The stand supports the trolley at a 50-degree angle so that the bolts do not contact the skid. 

The stand is made out of 4x4x0.5 square tubes because the dimensions are sufficient to support the trolley when the wheels overlap plate for the trolley and for the sidebars to restrict side movements.

As seen in Figure 3, the trolley and air hoist is already attached to each other and only needs to be rotated and picked up vertically.

The skid is made out of W6X25 beams. 

The cross beam supports on the skid is placed under the edge of the stand to support the maximum weight from the trolley and the center of gravity from the air hoist.

The skid is made out of W6X25 beams. 

The cross beam supports on the skid is placed under the edge of the stand to support the maximum weight from the trolley and the center of gravity from the air hoist as seen in Figure 5.