mechanical_gifs

Silencer.

Silencer.

Hm..so it doesn't reduce damage after all

Well if you want it to actually work it does. Because the bullet is typically travelling faster than sound and produces a sonic boom. So for a suppressor to effectively reduce the sound you have to use subsonic rounds which have less velocity and therefore are less powerful.

which have less velocity

True... sometimes.

45 acp is a very common handgun caliber but it is already subsonic to begin with so you'd already be getting the most out of the suppressor with normal ammo. In other words using a suppressor is going to make no significant difference whatsoever.

Similarly most .22lr ammo fired from a pistol will be subsonic as their barrels aren't long enough for the round to get up to speed.

You are correct about other calibers though for example 9mm which is the most common handgun caliber. In order to be subsonic they need to lower muzzle velocity, but that brings me to the next part of that sentence.

therefore are less powerful.

If we're being technical that's not always true. If you scroll around here you'll see that it is very possible for a subsonic round to be as powerful or more powerful than a supersonic round. (Keeping in mind that 1125fps is the magic number for the sound barrier and ft/lbs is the metric for "power".)

That's accomplished by using a heavier projectile rather than less powder to propel it. The trade off being more bullet drop and less range (because of lower initial velocity not strictly because of the heavier projectile).

Sorry to be a pedantic dork but I love suppressors and ballistics.

And it doesn’t reduce accuracy. Video games have lied to us for years!

Oil fire-fighting machine made from pair of MiG engines & tank parts

Considering the traditional method was to use dynamite to basically blow out the fire, this is a significant step up.

It looks like it came straight out of Red Alert 2.

https://youtu.be/L77BSBKvMJk

Here they are in action in a short IMAX documentary about the awful oil well fires that Saddam Hussein lit when they retreated from Kuwait:

EDIT: Jump to 20 minutes - sorry I have no idea how to do time-based links from mobile.

https://youtu.be/L77BSBKvMJk?t=1192

Timestamped:

Harmonic Drive Gear Reducer. Look at the text on both top parts.

This is a HarmonicDrive "drivegear" 100:1 gear reducer which uses a flexing metal part to engage the teeth around the inside of the outer ring in a way that seems a bit like actual magic in practice.  This unit is a CSD 40-100 as described in the company's online .pdf catalog.  The black thing underneath is a servo motor.  Here's a simplistic .gif that illustrates the idea, from   Wikipedia

Please excuse the r/mildlyinfuriating camera refocusing :(

Slightly better video at gfycat:  https://gfycat.com/gifs/detail/BlankUnlinedBluefintuna

This is a HarmonicDrive "drivegear" 100:1 gear reducer which uses a flexing metal part to engage the teeth around the inside of the outer ring in a way that seems a bit like actual magic in practice. This unit is a CSD 40-100 as described in the company's online .pdf catalog. The black thing underneath is a servo motor. that illustrates the idea, from Wikipedia

Please excuse the /sub/mildlyinfuriating camera refocusing :(

Slightly better video at gfycat: https://gfycat.com/gifs/detail/BlankUnlinedBluefintuna

I'm not seeing the "magic" here. What am I missing?

here

The part being spun by the finger in the gif spins at a different speed than the lower, larger portion below it. Every time they stop spinning you can see the text on the two halves is slowly drifting apart from each other.

Making wooden balls

They might be beads.

what's the little poke for? just to remove the little tuft of leftover material at the center?

Great band name

The pre-cogs know the future and they're never wrong.

Sandbag filling attachment

Neat! How long does it take to hookup all the empty bags though.

Several years in a top secret underground development lab.

Me near the end: "All they need now is a way to nicely tie the bags up"

"Ok where can I order?"

Isn't this what Lance Corporals are for?

15 hours of bridge demolition in 15 seconds

This is like watching deep sea crabs strip a whale fall

It would be the freakiest thing driving under that bridge the day before and then doing the same the next day realising the bridge was just gone.

They were all like "fuck you, bridge!" and he was all "come at me, bro!" and then they were all pew pew, smash, karate kick and then he died. It was super sweet.

Wow, where is this? In Boston it takes ten years to get road work done

Ever wondered why we need kneecaps?

Aaah. I thought kneecaps where to make sure that torpedoes had a good way of making people pay their debts. This also makes sense.

I'm pretty sure it works the same way, just with the elbow it's part of the ulna already so the "elbowcap" doesn't need to be an addition. It's a little different of a joint, I think.

(I'm a computer engineer don't ask me more I don't know)

... torpedoes?

Zirconium forging

I wonder what this piece is to be when it's done

I have stabilized the video for you: https://streamable.com/vzvju

 how to use | programmer | source code | /sub/imagestabilization | for cropped results, use /u/stabbot_crop

/u/stabbot

According to Wikipedia, zirconium metals can be used in turbine blades for jet engines or gas turbines because of its strength at high temperatures. It is also used in nuclear reactors for its corrosion resistance and its low neutron capture cross-section (whatever that means). But it reacts with water at high temperatures to produce a zirconium oxide and hydrogen gas which was the cause of the Three Mile Island accident as well as the Fukushima Nuclear power plant accident when the reactors were cooled after the earthquake and tsunami.

The cubli.

https://www.youtube.com/watch?v=n_6p-1J551Y

Misses the most interesting parts.

self-assembling cubes

MIT students applied these as . Something like big hero 6.

Please do not bully the cube.

It did feel like a bit of a complicated way to make a simple gyroscope

Rotary speaker. Better with sound, still looks cool, though.

Ohh I see. They are just normal speakers that can spin around, which modifies their accoustics. I thought they were some crazy drivers that could somehow produce sound by spinning or something.

Check it out.

Wait, what?

I love that a silent video of a device that exists purely to make noise can be so interesting. Y'all are my kind of people.

Try one of these subthreads