GRIP A good grip means a job can be completed safer and faster.

• At least three jaw teeth should be engaged on the scroll at any position of the chuck jaws.
• A ground finish on the scroll tooth gives good grip.
• The RPM of the chuck affects the grip force exerted on the job. Maximum RPM is dependent on whether it is cast iron, SG iron or steel. Recommended safe RPM is governed by standards din6386.1 and VDI3106.
• Chuck must be properly balanced or grip and RPM are adversely affected.

RUN-OUT ACCURACY This can vary with size of chuck.

• For sizes up to 315mm diameter run-out accuracy should not exceed 40microns (.0001”)
• A 400mm diameter chuck run-out accuracy can be up to 75 microns
• For 500mm or 600mm diameter chucks run-out accuracy can be up to 100microns.

WEAR LIFE Correct material, accuracy of manufacture and finish of components determine life of the chuck.

• A ground finish on the chuck body will extend wear life.
• Surface of chuck should be blemish free.
• Chucks should be cleaned and lubricated regularly with oil for jaws and grease for scroll and pinion.

Please visit www.robinsoninternational.com.au for all your engineering tools.