Kibibble
The motors are strong enough, and I am not over driving them. The problem for me is the controller, and signal. Both of which are crappy. I am looking at a smooth stepper to fix one of those problems. Geckos to solve the rest. But even then, I can still miss steps.
DingbatCA
The you really need to get a better driver and/or clean up the signals! If your current drivers are not getting a good signal, or you current drivers don't respond reliably, then nothing is going to fix the problem, short of cleaning up the signal, and getting better drivers. Putting a kludge into the system to deal with one or more pieces of crappy hardware is a lousy solution, and I doubt very much it'll work anyway. Buy Geckos. For $100 you'll have the best stepper driver on the market, and your problems will completely go away.
If the brakes on your car only worked intermittently, would you fix them, or put a second set of brakes on to do the job when the first ones don't work?
Regards,
Ray L.