Общий каталог Widia 2017 - страница 680

problem thread with torn fi nish

chatter

cause

• Burs.
• Torn fi nish.
• Steps.
• Improper shim.
• Improper infeed.
• Poor rigidity.
• Insert movement.
• Improper infeed.
• Off centreline.

possible solution

• Use modifi ed fl ank infeed.
• Use full profi le insert.
• Increase coolant concentration.
• Increases m/min.
• Check machine “Z” travel axis.
• Check insert form.
• Check for correct shim in LT system.
• Calculate fl ank clearance.
• Use modifi ed fl ank infeed.
• Minimise tool overhang.
• Check for workpiece defl ection.
• Check insert and clamp.
• Verify that tool cutting position is at workpiece centreline.
• Adjust number of passes. Fewer passes reduce chatter.

built-up edge

• Speed too low.
• Insuffi cient coolant.
• Chip load.

• Increase m/min.
• Increase coolant concentration and/or fl ow.
• Adjust infeed angle.
• Increase depth of cut per pass.

deformation

• Wrong grade.
• Use modifi ed fl ank infeed.
• Speed too high.
• Use a more wear-resistant grade (e.g., TN6010™).
• Improper infeed angle.
• Reduce m/min.
• Insuffi cient coolant.
• Increase coolant fl ow.

chipping

broken nose

• Improper infeed.
• Chip load.
• Wrong grade.
• Incorrect speed.
• Poor rigidity.
• Heavy chip load.
• Small nose radius.
• Wrong grade.
• Improper infeed.

• Use modifi ed fl ank infeed.
• Increase or decrease number of passes.
• Eliminate spring passes.
• Use tougher grade (e.g., TN6025™).
• Increase m/min if chipping on trailing edge.
• Decrease m/min if chipping on leading edge.
• Minimise tool overhang.
• Check for insert movement/check clamp. Torque screw or clamp to correct value.
• Check for possible part defl ection.
• Calculate fl ank clearance.
• Ensure correct shim.
• Use modifi ed fl ank infeed.
• Decrease chip load.
• Use large nose radius if possible.
• Use tougher grade (e.g., TN6025).

fl ank wear Ensure correct shim.

• Improper shim.
• Use a more wear-resistant grade (e.g., TN6025).
• Wrong grade.
• Increase coolant fl ow.
• Insuffi cient coolant.
• Check the centreline height of the tool. (The smaller the diameter, the
• Off centreline. more critical the need for centreline accuracy.)
• Insuffi cient fl ank clearance.
• Calculate fl ank clearance and change shim to increase clearance on
• Improper infeed angle. worn fl ank.
• If wear is on trailing fl ank, increase infeed angle clearance.