So here are the photos of the brass tube truss support on the main beam - used 1/32 X .006 inch (0.81mm X 0.153mm) brass tubes from Special Shapes Co. I used 22 gauge single strand wires inside the tubes for reinforcements, and connecting the joints.
Next step was to design the trolley. given I started making this crane to simulate both working and non-working conditions, I decided to make the trolley movable as well. As for the basic structure of the trolley, used cardboard, pins, and small pieces of 2mm X 1mm styrene tubes as wheels.