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Old 11-15-2010, 10:09 PM   #31
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whatch these youtube video by jilles groskamp
http://www.youtube.com/watch?v=YOMu6Fu3orI
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Old 11-15-2010, 10:23 PM   #32
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Been trying to find those vids for a few days now but couldn't remember what driver it was or where I had come across them. Thanks
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Old 11-16-2010, 07:17 AM   #33
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this is going to open up a big can but a few weeks ago i took a spur gear and cut rectangle windows in it (on a CNC of course!) and installed needle bearings instead of ball bearings and what i noticed is that you can actually run a fair amount of slip (if needed) and the dif rings do not get damaged as well as the heat is also a non factor! it worked very well. theoritically its all about surface area and a needle bearing has alot more of it so this means you can get away with only running three or four needle bearings and get the same surface area of a dozen ball bearings. i wish i could source out some ceramic rollers in .125 or 3mm diameter as it would be even better. one thing though is that your rings need to be perfectly flat to get the best results. i will post some pix later today
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Old 11-16-2010, 08:26 AM   #34
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Originally Posted by MantisWorx View Post
this is going to open up a big can but a few weeks ago i took a spur gear and cut rectangle windows in it (on a CNC of course!) and installed needle bearings instead of ball bearings and what i noticed is that you can actually run a fair amount of slip (if needed) and the dif rings do not get damaged as well as the heat is also a non factor! it worked very well. theoritically its all about surface area and a needle bearing has alot more of it so this means you can get away with only running three or four needle bearings and get the same surface area of a dozen ball bearings. i wish i could source out some ceramic rollers in .125 or 3mm diameter as it would be even better. one thing though is that your rings need to be perfectly flat to get the best results. i will post some pix later today
Ok, here's the first worm.

I can't see how this would work very well or last very long and here's why. The outer part of the needle has a longer distance to travel than the inner part. In order to get a needle to follow the circle of the diff ring, it has to slip across it's entire length. It wants to roll straight. A ball doesn't care what direction it rolls. You would have to use tapered roller bearings to make this idea work.
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Old 11-16-2010, 08:39 AM   #35
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Quote:
Originally Posted by MantisWorx View Post
this is going to open up a big can but a few weeks ago i took a spur gear and cut rectangle windows in it (on a CNC of course!) and installed needle bearings instead of ball bearings and what i noticed is that you can actually run a fair amount of slip (if needed) and the dif rings do not get damaged as well as the heat is also a non factor! it worked very well.
http://os.3racing.hk/products.php?products_key=4773

3Racing has a diff for the Sakura that uses that concept. Always wanted to try one....... How does the old saying go? A test is worth a thousand opinions?

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Old 11-16-2010, 02:53 PM   #36
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Ok, here's the first worm.

I can't see how this would work very well or last very long and here's why. The outer part of the needle has a longer distance to travel than the inner part. In order to get a needle to follow the circle of the diff ring, it has to slip across it's entire length. It wants to roll straight. A ball doesn't care what direction it rolls. You would have to use tapered roller bearings to make this idea work.
then how do they work in the first place?? a ball diff is nothing but a thrust bearing and you can by needle thrust bearings all day long , thats where i got the bearings from! this is why the bearings are placed on a radial pattern.it does work and works quite well on my d-drive cars i can slip it and it feel like a slipper clutch instead of grabbing like a ball diff does. if it didnt work there would be no such thing as a needle thrust bearing!
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Old 11-16-2010, 03:20 PM   #37
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Originally Posted by woodys3b View Post
Ok, here's the first worm.

I can't see how this would work very well or last very long and here's why. The outer part of the needle has a longer distance to travel than the inner part. In order to get a needle to follow the circle of the diff ring, it has to slip across it's entire length. It wants to roll straight. A ball doesn't care what direction it rolls. You would have to use tapered roller bearings to make this idea work.

I see what you are saying, but think about how a car wheel bearing works. It is the same principle.
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Old 11-16-2010, 03:34 PM   #38
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I see what you are saying, but think about how a car wheel bearing works. It is the same principle.
Car wheel bearings are tapered needle bearings.
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