Our spindle has been screeching like that since the day we received it early this month. It only screeches below about 10,000 RPM.
On the day we installed it we ran about 10 minutes of low speed (4700 RPM) just to make sure it was slightly warm and then we ran the break in procedure.
For the last several days, when we go to use the CNC, we start off by doing a warm up cycle which takes about twenty to thirty minutes. (Side note, It might be a good idea to create a “Warm Up” G-Code routine to run regularly). The warm up cycle includes running it for about 5 minutes at each of five different RPM settings increasing from low to high. Once it is warmed up, we rarely ever hear the screeching again except from accelerating from a dead stop to about 18,000 RPM.
Is it advised for me to open my own support ticket?
Just to add to this.
I live in Colorado, our Altmill is in a Cinder Block Shed outdoors. The inside temp of the shed was below 20deg F ( -7 C) when I arrived today. The spindle was screaching as would be expected below 10K RPM. Just for kicks, I ran the Break In routine. When I checked it once it was complete, it was smooth as butter from 7400RPM on up to 20K RPM. Break in and/or warm up makes a huge difference!