Cylo's garage Precision Spindle Metrology part series:

1. PRECISION SPINDLE METROLOGY Pt. 1: Fundamental Concepts

https://www.youtube.com/watch?v=gt2gK-oxy5s

2. PRECISION SPINDLE METROLOGY Pt. 2: Sensitive Direction

https://www.youtube.com/watch?v=ZR-OUdCzEb0

3. PRECISION SPINDLE METROLOGY Pt. 3: Measuring Error Motion

https://www.youtube.com/watch?v=JvFIJDv9GsQ

4. PRECISION SPINDLE METROLOGY Pt. 4: Error Separation and Measurement Demo

https://www.youtube.com/watch?v=_3BzMOeJX14