Presentation on theme: "METAL GRINDING. Terminology Grinding Wheels A grinding wheel is an expendable wheel that is composed of an abrasive compound used for various grinding."— Presentation transcript:
Grinding Wheels A grinding wheel is an expendable wheel that is composed of an abrasive compound used for various grinding and abrasive machining operations.
Grinding Wheels Many different styles available Choose correct type & grit of wheel Replace once when wheel reaches ½ of its original diameter.
Ring Test Good – Ring Bad – Thud ALWAYS TEST WHEELS BEFORE INSTALATION ALWAYS TEST WHEELS BEFORE INSTALATION
Wheel Identification Size: 10” x 1.5” x 1.25” Wheel Diameter x thickness x arbor size Grit : How aggressive the wheel will grind Higher Grit = Smoother Wheel RPM : How fast the wheel can spin safely Use wheels that meet or exceed the grinder RPM rating! Color: Grey & Brown – workhorse grits, mild steels Pink & White – harder steels that require cool grinding surface Ruby Red – Tool steels and sharpening
COURSE GRIT WHEELS Deeper cuts More aggressive 0-24
FINE GRIT WHEELS Sharpening Finishing Less aggressive cuts 80-120 grit
WIRE WHEELS Watch out for flying wires! Removes rust & paint Rough Polishing
Dressing a Grinding Wheel Adjust tool rest to proper gap for dressing Turn on grinder Hook dressing tool on tool rest Put light pressure on wheel while moving back and forth Continue until wheel is smooth Readjust tool rest to 1/16” LINK
Don’t grind soft metals! Aluminum, copper, brass, etc. The metal is too soft The heats up and melts into the grain It will need to be dressed
Safety Rules: Adjust tool rest to 1/16” MAX from wheel
NEVER GRIND ON THE SIDE! 1. They are not even The sides are not trued during manufacturing 2. Not designed to handle heavy loads. May shatter leading to a very nasty result.
Safety Rules PPE – Glasses, shield, dust mask, ears NEVER wear gloves! Hold the piece with a locking pliers if it gets hot. Stand to the side during startup Inspect wheel Re-Dress uneven or loaded wheels Wear a mask Keep rest 1/16” from wheel
Safety Rules: Hold work by hand or with a clamp or vice grip Do not adjust or repair while grinder is running DO NOT FORCE IT! Keep your work piece on the tool rest at ALL times
Portable Disc Grinder Angle Grinder Hand Grinder
Types of Discs 1. Grinding wheel Weld preparation Removing slag/unwanted welds 2. Fiber Cut-off Wheel Metal cutting Use at a 90 degree angle only 3. Flap Disc / Sanding Disc Metal finishing 4. Cup brush Used for removal of paint Weld cleanup Hold with EXTRA force!
Standard Discs Used for grinding, de-scaling, polishing, blending, and finishing. Semi-flexible backing Fits curved & rough surfaces Leaves a smooth & swirl-free finish.
Raised Hub / Type 27 Hub is raised in the center 1/8” thick Light Grinding Cutting off Notching ¼” thick Heavy duty grinding only
Saucer Shaped / Type 28 Identified by saucer shape. Easier to use than raised-hub discs Designed to be held at shallow angles
Changing the Discs UNPLUG IT!!!!!!!!!!!! Engage the spindle lock Use the correct size wrench Wear gloves and remove wheel Snug new wheel with arbor wrench!
Can be a workout Using the portable disc grinder is hard work Rest frequently to avoid fatigue
Fighting Fatigue – Handle Attachment Reduces stress on hands and arms Necessary for deep cuts Makes it easier for disc change-over
Fighting Fatigue- Speed Lock Locks the grinder into full speed (Cruise-Control) Convenient for heavy grinding Several styles All are located on the power switch
Safety Rules PPE: Eye protection, long sleeve leather gloves face shield is recommended Use correct wheel for the application Check condition of wheel before each use Replace once wheel is half gone Do not remove the wheel guards Secure your work piece Shoot your sparks in a safe direction LET THE GRINDER DO THE WORK Never set it down on while the disc is spinning
Pneumatic Grinders Use compressed air instead of electricity Better for extended grinding applications Need a good air-compressor to keep up Same attachments available as electric