If a player crews Mindlink Mech with a nonlegendary permanent that is not normally a creature or Vehicle, the resulting permanent Mindlink Mech becomes is a 0/0 artifact creature and will usually be put into its owner's graveyard. This is because a copy effect can't set the power and toughness of a permanent if being a creature isn't part of that permanent's copiable characteristics. The crew effect is then applied after the copy effect, and it becomes a creature with no defined power or toughness, so both are set to 0.