Spindle not getting up to speed

Hi my machine is no longer getting up to 10k rpm, it initially dropped to 7500, but is now at 3k, dosn’t seem to have any other problems has anyone had a similar problem to this?

There are several reasons that the spindle speed might have dropped. DO NOT remove or loosen the spindle from the machine or the machine’s calibration will be affected. Has your machining been producing small chips? If yes, it is possible that a small chip has made its way between the spindle collar and spindle carriage and is bogging the spindle motor down. Turn OFF the Pocket NC power supply and turn the spindle by hand. Does the spindle turn freely or do you encounter resistance? If you feel that the spindle is not turning freely, then use a sparingly amount of isopropyl alcohol around the spindle collar to flush any chips. Spin the spindle to help dislodge material. Another possibility is that the spindle’s tuning has been affected. On the rear of the spindle motor (right side of the machine as you look at it from the front) is a cover secured by four phillips head screws. Remove this cover (and rubber gasket). Behind the cover is a circular circuit board that contains three hall sensors. The rotation of this circuit board determines the tuning of the spindle motor. Pinch the circuit board between your fingers and try to rotate it. Is the circuit board secure or does it rotate? If it is rotating, then the motor needs to be retuned and the fasteners that hold the circuit board in place tightened, so that the board does not move. If you do find that the circuit board is loose, then use the MDI command M3 S10000 to turn the spindle on and command it to a speed of 10,000 rpm. Slowly rotate the board while observing the “user interface” spindle speed display. Stop rotating the circuit board and tighten the fasteners once the desired speed has been reached. Verify that the spindle is spinning the correct direction. Place your finger on the tool holder and feel that the spindle is rotating away from you. If neither of these troubleshooting steps work, contact us at service@pocketnc.com and we will work with you to resolve your spindle problem.