Bosch Dual Mode Sander

What is dual mode and when should I use it?
Dual mode sanders mean they have two orbit patterns. Most have around 3/16"(5mm) and 3/32"(3mm) orbits. The larger orbit is meant for heavier stock removal grits (36-100) on wooden surfaces, while the smaller orbit is for cleaning up the large orbit scratches and finish sanding grits (120-220)

What's VSC?
Depending on the abrasive and grit, some discs can be more aggressive than others and they can grab at the workpiece. Naturally, you'll want to press down harder to keep a jumping sander or loose board under control which now you're working your sander harder than needs be. If you have Variable Speed Control sander (VSC) then we recommend to set it at 3 or your middle setting to start. This way you have some room to adjust for both your style of sanding and the application you're sanding. Turn the setting up to max and use 36 grit, you will do some heavy stock removal but creates heat and a lot of dust. For the finer grits, too much suction from the vac causes the workpiece to get sucked up to the sander. Naturally, we do the same thing and add more pressure down to the sander. Drop the amount of suction and slow the sander down to midway. Adjust as needed. When sanding between coats of finish, turn the sander down low and switch to the 3/32" orbit. Two reasons, one is the sander isn't needing to be aggressive on this application and second, you're generating less heat which doesn't soften the finish causing loading on the disc. Also using the 3/32" orbit from 120 and higher is recommended to remove the heavy swirl marks associated with the larger orbit.

Festool RO150 Dual Mode Sander

Is a dual mode sander right for you?
Dual mode sanders are two sanders in one unit. If you do a lot of glue-ups, table tops, benches, hardwood floor install/refinish or panels then you'll find a benefit in having the dual modes. If you have smaller projects, just starting out in working with wood, or weekend warrior then the dual mode might not be the sander you need now.
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