Independent suspensions?

I have been trying to figure out how to put an independent suspension on a Huge scale RC.  What I have noticed on large cars is that unlike small RC cars the rod going from the dif to the wheels is solid and can't extend/shrink.  Why doesn't this bind up?
I have also noticed that for some reason they don't line the suspension up to move exactly up and down. The wheel's pitch is actually set up to change as the suspension depresses.

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Re-design5 years ago
The radius of the swing, taken from the center of the axle is the same of very close so that the length of the axle doesn't change so there is no binding. The universal joints have a small amount of play in them also.
Take a look at something like the HMV and there are CVJs between the diff and the wheel.

Also, take a look at "Portal Axles" - I think the HMV has portals too.

Steve
jj.inc (author)  steveastrouk5 years ago
The cvj was cool, but it still doesn't explain how a solid shaft can compress when the vehicle hits a bump.
It doesn't - the shaft is splined UNLESS the suspension is set up as a wish bone type.
rickharris5 years ago
I a real car the axle would have a sliding spline on it along with 2 universal joints to allow the wheel to rise and fall freely.

I addition there will be a torsion rod to transmit the movement of one wheel to the opposite side to try to keep the body evenly balanced.

Perhaps the most famous method other than this was the mini hydro pneumatic suspension.
jj.inc (author)  rickharris5 years ago
I know I normally need a spline, but I can find one because ATV's and Car's with independent susspensions have solid rods. U-joint, no sliding or moving, to U-joint. I don't get it at all. Unless maybe the spindle thing the wheel attaches to slides in and out of the bearing in the axle carrier.
The spline is in the hub if not in the shaft. The movement is actually very slight.
Vyger5 years ago
There is a guy who developed a chain drive vehicle that is pretty incredible. Each wheel can move totally independent up or down and the power is delivered by a chain and sprocket rather than a drive shaft.

Here is a video of it.

http://www.youtube.com/watch?v=w_F7QrR4Ur8

No that would make a cool RC car.
jj.inc (author)  Vyger5 years ago
Thats awesome. A while back while making a 3-D tank model for a friend I acutally did that with solid shafts instead of chains. Just two 45 degree angle gearboxes. It was sweet, the only thing was, it couldn't get one wheel up that high, I wonder how he made the suspension work.