idle thoughts on metal keyed/eared washers, carbon

[reelgood]

I have been thinking all talk is about the drag washer that go between the metal, but what about optimizing the metal surface as well?  Golf clubs have those grooves which through friction impart spin to the ball. They even made the square "U" shaped grooves illegal in the PGA since they were too effective.  What about somehow cutting tiny grooves into the metal in a radial pattern?  Has this ever been tried and would it increase the coefficient of kinetic friction between fiber and metal without significantly increasing the static? Would they stand up to the rubbing of the carbontex without being sanded out? 

Another somewhat related thought is that carbon fiber brake rotors were once used in race motorcycles but this was stopped as they occasionally shattered with disastrous results (200 mph on the daytona banking with no brakes) and some deaths.  These brakes actually didn't begin to work well until after they heated up, when cold they had very poor braking.  This may have been a result of the brake pad material and is probably moot in a wet drag anyway, but if running dry carbon I wonder if that comes into play. 

This stuff would be great for a kid in a high school physics class to do for a project and figure out for us 

[Bryan Young]

The metal groves in the golf clubs is to add a bite when the ball comes in contact with the head of the club.  What happens is that the ball compresses, and with the lift of the club head during the swing, the groves bites (and sometimes slices into) the ball giving the ball greater spin as it leaves the club and returns to the round shape.

Carbon fiber rotors were a bad idea as carbon fiber weaves are not ridged on it's own.  It needs a medium for that, and that is what shattered.  The ridged material could not handle the forces exerted by clamping calipers.  There have been and may still have carbon fiber type of break pads, and they did pretty well as I recall, but again, the medium that the carbon fiber stiff played a major factor.  The use of carbon fiber and metal washer configuration, the carbon fiber provides the friction surface and the metal washers provides the support via a sandwiching the carbon fiber washer between two metal surfaces, and thus, very low chance that the carbon washer will shatter/tear.

By the way, from the racing perspective, racing pads will not operate cool.  The pads are just too hard to work well when the pads are cool.  They need to be heated up, and in some, where the rotors are red hot, for the breaks to work well.  The pad material is so hard, that it needs the heat to soften the pads to provide better contact with the disk.  This differs from normal driving brake pads where they are already soft, and when heated up, gets too soft that it looses friction (known as fading).

[qcguy4198]

Please continue the idle thoughts...!!
I love this kind of stuff...it's 52 deg. down here in LaFLorida this morning with a 20knot wind blowing across the water...and this board is about as close to fishing as I'm gonna get today.

[reelgood]

That bite is due to friction though I think, and maybe on a wet drag the bite won't be enough to increase start-up much but would be a way to increase the drag, for example if you can't fit 5 in a stack but want more than 20# out of 3 or whatever. Also, the grooves would actually provide a place for displaced cal's grease to go like a tire tread, so this could push the result in the opposite direction than desired.
I dunno  

As for the carbon/heat thing, I brought it up thinking that maybe in a dry carbon "clutch", drag performance, at least in terms of absolute #, would not decrease with heat and may actually increase. This is not to say this outweighs the other benefits of a wet carbon clutch I don't believe it does.  Maybe I am a little partial to dry clutches I love my ducati  

[reelgood]

52 is as high as it's going to get today in NJ and I am considering going fishing since this might be one of the last nice weather days this year 

[Keta]

Please continue the idle thoughts...!!
I love this kind of stuff...it's 52 deg. down here in LaFLorida this morning with a 20knot wind blowing across the water...and this board is about as close to fishing as I'm gonna get today.

18°F here in SE Oregon this morning.