ROCK RIVER TOOL, INC.
STANDARD & SPECIAL CARBIDE TIPPED CUTTING TOOLS
Phone (800) 345-8924 | FAX (800) 867-9312
PROBLEMS |
PROBLEMS |
PROBLEMS BY CAREFUL ORIGINAL SET-UP |
MACHINE CONDITION TOOL CONDITION FEEDS & SPEEDS COOLANT |
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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 to avoid thermal shocking carbide. | |
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. OVERSIZE 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. | |
REAMING PROBLEMS | POSSIBLE CAUSES | POSSIBLE SOLUTIONS |
1. POOR FINISH | ||
Unequal chamfers | Regrind reamer with equal chamfer angle. | |
Incorrect margins | Regrind reamer with narrow margins for reaming lower tensile materials. | |
Excessive spindle runout | Increase reamer back taper (will lose size faster). | |
Chatter | Reduce speed and increase feed rate. | |
Use power feed unless material is hard. | ||
Use right or left spiral fluted reamer. | ||
Grind secondary lead angle immediately back of 45º chamfer. | ||
2. OVERSIZE HOLE - TAPERED HOLE - BELL MOUTH HOLE - POOR FINISH | ||
Misalignment | Use bushing -- .0002"/.0003" over reamer diameter. | |
If hole location varies, use floating reamer holder. | ||
Increase reamer back taper (will lose size faster). | ||
Insufficient cutting action | Specify reamer with positive radial rake to reduce cutting pressure -- may produce slightly larger diameter holes. | |
3. EXCESSIVE TOOL WEAR | ||
Insufficient stock for removal | Decrease previous operation drill size to allow more material for removal by reamer - leave about 3% of hole diameter for cast iron and more stock for non-ferrous materials. | |
Excessive reaming pressure | Increase feed rate. | |
Reduce stock to be removed by increasing previous operation drill size -- leave about 3% of hole diameter. | ||
Misalignment | See problem #2 above. | |
4. CROOKED HOLES | ||
Not drilled straight | Correct previous drilling operation -- reamer will follow the drilled hole. | |
Increase reamer attack angle (chamfer) to 120º/180º included angle. | ||
5. TOOL BREAKAGE | ||
Excessive reaming pressure | Reduce stock to be removed -- see problem #3 above. | |
Misalignment | See problem #2 above. | |
MILLING PROBLEMS | POSSIBLE CAUSE | POSSIBLE SOLUTION |
1. ROUGH FINISH | ||
Dull cutting edge | Resharpen to original tool geometry. | |
Wrong feeds & speeds | Increase speed -- also try reduced feed. | |
2. EXCESSIVE CUTTING EDGE WEAR | ||
Wrong feeds & speeds | Increase feed (should always be over .001" per tooth) -- especially when machining ductile or free machining materials. -- Also try reduced speed | |
Rough cutting edge | Lightly hone cutting edge with fine grit diamond hone. | |
Insufficient coolant | Increase coolant flow -- review type of coolant. | |
3. CHIPPED CUTTING EDGE | ||
Poor chip removal -- | Use tool with larger flute space -- larger diameter or fewer flutes. | |
Recutting work hardened chips | Increase coolant flow. | |
Vibration | Increase rigidity of set-up, especially worn tool holders. | |
Incorrect carbide grade | Change to tougher carbide grade. | |
4. CHATTER MARKS | ||
Insufficient machine horsepower | Use tool with fewer flutes as correct speeds & feeds must be maintained. | |
Vibration | Consider climb milling. | |
Use larger diameter cutter. | ||
Resharpen tool with more clearance. | ||
5. GLAZED FINISH | ||
Feed too light | Increase feed. | |
Dull cutting edge | Resharpen tool to original geometry. | |
Insufficient clearance | Resharpen tool with more clearance. | |
6. POOR TOOL LIFE | ||
Excessive cratering | Increase speed or decrease feed. | |
Change to harder grade of carbide. | ||
Milling abrasive material | Decrease speed and increase feed. |
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Increase coolant flow. | ||
Climb milling better than conventional milling. | ||
Milling surface scale | Conventional milling better than climb milling. | |
Milling hard material | Reduce speed -- rigidity very important. | |
Insufficient chip room | Use larger diameter tool. | |
Delayed resharpening | Prompt resharpening to original geometry will increase total tool life. | |
Thermal cracked carbide | Increase coolant flow at all times. | |
Climb milling is cooler than conventional milling. | ||