Equipment Check: Random Orbital Sander
90 PSIG (6.2 Bar) is the required operating air supply pressure. Check the air pressure at the sander while it is running. Note: Promote the use of Dynabrade maximum flow plugs and couplers to ensure proper airflow.
Confirm that the tool is running at the rated “Free Speed” RPM. On an average a 10,000 RPM non-vacuum sander will run at 9,500 RPM; a 12,000 RPM non-vacuum sander will run at 11,500 RPM.
A vacuum sander normally runs slightly slower.
Inspect the balancer bearing (pad bearing). Remove the back-up pad and rotate the balancer bearing shaft while holding the counterbalance stationary. The balancer shaft should turn freely.
Inspect the face of the sanding pad. The pad must be flat and smooth, without any defects. Check if they are using a Dynabrade back-up pad that is “weight-mated” to the sander. Using another pad can make the sander vibrate excessively and lead to an unacceptable finish.