The 9903 is claimed to be the quietest in its class, a mere 85 decibels. That’s comparable to a car engine or hair dryer. It’s unusual for a power tool (especially a commercial/professional model) to be designed for quiet function. Nonetheless, it is a nice perk.
Weight is important for belt sanders. The heavier it is, the less the user has to press down while using it. The 9903 comes in at 9.5 pounds. This is heavy enough to be really helpful in the horizontal position, and heavy enough to prohibit any extended use in the vertical or upside down position.
Another unusual feature about this Makita tool is the 16’ cord. It’s really convenient, though, to not have to find an extension cord for every situation. This is an unexpectedly helpful design feature.
The 9903 has a perfectly flat topside of the motor. This is a very useful feature in belt sanders that is entirely too uncommon.
The 9903 uses an auto-track feature to keep the belt centered. This means no adjustment is necessary to keep the belt on track.
The 9903 comes with a cloth dust collection bag. The bag can hold a few ounces of sawdust.
The 9903, like many commercial grade belt sanders, has a variable speed motor.
The Makita 9903 has a very traditional, boxy belt sander design. Like most handheld belt sanders, the 9903 is operated by a trigger grip for the right hand. The pistol grip design combines easy use with a comfortable, ergonomic resting position for long periods of use. It also has a standard forward grip for the other hand. However, the 9903’s forward grip is basically a narrow nub on the front end. It could stand to be about twice as wide for maximum comfort. The user could rest his hand flat on the top of the sander if need be.
The 9903 has Makita’s most powerful belt sander motor. It’s 8.8 amps rests solidly toward the upper end of the range of belt sander motors. Some models get all the way up to 10 or 12 amps, but the majority of models runs around 5 or 6 amps. The additional power helps push the 9903 over into the commercial quality tool category. The 8.8 amp motor can power the belt up to 1,440 square feet per minute. Again, that is close to maximum performance from a handheld sander.
With the speed control, the user can set the sander on the work piece at a slow setting, then gently work up to maximum speed. This is an absolute must-have for any halfway serious user of a belt sander. Without variable speed control, it is extremely difficult to introduce the sander to a workpiece without gouging the surface.
The variable speed is also useful for softer materials, like drywall joint compound or balsa wood. In these cases, the slower speeds must be used simply to avoid burning the material up or sanding all the way through
When a belt sander’s top is flat, the tool can be flipped upside down, blocked in, and used as a stationary belt sander. Such a setup allows the user to bring work pieces to the tool, granting much finer control over the sanding project. This is most useful for fine woodworking, machining small parts, or sharpening blades.
Block the sander in for safety when using it upside down. Set the top surface of the motor upside down against a work bench. Then tack a 2×4 frame around the motor to hold the tool still while it is running. Screw the frame into a workbench below for increased safety.
The 9903 has a flush sanding feature (see below). In addition to its intended use, the rounded nose of some belt sanders is usable as a contour or curve sander. This means the sander can be used to gouge out a curve in a flat wood surface. The 9903 is marginally usable as a contour sander. While the lip of the sander is far enough back from the nose of the belt to use for flush sanding, it’s still pretty close.
Like most commercial grade belt sanders, the Makita 9903 uses a 3”x21” belt. The increased length adds a little extra sanding surface area, but the three inch width makes it easier to get in small spaces. Sometimes that additional inch of a four inch belt really seems to get in the way. The 9903 doesn’t have the largest belt available, but it’s a good middle-of-the-road size.
When the belt moves off center, the workpiece usually ends up gouged and the belt is burned up quickly. It’s important to keep it straight. Auto-track systems sound great, but many times are less reliable than manually adjusted systems. Don’t be over-trusting, check the belt’s position regularly, and the auto-track system works just fine.
Makita includes a 90 grit sanding belt with all 9903 purchases.
Sanders are one of the messiest power tools out there. When in use, a heavy dust is continuously generated and generally spews all over. To solve that problem, most belt sander manufacturers worth their salt have added either a dust collection bag or a dust collection vacuum port. One drawback of cloth dust collection bags is that if a fine material is being sanded (light woods like pine or fine grained materials like plaster) the dust will often pass right through the pores of the cloth bag.
The 9903’s bag is connected to the motor via a port that is just the right size for most shop vacuum hoses to fit over it. When a port is actually intended for vacuum hookup, the hose usually fits inside the port. It doesn’t seem like Makita meant for the port to be used with a vacuum, but it fits and it’s handy.
While the Makita 9903 has an unimpressively standard design, the tool really brings some unique features to the table. It combines a high-end motor with very quiet performance.
It’s clear that Makita thought outside the box with this line of belt sanders. The end result is a powerful tool that keeps up Makita’s growing good name.