Swirl-Free Checklist for Dynabrade Random Orbital Sanders

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.

Back-Up Pad

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.