| COMPLAINT | CAUSES | HOW TO CORRECT |
|---|---|---|
| Chatter | Faulty coolant | Clean coolant tank and lines. Replace dirty or heavy coolant with correct mixture |
| Out-of-Balance | Rebalance on mounting before and after dressing. Run wheel without coolant to remove excess water. Store a removed wheel on its side to keep retained water from causing a heavy side. Tighten wheel mounting flanges Make sure wheel center fits the spindle | |
| Wheel out of round | True before and after balancing. True sides and faces |
|
| Wheel too hard | Use coarser grit, softer grade, more open bond | |
| Improper dressing | Use sharp diamond and hold rigidly close to the wheel. It must not overhang too far Check diamond in mounting for rigidity |
|
| Faulty work support or rotation | Use sufficient number of work rests, one every 9 inches of work length, and adjust them more carefully. Use proper angles in work centers Clean dirt from footstock spindle and be sure spindle is tight Make certain that work centers fit properly in spindles |
|
| Improper operation | Reduce rate of wheel feed | |
| Work vibration | Reduce work speed Check workpiece for balance |
|
| Outside vibration transmitted to machine | Check and make sure that the machine is level and sitting solidly on foundation Isolate machine and foundation |
|
| Interference | Check all guards for proper clearance | |
| Wheelhead | Check spindle-bearing clearance Use belts of equal lengths or uniform cross section on motor drive Check drive motor for unbalance Check balance and fit of pulleys Check wheel-feed mechanisms to see that all parts are tight |
|
| Headstock | Incorrect work speeds Check drive motor for unbalance Make certain that headstock spindle is not loose Check work-center fit in spindle Check wear of faceplate and jackshaft bearings |
|
| Spirals (traverse lines) on workpiece with same lead as the rate of traverse | Machine parts out of line | Check wheelhead, headstock, and footstock for proper alignment |
| Truing | Point truing tool down 3 degrees at the work-wheel contact edges Make edges of face round |
|
| Check marks of workpiece | Improper operation | Do not force wheel into work Use greater volume of coolant and more even flow Affirm the correct positioning of coolant nozzles to direct a copious flow of coolant to the wheel-work interface |
| Improper wheel | Make the wheel act softer. Use a softer grade wheel Review the grain size and type of abrasive. A finer grit or more friable abrasive, or both, may be called for. |
|
| Improper dressing | Make sure you have a sharp, good quality diamond that is well set Increase speed of the dressing cycles Make sure the diamond is not cracked |
|
| Burns or discoloration of work | Improper operation | Decrease rate of infeed Do not stop work while in contact with wheel |
| Improper wheel | Use softer wheel or obtain soft effect Use greater volume of coolant |
|
| Improper dressing | Check dressing tool for sharpness Increase speed of dressing cycle |
|
| Isolated deep scratches on work | Improper wheel | Use finer wheel and consider a change in abrasive type |
| Improper coolant and/or coolant filter | Use coolant that settles chips Check coolant filter |
|
| Fine spiral or thread scratches on work | Improper operation | Reduce wheel pressure Use more work rests Reduce traverse with respect to work rotation Use different traverse rates to break up pattern when making numerous passes Keep edge of wheel from penetration by dressing wheel face parallel to work |
| Faulty wheel dressing | Use slower or more even dressing traverse Set dressing tool at least 3 degrees down and 30 degrees to the side from time to time Tighten holder Do not take too deep a cut Round off wheel edges Starting dressing cut from wheel edge may help |
|
| Narrow and deep regular marks | Wheel too coarse | Use finer grain size | Wide irregular marks of varying depth | Wheel too soft | Use harder grade of wheel |
| Widely spaced spots on work | Oil spots or glazed areas on wheel face | Balance and true wheel Keep oil from wheel face |
| Irregular "fishtail" marks of varying lengths and widths | Dirty coolant | Clean tank frequently Use filter for fine-finish grinding Flush wheel guards after dressing or when changing to a finer wheel |
rev 2/22/03