Shaft-cut during pre-cut

The stem’s cutting surface after the pre-cut is not straight but rippled/wavy.

• Bearing play in the installation.
  Solution: the bearing needs to be checked, adjusted or replaced
• Flatness of the saw blade (sidestroke) caused by production of new saws or already installed saws - poor control of the flatness during the process of re-sharpening.
  Solution: dismantlement and repair of saw (levelling)
• Tension of the saw blade (fluttering or staggering of the saw blade while cutting). The saws need to be tensioned in dependence of the rate of rotation of the saw-shaft (tougher/softer). The determination is based on machine-data and experiential value.
  Possible cause: production faults at new saws or already installed saws - poor control of the tension during the process of re-sharpening.
  Solution: dismantlement and repair of the saw blade (tensioning)