Dump Cylinder sizing

[kennyd]

Baum has some great calculators as well: Baum Hydraulics Corp :: Spec Calculator

 

[Iplayfarmer]

I saw a dump trailer at a local trailer store today, that somebody had overloaded, and tried to dump. The twin cylinders appeared to have moved something, but it wasn't the load. Instead of lifting the load, they just pushed the frame away from the load. So if your going to increase the lift strenght, make sure the frame will handle what they cylinders are putting out.
David from jax

A few principles of trigonometry and a scientific calculator can be very helpful in determining the forces on the dump bed and on the frame.

If you define your ram angle as the angle FROM VERTICAL then Cos X ram force = the amount of vertical force your ram will exert. Sin X ram force = the amount of horizontal force acting on your frame.

Your 10 degree angle in this case would be 80 degrees FROM VERTICAL. Your 3 inch cylinder with a surface area of pi times 1/2 the diameter squared (7.07 square inches) times the pressure (2500 psi) has an absolute force of 17,671 as JJ suggested. The cosine of 80 degrees is roughly 0.174. 17,671 X 0.174 = 3,068.5. To no ones surprise JJ is correct.

Sine of 80 degrees is 0.985. The horizontal force of the ram pushing on your frame is 17,671 X 0.985 = 17,402 lbs. Build your frame accordingly. If you go to a 4" ram the horizontal force is roughly 31,000 lbs. That's 15 1/2 tons.