to* listing oí manufacturer*.
KEY: MT = Morse taper. OD = outside diameter. Bed Type: AL = aluminum. CI = cast iron, ST = steel. TS » tubular steel, WO ■ wood. Drive Type: ED = electronic, RD = Reeves drive, SP-# = step pulleys - * of speeds. Y = yes. N = no. — = not applicable. •Setscrew secures faceplates and chucks.
9 american woodworker ▲ 1997 buyer's guide
Maieriale proieito da copyright
Finish faster. Random-orbit sanders work well for flat and contour sanding, and they leave a virtually scratch-free surface.
Random-Orbit Sanders l^Jothing beats random-orbit sanders for all types of flat sanding work. They're powerful and aggressive enough for heavy sanding, yet smooth enough for finish work—even on delicatc vcnccrcd surfaces. With their combination of rotary and orbital action, random-orbit sanders produce a scratch-free surface even sanding across the grain, so you can sand face frames after assembly. These sanders perform so smoothly that you may end up skipping some grits without sacrificing surface quality.
Random-orbit sanders come in electric or pneumatic (air-powered) models. The pneumatic sanders require a big (5-HP or larger) compressor to run. Both types arc sizxd according to the diameter of the abrasive disc they use. There are 31/2 -in., 41/2 -in., 5-in., 6-in. and 8-in. models.
OTypes of Sanders
These heavy-duty sanders are the most powerful among electric random-orbit sanders, but their offset motors make them the most prone to vibration. Two hands are needed to balance these tools, and a dust-collection hookup is a must.
Features to Consider
If you plan to do a lot of sanding on large, flat surfaces, consider purchasing a 6-in. sander—one that lakes 6-in.-dia. discs. For general-purpose sanding, 5-in. discs are the most convenient to use, and they are also the most commonly available.
Variable speed control allows you to slow down the sander for delicate work like buffing, polishing, or lighl sanding between finish coals. Variable speed control is also useful for sanding contours, edges and metal. Some models have a speed control dial separate from the irigger switch, so you can change speeds while you're sanding.
On this type of sander, the motor is positioned directly above the sanding pad, and there are usually two handles. The primary handle has a trigger-type switch.
These well-balanced units are designed so that you can use them with one or two hands. Beefier in-line models approach right-angle sanders in power; lightweight models can fall into the palm-grip league. Overall, their combination of power, balance and smooth operation makes in-line sanders the most versatile of the random-orbit sander types.
Air-powered sanders are usually more aggressive than electric models, and they tend to run more smoothly. They're also smaller and lighter, so they're easier to control and less tiring to use. Pneumatic sanders require a 5-HP or larger air compressor to run efficiently.
This type of sander is essentially an in-line sander without the handles. These compact models provide moderate power and excellent balance for light-duty use.
Options Worth Having
Replacement backing pads. For sanding contoured parts, you'll want to use a soft backing pad.
Abrasive and polishing pads. Use woven abrasive discs for sanding between coats of finish. Sponge pads are available tor polishing.
Adding a suction hood will increase your sander's dust-collection efficiency. For dust control during heavy-duty sanding, use a vacuum hose to connect your sander to a dust bag or shop vacuum.
For More Info
Check out the detailed test results in our "Buyer's Guide to Random-Orbit Sanders/' AW #39 (August 1994).
Pressure-Sensitive Adhesive (PSA) vs.
Some random-orbit sanders are designed to use pressure-sensitive, adhesive-backed (PSA-type) discs, while others take hook-and-loop discs. Though they're more expensive than the PSA variety, hook-and-loop discs can be removed and reused many times. Hook-and-loop discs also make it easy to switch grits.
Setting a spinning pad on your workpiece can create swirl marks or even gouge the surface. A brake keeps the pad from freewheeling too quickly.
Was this article helpful?