Hi Jamie, no these do not wear out.As the front is cut for the plinth,these are always unstable.Levelling is key.Also, a flat concrete floor is ideal,if it is on a wooden floor,it moves a lot and can walk out of the gap.Get as level as possible.have the legs raised as high to the base of the machine as possible so it is not balanced on spindles and do not underload it.Hope this helps.All the best.
Foxy, August 2008