Inertial Gyroscope Spin Up and Demo 

Spindown takes >10 minutes. The fact that any bearing has such little friction after all these years is simply amazing.

I used to work on the F16 inertial nav. Unit. The grease for the bearings was like a solid when cold. The first step in powering up the unit was to heat up the lubricant to become a fluid like substance first.

Burroughs had a 36" fixed head disk array back in the early 60's. The hub was phosphor bronze and weighed 25lbs alone. It had reginrative braking, using it's own inertia to slow down. One story goes when they pulled the unit out to be delivered to a service center, they forgot to set the brake. So it was still spinning when it was loaded onto the truck. When they made a sharp turn at a corner, the storage array preceded right out the side of the truck!

Geez -- if that was the "noisy, crusty" bearing, imagine how long it would've taken to spin down if it was a brand new bearing!

Back in the 80s and 90s I worked on these type of gyros at Litton Guidance and Control in SLC UT. Then, they started using ring-laser gyros and solid-state gyros. I left in about 2004, so I don't know what they use, now. It was already so noisy in the Test Area that you never heard the gyros spinning-up or down. Ho-boy but were they accurate. They could accurately measure the earth's rotation in real-time. The "stations" or pedestals we tested them on were 12 foot blocks of granite, per station, positioned in the ground. Thanks for this demo. Brings back memories.

I just watched a gyroscope spin down for ten minutes fifteen seconds. You win the Internet today.

sounded like a wanna-be Seagate ST225

This is the best video I have watched yet this year.

Wow, that rotor must be HEAVY for that long of a spindown with such noisy bearings! - I wonder how much mechanical energy is stored in that rotor - it's amazing!

Always interesting to hear the resonances while powering up or down such high speed devices, I have two turbomolecular pumps one at 50k rpm and the other 72k rpm maximum speed.

Sorry for the oopsie on the first version of this video and the lost comments. Had to delete it and reupload this one to correct for (yet another) big bad typo. And yes this is after proper cleaning and lubrication.

I _can_ skip to the end... But I *WON'T* . This is too awesome!

It just sounds like... power. Kind of like when the Ghostbusters’ proton packs power up - barely contained power just WAITING to bite you. +1 for “rippems” and “safety squints”.

Sound reminds me of the old MFM hard disk I had on an Amstrad PC1640.

I love this old gyroscopes, there are fascinating things and the sound is always great!

That's a familiar sound in an airplane...When you turn the master switch on, the electrical gyro in the turn and bank indicator spins up (in a small General aviation plane, it's only 12 Volts DC though). There's also a vacuum operated gyro in the attitude indicator and the directional gyro (DG).

Lovely. Fixing & fitting inertial nav platforms, as well as pitch + roll + yaw rate gyros for stability augmentation flight control systems was bread & butter for Nav Inst trade in the military. That gyro spin-up sound brought back fond memories, Thank you so much.

Your whole channel is fascinating and should be way more popular imo.

Rippems and safety squints.................It's gonna chooch

Sounds as rough as a bear's arse mate! I worked on (Single Gimbal 1 axis) Rate Gyros for Autostabibilisation one each for pitch , roll and yaw, (As is the one you have) on Phantom aircraft. I also worked on Rate Integrating gyros also called Rate/Rate gyros, Ferranti FIN 1063, as well as displacement gyros DGA and VFRS on Phantom back in the 1980's. In a Cleanroom. That's quite big for a rate gyro, the ones I worked were about the size of two cigarette packets and had a torsion bar calibrated to the variable reluctance pick off to output a voltage proportional to the rate of angular disturbance, (angular velocity) about the sensitivity axis. They also cleverly used eddy current damping provided by a pure copper vane between the attraction poles of two rare earth magnets. Inertial platform displacement Gyro's I also worked on could not be moved from the test stand for at least 15 minutes until they had finished spinning down. Inertial, rate integrating, or Rate/Rate gyros have much smaller rotor masses and temperature controlled viscous damping, they tend to spin down within a minute. Inertial platforms use a combination of Displacement Gyros, Rate Integrating gyros as well as North South / East West and Z, (gravity) force feedback accelerometers, and some nifty second order differential equations to calculate the cross product accelerations the accelerometers detect as the control servo signals try to maintain the accelerometers at their null positions. (The actual acceleration signal is proportional to the feedback error signal which drives the accelerometers to null). The purpose of an inertial platform is to provide a stable motionless base for the accelerometers to measure how much distance has been travelled by the vehicle carrying, it in the three dimensions in which it can move. (Information nobody asked for, but you might find interesting)

this is so frickin cool. I never thought I'd geek out so much over gyros, never gave them much thought before but damn they're awesome. edit Thanks for leaving the 11 minutes of spindown!

I implore everyone who is interested in physics to experiment with a gyroscope, because to understand the conservation of angular momentum is to understand most of physics.

_"Coming up next on _*_'unintentional ASMR'_*_ : Jackhammers of the 1930ies"_

Achtung! Small flywheel running at 24k ripms is like a small bomb. Please inspect the bearings, lubricate, and ensure unit is well assembled before running.

Very cool watching the spin up and spin down, always interesting to hear the sounds of these high speed devices. The highest speed rotating device I normally deal with is the video head on an Ampex VR-1200 Quadruplex videotape recorder, 14,400 RPM and that includes the headwheel as well as a rotary transformer to couple the video to the preamps, it uses an air bearing.

I have a couple similar , not motor driven , they were for jet fighters heads-up display for targeting . They were air driven , pitot tubes in the jet brought air in to drive the gyros , more electronic in my gyros - the electronics in mine are to keep at a specific temp for the bearings . I really miss the old surplus places , so much neat stuff ;)

This reminds me that I really would love to find a video showing off the gyroscopic camera stabilisation rigs used for tracking shots on Das Boot. :)

I love that sound when you power on or off the airplane!

The aviation AC power supply is 400Hz rather than the 50/60Hz used in people's homes so that the transformers aboard can be smaller, and therefore lighter. For the same reason, nowadays many computer power supplies take the AC input, rectify it, then use a transistor or special chip to turn it into much higher frequency AC so that it can be changed to a different voltage with a smaller transformer. I have my suspicions that this is one of the reasons why laptop power supplies fail so often...

I love the sound of 400hz, it makes me think of traveling somewhere cool on a big airplane

“Safety squints”? “Ripms”? Now you're sounding like AvE... So, when the next Apollo confuser video coming out??? 😁

Glad you engaged your safety squints but having the mother ready on speed dial is equally important 😬 Luckily it all went well 😄👍

Gripping crescendo! Good stuff!-

beautiful device!!

Wooooooo Ed! Love his Nike site. Tracing the microwave routes in the Chicago area was so much fun.

The ultimate fidget spinner

Did a lot of work with gyros in the marine setting... Considerably larger than that unit... And the things sounded at least as scary starting up, and hours to stabilize. That sawblade whine brings me back.

Love that start up and slow down sound, i think it will send me to sleep

Nice use of AvE lingo. Man, that bearing sounds harsh....

Hello Marc. I recently discovered your channel, and I became a true fanatic. I have to admit that your laboratory gives me a little envy, it's incredible! Just yesterday I went to visit the computer museum of my city. Greetings from Buenos Aires, Argentina.

I love the spin up sounds

There was a Cambridge US company that spent decades trying to store energy with high ripm devices. One use was to replace batteries in certain applications. The company reincarnated several times.

love the sound of it spinning up

Great series! Though I believe in a rate gyro the displacement is proportional to the rate of rotation. Cheers - mark

That sounds so badass

Safety squints? I think a full safety cage might be in order. Cool video. I was thinking about getting a simple gyroscope as I study physics to help with understanding angular momentum, but after seeing this, I might up my game. I wonder what this would look like with one of those high-speed video cameras.

This seems to be a custom modified sine wave inverter (just an H-bridge). Even though it's not as bad as the much higher frequency pulse trains from variable frequency drives, some caution may be necessary. Older motors can get damaged with inductive spikes from those types of waveforms due to insufficient/old insulation. Voltage peaks at the device will increase with longer wire lengths. The bearings may also sustain continuous damage if you were to ground the device being powered, due to induced EMI flowing from the rotor, through the bearing, into case ground. In essence, it becomes a mini EDM machine with microscopic sparks eroding the bearing surfaces. Even if it's only 10mA or so, it will take its toll over time. However, that issue affects variable frequency drives with high switching frequencies, and wouldn't be as bad in this case. You should still measure current to ground from the metal of the unit, just in case. And the last obvious thing is EMI in general. Shielded cables are recommended so that nearby electronics aren't affected as much. Custom filters will help as well. The position resistor wires will likely be very contaminated with EMI and may need filtering themselves. If you guys liked this video, I highly recommend searching for "FIN-RPMD-Explorer" on RU-vid. First result. It's one of the most beautiful videos of its kind, in existence. Please take as look as well Marc, I think you will appreciate it if you haven't seen it before.

Nice video clip, keep it up, thank you for sharing it :)

yes still here, good one thanks.

That was .................. fantastic!

When is ebay going to add a search by crustiness level!

Say what you will about crustyness, but that gyro performed admirably. I suspect that the long take was caused by dry bearings (to be read, with dry spots). You can actually hear the race path smooth out and the pitch even out to what you'd expect to hear (think of it like a needle scratchy sound).

suitably impressed

Just love your lunchbox power supply!

As a kid I was totally transfixed by things spinning down. At the age of 48 I still finds it relaxing. I am weird.

omg he IS an AvE fan! I had my suspicions. This is GREAT!

Mind sharing some info on the type of motor(s) and gyro you're using?

Sorry to see the old gyro is tired, well at least you gave it a spin.

Thanks, Marc. I watched EVERY SINGLE SECOND of this, undistracted, laying in bed. It's a good thing to develop patience.

This is the exact sound you’ll constantly hear inside a UH-60 helicopter. It’s just the same frequency that comes from all the pumps and instrumentation gyros in the aircraft along with the twin turbines. I’m a retired Infantryman from the 101st ABN and we spend HOURS in the back of these things after a few years in the unit. I was on the path to going to flight school but, war happened and I married my wife (this was 33 years ago, lol) and the rest is history.

Not Kidding- when I got to the end I started dozing off with the full head nod and that's when I heard it "STILL AWAKE?" My head popped up and I just started laughing!! lol

I wonder if you replace the bearings or is it just to complicated?

The Closed Captioning that RU-vid generates when the gyro spins down is hilarious. 15:57

I like to imagine that the engagement graph for this video mirrors the RPM.

incredible bearings it must have i have never seen anything with such low friction to be that long to stop or it will spin a 10000000000 rpm

I want this sound ever time I start my car.

Do I get a prize for watching the whole spindown in real time??. Seriously though, very interesting and impressive.

Enjoyed it

that’s cool as hell!

Those cheap Ebay $13 non contact tach go to 99,999rpm - lol -, you just need to paint a white line on the drum.

Amazing

Beautiful........

Reminds me of my first Quantum SCSI hard disk drive back in 1990. lol ! BTW, how do they go about balancing such a high speed device precisely enough for it not to want to move all over that table ? I've watched until the very end. And for some strange reason, I feel relaxed now... I'm so glad that the gyros in my iPhone aren't this noisy, and don't consume this much power ! One question: why does it need to turn this fast ?

I would have wanted to take it apart, check the bearings, and apply lubrication as needed before spinning that thing up. I wonder how many decades it has been since it was last spun up. I would have wanted more protection or distance between me and it.

+AvE influence reaches far across the youtube "ripums" and "safety squints"

Maybe 40 years ago, I had a friend who was an instructor at the Brisbane AU airport, teaching trainees to maintain and repair radar and communications equipment. He told m a story about a plane who’s radar navigation was not working , he flew from Cairns to Brisbane about 1200 miles ( by road) he used his inertial navigation instead. When he got there and parked in his allocated parking spot, his inertial radar was out by only 5 or 6 metres.

Where do i have to search to buy one of these ?

What prevented it from flying off the table at such a high RPM?

I wonder what that looked like under a FLIR camera with crusty bearings?

How do I get these bearings for my skateboard?

The spin up noise reminds me of the suspenseful noise in the gravity movie

I really hope the museum lets you borrow or swap out the memory module on display, its doing nothing and no benefit! lol it would be in their interests to see a working AGC!

That little remix at the end made me laugh, it reminded me of Taz from Looney Tunes spinning. Excellent video, thanks for sharing.

Can't you speed up the spindown time by connecting a resistor to the power input?

It sounds as if it has crusty bearings. I'd like to ask two questions : 1. Would a gyro like this normally spin in an evacuated (semi-vacuum) enclosure to reduce windage? 2. Does the rotation of the earth affect it at all? Can it even detect such a slow movement? I know that electronic gyros can - but a mechanical one - though I know there were mechanical gyro-compasses. I had an old artificial horizon unit once, but it wasn't electric. It had an enclosure in which air was evacuated (possibly by engine vacuum in a plane), and allowed a bleed of air into cups that were cut around the periphery of the gyro wheel to spin it up. I never did spin it up to speed, because I didn't know how to produce a good enough vacuum.

McMaster-Carr has 24,000 RPM bearings. These wonderful toys went up in flames in the US Navy Torpedo Gyroscope system. 🧐 Thanks.

I know this is an old post but how about adding a tachometer to it so we can see the rpms. I’ll bet you have an old chart recorder you can connect to the position resistor also!

Fascinating..

can you imagine a modern car with DSC having an old gyro like this rather than the modern electronic versions, how much noise it would make haha.

Those bearings sound horrible on RU-vid, but considering the spindown time they can't really be all that bad. I have to wonder how much of that 2A steady-state draw is the idle current for the inverter. I woudln't expect the gyro itself to be taking more than 3-5W steady state with no platform movement.

Does it show the rotation of the earth?

At time 6:40, this is what you hear when you de-energize the busses on a Boeing 727.

I now know where the noise that airplanes make is coming from. lol.

Those poor bearings sounded just awful! Are you going to try to rebuild them? What yaw rate did it take to move the gimbal to its stops?

Could you add a stepping motor and turntable and some feedback electronics to show the rotation of the earth(assuming you're not on the equator)? You'd need to remove the springs. Also, that sounds awful

Surely there must have been sound dampening in Apollo. Imagine the noise of an entire platform of these things.

Does the vibration affect it?

CAN WE SEE AN FFT OF THE SPINDOWN REAL TIME PLEASE THANKS LOVE YOUR WORK :D - nerd in canada

Looks like a sci-fi, Captain ! Start the warp guidance system.

What's the green wire dangling from the power cord?