"We've mounted our twin 5-foot flywheels on a perfectly balanced custom axle..." on 2 rickety metal sawhorses and secured with a single guitar strap.

I work as an industrial mechanic and I always tell the new guys, no matter how fast something looks like it's spinning, it always has way more momentum and torque than you think it does.

Flywheels always have a resonance region. When I was a power plant mechanic on nuclear powered submarines our main engines would hit a freaky sounding region where the turbine blades would sound like a wolf howling then they would warm up and pass through that region.

I love how this guy took a big steel drum full of rockets and explosives and somehow managed to make a possibly even more dangerous version with pure kinetic energy.

When the flywheel started to slip, the only reason I wasn't terrified was I realized that if that thing had slipped off, I'd be hearing about this on the evening news, not on youtube.

I am amazed they were in the same room as this monster under the test

me at the beginning: "Hmm why all the dislikes? This is decent content" me at the "end": "wow what a terrible place to end the video"

Cool idea...That was one of most dangerous concept tests I've ever witnessed. if that thing had wiggled a little further and touched the ground it wouldn't have stopped spinning until it hit New Zealand.

Showing me a "part" doesn't make me want to pay for discovery to see what whole thing. It just annoys me.

I'm constantly surprised how often folks fail to appreciate the danger of spinning objects, so it is delightful watching folks who get it. Freaked out is the correct response

Anytime you're spinning anything at that kind of speed. You are going to need to balance the shaft and those flywheels. The more speed you put into them the more pronounced the imbalance will be. These two have enough experience they should have known that. For anyone who doesn't know what I'm talking about. Have you ever had your car suddenly start shaking violently when you drove to fast? When you took it to the mechanic they told you the wheel threw off a wheel weight? That weight is there to balance out the vibration induced small variances in the build of the tire. After working in the sheet metal industry for 12 years. Just because you order a piece of sheet steel and you laser cut it. Doesn't mean that the material is perfectly flat. You would have to order jig plate, plate steel for that. Which even then still has a tolerance range on material thickness. It's just a tighter tolerance than normal sheet steel. So would still have to have someone come in and balance the assembly.

In the late 1960's, the Librascope computer disk, capacity about 20 megabytes, had six or eight disks of about this diameter, although each was presumably somewhat thinner than yours. Two three-phase motors were used to bring it up to speed, and then one used to keep it spinning. We did calculate that if the building and casing of the device were to suddenly vanish, the disks would have enough momentum to roll over the Bay Area foothills and into the ocean.

i like how all these incredibly smart people made all this cool elaborate stuff. and went it came to the brake they were like "eh, i'll touch it with a 2x4"

Seems like the sort of test to do in the bottom of a retired swimming pool, while observing with a drone, from a bunker.

As kids we used to play on these flywheel devices, except they were mounted horizontally and had grab bars. They were known as 'Merry Go Rounds'. They are becoming scarce these days.

Adam and Adam showcase alternatives to the Atom.

Adam and Adam could be complementing themselves but we'd never know 😂

Honestly... I wouldn't even attempt this before having those plates faced on both sides. Giant flywheels are always perfectly balanced.

If both of those wheels don't hit the ground at the same time and get the same amount of traction (impossible), it will take off in whatever direction it wants. Heavy vehicles in front of it will just send it up into the air. I can't wait to see the next episode.

I love how excited Adam always is doing builds. His enthusiasm is contagious

rotating masses have resonant frequencies at a number of harmonically related rpms. When accelerating them up to the desired speed, you have to quickly accelerate it past and through the lower resonant speeds so it doesn't spend too much time resonating at that speed. I used to work with a high speed turbine (10K rpm) and its programmable inverter/accelerator.

Employees watching this episode and realizing why their parking spot was moved to in front of the garage that day

I worked at a boxboard mill and the Boiler facility that provided steam for heating the drying drums also provided compressed air for the whole mill. The air compressors had 6 foot diameter pulley/flywheels and a valve control. When the system was at pressure, the cylinder valves would lock in the open position the current from the motors was cut off, and the pistons would reciprocate without compression driven by the flywheels turning several hundred RPM. When the system pressure fell sufficiently, the valves would close, and the current was applied to the drive motors assisted by the inertia of the flywheel/pulleys, and the compression cycle started again.

A scary and dangerous experiment, I was worried about how the axle was merely strapped down, and that the trestles were not even fixed to the floor.

Treating this like a full video makes you feel like you just walked in late to a very important meeting but nobody noticed, and they've already made a bunch of incredibly irresponsible decisions without you and just asked "Okay so are you ready to go?" and you just say "yes" without fully realizing what the project actually is

I think they need to go faster to get over the vibration (though obviously in a safer place). Turbomachinery often briefly passes through regions of resonance before reaching the desired speed. Problems arise when you stay in those regions of resonance and let the vibrations grow without bound.

We had 2 ton flywheels on the ends of these massive diesel engines in our refinery. They only spin at 100 rpm, but it takes almost 20 seconds for the engine to come to a stop...with compression braking of 12 pistons the size of human beings.

I can watch things get destroyed to bits via explosives, have destroyed things in R&D and was always excited. When this thing started to shift I felt it in my gut that this was a bad idea doing it in that building with other businesses in the area. :o

Definitely has “Cannonball Incident 2.0” potential

I'm surprised they did this test in a warehouse. They were careful, at least, but I'd assume they wouldn't want to spin it up in a city at all. If it runs off in a desert you just need to go get it back. If it runs off in a city, you have problems.

Wow finally Adama Savage content that has that Mythbusters feel to it! Crazy ideas that feel like they aren't just for the craziness of it, and the intensity of the danger involved in learning about something's limits!

Adam, flywheels are normally used for stability not momentum. If you have left the rockets on the wheel, for forward momentum and added the flywheels the rockets would have provided forward motion and the flywheels would have kept it from deviating from its forward path.

should do this in a dry dock or somewhere similar. I felt my blood pressure drop when they realised it was out of balance.

There is no way those steel wheels are balanced enough to not vibrate like crazy! And the way they are attached to the hub is also very sketchy 😂 I love it

We need Jamie in this! He would make some sort of intricate balancing jig and it would be ready in the next shot 😞

To see that Adam is a hugger makes me love him even more. Three thumbs up.

As a certified vibration analyst and an industrial millwright i have some serious reservations about this test. With all due respect for the people involved a couple of key things need to be done. 1) do a resonance test on the assembly. This will show the natural vibration frequencies of machine., for example if the unit has a resonate frequency of 350cpm when it reaches 350rpm or any multiple of it it could shake substantially and lead to a very unpleasant situation. 2) The axle housing only appeared to be held in place by a strap wound around it and there was no means of applying a braking force to the discs. Some sensationalism can be dangerous.

I did a research project with a one tonne 1 meter steel flywheel that span up to 6,000 rpm. Equivalent stored energy as a 10 tonne truck going 100 mph. Pretty interesting standing next to it going full tilt.

I work for an industrial fan company. Largest fan we ever built was 14'2" in diameter mounted on a 30' long shaft. 90,000 lbs. 14,000hp electric motor. Was at a power plant. Turning at 760rpm.

Impressed and enthused. Wish you all the very best

"Um... everyone clear this side of the building." What's scarier: Adam saying that or Oppenheimer?

Why is discovery Australia the best discovery channel?

Adam - Spinning flywheels don't store power - They store kinetic energy. The RATE at which the energy is extracted/used is power. They can supply large power for short intervals, or low power over long intervals. Either way, the total energy available is the same.

Adam you're a Savage, I went and watched that episode right away.

Geeze, can you imagine the insurance nightmare for this episode?

As a guy who work on 8ft circle saw I'm amazed that they never applied internal tension to the disks. Or balanced them. Saws are hammered to run at certain rpm without wobble.

The potential for this idea is fascinating and terrifying. I think it’s right up Adam’s alley! 😂

Really really cool fly wheels experiment... alot better then I was expecting... 👍

If anyone would be involved in constructing a device that could rip through walls like they were built of melted ice cream, it would be Adam Savage...

When it turned and that "oooh" was uttered, it was like something out of a sci fi horror. A machine gone rogue.

As a mechanical engineering student, all of the equations behind this are so fascinating because it's what I'm learning about right now

If those flywheels were truly made to specs, I bet that small strip of tape they added for reference was just enough to imbalance it. Might have also been smart to put some golfball dents to reduce drag - or even put most of the mass at the outer edge, like real flywheels.

I've designed a flywheel energy backup system that spun a 600-pound flywheel up to 8000 rpms. It was part of a system that generated 800-Volts of DC Power, that was converted to 480-volts of AC.

"Hopefully it will be ok" was not the words I was expecting from the expert. Lol

You should have Metal C Clamped the Core Axle container to the Horse tables, and anchored the Horse tables in a sand bucket to help absorb teeder toddling of the structure. I would have also have put up 5 layers deep (and as high is the device is) Sandbags like what I assembled many in Iraq. Sand bags really absorb energy, and is reuseable when need be. I would have considered doing a Belt pulley start rotation engagement system, or using like a motorcycle transmission with a clutch to engage the special center spin lock. The clutch pivot system will allow you to engage, and disengage without yanking it. I really reconmend if all possible, balance the iron place so you get less wobble. This information comes from a Disabled US Veteran who used to spec performance his 91 Integra. Give it some thought and let me know

I wanna see more of the tests at site I would live to see the process of test, creation, retest and recreation for the flywheel motor.

"The power in this flywheel scares the pants off of me." Let's use a ratchet strap too hold it down.

The second it started rotating on the platform, my nerves fired up, that was terrifying, and I'm only watching the video!!

Can't believe how half arsed this while thing was and I love Adam and mythbusters.

As part of the Nerf Community, Flywheelers always have a special place in our hearts for their ease of modibility and power, though I'm more of a springer man myself

Have you guys heard of hay balers? You could have gone to a junk yard and found a couple cast iron flywheels with similar inertia that are already balanced.

So much in this video that would get anyone fined severely for safety violations. Woah.

These guys do a great job of using dialog to explain things they both definitely know, without being condescending.

I think new Adams favourite part of any mission is the man hugs at touchdown.

At first I was like "Wow... Tori Belleci is really aging!"

Wish Grant was here to see this. We miss you Robo Grant.

6:56 yea use the corner of a wood plank against metal and push into the middle which would be the hardest point to stop it at and tell us its hard to stop

Mounting this thing with those tiny straps is insane. Especially for some engineers. The whole thing should be anchored to the ground and the axle should be welded to the rack.

Having experience on the farm operating a buzz saw on a tractor-powered PTO, if those large discs aren't properly balanced, tempered, and tuned, they'll start to set up a vibration frequency and the force of rotation will stretch the metal. Depending on temper patterns in the metal the enlarged metal will try to find room around itself and wobble. Saw blades tolerate a certain RPM. Above that they start howling and wobbling, looking like they are made of rubber.

I imagine this would be ok to test in a desert surrounded by miles of sand dunes

Ford used to use a 300 cubic inch, 4.9 l inline 6 in all sorts of different chassis from school buses, dump trucks, to quarter ton pickups. The school bus and agricultural powerplants had nearly 3 foot wide flywheels. The torque advantage of that huge flywheel made the difference of a light duty pickup application, to a max out load conditions.

The reason for the vibration is due to the extreme amount of runout in your axle assembly. If you true that whole thing up and balance those enormous round plates all of that vibration should start to disappear. Another problem I see is rigidity. You've got everything there coupled together with a very small bolt circle. You probably want a bolt circle and an axle size on par with a semi truck. You're at passenger car level right now. Also, you need to bolt that thing to the floor. Those saw horses were moving all over the place even before you decoupled the motor.

Really bums me out how sensationalized Discovery has become. The average physics/applied science youtuber has better content than this now.

I'm trying to tell myself, don't be scared because it's a video. Then the thing started to move on the horses. Gave me goosebumps!

ohh man the skycrane that was JUST MADNESS! ...and it worked perfectly TRUE GENIUS loving this if i were lost in space these two are the ones id want on my team.

Just curious... Wouldn't setting the axle in a groove take care of the movement problem while spinning it up?

So is there going to be a Part II for this video?

This is so cool, seeing lectures from awesome professors then actually seeing people in the field exploring Engineering and really using the their minds to explore and play/create onto something, we need so much more of this on you tube. Keep it up

As a non-engineer, I have no concept of the energy stored in those flywheels. It would be terrifying to be near it, for sure, but that's about it.

I love how even after try to slow it down with a 2x4, the thing’s still spinning in the next shot.

“Perfectly balanced axle” *disengages the coupling via yanking a rope.* They make industrial clutches for a reason people. Also, they could have done this whole thing using actual flywheels, or balanced pulleys meant to do this job. Not unbalanced steel plates.

Momentum is such a powerful tool in storage of energy and dissipation over time. During my first year physics course, at the ol uni, I built a demonstration of how force vectors are altered by utilizing rotation. Angular Momentum is beautiful. When you spin an object from a fixed location it can do such amazing things!! Love this video!! 😀

wow well wow . brilliant concept .

Wow.. nasa photographers were already ready to take the video of the rover descent. Great work. This is the real timed photography.

When I was. Freshman in High School I took wood shop. We were all required to build something, and I had to figure something out using scrap wood. One guy made a salad bowl for his mother. He took about 8 1” sheets and glued them together, then stopped and shaped the bowl with the wood lathe. One day he was going g t it. Almost done and he wanted it don’t by Christmas. All of a sudden the bowl broke loose. He had carved through the screws holding the bowl to mount. First it spun to the right, where it kind of danced around a bit where it hooked up and flew out of the shop window after hitting a dust pan and launched into the Security Guard’s house next door. That was some fun!

WHY NOT LINK TO THE FULL EPISODE, DISCOVERY??? Like, you leave me on this cliff hanger and I WANT MORE

this is AWESOME!!!

Looks great. A massive fly wheel.

I'm surprised the first thing you didn't do was check to ensure they were equal in weight and balanced. Like balancing a tire.

Now sharpen the wheels and turn this thing into the world's largest deli slicer!

The way the curiosity rover landed is simply amazing

"My day job: I work for a place called Jet Propulsion Labratories..." Ya know, in case you haven't heard of it... 😂

Has anyone heard from these guys recently?? Starting to get a little worried that part 2 did not go as planned after having watched part 1

two adams geeking out. i love it

All the challenges shown here, plus the added challenge of flying, is why helicopters are such amazing & insane machines. Lots of rotating, vibrating mass which is constantly trying to escape control.

Anyone know if they ever finished it and where I can find that?

Back in the mid 1980's I took a tour of the Princeton Plasma Physics Lab with my engineering classmates. The host told us that they had a massive flywheel spinning at ridiculous RPM in there, and if it shook loose of its mounts it had enough energy theoretically to roll all the way to Los Angeles.

The contrast between narrator adam taking himself seriously and on film adam not taking himself seriously at all is pure gold.

I love this show and the guest is a living legend. If you’d just switch once and for all to metric units… it’s 2021 guys!

Incredible!