Square Driveshaft
Thread Starter
|
just another Rockwell looser
Joined: Feb 2003
Posts: 4,042
Likes: 0
From: Cocoa, FL
Square Driveshaft
On an episode of spike tv's extreme 4x4 they fabricated a square drive shaft. They used two sections of square tubing one slightly smaller than the other to slip inside the larger peice of square tubing. then they welded the yokes to the two pieces of square tubing somehow,
i was wondering if anyone has tried this and if so how well did it work, it seemed like a cheap and easy way to make me a front driveshaft instead of paying somone to lengthen mine,
thanks, Nick
i was wondering if anyone has tried this and if so how well did it work, it seemed like a cheap and easy way to make me a front driveshaft instead of paying somone to lengthen mine,
thanks, Nick
Postmaster
Joined: Mar 2001
Posts: 4,968
Likes: 3
From: So Cal
When I was in engineering school, they had some classes on strength of tubes and rods. Turned out that a round tube had quite a bit of strength, almost as much as a solid round rod when it came to torsional stress.
It has been years, but I think the weakness of the square tube is that it has 4 corners where stress under torsion(twist) can build up and cause the tube to fail. A round tube has no corners and distributes all the stress over the entire surface.
Square might look cool but round tubes have been in style for a hundred years or more, probably for a good reason.
Just my opinion,
Jim Henderson
It has been years, but I think the weakness of the square tube is that it has 4 corners where stress under torsion(twist) can build up and cause the tube to fail. A round tube has no corners and distributes all the stress over the entire surface.
Square might look cool but round tubes have been in style for a hundred years or more, probably for a good reason.
Just my opinion,
Jim Henderson
Junior User
Joined: Oct 2004
Posts: 69
Likes: 0
From: Ketchum, OK
The stresses can be calculated using the following formula:
Stress Allowable = Tc/J
T = Torque (in-lbs).. or ft-lbs * 12.
J (polar moment of inertia)
-for a round tube, J=Jhollow = pie (ro^4 – ri^4 ) / 2
-for a square tube, J=Jhollow = J outer - J inner = (1/12 b*h(b^2-h^2)) outer - (1/12 b*h(b^2-h^2)) inner.
c = 1/2 of the outer tube size
But you're right, round is better for torsion (twisting). Square is better for structural bending (such as a frame).
Stress Allowable = Tc/J
T = Torque (in-lbs).. or ft-lbs * 12.
J (polar moment of inertia)
-for a round tube, J=Jhollow = pie (ro^4 – ri^4 ) / 2
-for a square tube, J=Jhollow = J outer - J inner = (1/12 b*h(b^2-h^2)) outer - (1/12 b*h(b^2-h^2)) inner.
c = 1/2 of the outer tube size
But you're right, round is better for torsion (twisting). Square is better for structural bending (such as a frame).
Thread
Thread Starter
Forum
Replies
Last Post
95F150SuperCab
1987 - 1996 F150 & Larger F-Series Trucks
2
May 12, 2012 07:49 PM
