Carbon Fiber Clutches?

2ooosrx

2ooosrx

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Me being a curious kid and always wondering why things are done a certain way, I am just wondering why they have never tried to make a carbon fiber primary or secondary clutch? Strength would obviously not be an issue. I am always try to think of ways to reduce rotating mass and those clutches are heavy in my opinion. I know they are made of almost entirely aluminum. The only thing I can think of is if they would not be able to disapate heat aswell as aluminum? I bet if you had both primary and secondarys made from carbon fiber, there is at least a 5 pound rotating weight reduction. Once again, I do not have all the answers so I am wondering if they have thought about this before. They would cost a crap load though. What is your opinion on this? Thanks
 
i think cost is the primary factor. they have carbon fiber rotors and i believe those run $1200 a piece!?!?! the other thing that is good tho is that heat is not a problem. a good friend on here told me that the good side to carbon fiber rotors is that the hotter they are the better they grab, so clutches would grab the belt tighter. this could be a downside also because of the cold temps sleds experience it may take awhile for the belt to grab on not slip when you first grab the throttle. the thing i am most interested in is losing all the moving parts from a sled. for example, the crankshaft rotates and turns the primary, which turns the belt, which turns the secondary, which turns the shaft, which turns the gears and chain in chaincase, which turns the drive shaft and cogs, and then finally turns the track. i like the ideas beind the rmi and diamond drives, the only problem is is that the rmi leaves a rather LARGE hole in your frame if you remove it, and the diamond drive rights were bought out by Cat and it takes custom work and set up to get one in. they lose weight and reduce the amount of moving parts. maybe someone else will chime in on the carbon fiber but thats the info i have on it.
 
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Very helpful information you provided. I am in the same boat as you in terms of how they get the power to the track. That is the primary reason I asked this question. This is one of the reasons we made the belt drive. It is taking 4 pounds of rotating mass away in the gears alone! Then we are running both an aluminum drive axel and hopefully an aluminum jack shaft. We will be testing all this stuff this year on my sled and see how it all works out. If we are able to get an aluminum drive axel and jack shaft to hold up to the power (outlook is pretty good), we can drop another 5 pounds of rotating mass right there. Then a lightweight brake can get you another 2 pounds, or if you get a 2001-2002 rotor then have it drilled out by us, we take a pound out of the brakes. You are already at 10 pounds less of rotating mass in the drive to the track alone. That is alot of weight! Thanks for the responce.
 
What's the deal with the diamond drive as far as performance (acceleration, top speed, reliability)? If I could find a DD for a low price I might consider fitting it to the 99 sx if it's a big performance gain... Then again I can see it just being a big PITA to fit it for what it's worth ( a couple pounds and some acceleration)
 
i think carbon would be to light, the cintrifical force that would be needed to activate your clutch would be like 20,000rpm, also carbon is very flexible and the cluctches would flex back and forth. they could maybe make a fiber reinforced material that would be aluminum and carbon, just like the h22 and nsx cylinder sleeves.

I work with carbon daily and other composites, also I have a small hobby shop set up where I am currently making custom car parts, and will be in the snowmobile marktet soon im looking into making kevlar clutch covers now.

as for the clutch there are things that could probably be done, like the sheilds or coveres on the secondary.

you also might want to look into carbon idler wheels. carbon brake disk.


dont get me wrong it could be posible but the cost and the size and whight would be minimal, compared to aluminum, for example at work we just made a carbon fiber stinger for one of the aircrafts to replace a aluminum on and it ended p whieghein 23lbs insted of 25.6lbs as the carbon walls had to be thicker for the ectra strength.
 
I think part of a reason to stay with aluminum for at least the primary is the flywheel effect it provides. That mass in motion can be a help if it is in the right spot.

If you were to go as far as Carbon Fiber why not Titanium as well. If it can't be made out of one then use the other. As long as we are thinking about what if's. Then again sled with all Ti parts would be $50K

Also the weights would still have to have the same mass that much needs to be the same no matter what the clutch is made from.
 
the centrifugal force wouldn't be hard to compensate for. for the primary you add more weight to separate the sheeves and for the secondary you use less of a spring force. the thing with it being light is that you have the ability to put the weight you need where you want it, and with it being light it will spool faster and create less drag on the drive train. like i was told, carbon grabs harder when hotter and it is harder when hot too i believe which are both positives. the only thing is practicality. how much is it gonna cost? a ridiculous amount. who's gonna test it, whos gonna shell out for a form and take the chance of it not working and having nothing to show for it? its just not pragmatic, or even in the realm of being. the hyperlite is a good way to go, solid aluminum. as for primary, nothings wrong with the stock, they hold up under turbos, but if you want you can go to a four post micro belmont which i believe is all aluminum as well. theres a way to make it more efficient... there deffinetely is a way.
 
TJ500 said:
can carbon fiber be machined like aluminum?...
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yep it can also be water jet cut, but you have to remember that it comes in a roll of cloth and gets its strength from the direction of the fibers if you start to machine it your losing strength.


Also for it to hold up in a clutch without felxxing it would have to be about about 1inch thick on both sheves, i dont think it could hold the wheight also you prob couldnt use the same belt would have to have a new belt made. I work with it on a daily basis and its major benifit is it fatigue factors you can bend aluminum back and forth and it snaps, you can bend carbon all day. It would want to flex to much on a clutch.

But anythings possible im just saying the size of the clutch would have to be huge to make it stiff anough and it would be the same whieght by then.

Titanium would be the way to go, but who has the cash. :letitsnow
 
jaysV-MaxSx700canada said:
yep it can also be water jet cut, but you have to remember that it comes in a roll of cloth and gets its strength from the direction of the fibers if you start to machine it your losing strength.


Also for it to hold up in a clutch without felxxing it would have to be about about 1inch thick on both sheves, i dont think it could hold the wheight also you prob couldnt use the same belt would have to have a new belt made. I work with it on a daily basis and its major benifit is it fatigue factors you can bend aluminum back and forth and it snaps, you can bend carbon all day. It would want to flex to much on a clutch.

But anythings possible im just saying the size of the clutch would have to be huge to make it stiff anough and it would be the same whieght by then.

Titanium would be the way to go, but who has the cash. :letitsnow
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As for titanium, titanium is about 60% HEAVIER then aluminum so there is no reason to go to titanium in less you desire more rotating weight. As for activating a clutch, I do not understand what you mean by being to light. The thing that activates a clutch are the weights, it has nothing to do with the housing. Going lighter would not change activation RPM as you could change it by going to different primary weights. Lighter rotating weigh would just result in better overall performance. Maybe I am miss interpreting what you are saying slightly. Little confused by what you are saying.
 
Yes titanium is 60% heavier then aluminum but it is twice as strong so you could reduce the sheeve wall thivkiness in half for the same strength and then it would be lighter, for example:

aluminum sheeve 10lbs
titanium sheeve same size 16lbs
make the titanium sheeve have the size and its 8lbs


as fro the carbon being to light although the wheights are what activates the clutch if you removed them the clutch would still pull outwards cause of centrifical force, it could maybe be done with alot of engineering you would have to change the spring and the whieghts, but as i said before to make it strong anough so it wouldnt flez it would be the same wheight or more so it would be pointless, unless you made carbon sheeves and mounted them to som esort of aluminum frame.


for example buy flex ability if i take 1/4 piece of aluminum thats a foot long its pretty unflexible, but if you take a piece of carbon the same size you can bend it easyier.

That being said everything is posible and it would be fun to fool around with in the future start with a 2inch block of carbon which would be about 285 layers of cloth at $125 a yard it would about $5000 just for materials, then machining and engineering.

it would be much more economical to go with titanium or a hibrid of carbon and aluminum.
 
jaysV-MaxSx700canada said:
Yes titanium is 60% heavier then aluminum but it is twice as strong so you could reduce the sheeve wall thivkiness in half for the same strength and then it would be lighter, for example:

aluminum sheeve 10lbs
titanium sheeve same size 16lbs
make the titanium sheeve have the size and its 8lbs


as fro the carbon being to light although the wheights are what activates the clutch if you removed them the clutch would still pull outwards cause of centrifical force, it could maybe be done with alot of engineering you would have to change the spring and the whieghts, but as i said before to make it strong anough so it wouldnt flez it would be the same wheight or more so it would be pointless, unless you made carbon sheeves and mounted them to som esort of aluminum frame.


for example buy flex ability if i take 1/4 piece of aluminum thats a foot long its pretty unflexible, but if you take a piece of carbon the same size you can bend it easyier.

That being said everything is posible and it would be fun to fool around with in the future start with a 2inch block of carbon which would be about 285 layers of cloth at $125 a yard it would about $5000 just for materials, then machining and engineering.

it would be much more economical to go with titanium or a hibrid of carbon and aluminum.
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Is that 3k carbon? The stuff that I used to work with was .015-.020" thick, are you vacuum bagging to push out as much resin as possible for strength?
 
7075 aluminum which is what we use for our overdrive sheeves is plenty strong for a clutch and there is much material that can be taken out. If you compare 7075 aluminum with titanium, having the same strength as the aluminum (aluminum would have more wall) the aluminum would be just as light if not lighter then the titanium. You also have to consider other aspects of this and that is that aluminum disapates heat extremely well keeping your clutches cool. Titanium would not be a wise choice of material to use for this purpose.
 
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Sxr700Bandit said:
Is that 3k carbon? The stuff that I used to work with was .015-.020" thick, are you vacuum bagging to push out as much resin as possible for strength?
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im talking about plain weeve, 5.7oz after vacum bagging it measures about 7thou, it used to be $27 a yard like a year ago now its outragiuos
 
jaysV-MaxSx700canada said:
Yes titanium is 60% heavier then aluminum but it is twice as strong so you could reduce the sheeve wall thivkiness in half for the same strength and then it would be lighter, for example:

aluminum sheeve 10lbs
titanium sheeve same size 16lbs
make the titanium sheeve have the size and its 8lbs


as fro the carbon being to light although the wheights are what activates the clutch if you removed them the clutch would still pull outwards cause of centrifical force, it could maybe be done with alot of engineering you would have to change the spring and the whieghts, but as i said before to make it strong anough so it wouldnt flez it would be the same wheight or more so it would be pointless, unless you made carbon sheeves and mounted them to som esort of aluminum frame.


for example buy flex ability if i take 1/4 piece of aluminum thats a foot long its pretty unflexible, but if you take a piece of carbon the same size you can bend it easyier.

That being said everything is posible and it would be fun to fool around with in the future start with a 2inch block of carbon which would be about 285 layers of cloth at $125 a yard it would about $5000 just for materials, then machining and engineering.

it would be much more economical to go with titanium or a hibrid of carbon and aluminum.
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How do you think the moveable sheave would move outwards if it didn't have weights in it? There would only be force in the radial direction normal to the crankshaft axis. There is no force in the direction of the crankshaft axis, therefore no force acting on the clutch to cause it to move. Only force that could move it is vibration forces, and if there is any sort of spring in the clutch vibration forces sure aren't going to overcome the force of even the weakest spring you can find. With no flyweights to put tangential force against the rollers, the moveable sheave will not move regardless of how many millons of rpms you sping the clutch.
 
there will be force without the wheights, im saying the clutch wheights are calibrated to control this, You would have to have pretty heavy wheights to ingage a carbon clutch and i dont think it would be able to hold up to the whieght.

the whieghts are calibrated to control the activation point without them the movable sheeve will still want to close, its just physics, but at a much higher rpm.
 
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