, but imo the difference would be inconsequential (easily dwarfed by the losses in the bearing surfaces). So really it's just if the pulleys fit.

@ryanp6267

3 ай бұрын

Straight cut gears like spur are noisy though. Planetary is best of the gear choices. Don’t know enough about belts

I'm just now thinking of a design requirement that I'm not sure you thought of. The flywheels should spin away from the audience. If the system fails and the rapidly spinning heavy wheel detaches, you want it to ride away from the people.

I am a mechanical/production engineer... The problem with gears (of any type) that you are going to run in to for your application is backlash and maintenance. There will be an (extremely small) amount of play between the teeth of the gears if adjusted correctly. This extra space is impossible to avoid, difficult to adjust, and will get worse over time as wear occurs. It is also necessary to to have some level of this backlash in order to prevent extreme tension, heat and unnecessary wear from occurring on the gears as a result of the gears not meshing properly and being too close together. Helical gears are much more difficult to get that mesh correct because it isnt obvious whether they are too tight or too loose without really taking the time to measure each one. The more gears you add, typically the more backlash from input to output you have (ie an overall uncertainty and slop). This slop will lead to energy losses and less precision. This is why a car for example typically loses around 20% of its horsepower between the engine and the wheels. The majority of those losses are occurring in gear meshing. For the purpose of a car, that is fine because it just needs to go forward or backward. the actual amount it goes forward or backward per RPM of the engine doesn't matter. For the marble machine, the precision of the input-output ratio is the ONLY thing that matters for tight music. Also, for maintenance, the more gears you add, the more difficult it is to adjust because adjusting or shimming one gear affects the next gear and the gear after that in the sequence. As the ratios and amount of gears increases, there will be more and more slop, uncertainty, wear and significantly more maintenance for every gear that is added in sequence. In order to adjust backlash, you will need to shim and be able to adjust the position of every one of the axle's alignment, angle, and position to thousandths of an inch (and keep it steady after the adjustments) and you need to measure every gear with a dial indicator. every time you shim one gear, you will likely have to do each gear all over again, and you will need to do that periodically as they wear down. Speaking of gears wearing down, with gear to gear contact, you will also need constant lubrication or it will wear out extremely quickly, especially with helical gears which tend to gouge and dig when under lubricated or they simply shear. This will make that backlash and maintenance issue exponentially worse unless you can keep the gears doused in lubricant. It may turn into a constant battle to keep your gears aligned as they wear down (unevenly, I should point out since you have a reduction and one gear has significantly more teeth than the other. the small gear will probably wear out 50x more quickly than the large gear for a 50:1 reduction. that is one of the benefits of a planetary gearbox... it is usually sealed and flled with oil and also the planetary gears split the load of the sun gear so they don't individually take as much abuse and will last longer. the downside is more gears in sequence=more backlash and slop and power loss). Without being doused in oil or grease, sequential start making a screaming noise as if to tell you they are in pain. Speaking of noise, a bunch of meshing gears will be very loud, and will get worse (like knocking, clacking or ringing) if the gears have too much backlash, and will grind and scream and screech and be very difficult to turn (especially helical gears) if they are ever under lubed or don't have enough backlash or are misaligned in any way. helical gears specifically bind in a way that halts them when they are underlubed, misaligned or don't have enough backlash, which could be potentially catastrophic to the marble machine (if one component suddenly halts and everything else keeps on going with the momentum of the flywheel). This is music we are making, so this kind of noise will be undesirable, as will the vibrations it may cause. This project is a lot of precision and painstaking work, not to mention your own safety of standing in front of it. a catastrophic failure due to helical gears binding would be a nightmare. Something like a nylon or high density polyethylene gear (like a cutting board material) or Polyoxymethylene (POM) would be better than metal gears (if the torque application isn't too high as to shear the plastic gears) because the polymers would be self lubricating (to an extent) and would not ring like metal would. you would need drastically less lubrication and the maintenance and gear backlash/alignment adjustments would be far more forgiving if you ever make a mistake. You would still need lubrication to reduce wear, but mainly to reduce heat and the fatigue that would set into the gear (especially the smaller gears in your reduction). Plastic gears are also much cheaper to replace, especially if you just replace all of them periodically as a complete set after x amount of hours of it spinning or rotation counter so you can do it consistantly... the same way maintenance intervals are on industrial machinery and engines. Another benefit is the plastic would just shear in the event of a catastrophic failure rather than creating a massive and sudden force that tears the marble machine apart, which would be possible with the momentum of a flywheel and metal helical gears if they bind. If you go with a polymer gearset, you wouldn't want to 3d print or cnc from a block of plastic as your manufacturing method, either... you'd want it to be injection molded so the shape of the particles and the material properties are formed to the shape of the gears under pressure. this would also maximize the strength, rigidity, and longevity of the gears as it would absolutely minimize discrepancies in part density and cavitation. You would also get a less porous part which is less susceptible to water absorption (from humidity) which can cause premature part failure. Once you had the molds for IM or some sort of forging process, it would also be easy and cheap to replicate new replacements. If you have some money to spend, you could probably get your own injection molding rig and use your other tools like your cnc or 3d printers to make the molds for it. youd make much stronger parts this way than a cnc or 3d printer could make using the same exact material. It may also be worth looking into carbon or fiberglass reinforced polymers as well, since we need extreme rigidity for this application. flex in the gears basically means more slop and your backlash adjustments meant nothing. Enough about gears and manufacturing though... I would recommend taking note of how automotive applications control the timing of interference engines, since the slipping or any discrepancy of timing in some of the high performance engines would result in catastrophic failure like a detonation, pinging, overheating, afterfire or even contact between the pistons and valves (not quite f1, which use either EXTREMELY precise and harmonically balanced gears almost like swiss watch... and they do that because 20k rpm is way too fast for a chain... or they use pneumatic/solenoid valves and dont have a spinning linkage from the crank to the valves at all, only a timing gear with sensors that open/close the solenoids). I mean like the these sport motorcycles and drag race engines run upwards of 12k RPM. Almost all of them use a timing chain with an oil/hydraulic tensioner that uses the oil pressure to vary the amount of tension on the timing chain. Often they will tension both sides of the chain and have a plastic chain guide between the tensioner and the hydraulic tensioner to spread the pressure along the entirety of the chain so it is impossible for it to slack or stretch. Specifically, they usually use a "double roller chain" and the oil hydraulic coupling is used off of a dry sump oiling system which is also run off of the crankshaft directly and is a pressurized oil pump. once the motor starts spinning, it it pressurizes the tensioner and the tensioner provides a tension that is proportional to the rpm. The benefit here is since there is tension on the chain (or belt), you can reduce the amount of backlash that would have occurred with the direct gear mesh. the roller chain has bearings inside each chain link and shouldn't ever really cause wear on the sprockets. the oil/hydraulic tensioner is self adjusting and should always be a perfect tension to reduce slack or stretch. The benefit of the chain and sprocket over a timing belt and pulley is that the rubber belt (although extremely stiff and it contains fibrous material) is still able to stretch, it will produce more heat, and it is more likely to slip. the chain will not stretch under tension until extreme RPM, and may be tighter for music, although if you want the hydraulic tensioner setup, you will need a pressurized pneumatic or oil system. I haven't done much research as to which is for this application, these are just my initial thoughts and my take on what to look into next.

@electron2601

3 ай бұрын

Wow amazing advice! Have you thought about signing up on the link above and posting what you said there? I felt like I learned so much from all the time you spent writing all this! This needs to be pinned on the top.

@HannahFortalezza

3 ай бұрын

I feel like the timing belt is the best option. It minimises the need for precision, it’s relatively efficient (lighter than a chain, though some losses will be experienced by the stretching/compression of the material) and the noise it produces will be minimal (esp. compared to chain/sprockets or gears where correct mesh is absolutely critical). There are plenty of motorcycles with belt drivers that don’t have issues and put out significant torque, and the amount of stretch would be minimal for the application. There may be a need to run two steps of reduction depending on the force calcs.

@theyachtclub264

3 ай бұрын

@@HannahFortalezza you may be correct. The precision you minimize the need for is gear meshing, but with a belt and spring tensioner you would lose some precision as a matter of uncertainty in the timing (ie it doesnt give a perfectly consistent input vs output… although it will be very close every time) unless you could keep the tension in the belt perfectly and as long as the belt doesn’t stretch or start to wear down or create residue. I know what you are talking about with the motorcycle drive belts… I think a better example would be timing belts connecting the camshaft (and timing) and the crankshaft and it is critical there is never discrepancy. Most engines use timing chains, but some use rubber belts for their timing. If we use the motorcycle drive belt example you mention, im basically pointing out that most motorcycles use chains instead. The chain is superior in most cases, as it also has a bearing in each link of the chain so it is static (ie stationary) friction on the contact between the pulley/sprocket and the belt/chain whereas the belt is kinetic (ie moving/sliding) friction. The bearing on a roller chain doesn’t move relative to the sprocket once they are touching. The belt has to slide on and slide off every notch of the pulley every time it goes around and it gets worn out eventually and also creates a gross rubber residue that gets all over the place over time. Kinetic friction (friction of sliding) is also a much weaker force than static friction (friction force that would need to be overcome to cause a stationary object to move)… and that is the reason the belt is much more likely to slip or skip a timing notch… although for the marble machine it probably wouldnt have that issue. The issue with it is the loss of energy and power through the kinetic friction. It is very difficult to account for and is going to create some amount of slop in the input vs output. Both a chain and belt can be effective in controlling timing, but the chain is the superior of the two options. Some of the benefits of the belt are ease of removal compared to a chain, the belt does not need to be lubricated, and also if a chain does break, theres a chance it gets whipped around the sprocket and kills somebody. The belt would just hurt but probably not seriously injure or break the machine. I dont think the marble machine is going to be nearly enough torque or momentum to break a single roller chain much less a double roller chain. To further explain static and kinetic friction (because it is a very important concept), think of the wheels on your car. As they roll, a rubber particle on the outside of the wheel touches the ground and is stationary for the millisecond the car rolls over it. It is not sliding on the road. It is more or less stationary with some other particle on the road as the wheel turns and the car moves forward. Then that particle gets picked up off the ground as the wheel keeps turning. It never slid, the rubber particle was almost stationary on the road despite the wheel turning. That is mostly static friction. The coefficient of static friction is greater than if that particle was just sliding and skidding on the ground (kinetic friction) by a huge factor… like 2-5x more. That is why antilock brakes will slow you down faster than locking all 4 tires. The antilock brakes are causing your tires create static friction instead of kinetic friction. So now, Think about a tracked vehicle like a snowmobile, a bobcat loader, or a tank. That is only static friction. With a round tire like on the car, there is some level of kinetic friction and slipping when the rubber tire particle first contacts the road particle and also when it gets lifted off the road The chain system is like the tracks of a tank, and the belt system is like a tire. The chain system is much more solid, precise, and durable. There is no slippage and basically it never wears out. The downside is it is easy to replace and maintain tires, its much more difficult to replace and maintain your tank treads. You dont need to replace your tank treads very often, but you need to keep them greased. No matter how much grease you put on them, it will never slip. No matter how much you try to push or pull it, it will never slip. The same cannot be said about rubber tires or rubber v belts. I dont know the level of precision that would be lost with a belt vs a chain, but there would be some losses. The chain would be superior for this application because you want precision and to minimize replacement parts and taking the marble machine apart. Greasing the tank treads is easier than replacing a tire in this application, i think. That is my opinion though, and a belt might be precise and durable enough to work just fine. I dont know the torque specs and dimensions of the marble machine. Its a lot of work to do the math on the amount of uncertainty the belt would have (probably less than +\- 2%) compared to the chain… but its not even worth doing the math imo because conceptually the chain is more precise and more durable. Why even bother? The chain is not perfect either, by the way. It is just closer to being perfect than belts or gears. As for movement and transferring energy, nothing is perfect because entropy and heat will be created in any thermodynamic process that involves kinetic energy transfer. The only thing I can think of that can be infinitely precise is magnetism as a tool of measurement (if you are interested, look up an LVDT low voltage displacement transformer… its a theoretically infinitely precise im measuring distances by using a displacement to force a magnet through coiled wire… kind of like a solenoid… and it creates an analog electrical output which can be read. You are using a force of nature to measure something rather than any measurement a human or robot could make. They use them for a lot of construction projects and to make predictions about soil composition before they build by seeing how far the ground presses. They also use it to find where to put drainage fields for septic and to avoid contaminating the ground water. They also use little tiny lvdt’s to measure arteries during surgery so they can make/use the appropriate sized tools and whatever else they need. I know specifically theres like a tube the doctors have that fits in the bloodstream before they patch it up so you dont bleed out after a heart transplant or something. Idk, im not a doctor.) Its pretty freaking cool.

@brokeboygarage4152

2 ай бұрын

Thank you I was about to write a long winded reply myself but I read yours and you explained it exactly the same way I would have very clearly I might add

@Guardian_Arias

2 ай бұрын

Im partial to flat belts on flat pullies with high tension using an idler. It has done wonders on my 3D printer and lowered the noise floor. It had gotten to the point where the noise from the belts meshing with the pullies on the stepper motors was second to the parts cooling fans. This of course is best utilized on static ratios. If you need variable ratios like in a transmission, then experiment with two balls, where the output ball makes the input ball spin via friction at the contact points. You can then vary the output ratio by adjusting where the balls make contact. if both are touching at the widest circumstances relating to the axial axis then they are at 1 to 1 if you then adjust one to be at the widest and the second near the top then you can get higher or lower ratios depending on which ball is at its widest point. also, that's if both balls are of equal diameter, you could use different diameter balls.

When you try to create a musical instrument, just to go and tour around the world and end up with a mechanical engineering degree and a background in project management

@phonkey

3 ай бұрын

It's a story as old as time.

@jamesdominguez7685

3 ай бұрын

I look forward to the movie version. So many montages!

weve been yelling "design requirements" since the start of MMX haha, glad martin has now realized how important they are!

@jamesdominguez7685

3 ай бұрын

He's a lifelong artist learning to be an angineer. Reprogramming brains takes time and effort. :)

@Schmidtelpunkt

3 ай бұрын

Yes, a lot of engineers did, in kind of a pavlovian reflex. But before he scribbled that behemoth of a marble machine he is now aiming for, there was no way to know what the design requirements would have been. In that process he made several changes which would have made all those perfect plans crumble. And even now, I doubt this first module will stay the same when the other parts come into existence because there will be issues he could not foresee.

@starblaiz1986

3 ай бұрын

​@@SchmidtelpunktThat's why a requirement spec document is a living document - you put down your best guess at the time, and you itterate and modify and adjust and correct and update as you learn new things about the project through prototyping and experimenting. The point is so that your changes in ideas are deliberate and measured and with reason, and not just random or "whatever I feel like at the time". The freedom and creativity comes from the experimentation and prototyping, but those things should be done with an ultimate goal to either validte, add, remove, or modify requirements in the requirements spec. There is often a test spec document too for testing of requirements, although these days people usually merge the two things as there's obviously a lot of overlap, and there's a valid argument that every requirement should have one or more tests, and every test should have a requirement.

@Schmidtelpunkt

3 ай бұрын

@@starblaiz1986 The problem is that as an instrument it has to "feel right" for the musician. No matter what you assume, if it fails to allow being used intuitively, it's worthless. Which is as much as he said. Which is also what all engineers gladly ignored.

@Kandralla

3 ай бұрын

@@Schmidtelpunkt MIL-STD-1472 HF-STD-001 ANSI/HFES 100-2007 ISO 9241-210 There are more than I can list here. Engineers don't ignore it. People ignore it, just like people ignore stuff in other realms of their life and work.

A belt can also be helpful with protecting your machine from damage. If something binds or stops a spinning part, the energy needs to go somewhere, and often it will break something. But if you have a belt between the power source, and the bound part, it allows the belt to slip or be the breaking point. Thus protecting the more expensive parts.

@InventorZahran

3 ай бұрын

Belts, tires, elastomers, clamp surfaces; rubbers are always the expendable components that wear out while protecting the metal beneath them.

@daniellclary

3 ай бұрын

@@InventorZahran Yep, lots of options. I been discovering that while upgrading my Xmaxx RC truck.

@SteevyTable

3 ай бұрын

Unless it's my 3D printer. The x-axis belt ripped the carriage in half.

7:21 - I find it poetically paradoxical to see the word “nuance” in ALL-CAPS in BOLD typeface and a GIANT point-size across the entire width of the screen… NUANCE. 😂

Circular gears are the way to go. Pentagons have caused headaches for me in the past

@sphygo

3 ай бұрын

I really like triangles personally, but I understand the appeal of circles too

@decmccoy6731

3 ай бұрын

I’ve had good luck with squares, but circle might be the way to go for the MM

@jamesdominguez7685

3 ай бұрын

Is there such a thing as an irregularly-shaped gear with movable edges so you can theoretically change its gearing ratio without removing it from the machine? It couldn't be circular, but I imagine a opentagon or hexagon might work, with some kind of lock-nut to shift the toothed sections in and out. Is this a thing? Actually... now that I think about it, the diameter would effectively change as it rotates, which would lead to irregular timing. Don't mind me.

What you are describing at the end of the video is model based systems engineering. It is one of the newest and fastest growing engineering disciplines, even though it is something engineers have always done to one degree or another. The systems engineering field seeks to improve the efficiency of the design process by developing a model of a system that can easily be changed and optimized before any cad programs are opened, any metals are machined, or any testing is done.

@cenotaph152

3 ай бұрын

The most essential aspect is defining almost every single requirement for the system early on and figuring out which requirements are dependent on one another.

If you run gears i recommend a plastic or nylon paired with a metal gear. Dedicated wear location, and keeps them quieter than metsl on metal. If it was good enough for engines it should work fine for the mm

@thomasbecker9676

3 ай бұрын

Nah, Martin knows better than engineers.

@Lu-db1uf

3 ай бұрын

@@thomasbecker9676 lol you must be new here

@thomasbecker9676

3 ай бұрын

@@Lu-db1uf Not at all. I was being sarcastic; seeing as after years of marble machines and KZread, Martin seems to still not understand basic engineering and design principles.

@kishinslayer2228

3 ай бұрын

​@@thomasbecker9676 he's learned a lot. There are engineers who have been doing the job far longer who know less, and there's some who have been doing it for less time who know way more. Everybody learns differently, the only reason any failings are exposed at all is because he posts everything and willingly exposes them. That's no reason to be a dick to him.

@MarkkuS

3 ай бұрын

Jeah, they even give better lifetime characteristics for some plastic gears for low torque applications.

Similar to timing belts, you can use roller chain (aka, bicycle chain). Very efficient, and designed for the power levels generated by a human being. Also, you can use off-the-shelf bicycle parts for your gear shift.

@brandergout

3 ай бұрын

And dust/grime tolerant! As the machine will be dissassembled, moved, packaged, transported, reassembled, and used in many locations- dust/grime will certainly be an issue, and roller chains are very well proven in this regard.

@derBartzer

3 ай бұрын

though the same, why not use the stuff which is already concept proof

@teebosaurusyou2-un2nz

3 ай бұрын

Google DuPont Teflon Chain-Saver Dry Self-Cleaning Lubricant

@TheHenirik

3 ай бұрын

There might be a torque issue in using bike chains, but other then that i agree the type should probably be considered

@jamesdominguez7685

3 ай бұрын

The second gearing stage that connects directly to the flywheel is likely to be under a HUGE amount of tension, so it would need to be a super robust chain. I was also concerned about noise levels, but in my experience bike chains aren't usually too loud - most of the audible noise from bicycles is from the gearing ratchet going "tick tick tick tick". In that topic, I hope Martin finds some much quieter parts for the ratcheting systems in the Huygens drive, because the prototypes were VERY loud. It's just a standard issue with any kind of ratchet system: they're nearly always noisy as hell.

I concur with the bicycle chain and gear solution. Also gives a proper workout on the go

bike chain are more efficient than bike belt and you can get replacement part anywhere in the world for the gearbox you can also use a bike derailler .

@lupeters213

3 ай бұрын

Timing belts can be bought from most industry suppliers. Chains need to be lubricated, lengthen over time and wear down the spur gears they run on.

@Alex_Vir

3 ай бұрын

​@@lupeters213 the belts wear down their gears too, and wear themselve as chains do, and with a bit planning there isn't any issue in any of the szenarios with accessability of replacement or repair parts. One upside of the belt would be a bit of noisereduction as there isn't metal on metal but metal on plastic rubber (idk something not metal)

This is a lovely update. Seeing Martin get so much feedback, and realizing he should not discuss the practice, but the bounds and discuss it abstract. Once the design is done in abstract, it shows which restrictions are there and make informed decisions at an abstract level. And then you can look at the implementation details. Which will still have many (e.g. if I use off-the-shelf component X, where do I place that on the machine so it can reach Y. At what point should we not use X, but Z since that has a bigger reach... and what is the cost of using Z). That is a separate puzzle. Lovely stuff. Essentially you're architecting top-down.

Martin, you have come so far! Personally I watch the videos here, not because I want you to complete one machine or another, but because I am invested in your learning journey. Journey that I find to be relatable to my own. So keep learning and keep improving! I know that I at least will keep watching.

I couldn't find another comment on that diagram at the end so here's some info if you're interested. On the left you see an input shaft with input torque T1 and angle of rotation theta1. D1 is a damping factor, which is friction that acts against the torque. It generally increases with rotation speed. J1 is the moment of inertia of the input shaft. It connects to a driving gear with N1 number of teeth which meshes into the driven gear with N2 number of teeth. The driven gear is connected to the output shaft of moment of inertia J2 (J2 includes not only the shaft itself but everything else attached to it in the whole machine), with rotation angle theta2. Its own damping factor is D2. K2 is a spring load on the output. (I'm assuming it's a torsional spring load (a resisting torque that increases with rotation angle), as this diagram appears to be a single DOF system, although I do not know where a torsional spring load might come from in your machine. It seems highly unlikely that you have a resisting torque that increases with every turn of the crank). On the right you see an equivalent one-shaft diagram. Meaning if you had a shaft of moment of inertia Je, with damping factor De and spring constant Ke, then this system while subjected to an input torque T1*N2/N1 would behave exactly the same as the system on the left having input torque T1. The purpose of making this diagram is mainly to simply your calculations. On the left, you would have to perform the same calculation on every shaft starting from the output all the way to the input(which is a lot when you have multiple shafts and gear trains in-between), while the diagram on the right allows you to calculate it all at once. It's also useful for showing how the input torque requirement changes according to your gear ratios and shafts' moment of inertia, which may give insight for knowing where to optimize. After this, you can directly set equations such as T=J*(theta")-D*theta'-k*theta where, after setting the desired output angular acceleration theta"(which is calculated from the desired max rotation speed and acceleration time) you can calculate the torque. If it's low enough, you're good to go. If it's too high for human effort, optimization is needed. Source: I'm a mechanical engineer. Opinions are more than welcome.

You might look into manufacturers for pumpjack engines. They are a very large sincle cylinder engine that will almost always use a very large, heavy flywheel.

Martin, as a self-taught engineer (QC and software QA), I can tell you that requirements are the first thing you need in any sort of an undertaking. In commercial orders, they keep you from being surprised in a bad way. In a passion project, their role is more like keeping oneself on track instead of chasing all sorts of nice-to-have things. And in a passion project that's done by a big team it's even more vital to keep everyone on the same track. When you have a very talented and passionate team, it's too easy to get carried away, and requirements provide that much needed solid ground.

Honestly doing design thinking on pen and paper is one of the first things they taught me at engineering school, then when i studied front end software development it's the first thing they taught me when it came to ux/ui design, so yeah, just writing out simply your ideas on a piece of paper and doing your reflection and analysis there is the way to go before and more involved process like cadding or doing some mockups/prototypes

Martin is getting a degree in engineering in the slowest way ever known to mankind 😂

@raphofthehills4405

3 ай бұрын

8 years, and counting... 😅

@DominusFeles

3 ай бұрын

@@raphofthehills4405 He started the first build late 2014, so we're actually looking at over nine years 😅 And that's only counting marble machines, he'd done other builds before those 🧚‍♀️

Love following you on this journey, so much new discoveries every week.

Have you considered grabbing the gear system out of an old industrial lathe? They have a great many combinations of gearing, controlled with either levers or knobs, they are, by their nature, machined to very tight tolerance, incredibly robust, and can be picked up rather cheaply.

@JanTuts

3 ай бұрын

It would also be funny to have him consult the table, to see which lever combination he needs, and set the machine up for the correct _thread pitch_ for the next song :P

@chrislewis6050

3 ай бұрын

@@JanTuts Eh, he can make his own labels. !)

I absolutely love following your journey to create a marble machine. I want to be a mechanical engineer when I finish with scool (1.5 years of high-school left) and I have learned a lot from watching your videos. I cant wait to start my engineering studies, thankyou Martin for fueling my love and interest in engineering 😁

A flywheel off a power press is what you want, Martin

@justinmews

3 ай бұрын

Another suggestion is a flywheel from a powerhammer. Similar application.

For flywheels... look into antique tractor and PTO flywheels (John Deere, Farmall, Ferrari, etc). There's some that are portable gearboxes with massive flywheels to operate irrigation pumps and other equipment. It's worth a look. Maybe find an antique tractor show to visit. You might find someone that has exactly what you need in the back of a barn somewhere.

Brilliant! Can’t wait to see where this takes us. You explained well enough for me to understand the task ahead. Good luck my dude

Awesome video mate. It has been a real joy to watch your transformation over the years. I have learned a lot about critical thinking, just watching your processes. Keep up the great work, looking forward to more videos.

Praise Halolo Renerd

@yusefaslam9675

19 күн бұрын

😭

After hearing you talk about first principles you started giving me hope that you would listen to the collective wisdom and stand on the shoulders of the giants who have come before you. Now I think you’ve finally begun to understand the significance and benefits of a proper engineering and design process. Iterating in schematics and spreadsheets, using proven designs and off the shelf components, consulting with subject matter experts, and (what usually makes or breaks new designs) letting the requirements drive the design exclusively… your chances are better than ever!

I'm very happy to see you continuing the journey!

Love your Work, Music, Art and Inspiration you Bring to all of us viewers! I said to myself before starting this video, that it depends on application/device/etc you are trying to produce. Using VESC based systems has taught me a lot, and there is so much more to learn! Gearing with KV in mind, Gearing with Amps in mind, Gearing with Volts in mind. Gearing for heat dissipation, and more.

Martin, I believe what you are coming to is Kinematic modeling. It was first really made a formal system by Franz Reuleaux who is considered the father of modern Kinematics. As part of his system, Reuleaux sold Kinematic teaching models which are essentially small hand cranked devices designed to demonstrate just one element at a time. Relatively few of his models still exist, but I got to visit (and play with!) the largest collection (at Cornell university). I'll be publishing a video at some point!

Love hard core engineering content... Gears, Yes! So glad to get back on the Marble Machine video train.. Thank you Martin!!

Ok, I hope you see and get to read this.. I worked on a project at my first workplace that we made a Staple making machine that put barbs on the staples as they were formed. We had to move power from a motor to the flywheel. a Big 100kg flywheel that had a cutter and several "knockers" in it. This basically powered the cutting of 3 mm wire and bending (with the flywheel) which as the main method the machine ran by. We transferred power from the motor to the flywheel by 2 pulleys and a Vee belt. The pulleys had three sizes so you could run faster on smaller wire sizes or slower on larger wire sizes.. This is because when you increase the speed.. You reduce the torque. So 3mm wire on the max speed causes the machine to go into a stall situation. Where you lose speed with an operation. As the machine does more operations.. it eventually comes to a dead stop. NB : This is where variable drive systems have problems. Inconsistent power input versus inconsistent power use. They slip to keep the 90% efficiency. So they fail more often from all that slipping. (hence we recommend against Variable slip drives.) I personally would recommend not using a timing belt for drive system. We built a coiling machine that made 1 meter wide coils of 25m wire coils. It was driven by timing belts.. Pneumatic clutch system to engage the power. double sided machine. It worked great for 8 months. Then drive belts jumping teeth, riding over the teeth and wear on the gears. We ended up spending so much on repairs.. We converted it to a Vee Belt drive after a year. The timing belt pulley can not handle torque over time. The teeth basically become knives and that means new parts every x months and looking at your gearing ratios.. those small timing pulleys are going to wear out in weeks.. Helical gear - Precision. They are efficient, but they are also High tolerance and high tolerance means lots of resistance to initial movement. Spur gears - I have worked with a gearbox that uses spur gears to move wire products at speeds where you can no longer see the products. Crimping / cutting and ejecting a wire piece at 30 meters / second. The gearbox whines at 97 Db its that fast. Input motor is only 1.5 HP, put through 9 gears in a single box and output onto the shafts of the crimper and cutters through flexible shafts. The great thing is that you can turn the input by hand and get 10m/sec on the output. If you are working with a slow speed.. this gearbox setup should last a lifetime. We ran at 30m/s for 12 months on a brand new gearbox.. 6-8 months on a old rebuilt gearbox. You could rebuild the entire gearbox in 4 hours. My recommendation is Spur gears with Vee belt speed control. Do the gearbox as close to the output as you can.. Fast spinning things should be kept to a minimum and as short as possible / covered up. It only takes 1 fraction of a second to lose your life.

You might want to take a look at agricultural flywheels. These will be bigger and potentially meet the need. Something from say a threshing machine.

@LeePorte

3 ай бұрын

I was thinking construction such as a D11 dozer or marine diesel engines

Straight cut gears are more efficient, anything else has a sliding contact patch that induces additional friction losses. Also bevel gears induce an axial force that pushes the gears away from each other, requiring thrust bearings to mitigate (more friction)

@youareliedtobythemedia

3 ай бұрын

Yep. But they are also louder

Whenever engineering process gets discussed I can't help but feel this would go so much smoother if Martin would take one semester of an engineering design course. I remember in my first semester of undergrad getting so much theory of engineering shoved down my throat. Like basically the first thing we did was learn how to be rigorous with our requirements models and ensure they could act as a contract between engineers and out to clients. And now, since Martin is stepping into a partial managerial role, having those robust requirements models is imperative for getting creative ideas flowing while still having the correct overall direction. I do get a bit concerned with the documents that put requirements next to suggested designs. I have always found it useful to see the requirements before seeing any previous work to avoid cognitive anchoring and to make it easier to question decisions. To be fair, I haven't done any of that super rigorous work since my undergrad, but it is very much a useful framing tool no matter what and helps in being able to communicate with other engineers as Martin is having to discover on his own.

When it comes to gear boxes for cars the most common is helical gears, and the main reason is noise. In race cars there’s usually straight cut gears, as they can handle more torque, and allow for changing gears without using the clutch. And noise is usually not a problem with race cars. Also, most older cars have straight cut gears for the reverse gear. You can hear the gears when running in reverse with some speed.

@mahekorvenoges550

3 ай бұрын

Would a helical timing belt also be quieter than a straight-cut timing belt?

@jesperwall839

3 ай бұрын

@@mahekorvenoges550 Probably louder, as the groves follows the belt.

Maybe companies producing train wheels can make a flywheel the size you need

You have such a brilliant mind. Love your knowledge and creativity 😊.

Shout out to the masterchief of design requirements

re the flywheel: unless you're planning on spinning it at thousands of RPM or attaching it to a starter motor, there's not a lot of point to using an automotive one. a custom one is probably fine because you're unlikely to ever break it. getting the mass and balance right is more important than trying to shoehorn in something close enough just because it's a catalog part.

Through your tribulations in engineering, you have created one of the best ways to popularize and educate about engineering.

Regarding the CVT for the gear box: if CVTs cannot maintain a constant speed, it would be disqualified as a solution. If, however, the CVT can maintain a constant speed, but the speed settings are not consistent (that is, it is difficult to reproduce a prior speed setting), that would seem to be a minor issue that in some respects mimics human error. (Musicians with perfect pitch exist, but I've never heard of a person who can precisely set a metronome to a specific beats per minute.) In my opinion, one of the advantages of a CVT would be the ability to alter the tempo during play. That would allow slowing down at the end of a song, or simply varying tempo ad hoc in the midst of a song. Just as differing volumes add subtle nuances (and emotion) to a song, so, too do varying tempos. If the entire song is played at one tempo, it will definitely have a robotic feel. So ... if CVTs are deemed unsuitable for the gearbox, I think the gearbox should allow on-the-fly shifting to different ratios. Admittedly, there may be a noticeable step change in tempo, but the inertia of the system would probably smooth those changes out to the point of making the tempo change appear gradual.

Maybe you could find a used cast iron flywheel from some old farming/industrial equipment and repaint it, those pop up every now and then, but might be easiest to find at yard sales on old farms. I always felt that those hundred year old flywheels, that often still are in decent condition, should be reclaimed instead of scrapped with the rest of the machines. Also whats the efficiency difference between a timing belt, a v-belt and a micro-v belt commonly used on cars? And if you use a planetary box, you could always combine it with a belt or chain if height or cg is a issue. CVTs are great in theory but unless you need to change the gear rate often in seems unnecessary, and they are not known for being the most reliable type of gearboxes, though that might be a design and maintenance issue.

Dude you're just crazy! Can't wait to see you in concert with your machine in switzerland in some years❤

12:24 Martin, you really should try to model your requirements using system modeling tools like Capella, and then simulate your system in 1D modeling. It's like trying to model something with a pencil and a piece of paper, but using mathematics in computer modeling tools.

A weapon to surpass Metal Gear. RUBBER BELT

@purepix_fr

3 ай бұрын

"Kojima liked your comment"

@InventorZahran

3 ай бұрын

Metal Gear Solid Rubber Belt Flaccid

@olabystrom5265

3 ай бұрын

Here looking for the Metal Gear reference comment as soon as it was mentioned! 😂👏🏼

So excited to see you venture into the world of analysis engineering! By the way, big flywheels are rare because RPM is so much more practical to handle than size and mass. Also, be aware, flywheels can cause death. They are no joke, even at moderate speeds. Containment should be a concern you address.

I clicked on this video to get the answer to this question

@markzubeger

3 ай бұрын

You get the answer?

@andiarlt

3 ай бұрын

@@markzubeger 0:40

@mrping2603

3 ай бұрын

A simple question never has a simple answer

@thomasrogers8239

3 ай бұрын

So sorry you didn't get the answer you were looking for.

@satansbarman

3 ай бұрын

​@@thomasrogers8239I'd say he got the answer he was looking for, not the one he wanted.

When I see footage of the MMX it still evokes a swell of emotion in me. What a beautiful sculpture. It still feels a great shame to me, that it wasn't fit for purpose. But watching your journey and seeing this new machine slowly emerge has it's own kind of feelinf

I would argue that your real world iterations did not fail but brought most of your viewers. Design discussions and CAD videos only get you so far (for that part of your creator work)

The answer to the simple question is a straight gear. Helical gears do only have a benefit of a better NVH performance, which is getting an issue by increased RPM. Regarding the straight gear there are although ref. profiles which are beneficial for the friction reduction. Those low loss gears have an increased pressure angle and reduced overlap. Planetary Gearsets (PGS) have in general a lower efficiency than a regular gear pair, due to the increased gear meshing bearings etc. in the PGS. Harmonic drives transmissions with their 100 or 200:1 ratios are very inefficient. However as mentioned transmitting torque depends on the application high center distances prefer belts or chains. If you are looking for gears u can get something existing for little money. Final drives of front wheel driven cars have usually a ration of 3-4 to 1. There you can get fine machined gears. Btw. You can although combine a plastic with a steel gear, which will although have an Ok NVH behavior

11.19 Im studying my second year of mechanical engineering and the first few years of the program this is almost exclusively what we do. We have done some small projects with cad and physical models but we mostly focus on theoretical parts on paper.

Sketching and planning on paper is great. You can also use scaled down simple models to test your design and share your ideas. Models are great if you like the hands on approach.

If you stare at the paper long enough, the solution should jump out at you.

the problem with belts is that under high load they require lots of tension to not slip. alignment is critical or you will get belts trying to jump off the pulleys. chain might be a better bet, For gearing a bicycle derailleur might be better. there's a really good reason why bikes still use chains. You could use an e-bike setup to help with the power input. This is also why the america's cup boats went from pedestals to cyclors due to the greater power input. Straight cut gears are more efficient than helical, helical also introduce an axial load on the shaft but helical is quieter.

and having working in consulting - getting design requirements from clients is the hardest part, the first part of the mandate was to take their requirements, map them out, point out contradictions and present them back to the client, "is this what you really want"... I'm kinda sad that between work and 3 kids i don't have time to dig into this with y'all

@electron2601

3 ай бұрын

Sounds like your job has put you under the weather lately. Have you thought about taking a week vacation somewhere?

I want to join and help, but I don't have the experience or knowledge base. So, instead, I'll stand back here, watching your videos, and cheering you on because you have gifted and smart folks helping you... and I seem to be learning more from your progress (even on MMX) than I think I can give back.

Spur Gears: These parallel shaft gears achieve high efficiencies, ranging from 94% to 98%. Ideal for lower gear ratios. Straight Bevel Gears: Similar to spur gears but with a perpendicular shaft arrangement. Efficiency typically falls between 93% and 97%. Spiral Bevel Gears: Curved tooth lines reduce noise and vibrations compared to straight bevel gears. Efficiency ranges from 95% to 99%. Stronger and less noisy. Worm Gears: Efficiency varies significantly based on lead angle, friction factor, and gear ratio. In higher ratios, efficiency drops. Generally ranges from 50% to 90%. Hypoid Gears: Achieve efficiency levels of around 80% to 95%. Suitable for very high gear ratios (up to 200:1). Helical Gears: Run at high pitch line velocity and achieve much higher efficiencies. Efficiency typically falls between 94% and 98%. Maximum gear ratios up to 10:1. Cycloid Gears: Work efficiently at relatively high gear ratios (above 30:1). Under normal conditions, efficiency ranges from 75% to 85%123. took 45 secs to make this list.

The planetary gears in a Toyota hybrid are driven in all directions; the magic in that system is that it can transfer torque from any of the three axes (outer ring to wheels and one of the motor generators, sun gear to the other motor generator, planet ring to ICE). Therefore I think that in principle they are quite efficient when used to gear up from planets to sun gear with fixed outer ring.

13:00 "Old habits die hard [...] I wanna see with my own hands" Woah man, when did i miss the bioengineering Wintergatan Wednesday? :D

For pre-made flywheels, old tractor flywheels are likely going to be the largest off the shelf ones at a reasonable price. Most of the old 2 cyllinder tractors (common up through the 50s) used large and heavy flywheels to flatten the power curve from the engine. They fall short of the 1m you want (0.5m is about the biggest) but are readily available and fairly cheap (other than shipping).

Herringbone gears are where its at Martin. 7:58 if you put you flyweight governor after the the CVT you should be able to play tightly.

Idk why, maybe because you both created beautiful and original musical instruments but I really feel that a collaboration album between you and That1Guy would be absolutely amazing and would complement eachother very well

I reallly can't wait to hear the next marble machine

You might look into v-belt pulleys from companies like TB Woods. They come in up to 56" OD and are statically balanced.

It suddenly feels like this project is progressing much faster and in a great direction! 😃 Cool to see the switch to 'Huygens' btw ^_^ Now I am worried that I mistook a genuine attempt by Martin to reach out as an imposter and made him feel bad 😬

i might send you down a rabbit hole but look how giant gears are made, the videos are facinating, they dig out giant holes in the ground and cast giant pieces of iron in sand, im sure you could get a flywheel made this way

While I'd like to contribute to the engineering server, I've only graduated in August, so I doubt I'll have the best feedback. What I will say is that I never looked at gears the same after my machine design (read, fatigue failure) class. We had a two inch thick book that was mostly tables of equations and a good section of that was for designing gears.

You learn how to say "idea"! wooh! proud of you!

I don't feel confident enough to join the engineering discord, but here is a suggestion. If you are making the flywheel, like you did in germany, get a balancing company involved, either by purchasing a machine or getting it sent off to be balanced. I do have a suggestion for a balancing company, which is based in germamy, and I have quite an amount of an experience with, and that is Hofman Balancing. They have experience with balancing industrial sized flywheels, which I believe the MM3 could be considered to have.

"It's the design requierements that will design the machine!" Epic micedrop! Damn! That made my day! Love you! (I never used so many ! in my live in one message😂😅 But really every sentence needed it. Thank you!!!

From musician to engineer to manager, what a journey for Martin !

This video series is a steep learning curve. Seeing the design go from... "Right! I'm even going to learn to lathe! Because "Tight Music" is the requirement. to.... We've got a team of engineers and theoretical physicists working on this and it's all sponsored (sic.) by one of the most trusted engineering companies in the world! Stop using the word "failure", Martin.

I'd look into what watches and clocks use for their geartrain. The massive up-gearing needed in spring powered clocks is a pretty good already established example of what you're doing here.

When this project started, Martin thought he was building a Marble Machine that he would take on tour. Actually, he was using his passion for and interest in music to fuel a KZread journey and demonstration of a person learning engineering.

Historical tractors like the Lanz Bulldog (?) have fairly large flywheels. But I don't know if you can still get them new and if those are suitable.

6:44 this has "express your feelings for me only using credit card numbers" energy

Someone brought up a really good point in your discord that you should probably start doing the calculations for your flywheel so you dont end up like MMX and end up with an unnecessary flywheel (it was the main conversation a little bit ago). I also thought that a steam tractor flywheel would be absolutely perfect for what you want just because of how accurate they are along with the varying size and good amount of momentum so if something were to go wrong, you would have much more time to fix it before it had significant loss. also want to add that there was also an idea to use a scaled down ship flywheel that you could have made custom, which would be very good and probably better than a flywheel, but it would be very very expensive compared to a decently cheap steam tractor flywheel. (currently looking for a dealer with no luck, just model dealers or ebay)

Semi truck tires seem like a great flywheel. Off the shelf and well balanced.

Old steam locomotive wheel as a flywheel - it's fancy, balanced and available in every depo 🙂

The takeaway I'm getting from this video series is that the real Marble Machine is the practical education in Engineering and Design we gained along the way.

@thomasbecker9676

3 ай бұрын

It's not practical at all.

@RatkingNyxu

3 ай бұрын

@thomasbecker9676 practical as in "pertaining to the actual practice or doing" - rather than via books, theory, and lecture

@thomasbecker9676

3 ай бұрын

@@RatkingNyxu And what is it exactly he's doing, besides finding new things to make videos about?

If we go the old way and go with rule of cool double helical gears all the way. But the new way is to buy a finished solution, I would go with the gearbox for this reason, it is a system that is already designed to meet the loads you would put into it.

It's so funny to imagine engineers arguing over gearboxes.

This whole project has proven to be the most convoluted way to indefinitely delay an album release ever.

I often do "theory crafting" as I call it before I start doing any kind of experimentation, because if you don't know what you want from something, what are you even designing for? Glad to know I'm not the only one :p

6:00 You can use the variable speed pully. That way you only need one belt position and no need for pully changes.

FLYWHEEL of the shelf. Look into ag equipment, specifically the hay baler. Many models of balers have different flywheels. From small balers to big ones. I'm certain you will find a flywheel that works for you.

You might address this later in the video, but I want to comment before I forget: don't forget that this is a musical instrument, so noise levels are also very important! Both using different gearing methods and building the parts out of different materials will affect how noisy the whole power input / flywheel assembly is. The most efficient gearing system in the world won't help you if it's too loud! :)

8:50 Bigger flywheels will have better moment of inertia but is that necessary to have that much? More moment of inertia also means it’s going to take a while to change bpm, will have a higher reaction force and more dangerous if a hand 🤚 accidentally interacts with it

I love how this channel has become Martin Discovers Engineering. Still looking forward to the world tour though.

I like the "soul" of marble machine one. This new things feels cold and soulless... but technically very mature.

CVT's demand a LOT of power to operate, in a classic sense. There is one that BMW made, which does not have such high losses, but it also costs nearly $40,000.

Every time he says "helical gears" the jellicle cats song starts playing in my head