Hi all,
We have made a 300x300 CoreXY. We made dual Z axis. Powered by 4kg Wantai motors.

Marlin 1.9 used, 12mm shaft on both sides. Lead screw 8mm, with single start 2mm pitch.

MKS gen 1.4 board with TMC 2208 is normal mode for all axis.

Whenever the Z is moving down, we are getting a screeching sound. Unable to bear the sound. Used lubricants. Still no result.

But when we hold the Z plate tightly by hand (when moving down), the sound stops.

When Z moving up, it's absolutely noiseless.

We found that lead screw brass nut is having some play. Is it due to that the sound is coming?

Thanks in advance.