Source: TOOLS OF THE TRADE Magazine
Publication date: August 13, 2012

By Michael Springer

Compatibility

The accessories for these tools represent six separate mounting types: Bosch/Makita, Fein MultiMaster, Fein SuperCut, Porter-Cable, Ridgid/Rockwell, and a new type of Ridgid mount that was introduced after I finished testing. Many OMTs include or can be equipped with adapters that allow them to use blades that don't match their mounts.

Adapters work best on tools with bolt-on accessories, because if there's any slop in the fit (as there sometimes is with adapters) you can make up for it by overtightening the bolt. You end up with a friction-fit, which is how accessories were attached in the days when the interface was a simple hole through the blade. Adapters will work with tool-less blade clamps, but there's no way to compensate for a questionable fit between tool and adapter or blade and adapter.

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Among the more common uses for an OMT on the job site are cutting trim in place (above), removing grout (below left), and cutting drywall (below right) and plaster. Other uses include sanding, scraping, and cutting metal.

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Accessories can be bolted onto the end of the spindle (below left) or attached by means of a tool-free blade clamp. Fein's clamp relies on a removable holding pin (below right), which installs through the accessory and is held in place by a spring-loaded lever. On the Bosch MX30E, blades are installed over a split post that spreads wider and pulls down against the blade as the locking lever is engaged (bottom). Bosch's older model (MX25E) still makes use of a bolt.
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Ergonomics

An OMT may be operated in multiple positions or for extended periods of time, so for the sake of comfort it's best to have smooth, contoured surfaces and rubber overmolding at the grip areas — including at the nose of the tool, which is frequently grasped during two-handed use.

Most of the tools have acceptably smooth surfaces for a variety of grips. The Bosch stands out for having the largest amount of useful rubber surfaces. The Porter-Cable tools are smooth enough, but the blade clamp lever gets in the way when you grip near the front.

Every OMT tested has variable speed. In most cases, there is an on/off switch near the center of the tool and a speed-control dial near the back. The location of the speed control hardly matters, though, because these tools are typically run at top speed. Ridgid's tool is the only model with a variable-speed trigger. This may have value for intermittent operation with some of the tool's other accessory heads, but the inability to lock the tool on is a negative when sanding or cutting for long periods of time.

The Ridgid and the cordless models from Makita and Porter-Cable have LED headlights that come on with the motor. They might provide usable light if you are cutting inside a cabinet. But if you're working on a reflective material like tile, they can produce glare that makes it hard to see.

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The accessories for the tools in this test are of five separate mount types. From left: Bosch/Makita, Fein MultiMaster, Fein SuperCut, Porter-Cable, and Ridgid/Rockwell

Cases

Cases are important because they protect the OMT and keep your accessories with it. Most OMTs come with hard plastic cases; a few come with soft fabric bags. A bag takes up less space, but I prefer a case because it offers more protection and you can stow the tool without removing the blade. If you do that with a bag, the blade might chew through the bag or cord during transport.

Most of the kits come with a small plastic storage box for blades and accessories. The box stores in the tool bag or case. Porter-Cable's corded model does not require a box because there's a blade storage area built into the case. The Ridgid and corded MultiMaster kits have no blade storage — though there is room for a box in the MultiMaster's duffel. Ridgid's case is too small to store much more than the tool and a few loose accessories.

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Every manufacturer except Fein offers some kind of an adapter for mounting different brands of blades on the machine. For more on blade compatibility, go to toolsofthetrade.net/chart.

Corded or Cordless?

I was surprised by how powerful the cordless tools are in comparison to corded models from the same manufacturer. If it weren't for the batteries' added weight and limited runtime, it would have been hard to tell the two types of tools apart. Of the cordless tools tested, the SuperCut cut the fastest. The MultiMaster came in second, closely followed by the Makita. The Porter-Cable lagged far behind.

I tested runtime by putting 60-grit paper on the tools, lightly sanding particle board, and timing how long it took to deplete the batteries. The Makita sanded for 43 minutes, both Feins for 33 minutes, and the Porter-Cable for 26 minutes. By way of comparison, I performed the same test with a leading 12-volt Max OMT, and it sanded for only eight minutes.

Despite the strong performance of most of these tools, I doubt many tradesmen would gain much by going cordless. Rechargeable batteries work best when they get regular workouts, and few would get that when paired with an OMT. If the tool sits for a period of time, the batteries may be low when you go to use it. This would be less of a problem for people who buy a cordless OMT that takes the same batteries as their other cordless tools. They'd be using the batteries often enough to always have charged ones on hand.

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Manufacturers offer a variety of cases. From left: Bosch L-Boxx, Fein case, Fein duffel, Makita duffel, Ridgid bag, Porter-Cable duffel, and Porter-Cable case. Bosch also offers a blow-molded case and a duffel.

PriceWise

OMTs vary widely in price, so before you buy, it pays to think about how often you'll really use the tool. The tradesmen I know who have an OMT say that they're glad to have it in the truck for those jobs that no other tool will do, but that they might use it only a dozen times per year.

When buying an OMT you should factor in the cost of consumables. Purchased separately, an assortment of five or six quality blades will set you back more than $100. Look for a kit that includes a decent variety of the blades and attachments you want to use. Don't be fooled by the numbers — I've seen 100-piece kits where 80 of those pieces were sandpaper.

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Most kits include a separate accessory storage box similar to the one in this Bosch case.

Bottom Line

If I were in the market for a corded OMT, I would buy the Bosch or the Fein MultiMaster; they're powerful and have quick tool-free blade-changing. The MultiMaster offers the advantage of being able to fit a variety of accessory brands, and the Bosch has a blade clamp that always locks tight the first time and won't snap shut on your fingers. Take your pick.

The Fein SuperCut is a top-quality tool with power to spare. It would be at the top of my list if I did the kind of work (removing sealants from exterior concrete wall panels or commercial glazing) where I used the tool hard every day. But it's too expensive for intermittent use and doesn't do anything that can't be done with the MultiMaster or Bosch.

Both the Makita and the Rockwell are solid second-tier tools that did everything asked of them — but the Makita did it better. The Porter-Cable and Ridgid tools felt like a compromise and trailed behind the other models.

Given how infrequently most tradespeople use OMTs, I would not recommend buying a cordless model unless you're already on the Makita battery platform — in which case you could get Makita's tool and be assured of having charged batteries around.

Michael Springer is the former executive editor of Tools of the Trade.