PROBLEM SOLVING GUIDE
AVOID PROBLEMS BY CAREFUL ORIGINAL SET-UP
MACHINE CONDITION Tool holder in good condition and secure part holding fixture
TOOL CONDITION Use cutting tool recommended for material being machined. Avoid excessive tool overhang.
FEEDS & SPEEDS Start with feeds and speeds recommended for material being machined
COOLANT Coolant flow must be adequate to avoid intermittent quenching and to flush chips promptly, avoiding the recutting of hardened chips.
DRILLING PROBLEMS POSSIBLE CAUSES POSSIBLE SOLUTIONS
1. CHIPPED CUTTING EDGE Excessive feed Reduce Feed
Excessive lip relief Reduce lip relief to provide smaller chisel angle
Vibration Frequently a worn drill bushing - Replace
Thermal cracking carbide Maintain adequate coolant flow at all times
2. SHORT TOOL LIFE Drill dwelling Maintain adequate feed at all times
Only one lip cutting Regrind with equal lip heights and chisel in center
3. DRILL WALKS OR DRIFTS Unequal lip heights Regrind with equal lip heights and chisel in center
Worn drill bushing Replace drill bushing
4. OVERSIZED HOLES Unequal lip heights Regrind with equal lip heights and chisel in center
Excessive lip relief Reduce lip relief to provide smaller chisel angle
Worn drill bushing Replace drill bushing
5. ROUGH FINISH Dull cutting edge Regrind with fine grit diamond wheel
Inadequate coolant Review type of coolant and maintain adequate flow