Knowledge Base
ENDMILL TROUBLESHOOTING GUIDE
PROBLEM | CAUSE | SOLUTION |
|---|---|---|
Chip Packing | Too great a cutting amount | Adjust feed or speed |
Not enough chip room | Use fewer flutes end mill | |
Not enough coolant | Apply more coolant | |
Poor Surface Finish | Feed too fast | Slow down to correct feed |
Slow speed | Use higher speed | |
Too much wear | Regrind sooner | |
Feed per tooth too high | Lower feed rate | |
Chip biting | Cut less amount per pass | |
Edge built up | Increase RPM, change to high helix angle | |
Depth of Cut too high | Reduced Depth of Cut | |
Chip welding | Increase volume of coolant | |
Chipping | Feed too fast | Slow down to proper feed |
Feed too fast on first cut | Slow down on first bite | |
Up milling | Change to down milling | |
Cutting edge too sharp | Hone cutting edge or allow break-in | |
RPM too high | Reduce RPM | |
Loose tool | Remove, clean and re-tighten | |
Tool rigidity | Shorten LOC, shorten overhang | |
Wear | Speed too fast | Use slower speed |
Feed rate too low | Increase feed rate or add coating if it is uncoated tool | |
Improper cutting angle | Modify Operating Parameters | |
Breakage | Feed rate too high | Reduce feed rate |
Tool large cutting amount | Adjust to smaller cutting amount per teeth | |
Too much wear | Regrind or use a new tool | |
Poor chip evacuation | Re-position coolant nozzle | |
Chattering | Feed and speed too fast | Adjust feed or speed |
Too long overhang or effective length | Use appropriate overhang or effective length | |
Loose holder (workpiece) | Hold workpiece tighter | |
Burr | Wear on primary relief is too much | Regrind earlier stage |
Feed too fast | Slow down to correct feed | |
Improper helix angle | Change to higher helix angle | |
Too long overhang or effective length | Use appropriate overhang or effective length | |
Side Wall Taper in Workpiece | Feed rate too heavy | Reduce feed rate |
Overhang of tool is too much | Hold shank deeper, use shorter end mill | |
Too few flutes | Use multiflutes end mills, use end mill with higher rigidity | |
Inaccuate Dimension | Too tough condition | Change to easier condition |
Not sufficient number of flutes | Use end mill with greater number or flutes |
DRILLING TROUBLESHOOTING GUIDE
PROBLEM | CAUSE | SOLUTION |
|---|---|---|
Drill Breaks | Spring or back lash in press or work | Test press and work for rigidity and alignment |
Too little lip relief | Regrind properly | |
Speed to low in proportion to the feed | Increase or decrease speed | |
Dull drill | Sharpen dril | |
Possible chip congestion | Peck dril | |
Outer Corner Breakdown | Uneven hardness in work material | Reduce speed |
Too much Speed | Reduce speed | |
Improper cutting compound | Use proper cutting compound | |
Hole too Large | Unequal angle or length of the cutting edges or both or both Loose spindle | Regrind properly and test spindle for rigidity |
Cutting Lips Chipped | Too much Speed | Reduce feed |
Too much lip relief | Regrind properly | |
Rough Hole | Dull or improperly ground drill | Regrind properly |
Lack of lubricant or wrong lubricant | Lubricate or change lubricant | |
Improper set-up | Check set-up | |
Too much Speed | Reduce feed | |
Only One Lip Cutting | Unequal length or angle of cutting lips or both | Regrind drill properly |
Drill Breaks in Brass or Wood | Chips clog up flutes | Increase speed
Use drills designed for these materials |
Drill Splits up Center | Too little lip relief | Regrind with proper relief |
Too much Speed | Reduce feed | |
Cracking or Chippings on Cutting Edges | Heated and cooled too quickly | Warm slowly before using. Do not throw cold water on hot drill while grinding or drilling |
Too much Speed | Reduce feed |
REAMING TROUBLESHOOTING GUIDE
Low cutting speed, high feed rates as well as the use of good cooling and lubricating agents provide the basis for good reaming practice. A further point to be considered is that a reamer – an exception is the machine bottoming reamer – always follows the direction of the pre-drilled hole. Subsequently, reamers do not correct alignment errors of pre-drilled holes. Errors between the spindle axis and the axis of the pre-drilled hole can be adjusted with the aid of floating holders.
PROBLEM | CAUSE | SOLUTION |
|---|---|---|
Oversize Hole | Excessive lip height variation | Regrind to correct specification |
Displacement in the machine spindle | Repair and rectify spindle displacement | |
Defects on the tool holder | Replace tool holder | |
Tool shank is damaged | Replace or regrind the shank | |
Ovality of the tool | Replace or regrind the tool | |
Asymmetric bevel lead angle | Regrind to correct specification | |
Too high feed or cutting speed | Adjust cutting conditions in accordance with recommended values | |
Undersize hole | Insufficient stock to remove | Increase the amount of stock to be removed |
Too much heat generated while reaming
The hole widens and shrinks | Increase coolant flow | |
The tool diameter is worn and is undersize | Regrind to correct specification | |
Too low feed or cutting speed | Adjust cutting conditions in accordance to recommended values | |
Pre-drilled hole is too small | Decrease the amount of stock to be removed | |
Rapid Tool Wear | Insufficient stock to remove | Increase the amount of stock to be removed |
Oval and conical hole | Displacement in the machine spindle | Repair and rectify spindle displacement |
Misalignment between tool and hole | Use a bridge reamer | |
Asymmetric bevel lead angle | Regrind to correct specification | |
Bad Hole finish | Excessive stock to remove | Decrease the amount of stock to be removed |
Worn out tool | Regrind to specification | |
Too small cutting rake angle | Regrind to specification | |
Too diluted emulsion or cutting oil | Too diluted emulsion or cutting oil | |
Feed and/or speed too low | Increase % concentration | |
Cutting speed too high | Adjust cutting conditions in accordance recommended values | |
The tool clamps and breaks | Worn out tool | Regrind to correct specification |
Back taper of the tool is too small | Check and replace / modify the tool | |
The width of the land is too wide | Check and replace / modify the tool | |
Workpiece material tend to squeeze | Use an adjustable reamer to compensate for the displacement | |
Pre-drilled hole is too small | Decrease the amount of stock to be removed | |
Heterogeneous material with hard inclusions | Use solid carbide reamer |