I have been testing the new Festool Rotex RO 90 DX (90mm, 3½”) sander for a couple of months. I have owned a Rotex 150 (150 mm, 6”) for some time now and feel it is the best small shop sander I have ever used. Like all Rotex sanders, the new Rotex 90 has an aggressive Gear Mode that really removes material and a Random Orbital Mode that improves that surface. The difference between Gear and Orbital Mode is like going one grade finer in abrasives at the twist of a knob. I was interested to try the new 90 because it also offers Delta Mode in which you replace the standard round sanding pad with a triangular-shaped one. Delta Mode allows sanding in some difficult places such as corners and internal details in a cabinet.
Festool Rotex RO 90 DX Sander Applications
The reason I purchased a 150 was for leveling large furniture surfaces. I am a committed hand plane addict but the sharpest cutter in the most carefully tuned plane will not yield a perfect surface by today’s standards. There are always minor ridges where the plane started or stopped. If you have to go against the grain, as on the far side of a knot, there is tear-out as well. While I leave all inside surfaces of my furniture as planed, I sand the outside surfaces to 180 or 220 grit. On most surfaces a well-tuned hand plane allows me to start at 180 grit, saving time, and hand planes are quiet, Zen-like, and virtually dust-free.
A hand plane also gives the very crisp look, with exactly chamfered edges, that are the hallmark of my workmanship. I did not invent this look it was indicative of 18th and 19th Century Furniture. My Rotex 150 maintains the perfect flatness of my planed surfaces while removing all traces of tear-out or plane stops and starts. I sometimes start to lose the chamfer at the edges but that can be quickly put back with a plane after the major surfaces are smoothed. I always start out in Gear Mode and then switch to Orbital with each grit change up to 180 grit. For surfaces that are to have a shellac finish, 180 grit is often my entire sanding regime.
First Impressions
When I hefted the new Festool Rotex RO 90 DX FEQ my immediate impressions were that it would rule in hard to get areas. Yes, the delta feature would ensure that but also the 3½” diameter disk could sand a deep rabbet. I questioned, however, whether it could level as well as the 150. Testing proved that the tool could get into places that amazed me but that it still leveled very well. Not as good as the Rotex 150 but still very level. Small size brings lighter weight making the 90 dynamic and easy to handle. After some breaking in it ran smoother and could be easily controlled with one hand; something that is difficult do with the 150.
Switching from the round sanding pad to the delta pad is very easy. Both the Round and Delta Pads use a bayonet lock. Simply turn the dial to the Delta Setting, which is the right of the three modes. Turn the round sanding pad counterclockwise and it is free. Now orient the Delta Pad with the tip pointing to about 10:00 o’clock and push it onto the arbor, then turn it clockwise until it snaps and you are good to go. To remove it you must depress a green unlocking button and turn counterclockwise.
The Festool Rotex RO 90 DX’s Delta position is best for changing between round sanding pads as well. For safety reasons, in either Orbital or Gear Modes, a pin pops up that prevents installation of the Delta Pad. Once the Delta Pad is installed the machine cannot be switched out of Delta Mode. The 13’-1½” (4 meter) power cord is a separate entity that bayonet-locks into the tool making power disconnection during pad changes easy. It is industrial quality neoprene cord that is oil resistant and stays pliable in cold temperatures. With Festool’s Tool Triggered Dust Extractor doubling as an extension cord running out of cord was never a problem.
Festool Rotex Sanding Pads and Dust Collection
A plastic shield can be snapped in place that surrounds the circular pad. This prevents the pad from coming in hard contact at a corner and scratching the adjacent surface. It also improves dust extraction. Like nearly all Festools, the Festool Rotex RO 90 DX has a dust collection port near the power cord’s bayonet lock receptacle that couples with Festool’s Dust Extractor Hose.
Dust collection was the deciding feature that attracted me to the Rotex 150; it is simply incredible. Dust extraction is a cornerstone of Festool’s design philosophy, a mindset I really appreciate. It is possible to sand flat surfaces with the 150 and not even smell the dust. I refinished the wood counters in our kitchen without having a film of dust on the kitchen table, which amazed my wife. Rounded surfaces or breaking corners is a bit more problematic but still very, very little fine dust gets into the air.
Noise Output
I have added noise level to my ratings as I think it is a very important consideration. I was forced to buy hearing aids last year. My wife long tired of the witticism that her voice was in the range I could not hear. The villains were Army artillery and machinery, routers being the worst. Audiologists agree that 80 dB is the sound level at which damage to human hearing starts to occur. Unfortunately, most tools in our shops are at or above 80 dB. Since the dB scale is logarithmic a sound increase of 10 dB is very significant. In my tests, the Rotex 90DX FEQ put out 96 dB without the vacuum attached. Since the tool will always be used in proximity to your ears, hearing protection is mandatory.
Use a Dust Extractor
Festool Vacuums (Dust Extractors) are quiet—as vacuums run. My aging Sears Shop Vac puts out 98 dB while our Sears household vacuum puts out 88 dB. The Festool Mini supplied with the test package emitted 86 dB, slightly better than our home vacuum. The Festool CT 48 in our shop emits 91 dB. When the Festool Rotex RO 90 DX FEQ was connected to either of the Festool Dust Extractors the sound level increased a few dB. I think this is mainly from the high-frequency noise produced by high suction drawing air through holes in the sanding pads.
The Festool Rotex RO 90 DX FEQ was every bit as good as my Rotex 150, with virtually no airborne dust using the circular pad on flat surfaces. The Delta Pad does not enjoy quite as efficient pickup as the circular pad but still more than adequate. I think this is because there is not a shroud down around the pad like there is with the circular pad. After torturing the Festool Rotex RO 90 DX FEQ with every smoothing situation I could find, I rate it an excellent tool that has a place in the sander pantheon. At $415 it is expensive but a Fein actually costs more and the extraordinary dust extraction is worth it to me.
Festool Rotex RO 90 DX Specifications
- Power Consumption: 400 watts
- Pad Diameter: 90 mm (3.5″)
- Rotational Speed: 260 – 520 RPM
- Eccentric Motion Speed: 3500 – 7000 RPM
- Stroke: 1/8″
- Systainer Size: SYS 2 T-Loc
- Weight: 3.3 pounds
- Included: Edge Protector, Plug-It Power Cord, StickFix V93 Soft Sanding Pad, StickFix V93 Delta Sanding Pad
- Price: $415
- Warranty: 3 years
