Festool RO 150 FEQ; Understanding the Rotex Dual Mode Sander
February 20th, 2008
The Festool RO 150 FEQ Rotex dual mode sander has a rotary orbital motion and a random orbital motion. Both motions have their advantages for a dedicated sanding task. The gear driven orbital motion is made for aggressive material removal and polishing, the random orbital motion is made for fine sanding.
1. Rotary Orbital Motion The rotary orbital motion is a combination of two movement patterns: The pad both rotates and has an eccentric/orbital pattern at the same time. The aggressiveness results from the fact, that the pad is gear driven and forced to spin as opposed to the random orbital motion where the pad spins due to centripetal forces and can be stopped by hand.
With this pattern the sanding action is almost as aggressive as a belt sander or a grinder. While a belt sander leaves typically deep linear scratches and a grinder deep circular scratches that are hard to sand out with the next grit up, the rotary orbital motion of the Rotex causes a random scratch pattern that erases itself during sanding. The result is a surface quality in each grit that is by far superior to a surface quality you can achieve with a belt sander or a grinder on the same grit level. And that means that the time needed for the next sanding steps with higher grits is cut down significantly. Bottom- line: Sanding with the Rotex in rotary orbital motion saves a lot of time since material is removed in an aggressive, yet smart way, providing always the best surface for the next sanding steps.
The rotary orbital motion combines a forced rotation with an eccentric/orbital motion.
2. Random orbital motion In the random orbital mode the main pattern is an eccentric
pattern. In addition the centripetal force resultant from the crankshaft offset causes the pad to spin. This is a weak force and pad rotation can be stopped if too much hand pressure is exerted on the sander. Due to the eccentric motion and the rotation, the tiny orbits are stretched into long curved loops, which, when interlaced, tend to eliminate any signs of swirl marks. The Rotex leaves a very fine finish in the random orbital mode. If a finer finish is desired, the Festool ETS150/3 is the sander of choice. Both are using the same abrasives, so they complement each other very well.
The random orbital mode combines small orbits with an unforced rotation.
August 21st, 2008 at 12:47 am
I have a Rotex 125 sander. I LOVE the sander, especially because it is so much easier on ME than my old Porter Cable random orbit sander. I am having one problem, though. On occasion, I am getting deep swirl marks, even after final sanding. They’re hard to see until I put a finish coat on, and then it’s too late. My normal routine, after planing my work, is to sand in rotary mode with 120 grit, and then, in random orbit mode, 120, 180, and finally 220. I can send you a picture if you’d like to see what the swirl marks look like. Any suggestions/advice would be greatly appreciated.
Jack Olson
jackdolson@rose.net