dead center

[ed1978]

off topic subject here. just giving you folks something to really think about. the exact center of a rotating shaft or object does not rotate. thus the phrase dead center. think about this.

 

[ning]

off topic subject here. just giving you folks something to really think about. the exact center of a rotating shaft or object does not rotate. thus the phrase dead center. think about this.

It rotates, but it doesn't travel due to the rotation like every other point on the rotating object.

 

[workinonit]

Based on what I read that is still up for debate. I can see the argument for both answers.

 

[old and tired]

It might not "move" but it has to at least spin on an axis.

 

[CH4Ohio]

off topic subject here. just giving you folks something to really think about. the exact center of a rotating shaft or object does not rotate. thus the phrase dead center. think about this.

I guess this is true in the theoretical geometry sense that a "line" through the exact center of a "cylinder" might not rotate when the cylinder rotates. But it's important to also remember that this line is a theoretical 1-dimensional concept that has no width, only length. I don't think this really translates with any practical value in the notion that the "center" of a "shaft" doesn't rotate.

"Dead center", "dead slow", "dead reckoning", "dead-on" -- I think they're all descriptive but don't necessarily indicate lack of movement.

 

[/pine]

Without looking up the mechanical theory on the subject...It seems to me that any point on a diameter line would be rotating at the same RPM as any other point...

...i.e., the RPMs do not get progressively less towards the center it (RPM) remains constant...if the center is part of the same mass how can it not be rotating ?

question for the OP...what size is the shaft (moot) but what size is the "center" one molecule ?

 

[Beaver Cove Deere]

I true dead center is fit into the headstock of a lathe. A live center is fit into the tailstock. If you want to turn a taper then you offset the tailstock. Of course this was before CNC machines.

Our next class will cover centerless grinding.

What did I win? LOL

 

[ning]

Without looking up the mechanical theory on the subject...It seems to me that any point on a diameter line would be rotating at the same RPM as any other point...

...i.e., the RPMs do not get progressively less towards the center it (RPM) remains constant...if the center is part of the same mass how can it not be rotating ?

question for the OP...what size is the shaft (moot) but what size is the "center" one molecule ?

Even molecules rotate. I don't know if photons do (I suspect not), but atoms and electrons do too.

If the cylinder is a fluid, it's quite possible that the very center literally doesn't rotate (ref: eye of the hurricane - the closer to the center of fluid rotation you get the less rotation there is... off topic - the rate of flow of a fluid approaches zero at the wall of the conduit, which is why you get crap deposited in pipes and on fan blades), but I'm pretty sure we're talking about solids here.

 

[CH4Ohio]

I need to figure out a way to mount my mower spindles at this dead center point so I can eliminate the need for bushings and grease fittings.

 

[/pine]

..."Dead center", "dead slow", "dead reckoning", "dead-on" -- I think they're all descriptive but don't necessarily indicate lack of movement.

Don't forget the Grateful..