How do they compare to one piece. Of we could get fixed yoke output on transmission instead of slip yoke, would you build a two piece the same or with different considerations?
I ask these questions below because people confuse what a 2pc shaft is.
OK are you asking how does a single piece shaft compare to a 2 piece shaft ?
Or are you asking how a slip yoke shaft compares to a shaft with a stub and slip...
A 2 pc shaft is only a shaft that is actually 2 separate shafts, divided at a u-joint coupling
Or are you asking if i would build a 2 pc shaft like i would a single, a 2pc would be planned the same way with the same requirements as a single need to be known, or some vehicles use a 2pc for poor design reasons, such as a company that modifies hummers, they fuk it up putting **** all over and then i gotta make a 2 pc that is able to clear all the nonsense they put in the way
Understood thanks.
From your explanation it isn't so much the weight, as it is the ability of a larger diameter shaft to deal with the increased centripetal forces that are because the shaft has some runout, bend, etc.
Runout isn't the issue, 0.0 runout will still have a negative effect if the speed of that shafts length by diameter is exceeded.
Lets say you wanted to instal a shaft in a nascar vehicle thats shaft speed is going to be 8500 rpm and going to span on center between 45/46"
The 2' shaft would be the greatest since it will be the lightest, but it's going to do that wave like issue and rip into 2 at around 4500 rpm, so then you want to keep weight down still and find out 3" is gonna fail around 63/6500 area, 3.5" isn't all that far off, but it's still lower than 8500 rpm so then 4" has a 7/800 rpm beyond the 8500 use area.
If we made the shaft longer, those speeds of failure come in earlier, because of that issue this is why there are 2 pc shafts.
Sometimes there are 2 pc shafts because splitting the shaft into 2 you can use smaller shaft diameters and you can stuff more stuff into a single area... and have a smooth aero effective floor, see mercedes, bmw, porsche and other euro cars for that style of thinking.
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