A manufactured, cold, turbomachinery blade will deform elastically under the design centrifugal, aerodynamic and thermal loads, giving the hot blade geometry. The hot-to-cold transformation or blade unrunning process consist in the calculation of the cold blade geometry which, when subject to the design conditions, will deform to match the given hot blade geometry. This paper will use a simple spring-mass model to show how the selection of geometrically linear or large displacement, geometrically non-linear, structural solvers affect the hot-to-cold transformation for compressor blades. The geometrically linear solver gives good results below a certain value of the rotational speed, which depends on the blade geometry and on the ratio of density to elastic modulus of the blade material. Above that speed, the geometrically linear solver predicts unrealistically high deformations. This model is applied to a realistic compressor blade, showing the same behavior.