torque on uniformly distributed rotating beam 1

[1rusty1mecha]

I am building this lifting and rotating arm, considering the arm to lift and rotate uniformly distributed load of 20 lb/in over the length of 45 in. ( having center of pivot at 22.5 in. ) what kind of max torque should I expect as it is rotated from horizontal ( equilibrium position ) and gradually rotate to vertical ( 90 deg. ). Considering negligible friction at pivot. Is there any equation to express the torque at different angle of rotation. I have attached the picture for concept. Any hint or help would be greatly appreciated.

 

[handleman]

If it's really evenly distributed then the static torque at any angle is zero. It appears you are using SolidWorks or some other solid modeling software. Model in your load, put the system at the desired rotation, and then have the software tell you where the CG of the entire system is. The horizontal distance of the CG from the axis of rotation is the moment arm. Multiply this distance by the weight and you get moment.



-handleman, CSWP (The new, easy test)

 

[1rusty1mecha]

Thanks for the input. But, I was wondering the evenly distributed mass of circular disc shape would have static torque zero but the beam that I am working with would have static torque zero only when the arm is horizontal or vertical.