CHATTER MARKS ON WORK Work too high above centre. Lower work support blade. Too great an angle on workrest blade A 3O° angle should be a good average starting angle for most work. Long blades will cause chatter unless blade angle is reduced. Also for small diameter work it will generally be necessary to reduce angle.  Work support blade too thin Use a heavier blade. Blade length must be slightly longer than wheel width. Blade thickness should be under work diameter just enough so that it doesn’t cause wheel interference. Work support blade loose. Tighten clamping screws. Too heavy stock removal - particularly on infeed work. Try lighter cuts and more passes. Wheel out of round. Make certain cap screws are tight in mount. Use only one gasket under each flange. When two are used constant soaking and drying out may eventually cause loosening of cap screws. Type of wheel incorrect for particular job. Consult your grinding wheel manufacturer’s representative for specific particulars. Loose Wheel Mount. Tighten spindle nut or clamping screws through collet. Extraneous vibrations set up by nearby machinery. If impossible to change machine location, mount grinder on some vibration insulating material. Be certain insulation is thick enough to be effective. If it is not sufficient, the natural. frequency of grinder normally damped out by rigid construction may be emphasised and combine with external vibration to make conditions worse. Loose spindle bearing Adjust spindle bearings. If old type machine with plain bearings (not Filmatic) it may be necessary to rescrape bearings. Loose diamond holder; loose or cracked diamond. Tighten diamond holder clamping screw; reset or replace diamond. When shoulder grinding if regulating wheel is forward of grinding wheel, it prevents grinding to shoulder and causes work to pick up or chatter. Remove or change spacer behind regulating wheel so side of regulating wheel is back of grinding wheel. Work rest blade bowed so work not supported for full length. True edge of blade. Make certain support slot free of dirt before inserting blade.