Reason 1
Poor fixture rigidity
Solution
1. Analyze the direction of the cutting force and provide sufficient support or improve the fixture
2. By reducing the amount of back knife ap
3. Choose positive cutting, sparse tooth and unequal pitch tools
4. Choose an L groove shape with a small fillet radius and a small parallel land
Reason 2
Poor axial rigidity of workpiece
Solution
1. Consider a square shoulder tool with a positive rake angle groove shape (90° entering angle)
2. Choose an L-shaped insert
3. Reduce axial cutting force
4. Lower back-cutting amount, smaller fillet radius and parallel cutting edge
5. Choose a sparse tooth tool with unequal pitch
Reason 3
Tool overhang is too long
Solution
1. Minimize overhang
2. Use sparse tooth cutters with unequal pitch
3. Balance radial and axial cutting forces
4. Increase the feed per tooth fz
5. Use light cutting insert geometry L/M
6. Reduce the amount of axial back-eat tool ap
Reason 4
Milling square shoulders with a rigid spindle
Solution
1. Choose the smallest possible tool diameter
2. Choose positive rake angle and light cutting tools and inserts
3. Try to mill up
Reason 5
Vibration at the fillet
Solution
Use large fillet radius in programming to reduce feed
