Halliday & Matthiessen (2004: 512):
There is no causative form of the conative — that is, no word meaning ‘make…try’; this can of course be expressed analytically, for example:(she) made (him) try to eat (it)The causative of the reussive has help, and perhaps enable:reussive: John managed to open the lockcausative: Mary helped John to open the lock