position. ●milling the grooves 4.Reform the brackets: The brackets purchased need to be reformed,the length of the rotary hinges that connecting the bars is too large,so we decided to replace them by the screws.We need the saw and the fitter machine to be the tools of processing Auxiliary tools:saw,fitter machine. Procedure:disassemble the original rotatory joints,and replace them by the screws and nuts and gaskets we purchased.Clamp the screws and cutposition. milling the grooves 4. Reform the brackets: The brackets purchased need to be reformed, the length of the rotary hinges that connecting the bars is too large, so we decided to replace them by the screws. We need the saw and the fitter machine to be the tools of processing. Auxiliary tools: saw, fitter machine. Procedure: disassemble the original rotatory joints, and replace them by the screws and nuts and gaskets we purchased. Clamp the screws and cut