Disc Grinder Introduction

From CoMakingSpace Wiki

This is the content required for an introduction to our disc grinders - reading this does NOT replace the mandatory session with a tutor! It will make it a lot quicker though ;-)

If you need this introduction, please reach out to the following tutors: Lukas, Patrick, Luzian, Johannes

Let's begin! First off, make sure you have read the machine's manual, if available (should be linked from its InfoBox).


Personal protection: Protection - goggles.svg Protection - face shield.svg Protection - hearing.svg Protection - gloves.svg

Breathing protection might also help depending on your material, but unless it can filter fumes you should always take care of sufficient ventilation. [1]

Dangers Precautions
generation of hot sparks that are expelled in varying directions
  • wear goggles AND a face shield to protect your eyes
  • never use it without the blade guard
  • understand the spark direction, which will always be tangential to the point of the disc that is in contact with the workpiece
  • coordinate your activity with others in the area
  • do not attempt to vacuum up sparks! The dust collection bag could catch fire
sparks fly very far and deposit themselves as fine dust
  • metal fumes and fine dust can be a health hazard when inhaled [2]

take care of sufficient ventilation and/or wear a fume-filtering respirator when working with a grinder

Danger - heat.svg
the workpiece heats up and stays hot for a while
wear suitable gloves to prevent burns from sparks or the workpiece
possible kickback if the disc gets caught on the material
  • put the workpiece in a vise or clamp it down during grinding
  • hold the machine firmly with both hands, one-handed operation causes 40% of all accidents [3]
  • try not to shift the disc during a (deep) cut
  • let the disc get to full speed before you start grinding
aluminum and other non-ferrous metals (DE: Nichteisenmetalle) can clog regular abrasive discs and cause them to overheat until they break/"explode" do NOT use generic "metal" discs on aluminum! You will need to buy specialized aluminum cutting discs or accomplish your task with a more suitable tool.
a disc that is off-center or loose is very dangerous after inserting a new disc, let it run freely for a minute and make sure it runs safe and true

Changing Discs

Please avoid overtightening the nut holding the disc in place! It should only be tightened softly by hand but may be loosened with the associated "pin" wrench if necessary. The direction of the motor's rotation is enough to tighten the nut to the appropriate degree.

Suggested Reading

Besides these safety notes, you should know about abrasive discs, especially the difference between grinding and cutting discs!