Grinding machine troubleshooting chart (spindle heating, abnormal noise, chatter, dimensional drift)

Chatter marks appear (regularly spaced pattern or waviness on the workpiece surface)Common

Look at whether the pattern is evenly spaced, uniform over the whole surface, or irregular (Noritake separates countermeasures by these three cases). Chatter marks can be measured as a waviness pattern (Tochigi Prefectural Industrial Technology Center)^[1][2]

Likely cause	What to check	Action
Wheel unbalance	Static balance on a balancing stand; vibration reading of the balancer	Rebalance the wheel. After stopping the coolant, let the wheel spin idle to throw off the fluid^[1][3][4][5]
Wheel mounted poorly or mounting runout	Mounting on the flange; runout of the wheel periphery	Remount the wheel firmly on the flange and true it^[3][1]
Loose dresser mounting, worn dresser tip, or unbalanced truer (dresser)	Dresser mounting, tip shape, shank overhang too long	Fix the dresser firmly and replace one with a flat tip. Chamfer the wheel corners right after dressing^[6][1][3]
Vibration sources outside or inside the machine (coolant pump, fan, a nearby press, forklift, loose belts, vibration through the floor)	Does the vibration remain after the wheel is stopped, or disappear when nearby machines are stopped?	Remove or isolate the vibration source (balance the pump and fan, vibration-isolated installation, independent foundation)^[4][3][1]
Insufficient workpiece support (steady rest, center, chuck)	Is a low-rigidity workpiece supported by a steady rest? Condition of the center	Use a steady rest. Correct the setup^[4][3][7]
Regenerative chatter from a wheel out of shape, loaded, or shedding grains (waviness from the previous revolution grows on the next)	Condition of the wheel surface (loading, glazing, grain pull-out)	Perform truing and dressing regularly^[3][8]
Grinding conditions (large depth of cut, feed or workpiece surface speed) or insufficient spark-out	Conditions table	Reduce depth of cut and feed. Increase the number of spark-out passes. In cylindrical grinding, avoid synchronizing the workpiece and wheel rotation speeds^[3][1]
Coolant concentration too low, supply or pressure too low or too high, or foreign matter	Concentration (refractometer), nozzles, filtration	Restore the concentration to the recommended value. Adjust supply rate and pressure. Use clean coolant^[3][1]

Feed marks or a thread-like (spiral) pattern appearCommon

Likely cause	What to check	Action
Poor dressing leaves the wheel face spiral or non-circular, and that shape is copied onto the workpiece	Dressing feed and direction	Dress in one direction only and reduce the dresser feed and depth of cut^[4][6]
The working face of the wheel is not parallel to the longitudinal travel of the table	Dresser wear and heating; parallelism between workpiece and wheel spindle	Check the dressing tool for wear and cool it. Adjust the parallelism between workpiece and wheel spindle^[4][1]
Table speed (traverse feed) too fast or too much stock to remove	Conditions table	Reduce the table speed. Reduce the stock removal^[9][1]
Wheel out of shape because of insufficient truing	Runout and shape of the wheel periphery	True the wheel thoroughly^[9][10](1 source, for reference)
(Thread-like scratches) loose dresser mounting; wheel corners after dressing	Dresser mounting	Fix the dresser firmly and chamfer (put a radius on) the wheel corners right after dressing^[1][6](1 source, for reference)

Grinding burn appears (yellow or brown discoloration, spiral burn marks)Common

Besides visible discoloration, it creates a work-affected layer and tensile residual stress, which lower wear resistance and fatigue strength (Noritake). Grinding heat also causes grinding cracks and warping^[11][4]

Likely cause	What to check	Action
Dressing is too fine, so the cutting edges of the grains are small or glazed	Dressing lead and depth of cut	Increase the dresser feed (lead) and depth of cut, and increase the total dressing depth. With a rotary dresser, use down-cut and bring the speed ratio close to 1^[11][6][4]
Coolant is not reaching the grinding point, or the flow or pressure is too low	Nozzle direction, flow rate, concentration	Aim the coolant directly at the grinding point, increase the flow and raise the pressure. Use a coolant with good lubricity and penetration^{[11][4][9][12]}
Wheel speed too high or too much stock to remove	Conditions table	Reduce the wheel speed and the stock removal^[11][1](1 source, for reference)
Wheel too hard or too few pores	Wheel specification (grade, structure)	Consider a softer wheel with more pores, or a sharper abrasive (ceramic, CBN)^[4][11]
Large workpiece or end-face grinding: the contact area is large and coolant has trouble getting in	The part being machined	Combine the measures above. Review the conditions of the whole process^[11](1 source, for reference)

Grinding cracks appearCommon

Likely cause	What to check	Action
The surface overheated from grinding heat (same cause as burn)	Presence of burn; conditions	Same measures as for grinding burn (sharp dressing, coolant supply, wheel speed, stock removal)^[11][4]
Dressing feed or total dressing depth is insufficient	Dressing conditions	Increase the dresser feed and the dressing amount (total depth of cut)^[6](1 source, for reference)

Dimensions vary or drift over timeCommon

Likely cause	What to check	Action
Thermal displacement of the machine, or expansion of the workpiece from grinding heat	Dimensional change between morning and evening or after continuous running; difference between just after machining and after cooling	Warm up the machine. Keep the coolant and room temperature constant (ideally within ±1 °C between coolant and room)^[13][14]
Backlash in the feed system, wheel wear, or compensation values	Check whether the number of compensations is increasing	Review the compensation values. Inspect the feed system^[13](1 source, for reference)
Deterioration of table drive parts (ball screw, support bearing, guideways)	Do results vary even under the same conditions?	Replace parts on a planned schedule (consult the maker)^[15][13]
Hydrostatic block clogged, so hydrostatic pressure is poor	Flow rate of the hydrostatic section	Service the hydrostatic block^[16](1 source, for reference)
Grinding conditions (large depth of cut or feed, too much stock removal)	Conditions table	Reduce the depth of cut and feed, and reduce the stock removal^[1](1 source, for reference)

Poor surface roughnessCommon

Likely cause	What to check	Action
Dressing is coarse (large lead and depth of cut), or the dressing interval is too long	Dressing conditions	Reduce the dresser feed (lead) and depth of cut. Dress more often. Increase the dresser mounting angle^[8][1][6](1 source, for reference)
Wheel unbalance	Balance	Rebalance^[1][9]
Dirty coolant (sludge) or insufficient filtration	Settling tank, filtration unit	Renew the coolant and improve filtration^[9][17][4]
Feed or depth of cut too large, or wheel speed too low	Conditions table	Reduce the feed and the depth of cut. Review the wheel speed^[9][1]
Coolant concentration too low	Refractometer	Increase the concentration^[1][3]

Random scratches appear (short comma-shaped marks)Common

Likely cause	What to check	Action
Particles floating in the coolant are pressed into the grinding point	Filtration unit; dirt inside the wheel guard	Review filtration and clean the inside of the wheel guard regularly. Clean around the coolant system^[4][9][1]
Cracked dresser, poor mounting angle or fixing, or insufficient dressing finish	Cracks in the diamond; mounting	Inspect the dresser. At the end of dressing, make a few feed passes with no depth of cut (zero cut), always starting from the edge of the wheel^[6][1](1 source, for reference)

Taper or poor cylindricity (cylindrical grinding)Cylinder

Likely cause	What to check	Action
The dressing position and the grinding position are offset	Dresser position	Make the dressing position match the grinding position^[6](1 source, for reference)
Table swivel adjustment, steady rest position, or overrun at the end faces	Swivel scale; trial grinding	Adjust the swivel and correct the steady rest position and the overrun^[1](1 source, for reference)
Wear of the bed guide surfaces has thrown off the relationship of headstock, tailstock and wheelhead; spindle runout; machine level	Level; geometric accuracy	Level the machine. If that does not fix it, ask the maker to inspect and repair it^[13](1 source, for reference)

Poor roundness (cylindrical grinding)Cylinder

Likely cause	What to check	Action
Poor center-hole accuracy or foreign matter caught in it	Center hole	Clean the center hole or regrind it^[7][1]
Poor mounting of the wheel, workpiece or truer, or deterioration of the supports (headstock, tailstock, spindle)	Runout of the rotating axes	Correct the mounting. If worn out, ask the maker to repair it^[7][13](1 source, for reference)
Poor center pressure, a faulty driving dog, the chuck clamping position, or the rest setting	Setup	Correct the setup^[7](1 source, for reference)
Wheel glazed or loaded, or dresser worn	Working face of the wheel	Re-dress. Replace the dresser with a new one^[6][1](1 source, for reference)
Insufficient spark-out, or the grinding cycle	Cycle	Increase the spark-out. Change the grinding cycle^[7][1]

Wheel loading (chips packed into the pores, so the wheel stops cutting well)Common

Grinding force and loading can be estimated from the wheel spindle motor current (research by the Tochigi Prefectural Industrial Technology Center)^[2]

Likely cause	What to check	Action
Dresser tip is flat, or dressing is too fine	Dresser tip; dressing conditions	Replace the dresser and increase the dresser feed. Dress several times to clear the loading^[6][4]
Dressing lead is too small	Lead	Increase the lead. Clean the wheel face after dressing^[8][6](1 source, for reference)
Wheel specification (bond with small chip pockets, grit too fine)	Specification	Consider a bond that keeps its pores open and a wheel with a coarser grit^[3][4]
Coolant is not washing enough (supply rate, position, dirt)	Nozzle; filtration	Apply enough coolant to the grinding point. Keep the coolant clean^[3][9](1 source, for reference)

Wheel glazing (grain tips worn flat, the face turns shiny and does not cut)Common

Likely cause	What to check	Action
Bond too hard for the grinding conditions, grain toughness too low, or working speed too high	Wheel specification; wheel speed	Consider a softer bond (the wheel renews itself more easily), a friable abrasive, and a grit one step coarser^[18][3]
Dressing is too fine (small depth of cut or lead)	Dressing conditions	Increase the dressing feed^[8][4]
Wear of the dresser tip	Dresser tip	Replace with a new dresser^[18][6](1 source, for reference)

Workpiece is hard to release from the magnetic chuck, or chips and iron dust stick to it (residual magnetism)Flat surface

Likely cause	What to check	Action
Current was only switched off, without demagnetizing; faulty demagnetizer	Demagnetizing procedure; operation of the electrical parts (rectifier, demagnetizer)	Demagnetize with the demagnetizer before removing the workpiece^[19][20](1 source, for reference)
The workpiece itself is magnetized	Does iron dust stick to the workpiece?	Run it through a demagnetizer. Some materials are hard to demagnetize depending on their heat treatment^[21][20](1 source, for reference)

Magnetic chuck holds weakly or the workpiece shiftsFlat surface

Likely cause	What to check	Action
Workpiece is thin or small, and does not span the north and south poles	Workpiece thickness, size of the holding face, how it is placed	Place it with a separator (pole piece) between so that it spans both poles. Use a chuck whose pole pitch suits the workpiece thickness (a thickness of 2 to 4 times the pitch holds best)^[22](1 source, for reference)
Chips, burrs or dents on the chuck face; surface roughness	Chuck face	Clean it and remove burrs with an oilstone. If rough, regrind it^[23][22]
Workpiece not checked to be secured (for example, a loose switch on a magnetic auxiliary fixture)	Before grinding, are the workpiece and fixtures securely fixed?	Always check before work. Also consider secure fixing by means other than the magnet (a countermeasure from the MHLW case)^[24](1 source, for reference)

Poor parallelism of ground workpieces (poor flatness of the chuck face)Flat surface

Likely cause	What to check	Action
While regrinding the chuck face, heat from a loaded wheel made the chuck center bulge	Regrinding conditions	Lightly regrind wet with a coarse, medium-hard wheel, trued every time^[23](1 source, for reference)
Dirt, burrs or a crown on the table mounting face or the chuck bottom	Mounting faces	Remove the chuck, clean and correct both faces, remount it, and then grind the chuck face^[23][22]
The electromagnetic chuck was finished before it had warmed up fully	Time since it was energized	Energize it and run coolant to stabilize the temperature before finishing^[23][22]

Warping appears (surface grinding)Flat surface

Likely cause	What to check	Action
Grinding heat	Stock removal; coolant	Reduce the stock removal, increase the coolant supply and pressure, and use a coolant with good lubricity and penetration^[1][11](1 source, for reference)

Wheel spindle runs hot or makes abnormal noiseCommon

Likely cause	What to check	Action
The wheel ran for a long time unbalanced, and vibration damaged the bearings	Vibration; balance	Balance the wheel. If the bearings are damaged, ask the maker to repair them (if the unbalance has become a structural problem, a balancer will not fix it)^[5][10]
Insufficient lubrication or cooling of the wheel bearings (circulating oil amount, oil cooling)	Oil amount; oil temperature	Restore the specified oil and amount. Inspect the oil cooler and filtration^[25][26](1 source, for reference)

Will not move after a long shutdown, overload alarm appears, or the home position is lostCommon

Likely cause	What to check	Action
Abrasive dust has hardened around the moving parts (water-soluble coolant machines)	Heaviness of motion; overload alarm	Clean it. Even while stopped, run regular warm-up or dry runs^[27][28](1 source, for reference)
Rust on the ball screw	Does it stop when it moves to the end of the ball screw, for example in the dress cycle?	Consult the maker^[29](1 source, for reference)
The battery died and the home position data was lost	Low-battery warning	Replace the battery (with the power on) and set the home position again. Restore from backup^[27][30]

Table moves poorly or seizes (hydrostatic guideway)Common

Likely cause	What to check	Action
Hydrostatic block clogged, so the oil flow is poor	Even if the pressure is normal, has the flow dropped?	Service the hydrostatic block or replace it with a serviced one^[16](1 source, for reference)
Deterioration of table drive parts (ball screw, bearings, guideways)	Are accuracy problems appearing?	Replace parts on a planned schedule^[15](1 source, for reference)

Feed rate does not match or poor workpiece cylindricity in centerless grindingCenterless

Likely cause	What to check	Action
Regulating wheel speed and tilt angle	Regulating wheel tilt; speed	The faster the regulating wheel turns and the larger its tilt angle, the faster the feed. Match the conditions^[31][32]
Regulating wheel shape (the grinding wheel, workpiece and regulating wheel do not touch in a straight line)	Dressed profile of the regulating wheel	Redress the regulating wheel according to the machine maker's offset^[32](1 source, for reference)
Centerless grinding wheel out of shape from wear	Wheel surface shape	Correct the shape by dressing^[33](1 source, for reference)

📚Sources

Items without a mark are those on which two or more materials from different publishers agree. Values and intervals are governed by each machine's specifications. The text is summarized in Kezuriba's own words.