If I had to compile a short list of “my least favorite things to do in the woodshop,” then sanding would certainly be somewhere up near the top of the list, along with searching for lost tools and cleaning out the shop vacuum. Let’s face it, sanding wood surfaces smooth is usually a tedious, dusty business. Luckily, there are modern machines like the oscillating spindle sander to help make sanding less of a chore.
If you’re not familiar with this simple yet ingenious machine, an oscillating spindle sander (OSS) has an abrasive-sleeve-fitted rubber drum on a metal spindle sticking up through a metal table. As the motorized spindle and drum rotates, a mechanism oscillates it up and down repeatedly. The oscillation distributes the sanding load onto a greater area of the drum and thus reduces performance-robbing heat and clogging of the abrasive. Better still, the motion reduces sanding scratches, for a smoother final surface on the workpiece.
In the woodshop, an oscillating spindle sander is the perfect tool for sanding curved edges, especially concave edges on parts like shapely legs, rocking chair rockers or the arching frame of a bed headboard. An OSS can tackle convex or straight edges and narrow faces on smaller parts as well. You can also sand a curved slot or other open shape cut in the middle of a workpiece, as long as you can slip it over the end of the sanding drum.
A decade ago, most OSS units were full-sized, freestanding machines. But unless you plan to do some pretty heavy sanding day in and day out, it’s more practical and affordable to buy a benchtop OSS model. These portable machines are easy to set up and use when needed, then stow out of the way when sanding is done. To find out which of the current crop of benchtop machines are best for small shops, I tested five models with a thrifty-woodworker-approved street price under $500: The Craftsman #21500, Delta SA350K, General International 15-220M1, RIDGID EB4424 and Triton TC450SPS. I wanted to include the JET JBOS-5 (a tool which looks extremely similar to the General 15-220M1), but the company was not able to supply a test unit in time for this review. Also, I asked Grizzly to send their model G0538 to be included in the test, but they chose not to participate in the review.
Commonalities and Differences
All five sanders are compact machines with either cast-iron or cast alloy tables and plastic or sheet metal bases. Two models, the General and RIDGID, have tilting tables that allow you to sand beveled edges; the other three have fixed tables. Four of the five employ a capacitor start induction motor, the kind used in stationary power tools; only the Triton uses a universal motor, the kind found in portable power tools. Each machine has its own unique oscillating gear mechanism.
All OSS models feature interchangeable sanding drums of various diameters, for sanding concave curved areas of various radii. Selecting the largest diameter sanding drum that fits the radius of the workpiece makes it easier to sand curves smoothly. The five benchtop models come with drums/sanding sleeves ranging from 1/2" (5/16" for the General) to 2" or 3" in diameter. The RIDGID also comes with an oscillating belt sander assembly that interchanges with the sanding drums. All six models have on-board storage for the sanding drums, table inserts (these fill the space between the table and various diameter sanding drums), wrenches and accessories.
Testing 1, 2, 3…
I spent a considerable amount of time putting each of the five benchtop OSS models through its paces, sanding miles of serpentine edges in both hard and soft woods. I also sanded curved beveled edges with both models that feature tilting tables. I wanted to evaluate how easy the unit was to use and how much effort it took to change sanding drums. Naturally, I wanted to see how the machines compared in their sanding performance, both how strongly their motors ran during heavy sanding and how smoothly power was delivered via their oscillating mechanisms. I was also curious to see if machines with longer spindle strokes and/or faster oscillations per minute sanded more aggressively or not. Finally, I considered other features, such as each model’s weight and portability, as well as the effectiveness of its built-in dust control.
Which One’s Best?
So there you have it, five very different benchtop oscillating spindle sanders, each with its own particular blend of construction, features and performance. Curiously, unlike other power tool categories I’ve reviewed (belt sanders, cordless drills, etc.), one thing that really struck me about these sanders was just how truly different most models were from each other. While the Craftsman and Delta share the most family resemblance, the General, RIDGID and Triton are very different beasts indeed. The fact that all five models worked relatively well inspired me to go ahead and make suggestions about each one: If you have the need for a really heavy-duty machine and your shop space and wallet are ample, I have no reservations about recommending the sturdily constructed General 15-220M1. If, on the other hand, your sanding needs (and budget) are small, the affordable Triton TC450SPS will likely serve you well. And if a versatile benchtop sanding center is at the top of your wish list, the RIDGID EB4424’s dual-duty oscillating spindle and belt setups offer a lot of bang for the buck.
But which model gets my vote as the “Best Bet?” While the Craftsman 21500 offers an attractive machine for the money, I have to give the nod to the Delta SA350K. Its slightly larger motor, good dust collection and beefier oscillating mechanism that delivers smoother sanding performance, all at a moderate price, make it a great overall choice.