Stepper motor issues. Is it my electrical design?

Hello all,

I am developing a corexy printer and I'm having difficulty getting my stepper motors to perform the way they should. My setup:

I'm using a smoothie board 5x as my controller. The board has break out pins for Ena, Dir, and Stp/pull. From these pins, I have them fed into logic converters that take the 3.3V logic and raise it to 5v logic levels. From here, the now 5v signals are fed into stepper drivers that control my stepper motors.

So for the z-axis, I'm basically taking my logic and feeding it into two different stepper drivers. From there, the stepper drivers control their own stepper motor, but that doesn't seem to be working correctly.

My stepper motors are 2 phase, 1.68A per phase and I have my stepper drivers set to 2.5Amps. I'm getting some funky behaviors:
My z-axis steppers don't even move (although they make sounds).
For my XY motors, one of my motors moves waaaaaay faster than the other xy motor. At .1mm increments, they appear to move about the same, at 1mm increments the speed difference is very apparent, and at 10mm increments on motor flies around ridiculously fast multiple rotations and the other appears to glitch and stick a bit before popping over.

Any thoughts?

Reduce the max acceleration on the z. For the xy, it sounds like the drivers aren't configured the same or one motor isn't wired correctly.

First, you probably don't need the level shifters. I drive an external driver from my smoothieboard with no level shifters. It works perfectly.

If motors won't turn but make noise it usually means that you are very far off the mark current-wise, or you have one coil reversed, or your wiring is leaving one coil open.

The motor coil wires should be twisted pairs, one pair for each coil. You can twist wires very professionally and tightly by clamping one end of a pair of equal length wires in a vise and the other end in a drill chuck. Pull the wires tight and run the drill. You'll have nicely twisted wires in a few seconds.

Make sure you keep the step/direction/enable wires away from high current switched wires, such as motor coil wires, even if they are twisted.

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Ultra MegaMax Dominator 3D printer: [drmrehorst.blogspot.com]

I tried reducing z acceleration but to no avail. I definitely think its something to do electrically. But I also made a video of the problem [www.youtube.com]

I will try my setup without the level shifters....although, I have mixed feelings about that, given how much effort I spent in designing the circuit board haha.