Fabricated Toolpost - It's now better see pinned comment.

I hoped a solid toolpost would reduce chatter when machining harder materials. I fabricated one, but it has made zero difference over the compound slide, possibly slightly worse! It happens with cuts about 1mm deep or greater with a turning tool. Parting is basically impossible. Note these issues are only in the EN8 material I am trying at the end of the video, and at ~40mm diameter. UPDATE: Problem solved by changing PWM frequency on the VFD. It doesn't eliminate the problem completely, but makes it possible to part off, and take the depth of cut required for the problem material. It's a noticeable difference.    • Toolpost Riser Feedback and Vibration Fix