ballscrew to stepper shaft alignment

[marbles]

Hi there,

I had a moment today to look at the Z axis stepper to ballscrew connection on my DIY gantry cnc. The two shafts have been out of alignment for some time. The plastic bushing was really worn, see pick.

I took my time this afternoon to line up the shafts properly finally and put on a new flex coupling. Its defo running a lot quieter and smoother.

As I run the z axis pretty fast i’m still getting a slight vibration however. The z axis is 500mm with a stepper perched on the top :), see pic. I suspect one or both shafts having considerable run off and with the current coupler i'll not be able to eliminate that.
Q: Would I be better to get a couple of 1:1 pulleys and a belt and support the stepper upside-down off the back? I suspect the belt will do a fair bit to take out the micro vibrations.

Any thoughts or links welcome :)