Abstract: An adjustable supporting structure for use as a universal engine repair stand, or for other purposes, including two X-shaped end frames each comprising frame members having upper and lower ends and each having means pivotally interconnecting the frame members thereof between their upper and lower ends, two spacing means respectively interconnecting the frame members of the end frames adjacent the lower ends of the frame members for varying the spacings of the upper ends of the frame members, laterally spaced rolls extending longitudinally between the end frames and rotatably mounted on the upper ends of the frame members, a flexible sheet extending between and having longitudinal edges connected to the respective rolls, and means for selectively rotating the rolls in directions such as to selectively wind the edges of the sheet on and unwind them from the rolls.