Twin motor axis

Over on the Geckodrive group, a chap who seems to know what he is talking about said it is a seriously bad idea to use two motors on a single axis of a router or plasma table because of the risk of serious damage to the machine if one motor fails when the other continues. I am planning a large 2.5m x 3.5m router using 2 motors on the x axis, and that post reawakened worries. The idea seems fairly common, so what safeguards can be put in place to alleviate this risk?

Simon

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