"The Power In These Flywheels Scares The Pants Off Me" | Savage Builds 

"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.

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 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.

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"

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.

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

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.

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.

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

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

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.

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.

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

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"

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.

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

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

Adam and Adam showcase alternatives to the Atom.

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

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

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.

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.

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

Definitely has “Cannonball Incident 2.0” potential

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

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.

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.

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.

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.

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!

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

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...

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

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

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.

Why is discovery Australia the best discovery channel?

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

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.

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

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

This with the catapult are a perfect combo for battle

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.

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

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.

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

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

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

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.

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.

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

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

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.

Spinning a fidget spinner with an air nozzle creates an air siren :)

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

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

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.

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

Impressed and enthused. Wish you all the very best

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!

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.

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

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.

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

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!

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

Reminds me of the Tesla Turbine, which works using flat, circular plates just millimetres apart. It's so efficient we haven't yet invented materials strong enough to make a full sized one.

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

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

I love Adam Savage wearing a “Savage” shirt so you can tell which Adam he is

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.

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

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

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

How much energy can a flywheel store? Flywheel: "yes"

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

I was gonna say "such bunglers ..." but I liked the way he said: "don't get comfortable". That's the proper attitude.

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

The energy in those flywheels scares the pants off me too

I thought "how can they do something so reckless..." then I saw it was Discovery AUSTRALIA. All g'day mate!

Back in the 80s when I was a student engineer I worked for a company that made a 1,000 ton mechanical press that took the momentum of a 3 ft wide by 6 ft diameter steel flywheel spinning at some unearthly speed and clutched all that energy into a single stamp. It was so powerful it could stamp out a VW bug in one fell swoop! 😁

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

I'm so glad NASA or JPL or someone had their Lego rover project based learning program with Bobak Ferdowsi about 8 years ago and my son got to participate in it. Thereafter we were able to schedule a tour of JPL for the Thanksgiving week off school. How cool was it to be in the JPL/NASA control room where all the action happens?!!!

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.

*presses on the inner rim* "Look at how much energy it takes to stop the disks." Me: "This is why disc brakes are on the outer rim. *then proceeds to press on the outer rim*

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.

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

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!! 😀

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.

At work, we have three massive flywheels used as batteries, because we need all the energy accumulated in them in a moment, and the electric grid cannot provide that amount. They are underground, in a maze-like building, so that if they go flying, they have to transverse tens of walls.

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

0:06 when you forget someone's name...

I worked in a metal workshop and this was freaking scary! Can't imagine the force on those things

The way the curiosity rover landed is simply amazing

Adam: "What's the best way to build a rocket powered Panjandrum?" Rocket Scientist: "Get rid of the rockets!"

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

We need Part. 2 ASAP !!! 😂❤️👍

6:25 You should NEVER ‘pull off’ a flywheel. That ALWAYS gets messy😂😂

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.