search results matching tag: rotate

» channel: learn

go advanced with your query
Search took 0.000 seconds

    Videos (277)     Sift Talk (11)     Blogs (23)     Comments (816)   

Electromagnetic Railgun Firing Hypervelocity Projectile

Grooveless metal engineering

bremnet says...

No, it's not EDM. It's machined. We produce a variety of cylinder / piston pairs, some with keyed anti rotation or beveled flanges to prevent pull through. The achievement of a visually seamless interface between two parts is certainly not trivial, but with care and the proper sequence of machining steps (guess which face you mill last? right - the one the user sees as seamless) you can do this on good quality CNC's with the right cutters. EDM'ing the complex curved shapes that truly mate across the surface on the early parts shown in the video is very (prohibitively) difficult, as you have to rely on ram EDM which is plain nasty.

worthwords said:

It's a type of electro discharge machining. It has been around for a while but it's so damn satisfying!

Why Do Flat Earth Believers Still Exist?

transmorpher says...

Way too advanced for idiot flat earthers.

All you need to know that is that we have footage of the earth ROTATING on it's axis.

(And anyone can send their own camera high enough to watch the earth rotate)



Also the navy park their ships under the horizon (about 40 miles away from a target) so that there is no line of sight. Since their guns shoot in an arc, you don't need line of sight, so might as well keep the ship invisible.

Spinning Swing Challenge

oritteropo says...

The yt info is:

Le projet le plus fou de l'été !
Le premier tourniquet tracté par des bœufs en plein milieu d'un lac. Les règles du jeu sont simples sur ce drôle de manège : qui tiendra le plus longtemps !?
Grâce à un système de déclenchement fait avec 2 mousquetons de largage, dès qu'une personne lâche, la corde glisse et l'autre est automatiquement larguée. Au final, la force centrifuge était telle que personne n'a réussi à tenir au delà des 30/35 km/h !


Or, in English:
The craziest project of the summer!
The first ever roundabout (literally turnstile, means something like the rotating swings in children's playgrounds) towed by oxen in the middle of a lake. The rules are simple on this amusing ride: Who will hold on for the longest!?
Thanks to a trigger system made with 2 release carabiners, as soon as a person lets go the other is automatically released.
In the end, the centrifugal force was such that nobody managed to hold on beyond 30/35km/h (approx 20mph in U.S. measures).

moonsammy said:

Tried to watch it closely, but couldn't figure out how they had it rigged to release the 2nd person once the 1st drops off. Impressive!

McCain defending Obama 2008

bobknight33 says...

I agree there has been a F load of change in personnel. The real question is does this turnover occur in in business life?

If so then one could consider Trump as some kind of dickhead to work for .

If not then what is the reason for the difference?


I think there is much more going on behind the scenes. Why would one have a military General as your chief of staff?

With Obama's top level FBI as example --
Comey -- fired
McCabe- Fired
James Baker, general counsel -- Fired
James Rybicki Chief of staff -- Fired
Perter Strozk -- Fired
Lisa Page -- ???

If Hillary was elected not of their wrong doings would have come to light. All gunning to get Trump. Still that is just the FBI.


No wonder Trump is cleaning house so much. Some bad guys found? Some paranoia?
There isn't a day goes by without something big occurring.

There is still 3 big reports to come out.
Mullers findings.
The 2nd OIG report and Huber's findings

AG Jeff Sessions appointed John Huber will be the ‘top federal prosecutor’ who will be investigating FISA abuses . Huber's staff is over 400.


Also Guantanamo Bay, Cuba-- Expanding like mad...

$14 million to expand the prison in Guantanamo Bay, Cuba. This is a "strategically critical time-sensitive expansion project". DOD justification states the "current trial support facilities are incapable of handling the large number of personnel .
https://insidedefense.com/insider/pentagon-expand-gitmo-after-trump-orders-it-remain-open

The place can hold some 2300 prisoners, currently Gitmo is currently holding 41 prisoners.. Also the 137th, 428th, and 514th was deployed this month to Gitmo for a year . Rotating people out - possible, but some 500 troops for 41 prisoners?

What is so time sensitive for to handle trial support facilities are incapable of handling the large number of personnel .-- Where are these people coming from? What is coming down the pike?

Like I said above:
I think there is much more going on behind the scenes. Why would one have a military General as your chief of staff?

MilkmanDan said:

I appreciate your response to my question earlier, @bobknight33.

I don't mean to try to drag you back into the thread here if you're trying to disengage -- I dunno what you mean by #walkaway. Anyway, this doesn't require a response.

CeramicSpeed 99% Efficient Drive Shaft // Chain Free Bike

newtboy says...

The basic action is, but not the mechanism.
My idea....think spiral channels inside the tube with the cog shown attached to a piston that rides in the spiral channels. As you turn it and force is transferred, it forces the piston forward because the spiral turns rotational force into linear force. With a spring, you apply an opposing linear force so the piston only moves when those forces are unbalanced. This spring could be tunable so you select where the balance point of those forces is, thus selecting the maximum force you could apply before it changes gears for you. When there's more force applied, it "lowers" the gear, when less it automatically goes up a gear. No electronics or battery required.

eric3579 said:

At 4:20 of the vid i linked he shows what i think you are asking about.
Also @newtboy

CeramicSpeed 99% Efficient Drive Shaft // Chain Free Bike

newtboy says...

I thought this lends itself to a spring loaded spiral shaft automatic transmission, where the more torque applied, the more it compresses the spring towards the front crank, lowering the gear you're in. This could be adjustable, allowing a rider to select how hard they want to pedal and automatically adjusting the gears to keep that force stable at any speed.
A second gear in the rear, rotating in the opposite direction and sandwiching the drive gear, would go a long way towards stopping slippage and gear wear. They certainly need to ditch the aluminum gears, though.
Just what sprang to mind when I saw it.

ChaosEngine said:

I'm curious to see what mechanism they use to change gears.

Trapped cat outfoxes his bullies

You Will Not Believe What Obama Says About Trump

ChaosEngine says...

Right now, you need lots of samples from the target. They need to read a bunch of unusual sentences ("The method implies translation, rotation and transformation", that kind of thing), so the risk of someone "stealing" someone's voice is low at the moment.

FlowersInHisHair said:

Definitely not signing up for that...

CrushBug (Member Profile)

siftbot says...

Congratulations! Your comment on Rotating bamboo sword challenge. has just received enough votes from the community to earn you 1 Power Point. Thank you for your quality contribution to VideoSift.

ant (Member Profile)

siftbot says...

Congratulations! Your video, Rotating bamboo sword challenge., has reached the #1 spot in the current Top 15 New Videos listing. This is a very difficult thing to accomplish but you managed to pull it off. For your contribution you have been awarded 2 Power Points.

This achievement has earned you your "Golden One" Level 60 Badge!

ant (Member Profile)

Can you dodge Space Lasers ?

Mordhaus says...

Short answer, no, because you can't see them. They also would travel too fast. However, in most hard science fiction, rotating or changing the point of impact will tend to screw up the amount of damage they can do.

Patrick Stewart Looks Further Into His Dad's Shell Shock

MilkmanDan says...

@noims -- My grandfather had about 10 war stories that he rotated through telling, pretty much exclusively after one of my uncles "broke the dam" by asking him to recall things as they were at the Oshkosh air show standing next to a P-47 airplane like he had worked on.

By the time that happened, my grandfather was in his 80's and in very good physical and mental shape (cattle rancher that did daily work manhandling heavy feed bags around, etc.) but had a quirky personality because he was 90%+ deaf. I don't think that was a result of the war, hearing problems seem to run in the family.

Anyway, he frequently used those hearing problems as an excuse for not having to interact with people. He had hearing aids, but he'd turn them off most of the time and just ignore people. I think some of that was being an introvert, and some was probably lingering "shell shock" / PTSD effects. But overall he really adjusted back to civilian life just fine. Got a degree in education on the GI Bill and taught and coached basketball to High School students, then worked as a small-town Postmaster, and eventually retired to work the ranch. I don't think any of us in his family, including his wife and children, thought of him as being "impaired" by the mental effects of the war. But it was clear that some of what he experienced had a very deep, lifelong effect on his outlook.


I wrote out the 3 stories of his above because they seemed to be the ones that had the most emotional impact on him. To me, it was interesting that a lot of stuff outside of combat hit him the hardest. He also had more traditional "war stories" stuff about victories and bravery, like when his unit captured / accepted the surrender of a young German pilot in a Bf-109 who deserted to avoid near certain death from flying too many missions after the handwriting was on the wall that the allies were going to win. But by far, he got more choked up about the other stuff like having to knock that French girl off her bike and seeing starving civilians and being unable to help them much.

Like you said, more banal stuff side-by-side with or against a backdrop of horror. I think it's pretty much impossible to imagine what those sorts of experiences in war are really like and what being in those situations would do to us mentally. And then WW2 in particular just had a massive impact on the entire generation. Basically everybody back home knew multiple people that went away and never came back. Then when some did come back, they were clearly different and yet reluctant to talk about what happened. Pretty messed up time to live through, I guess.

Ever See a CT Scanner at Full Speed?



Send this Article to a Friend



Separate multiple emails with a comma (,); limit 5 recipients






Your email has been sent successfully!

Manage this Video in Your Playlists

Beggar's Canyon