You can start a pretty good argument on a job site simply by asking which is better: a fixed-head miter saw or a slider. Most builders have strong opinions one way or the other, but not me. I appreciate a slider's impressive crosscut capacity when I need it. But if I don't have to install oversized crown or extra-tall baseboards, I prefer a less cumbersome, fixed-head machine. My holy grail is a saw that combines the best features of both. And when I found out about the Bosch 12-inch Dual-Bevel Glide Miter Saw, I thought it just might be that tool.
No Rails, Easy Setup
Essentially, the new saw (model GCM12SD) is a slider. But instead of ungainly rails protruding from the back, the tool has a pair of sealed, heavy-duty hinges - mounted perpendicular to one another in a "T" configuration - that open and close as the saw head is drawn out or in. This "axial glide system," as Bosch calls it, is supposed to be better than a standard set of rails at resisting sag and side-to-side play, especially during bevel cutting. The lack of rails also makes it possible to set the tool up against a wall. Compared with some of the larger sliders on the market, the glide saw can save up to 12 inches of work space, Bosch says.
Before plugging in a new saw I always verify that the blade is square to the table and fence, and that the fence is square to the table. I check miter and bevel angles for accuracy and adjust the scale pointers until they're on the money. This exam didn't take long with the Bosch because the machine was perfectly set up right out of the box. Future tweaking should be a snap, thanks to the easily accessed adjustment screws and the easy-to-understand owner's manual.
Performance
Using the 60T blade that came with the saw, I cut a wide range of material and achieved uniformly excellent results. When I upgraded to a superior blade (a 96T Bosch PRO1296VFB), I noted slight improvements in smoothness and accuracy. For paint-grade work, the standard blade was more than adequate.
I found that the miter saw - as advertised - was capable of 14-inch crosscuts and 93/4-inch miters (at 45 degrees). It can also accommodate 61/2-inch material standing on edge, which makes it particularly well-suited for baseboard work. If, like me, you prefer to chop cut without gliding the saw head in and out, you'll appreciate that the hinges can be locked in the fully retracted position.
If I had to choose one word to describe how this saw moves, I'd pick the same one Bosch did: "glide." The hinged supports operated precisely and the pull-push action was very smooth. Even when coated in sawdust, the hinges never hung up or limited the tool's range of motion. Most of the controls are convenient and easy to operate. There's enough clearance beneath the miter lock knob to prevent knuckle-scraping, and the up-front bevel lock eliminates the need to reach around the machine to change the bevel setting. The plastic levers that lock the sliding fences and extension wings are also easy to manipulate.
I had some problems with the trigger lock. Depressing this thumb-operated safety switch so that the trigger would engage required an awkward grip and excessive effort. Suspecting a manufacturing defect, I requested a replacement handle, which proved easier to operate. I also found that the original trigger lock loosened up and functioned more smoothly after it had been used a lot. Nevertheless, I couldn't shake the feeling that the switching mechanisms on other Bosch miter saws I've used were more user-friendly. If you have an opportunity to try the saw out in the store before buying it, I'd recommend that you do so.
Size matters. Even though this 12-inch miter saw is less bulky than a traditional slider, it's no ballerina. At the zero miter setting, it's 33 inches deep, so if you were hoping to be able to set it up in a narrow hallway, forget about it. Despite the other advantages, swapping hinges for rails doesn't appear to offer much in the way of weight savings - the saw weighs 65 pounds and lugging it around a job site can get pretty tiring.
Dust collection. I tested the saw attached to a vacuum and to the standard dust bag. The dust bag worked as you might expect - poorly, especially when cutting at high bevels on the side opposite the bag's position. In these situations, a lot of dust simply dropped back out of the chute before reaching the sack. With the vacuum attachment, I found dust pickup to be reasonably effective when I was cutting 2-by material. However, it dropped off noticeably when I was cutting significantly thinner or thicker material. Although I didn't test the saw as part of a permanent shop installation, its no-rail design might make it a good candidate for use with a shroud attached to a dust collector.
Features
The dual-hinge innovation is impressive, but I was glad to see that Bosch didn't try to reinvent everything with this saw. Several features that have proven their worth on earlier Bosch models appear largely unchanged on this one.
The fence system is first-rate: The two sides are each a substantial 4 1/4 inches high and about a foot long. They checked perfectly flat and in plane with one another, and they reposition easily for bevel cutting. The saw base is a respectable 27 inches wide, with two pull-out extensions that add about 8 inches on each side for additional support.
Like most high-end miter saws, this one's equipped with a variety of detents for common miter and bevel settings and an indispensable override lever that makes it easy to select angles immediately adjacent to any of the miter detents. A bevel angle detent pin that engages at precisely 33.9 degrees makes it easy to cut 38-degree spring angle crown on the flat. But retracting the pin can be a hassle.
An adjustable depth stop limits the saw head's downward travel, allowing the tool to cut rabbets and dadoes. A table saw with a stacked a dado head will cut them faster - but if you don't mind making multiple, single-blade passes, the GCM12SD will get the job done. Unfortunately the depth stop on the tool I tested had about 1/16 inch of play, which was enough to throw off the cutting depth if I varied the pressure I applied to the saw handle. Also, because the saw blade does not retract behind the fence, I had to put a 3-inch spacer between the material and the fence to plow a flat-bottomed dado all the way across 1-by stock (2-by stock needed a 3 1/4-inch spacer).
Replacing blades on this saw is a cinch. I like to change blades fairly often, either to send them out for sharpening or to match a blade's tooth count and cost with the material I'm cutting. The lower blade guard on the Bosch pivots up and remains out of the way, freeing both hands to change the blade.
Thumbs Up
The GCM12SD may be the most innovative miter saw since the first slider arrived on the scene more than two decades ago. It's well-machined and solidly built and features an impressive cutting capacity in a relatively small package. When it comes to buying a versatile miter saw with all the benefits you want - and few of the drawbacks you don't - this may be as close as you'll get. For now.
Andy Beasley is a veteran woodworker in Colorado Springs, Colo.
GCM12SD Specs
Blade: 12 inches, 1-inch arbor
No-load speed: 3,800 rpm
Cutting width, 90 / 45 degrees: 14 / 9 3/4 inches
Cutting height: 6 1/2 inches
Miter cuts: 0 to 52 degrees L; 0 to 60 degrees R
Miter stops: 0, 15, 22.5, 31.6, 45 degrees L and R, 60 degrees R
Bevel cuts: 0 to 48 degrees L and R
Bevel stops: 0, 33.9, 45 degrees L and R
Weight: 65 pounds
Street price: $825 (list: $1,498)
Bosch 877/267-2499 boschtools.com
