Missing Z axis lead screw bushing?

The z axis lead screw on my machine is attached to the motor at the top end and simply sits in a hole in the aluminum frame on the bottom end. I can move the lead screw side-to-side slightly by hand at the lower end. This play in the lead screw seems to contribute to vibration noises and I’m wondering if I’m missing a bushing at this location.


Could I get a volunteer to check their machine for a lead screw bushing? Unplug your machine, reach into the z axis assembly and wiggle the lead screw at the bottom. Does it rattle back and forth, contacting the aluminum frame? Can you see a plastic bushing between the screw and the frame?

I just checked and I don’t have a plastic bushing. I can move it as well. I can’t say I’ve noticed any unusual vibration or noises but at the same time I’m brand new to CNC!

Nothing here; also can wiggle slightly

Ok, thanks for checking!
I notice the vibration noise when the z axis does a rapid travel, and I imagine this play contributes to the racket when cutting metals. Maybe I’ll make a bushing out of Teflon to see if it quiets it down a bit.

The only time an outboard leadscrew bushing is needed, is when the leadscrew is very long and rotates quickly, and might encounter “whipping”. That is not the case here–the leadscrew is short and sitff for its length. It is best to allow the leadscrew to self-align with the Z axis nut. Adding an outboard bearing/bushing will more than likely only lead to binding. Any sound during the rapid travel is more than likely some component resonating at the particular frequency of steps per second.