A - Straight shafted grass trimmers are generally better for getting under bushes and hedges. Some grass trimmers have bent shafts to reduce manufacturing costs, i.e fewer components. Straight-shafted trimmers require a gearbox on the end of the shaft; these expensive parts increase the cost of the product. Curved shaft grass trimmers are often fixed length, whilst straight shafts allow the user to adjust the working height of the trimmer, for a more comfortable working position.