Setting up and tuning dual-motor X axis

[lucan07]

I run a slaved axis without the fancy tuning just a pair of 23's and apart from homing seperately to ensure correct alignment at start, no other precautions, if slaving I would think the tuning needs to be identical whatever the complexity of the system.
However I did play with the idea of linking with double pulleys and a timing belt to keep in sync in case of problem, and also double pulleys on drive with two four fanned blades synced centrally 45 deg off sync so any deviation of 45 deg rotation would collide/contact forming connection and forcing an E stop, s well as providing visual assurance to alignment preventing damage. In the end I decided to go with my ears and a sprint.