Hi, thanks for reading this
My Triac spindle has started making a horrible noise when increasing in speed. It doesn't seem to matter whether the jump in speed is a relatively large one as shown in the video (link below) or a smaller incremental increase. The slowest speed I have noticed it making the noise is between 800 and 850 rpm. It is also possible to get it to settle down by increasing the speed well beyond the desired rate and then backing it off to the original speed. EG if the noise occurs at 2000 rpm, increasing the speed to 3500 rpm and then stepping back down to 2000 rpm stops the rattling sound.

I have also noticed that the top bearing support is getting almost too hot to touch after running the spindle for a few minutes whilst it makes the noise. I'm leaning towards a problem with the bearings and hoping that some of the members here will be able to give some insight
Many thanks in advance for any advice offered
Video Link:
https://youtu.be/8KDG7i_jGmE