Firstly, a bottom plate is arranged, and a large hole is drilled in the welding position on the bottom plate, and a plurality of V-shaped positioning blocks are arranged on the front face to avoid the welding position; Weld studs on it, put the parts on, cover the corresponding V-shaped blocks, and press them with nuts to weld them, and vice versa. Take it off after cooling, and repair welding if there is any instability! So, can this scheme solve your problem?