Runout
Runout is the amount of deviation from the true center of a rotating object, such as a spindle or a tool. It is an important factor in CNC machining, as excessive runout can lead to poor surface finish, inaccurate cuts, and increased tool wear.
Sources of runout can include:
- Misalignment of the spindle or tool holder
- Worn bearings
- Tool wear or damage
- Collet or tool holder issues
https://www.youtube.com/watch?v=ncbJkz1zHOI
Individual flutes might not be cutting if the runout exceeds the chip load of the cut.