Archived:Metal Grinding Introduction

This is an archived version of a central metal grinding introduction

This incomplete draft has never been approved by the Managers and thus has never been used!

This page has not been approved yet its purpose is to eliminate redundancy when giving introductions for the 3 metal grinding tools

This page is INCOMPLETE and still missing some important information before it can be used as a resource. Please use the "Discussion" feature above or talk to one of the tutors if you would like to help improve it. Thanks!

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This is the content required for an introduction to our bench grinder, rotary tool and dngle drinder - reading this does NOT replace the mandatory session with a tutor! It will make it a lot quicker though ;-)

Let's begin! First off, make sure you have read the machine's manual (see InfoBoxes).

Personal Safety

Due to the different dangers and health risks of the machines covered in this introduction, materials worked with and exposure time, the needed personal protection equipment varies:

Tool
Rotary Tool	MANDATORY	optional	recommended dependent on workload and material	recommended	optional
Wet Stone Grinder	MANDATORY	optional	optional (but you might want to hear if some thing goes worng) Under discussion	optional	MANDATORY
Bench Grinder	MANDATORY	optional	recommended dependent on workload and material	recommended	MANDATORY
Disc Grinder	MANDATORY	MANDATORY	MANDATORY	recommended	MANDATORY

Dangers	Precautions
generation of hot sparks that are expelled in varying directions	always wear goggles to protect your eyes make use of the grinder's plastic spark guards, if available do not attempt to vacuum up hot sparks! The dust collection bag could catch fire (it's fine when they have cooled down)
rapidly spinning exposed chuck & disk or bit	keep limbs, clothing, hair and other objects away from it always use covers, NEVER TURN ON THE ANGLE GRINDER WHITH OUT THE WHEEL GUARD if the disk is to large for the wheel guard don't use it
the workpiece heats up and stays hot for a while, overheating can ruin your hardening on tool steel	wear suitable gloves to prevent burns from sparks or the workpiece when you remove a lot of material dip your workpiece in water to cool it down fater
sparks can fly far and deposit themselves as fine dust, metal dust can be a health hazard when inhaled and may be abrasive	wear proper breathing protection if your material is harmful when inhaled cover nearby machines like the Metal Lathe
aluminum can clog an abrasive wheel and cause it to overheat until it breaks	do not attempt to grind aluminum
bench ginders: the workpiece can get caught on the wheel and get jerked from your hand	use the tool rests on the bench grinder whenever possible, make sure the gap between tool rest and wheel is small do not force your workpiece on the grinding wheels, it will just overheat them and increase the risk of kickback and ware them out faster
handheld grindes: possible kickback if the disc gets caught on the material	put the workpiece in a vise or clamp it down during grinding/cutting hold the machine firmly with both hands try not to shift the disc during a (deep) cut
kickback	let the wheels get to full speed before you start grinding don't use to much pressure because: the mechanical stress in the disk may cause it to rapture to much heat build up could change material properties the tool wheres out quicker the motor can overheat causing permanent damage to the machine you could slip away
when cutting the disk can get clamped from the sides leading to kickback	make sure the slot you already cut won't narrow
cut-off wheels could shatter under (side) force	do not apply any side force to these wheels
a disc that is off-center or loose is very dangerous	make sure it's properly fastened and the lock nut is on the right way (last only applies for angle grinders) don't over tighten then lock nut, it gets tighter over time after inserting a new disc, let it run freely for a minute and make sure it runs safe and true
no prevention of turning on after loss & restoration of power (keine Anlaufsicherung)	if the power has been lost for whatever reason, always press the "off" button before restoring it!
the blades you are sharpening become sharp...	do NOT test the sharpness with your finger or other body parts you want to remain intact

Rotary Tool and Angle Grinder

• Don't use the chuck locking nub while the tool is still moving. It is not meant to be a break.

Wet Stone Grinding

• Before you start:
  • Ensure the water trough is filled properly with cold water before you start to grind (there is a "MAX WATER LEVEL" sign). Be aware that the stone soakes up water, therefore you will probably have to refill the trough after a minute or so
  • Tighten the knob on the front of the machine (turn it clockwise until the wheel begins to drive)
• Keep an eye on the water level during grinding. Refill if needed.
• Do NOT grind a blade with the stone being dry.
• Use the stone evenly. Do NOT grind pointy things that will leave grooves
• UNDER DISCUSSION: don't wear hearing protection so you can hear when some thing is going wrong
• When you are done:
  • Remove the water. The stone is not supposed to be kept wet! (the trough can be detached from the machine)
  • Disengage the drive system with the knob (turn it counter-clockwise) on the back of the machine.