Care of Machine Spindles & Tool Holders

After purchasing new retention knobs and pull studs, always compare a new retention knob or pull stud to one that is in the machine at the present time. The retention knobs and pull studs must be identical.

Examine the retention knob or pull stud for damage, nicks or scratched surfaces. These must be removed if they touch the tool holder or machine gripper fingers.

Always clean the retention knob or pull stud and the tool holder before assembly.

Retention knobs or pull studs with o-rings must be examined to make sure that the o-rings do not show signs of wear, swelling, flat spots or cracks. Vaseline should be used to lubricate o-rings and helps sealing off leaks.

Tighten the retention knob or pull stud to the Manufacturer's recommended torque settings.

Use sockets to tighten retention knobs and pull studs. This will prevent rounding off of corners on the knob and insure that the person installing the knob or stud is not injured if the wrench slips.

Wipe off the tool holder and retention knob or pull stud with a clean shop towel before installing tools in the tool carousel. Make sure the taper angle on the tool holders is in good condition with no nicks or scratches.

Clean the tool carousel before installing new tools. Use a shop towel to remove grease and chips from the chain. Next, spray the tool socket with Stoddard Solvent, then blow off with an air hose. Spray on a light coating of oil such as WD-40.

Examine the transfer arm (which changes the tool in the spindle), make sure keys and all parts are tight and in good condition. Clean and lubricate the transfer arm in the same way as the tool carousel.

Insert the tool into the tool holder socket. Check that the tool is held in place by a good set of gripper fingers. The tool should snap into place and it should be necessary to give it a good tug to remove it.

Examine the spindle, make sure the drive dogs are in good condition and fastened securely. Check coolant tubing, electronic equipment, and equipment that is mounted to the underside of the spindle, for damage and make sure it is secure.

Remember to clean the spindle of the machine daily, with a clean shop towel, to prevent grease and oil build up. Examine the surfaces of the inside of the spindle for metal that is galled to the sides, and for chips and/or scratches. If necessary remove them with a scraper or small file, being diligent to remove only matter that is galled onto the sidewalls of the spindle.

If the finish on the inside of the spindle is still too rough, then use a spindle lap to smooth the surface. Start the spindle and insert the spindle lap. This will smooth the sides of the spindle and remove small particles and scratches that are on the sidewalls.

If the spindle has a large amount of material built up on the sidewalls or if the material has been torn out of the spindle, it is time to have the spindle re-ground. There are repair services that can regrind your spindle in your plant if required.

If all else fails, then call the machine tool manufacturer and make arrangements to have the spindle removed from your machine and sent out for repair or replacement. Some manufacturers can exchange spindles for just this type of situation. They can be installed in your machine immediately after removing the damaged spindle.

Retention knobs or pull studs are designed to be the weakest link between the spindle and the tool holder. For this reason they are not intended to last forever. Monitor their condition and be sure to include Retention Knobs and Pull Studs in your Safety Program.

After reading this, I am sure that you can see that preventive maintenance is possibly the best idea of all.

Copywritten by J&M Machine - Set Your Course for Quality

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