One of the biggest challenges of my plumbing and heating practice has nothing to do with pipe, water, or fittings. Instead, one of the most problematic–and recurring–issues is making the cuts required to install those things in all the materials we encounter in both new construction and service work. For example, for a new townhouse job we recently completed, the contractor asked us to cut combustion air grilles through 16 already-installed garage doors. (Why he asked is another story!) The doors were a sandwich of aluminum, foam, and cardboard. A recip saw would have destroyed the surrounding material, a jigsaw would have been very difficult to get finish-quality cuts with, and a circular saw wouldn't cut all materials properly or completely. A cut-out saw, however, with the right bit and a site-made jig, saved us precious time. The tool delivered finish-quality cuts quickly in flimsy materials and in an oddball location.
Because cut-out saws get us out of situations like this, we use them all the time. They're not designed as production tools, and I don't use them for hogging-out drywall or plaster to let a drain pipe through, but they're ideal for one-off jobs. Their bits and rpm are perfectly suited for working in a variety of modern materials–often composites of several different things–and their small size makes them a terrific choice for out-of-the-way cuts or working in tight spaces.
I tested four corded and two cordless cut-out saws. The corded tools are the Craftsman 26561, DeWalt DW660SK, Makita 3706, and RotoZip RZ20. The cordless tools are the RotoZip RZ18V-2100 and Ryobi P530.
For the first part of the test, I checked the contents of each tool's accompanying accessory package. Next, I looked at cutting power, feel, switches, line of sight, bit changes, ergonomics, and extra features. I evaluated these items with an eye toward overall ease of use in our everyday applications–which is an ever-changing mish-mash of cut-throughs and cut-outs that can be anything from cutting through tile for new shower valves or sink faucets to working in laminate countertops to plowing through siding or roofing materials for vents.
What You Get
There isn't a tool category I know of that ships with more accessories than cut-out saws. What you get depends on the manufacturer. While I most often use the tool in its basic configuration, I find that I use some of the accessories, like side handles and kit bags. Other items, like a flex shaft, don't really apply to my work.
Boxes and Bags. The DeWalt shipped with a hard plastic case; both RotoZips and the Craftsman came with a very nice, heavy-duty canvas bag with pockets and plenty of room for attachments and blades. I like the bags better because the boxes, though they work just fine, take up more space. The Makita and Ryobi did not ship with a toolbox or bag.
Attachments, Corded. The RotoZip and Craftsman each came with a removable side handle, a jigsaw-style handle attachment, a right-angle cutter head, and a circle cutter. The RotoZip also came with a separate bit case, three cutting wheels, three cutting bits, and a wrench. The Craftsman kit included two cutting wheels and four spiral bits, but also included a flex-shaft attachment and bit kit with various grinding and cut-off wheels. The DeWalt shipped with a circle cutter and a side handle. The Makita shipped bare-bones, with no attachments or blades, which is actually fine with me. My work requires that I mainly use the tool in its basic configuration. Besides, if I needed to grind something, I'd get my grinder.
Attachments, Cordless. The 18-volt Ryobi shipped with a circle cutter. The tool's battery and charger are sold separately, the idea being that you can swap batteries among various Ryobi tools if you're invested in that platform, and therefore don't have to buy a new battery every time you buy a new tool. This makes the tool very inexpensive. If you're not invested in the Ryobi battery platform, you have to buy the battery and charger separately.
The 18-volt RotoZip is sold as a kit with lots of accessories: the ZipMate right-angle cutter, two XBits, two ZipWheels, three collets, and the bag. It also ships with a battery and charger. It has a 30-minute charging system, and the tool accepts the new Bosch (RotoZip's parent company) 18-volt Bluecore nicad battery system.
Power & Performance
I field-tested the tools with my crew before taking them into the shop. Working in materials ranging from drywall and OSB to tile and metal roofing, we found the tools almost equally powerful and easy to use. They all worked well on site, and the odder the cut, the better they seemed to work. My guys really liked them for cutting holes for vent pipes in metal roofs–from inside the building. Using each tool with a multipurpose bit, they cut through the sheathing, tar paper, and metal roofing sandwich. We usually use a hole saw for this, but the cut-out saws out-performed them in this application, enabling us to get precise cuts in tough materials.
Another tricky cut we run into is replacing valves in shower enclosures. Often the stem on the new one is larger than the old one and we have to surgically widen the hole in the tile. Again, each saw enabled us in almost equal fashion to remove the tile we needed–and leave the tile that had to stay. Overall performance here showed that the tools in the group were nose-and-nose right out of the gate.
Power. To get a sense for side-by-side power and how cleanly each tool cut, I tested the tools in the shop cutting 3/4-inch-thick plastic laminate countertop with an MDF substrate using a multipurpose bit. The countertop was a chore for all the saws, and cutting went slowly. I was tempted to push the saws harder because all the motors had enough power, but you have to move slowly with a steady pressure with these tools to keep the bits from breaking. The power output among the tools was so close it was hard to notice any differences, even between corded and cordless models. If I had to pick, the corded RotoZip and Craftsman seemed to have slightly more power while the cordless Ryobi seemed to have slightly less. The rest, corded and cordless, were about even.
Following the Line. It's important to note that these saws cut best using a guide like a straight edge or template. Cutting freehand, it was somewhat difficult to keep the saws on the line. For hacking out sheathing to access something in the subfloor, that's no big deal, but for doing a sink cut-out or other countertop work, using the right guide helps ensure you get the cut you want.
Side Handles. The DeWalt, RotoZip, cordless RotoZip, and the Craftsman have detachable side handles, which gave me much greater control of the tools. The handle on both RotoZips and the Craftsman snapped on and off easily; however, I didn't like the corded RotoZip's or Craftsman's handle position. Each attaches to the right side of the saw with the cord coming out of the back of the tool. As a left-handed user, I found that the cord got in the way and that it was harder to see the cut. The RotoZip 18-volt has the same handle as the corded version, but because there is no cord to obstruct my view, using this saw was easier.
The DeWalt handle can be positioned on any side of the saw. The Ryobi and the Makita do not have provisions for side handles.
Close-Quarters Cutting. One of the great things about these slim tools is how close they can cut to things like a wall or backsplash–and the closer you can get, the better. The DeWalt, RotoZip, cordless RotoZip, Craftsman, and Ryobi all cut just under 1-1/2 inches away from an obstruction. Makita's slim design enabled it to cut within 1-1/4 inches of an obstruction–nice.
Noise. While I don't have decibel testing equipment, I sure could tell which tools ran the loudest and which purred. The corded RotoZip and Craftsman were extremely quiet. The DeWalt and RotoZip 18-volt were next, still comfortable to my ears. The Makita was getting noisy, and the Ryobi made me reach for the ear protection.