Indication
|
Cause
|
Correction
|
Cutting edge of drill bell forming and heat coloring.
|
DULL DRILL - Heating drill bit to point of removing temper.
|
SHARPEN DRILL - Reduce RPM or turning speed of drill. Increase
strokes/minute to reduce time of drill in paper.
|
Cutting edge of drill bell forming. No heat coloring. Spiral split
in drill.
|
DULL DRILL - Forcing drill through lift too fast.
|
SHARPEN DRILL - Reduce strokes/minute. Increase RPM or
turning speed of drill.
|
Drill breaking at shank. No bell forming, no heat coloring. Chips
free in drill.
|
Drill being deflected. Breakage due to fatigue.
|
Check head mounting square on rail. Make drill pattern in wood
stick - no paper. Make drill pattern in wood stick with paper. Note
deflection on wood stick.
|
Chips tight in hollow drill.
|
DULL DRILL - Crowding drill, punching rather than cutting.
|
SHARPEN DRILL - Reduce strokes/minute. Increase RPM or
turning speed of drill. Check for heat coloring of drill when increasing
RPM.
|
Chips tight in hollow drill.
|
Drilling paper with adhesive or thermal binding material.
|
When drilling cycle stops, drill a couple of holes in bond paper
to clear chips out of drills. Do not allow adhesive to harden.
|