Clutch disk/floater question

I was recently playing around with our clutch disks and floaters. I was able to make our flywheel machine able to cut the floaters. I am worried about heat generated during the grinding process, abnormal growth and distortion while cutting and am wondering if I should use some sort of water based machining coolant? I also made a fixture to hold the discs in the lathe and noticed that some of the discs had a good bit of wobble to them. Not sure exactly how much because I didn't have time to hit them with the dial indicator. Is this normal and how do I get them back to flat again or are they junk? I haven't had any abnormal wearing of the clutch or anything like that, it wears the same amount at all 6 stands after a run. How much do I need to cut off of the disc, or is a simple de-glaze ok? How often should I be pulling them and surfacing them? Thanks.

 

Thanks for the reply Mr. Canter, the .005" wobble, you are referring to the clutch discs correct? How much should I be cutting on the discs?

 

Generally on floaters if you can cut them wet, you will get a better grind. Just be sure you give them a good brake clean bath and wipe off before you run them.

Discs are usually slightly distorted through the carrier portion of the disc, this is normal. We don't let anything out with more than .010" variation in carrier height out the door using a runout checker (dial indicator and 3 points of rest on carrier). Generally when cutting the disc, you're really trying to knock the glaze off and establish a fresh material surface, but you also want the surface to be trued back up as well. Most people will cut the used disc until the material looks fresh across the pad, hard to give an amount, just depends on how flat they come out of the clutch, but if I had to pick an average, it's usually .003-.005"/side.

When you go to grind discs, are you using an input shaft or some sort of matching splined shaft to locate it? This is the best way as it will true the disc perpendicular to the input shaft. And DO NOT cut the discs wet and have a separate wheel for discs if you cut the floaters wet.

 

Thanks for the reply, does they type of coolant matter if it is oil based or water based for cutting the floaters? I recalled a post of yours where you stated that clutch discs were pourous and if one was to cut the using the wet method it would seriously reduce their clamping capacity. When I had the discs jiged up in the lathe, I was using an old input shaft. I do have a second wheel in case I would like to use the flywheel machine to cut the discs, but I worry about the disc being warped slightly and then bolting it down through the center hub onto the flat surface of the flywheel table. My worry would be that it would cut flat and true while being clamped down, but would go back to its distorted state after being removed from the table. This is why I opted to make a fixture so that I could cut them in the lathe.

Mike, I was told not to run anything less then 300 because because they have a tendancy to warp easier. I guess it depends on your application and how much heat your clutch setup is generating.

 

If you are only bolting to the hub and input shaft, then you would be fine as far as distorting the disc. if the clamp extends across the carrier outside of the hub's reach, then you may have issues. Most people when grinding discs just use the input shaft to turn and locate and it just rests naturally on the grind table or whatever fixture you use to rest it on. Generally don't have to worry about discs kicking back as the material cuts like butter.

When cutting floaters, it doesn't really matter what coolant you use as long as you get them clean as hell. We use water based blue stuff here, I think it's normally between 92-96%, and there are 5 jets hitting the floater at any given time, 3 around the wheel, one right before the wheel and one about 180 degrees from the wheel. Same stuff we use in the machine centers with the exception of machining Ti.

 

cutting fluid

Get some water based oil from a machine shop supply house like goodson the same kind you use in a valve grinding machine. Its reasonable and doesnt take much fluid to water ratio.

 

Exactly.. When I said 92-96%, I was talking about water content.