A dust mask is also necessary for most materials - see our page on dust for some harmful examples!
Dangers
Precautions
Exposed & rapidly spinning sanding media (disc, belt or sleeve): draw-in and cutting risk
will keep spinning for a few seconds after the machine is turned off
both disc and belt always spin at the same time on combination machines like the Holzmann BT 203-914
cuts can easily get infected due to particles that are rubbed in
stay clear of the sandpaper's edges
gloves: make an informed decision
tight and cut resistant gloves are allowed to protect yourself from cuts and abrasions[1]
however, the risk of a draw-in is still higher than with bare hands!
do not wear loose clothing or jewelry and tuck away long hair as they might get caught
guards around the belt rollers and a maximum gap of 3 mm between the sanding medium and the machine's table (or table inserts) minimize the draw-in risk
never leave the machine running unattended
always unplug the machine prior to any servicing
Flying splinters, dust or sparks
you MUST wear goggles. A dust mask COULD also be necessary depending on your material
you MUST hook up a shop vac for sanding wood and wood-like materials
When sanding metal, NEVER connect a dust extraction system, as sparks can ignite dust inside the vacuum, causing a smoldering fire. Always ensure proper ventilation and keep the sanding area free of flammable debris.
Risk of kickback
Always support the workpiece against the direction of the force applied by the sander:
let the workpiece (or workholding jig) touch the machine's table before the sandpaper and maintain contact with the table
the same applies to the fence (if you use one)
for freehand contouring work on a vertical belt sander, the top roller can be used without support
do not force the work piece into the sanding medium, only apply light pressure
keep both hands on the workpiece (or workholding jig) while sanding
As specified by the manufacturer, the Holzmann BT 203-914 and WilTec 65414 are not designed to grind metal. If you use it for light metal grinding/deburring, keep a bucket of water nearby to cool the workpiece, work in short intervals and stay careful not to overheat the machine and the workpiece. DO NOT use it for extensive metal grinding (no knife making, etc).
keep the sanding area free of flammable debris
avoid staying in one section of the sanding medium to even out heat and wear - move the workpiece along the table/fence if possible or use an oscillating sander like the WilTec 65414
Demonstration
The tutor will show you these steps in detail on at least one of the applicable machines:
belt sanders
adjusting the sanding belt (tension and "tracking"/direction)
when putting on a new belt, make sure you use it in the correct orientation
with the machine unpowered, turn the belt by hand (e.g. via the disc sander side). Observe if the belt slides off its track. If it is sliding towards the disc side, turn the tracking knob clockwise, otherwise counter clockwise.
make sure the belt is not sliding to either side before operating a combined machine every time, even if you are only using the other side (e.g. disc sander)
disc sanders
how to change discs without removing the table: removal / replacement (disc removal is not possible on the Record Power DS300 without removing the table)
always position your workpiece on the downward pushing side of the disc to direct forces towards the table where they can be controlled
spindle sanders
how to safely attach a sanding sleeve by compressing the rubber spindle end to end (usually with a screw) so it grabs the sleeve from the inside
adjusting sanding tables/fences
make sure table inserts or fences do not touch the sanding medium
always return to exactly 90°, not just the general neighborhood - the next Maker will thank you!
always clean the machine and its work area with a shop vac after use