dusty wrote:Failures may be practically unheard of but I can show them a half dozen or so if interested. More will likely be available when I unpack the PODs.
The real issue I think contributes the most is that once a deformation or bend in the yoke or stem of the caster occurs (even a small one), from that point on every single cycle to lift the Mark V with the caster assembly cam, it can only lift the machine at the deformed angle, serving to entice it to bend just a bit with every subsequent lift cycle.
The bedframe style casters originally used even have a tendency to bend on casters made in that style today. Have you seen that when you relocate a bed frame? Do you find them bent on newer Hollywood frames, but not so much on decades old high quality wooden frames?
Back in the day when American Steel was used to manufacture casters in America, they may have been materially stronger than those made abroad today. That could also be in play somewhat. The general design of the yoke and yoke housings have been strengthened in design, likely to overcome those obstacles.