CBN Wheel Troubleshooting

The fine grit CBN wheel is cutting better than a coarse grit wheel?

  • Is the wheel loaded up?
    • If so, it needs to be dressed according to our standards
  • If the wheel was directly out of the box.
    • Dress the wheel prior to putting it back on the machine
  • Are the RPM’s within the correct range for the wheel?
  • Are the wheels the same bond?

The CBN wheel is not lasting as long as it used to?

  • Is the wheel being used for the same application?
  • Does the wheel sound the same?
  • Belts on the machine could be slipping
  • Clamping could be coming loose causing vibration in the workpiece.
    • Is the clamp close to the periphery of the blade?
  • Is the wheel slipping on the arbor?
  • Are the RPMs dropping while grinding?
  • Is it a different carbide grade?
  • It could be spindle wear or bad spindle bearing
  • Is the bond the same or has it changed?

The CBN wheel is louder than it used to be?

  • Is the wheel loaded or glazed over?
  • Is clamping loose causing vibration and chattering in the wheel?
  • Are the spindle bearings bad?
  • Did the spindle speed change?
  • Is it a different carbide grade?

How to fix runout on CBN wheels?

  • Remove flanges from the wheel and clean wheel and flanges thoroughly. Put the flanges back on and check again for runout
  • Check the bore hole for scoring, scratches, or defects
  • Check the spindle for runout
  • Check the spindle bearings
  • Dress the wheel to the arbor

The CBN wheel is getting too hot (bluing on the part)

  • Can the spindle speed be adjusted?
    • Spindle speed maybe too high
  • Incorrect coolant placement
  • Using the wrong coolant
  • If the wheel is loading up take heavier passes
  • Take lighter passes
  • Lower the concentration
  • Try a coarser grit
  • Are you grinding a micrograin carbide?

Your CBN wheel is acting softer than the previous supplier’s wheel

  • Is the finish the same as you were getting from previous supplier
    • Grit could be finer or coarser based on supplier
    • Are the parameters the same as the previous supplier
  • Is the bond color the same as old supplier
  • Check the belts for slippage
  • What are the RPMs?

The CBN wheel is acting softer than it used to

  • Check the spindle bearings
  • Check for belt slippage
  • Are the RPMs decreasing during grinding?
  • Did the bond change?

Dressing sticks are not dressing the wheel

  • The dressing stick should always be one to two grits finer than the wheel
  • If it is a very fine wheel (D600 or finer) we don’t have a dressing stick that is able to dress it because it will rip out the diamond

Why can’t I use the same wheel if a switch from water to oil based coolant?

  • Water absorbs heat and oil does not
  • Oil needs a softer sharper bond
  • Oil is lubricating and water is not
  • Changing will cause tips to blue and the wheel not to cut

EC wheel causing more burrs

  • Volts are too low
  • Make sure it is a CBN wheel
  • Adjust spindle speed up and down to get best finish
  • Slow down the cutting process

Can I dress a metal bond wheel?

  • Wheel should be self-dressing if used properly on correct material
  • Would need to be reconditioned with spark erosion
  • Ask us about companies that will dress your wheel for you.
  • We do not have a way to dress a metal bond wheel

Hitting a gullet when facing is causing the diamond to blow out

  • Set the stops better in order to avoid the gullet
  • Use a smaller abrasive section such as 1/16” section instead of a 1/8”
  • You may notice a burr around the edge of the diamond wheel
  • This can cause diamond to separate from the core

Causes of a poor finish and how to resolve

  • Vibration in the wheel or spindle
    • Clamp the wheel a bit better
    • Make sure it isn’t glazed up
    • Change the spindle bearings
  • Check the belts and spindle
  • Wheel should be mounted on adapter and trued
  • Coolant placement could be off
  • Coolant filtration
  • Wheel is too soft and aggressive
  • Wheel is too hard causing bouncing or vibration
  • RPMs can vary the finish
  • Excessive Dressing
    • Use less pressure on the dressing stick
  • Reduce down feed or cross feed

Very general RPM range for wheels

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