
#import "/meta-environments/env-features.typ": *

= Disk Grinder

The disk grinder can quickly remove material from a metal workpiece. It uses a flat surface and so can grind workpieces to precise angles that are not possible on the bench grinders.

== Notes

// General and specific to Protohaven

=== Safety

#safety_hazard_box([#warning("DO NOT WEAR GLOVES WHILE USING THIS MACHINE.")

Gloves can be pulled around by the disk into the gap between the disk and the table resulting in serious injury.])

Do not leave the disk grinder unattended while the wheel is turning. Wait for the wheel to come to a complete stop before leaving the area after using the disk grinder.

=== Use

The disk grinder can remove a lot of material very quickly: use caution to make sure you do not grind off more material than required from your part.

== Parts of the Disk Grinder

=== Front View

#figure(
  image("images/disk_grinder-front-annotated.png"),
  caption: "An annotated front view of the disk grinder."
)

=== On/Off Switch

Use the green button to turn on the disk grinder. The grinder will take a moment to spin up to full speed.

Use the red button to turn off the disk grinder. The abrasive disk will continue moving at speed for up to an hour after power is turned off.

=== Brake

The brake will slow the abrasive disk. Stepping on the brake will also power off the machine.

Gently depress the brake to gradually lower the speed of the abrasive disk. It should take 30 seconds to stop the disk.

Stepping to hard on the brake bends the brake linkage, damaging the machine.

=== Grinding Disk

The grinding disk is a large, very heavy disk covered with 80 grit abrasive paper.

Only use the right side of the disk that pulls the workpiece towards the table.

=== Miter Gauge

Use the miter gauge to support a work piece while grinding. THe fence can be set at a specific angle to grind an angle in the workpiece.

=== Shield

The shield protects the top of the grinding disk from accidental contact and contains debris.

=== Table

The table is used to support the workpiece while grinding. The table can be tilted up to 45°.

== Basic Operation

=== Setting Up

Rotate the disk by hand to check for any places where the abrasive disk has worn or torn away.

If you find a spot where a small amount of abrasive has worn away, you can mark it on the table with tape and use undamaged parts of the disk. If a large section of abrasive has worn away, notify a shop tech.

=== Grinding

When grinding, DO NOT tilt the workpiece up to bevel the edge: the workpiece will dig into the abrasive paper and tear it, resulting in a region that is unsafe to use. Instead, set the table angle.

+ Turn on the metal grinder dust collector.
+ Turn on the disk grinder.
+ Hold the workpiece firmly.\
  _Use two hands if needed._
+ Register the workpiece flat against the table.
+ Only use the right side of the disk.
+ Present the workpiece to the disk surface.\
  _Make sure the workpiece does not get pulled down into the gap between the wheel and the table._
+ With steady and gentle pressure, move the surface of the workpiece slowly and smoothly across the face of the wheel.\
  _If you have marked areas where the abrasive surface is torn on the table, avoid those areas when grinding.._
+ Turn off the grinder.
+ Wait until the grinding wheels come to a complete stop before cleaning up.\
  _Gently press the brake pedal to reduce the disk speed._

=== Cleaning Up

Sweep up any dust.

Turn off the metal grinder dust collector.
