- Click on the problems below to see probable causes and solutions!
Problems:
Large peripheral wear
Causes
- Too high a cutting speed.
- Too low a feed rate.
- Up cut machining.
Solutions
- Reduce the cutting speed.
- Increase the feed rate.
- Use down cut machining.
Chipping
Causes
Too high a cutting speed.
- Too high a feed rate.
- Low cutting edge strength.
- Chucking insufficient.
Solutions
- Reduce the cutting speed.
- Decrease the feed rate.
- Use down cut machining.
Fracture
Causes
- Too high a cutting speed.
- Too high a feed rate.
- Low cutting edge strength.
- Chucking insufficient.
Solutions
- Reduce cutting speed.
- Reduce the feed rate.
- Use stronger cutting edge.
- Check the chucking.
Welding
Causes
- Chemical reaction due to high temperatures.
- Too low a cutting speed.
Solutions
- Use coolant.
- Increase coolant volume.
- Use or change the coating.
- Increase the cutting speed.
Thermal cracks
Causes
- Repetitive thermal shocks.
- Use of coolant.
Solutions
- Use air blow
Causes
- Repetitive thermal shocks.
- Not enough coolant.
Solutions
- Increase coolant volume.
- Decrease the cutting speed.
- Use a tougher material.
Vibrations
Causes
- Speed & feed unsuitable.
- Work clamp insufficient.
Solutions
- Change speed & feed.
- Use a short overhang.
- Increase work clamp rigidity.
- Use a larger webbed end mill.
- Use an irregular lead end mill
Breakage
Causes
- Too high a feed rate.
- Low rigidity end mill.
- Too long an overhang.
- Too large a depth of cut.
Solutions
- Reduce the feed rate.
- Use high rigidity end mill.
- Use a shorter overhang.
- Reduce the depth of cut.
Poor finish
Causes
- Too large a run out.
- Too high a feed rate.
- Too large a pick feed.
- Chips not evacuated effectively.
Solutions
- Reduce the run out.
- Reduce the feed rate.
- Decrease pick feed.
- Air blow.
- Increase coolant volume.
Large wall deflection
Causes
- Too large a depth of cut.
- Too high a feed rate.
- Helix angle to large.
Solutions
- Reduce the depth of cut.
- Reduce the feed rate.
- Use a smaller helix angle.
Chip packing
Causes
- Chip pocket too small.
- Too large a depth of cut.
Solutions
- Increase the chip pocket size.
- Reduce the depth of cut.
- Use a roughing end mill.
- Use a nicked end mill.
Long chips gathering around tool (vertical feed)
Causes
- Too low a feed rate.
- Poor machinability.
Solutions
- Increase the feed rate.
- Use step machining.
Large burrs
Causes
- Too high a feed rate.
- Too large a depth of cut.
- Large notch wear.
Solutions
- Reduce the feed rate.
- Reduce the depth of cut.
- Change tool or regrind.
Causes
- Machining exits the work shown as the red arrow (Up cut).
- Too high a feed rate.
- Too large a depth of cut.
Solutions
- Use down cut machining so exit is shown as the blue arrow.
- Reduce the feed rate.
- Reduce the depth of cut.
Causes
- Machining exits the work shown as the red arrow (Up cut).
- Too high a feed rate.
- Too large a depth of cut.
Solutions
- Use down cut machining so exit is shown as the blue arrow.
- Reduce the feed rate.
- Reduce the depth of cut.
This slide shows where the chipping of the workpiece occurs when using up cut machining. The cutting edge enters the workpiece at minimum depth of cut and works it way up to maximum depth of cut on the exit. It is here that the chipping of the workpiece will occur.
Causes
- Machining exits the work shown as the red arrow (Up cut).
Solutions
- Use down cut machining so exit is shown as the blue arrow.
Here it shows that by changing to down cut machining, the cutting edge enters on max depth of cut and exits at the minimum depth of cut. This helps to prevent workpiece chipping from occurring.
Workpiece chipping
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