[This story was revised on 3/23/15. Information was added that was not available when the story was published]
Bosch just announced a 10-inch table saw that will compete with the portable model released this month by SawStop. The new Bosch REAXX (for “reacts”) GTS1041A uses flesh-sensing technology to trigger a mechanism that retracts the blade below the table if the operator makes contact with the blade while it is spinning. But unlike the saws from SawStop, it does nothing that could damage or destroy the blade.
The REAXX will make its public debut on March 20 at JLC LIVE in Providence, RI. I'll be there to see the new machine, though not for the first time. I witnessed a demonstration of the saw in February at a private event at The World of Concrete but a non-disclosure agreement prevented me from speaking about it until now. After showing off the tool’s features the folks from Bosch recreated the familiar hotdog test, but with a bratwurst instead—because no self-respecting German (or German tool company) would choose a hotdog over a bratwurst.
During the demonstration a Bosch product manager held a bratwurst on a board and slid it into the spinning blade; the moment the wurst touched the blade, a mechanism in the saw dropped it below the table. It happened so quickly the wurst came away with little more than a scratch.
To the observer, triggering the Bosch safety mechanism looks the same as triggering SawStop’s: flesh touches the spinning blade, there's a loud bang, and the blade suddenly “disappears”.
But what happens to the blade below the table is different for each saw. SawStop not only drops the blade, it rams an aluminum block into it to stop it from spinning. This destroys the $69 cartridge assembly containing the block and more often than not, it damages or destroys the blade.
The Bosch mechanism drops the blade below the table and allows it to spin to a stop on its own. The blade isn’t touched and can be used again after the saw is reset. Resetting is a matter of reversing or replacing the cartridge that fires to retract the blade, and then swinging the arbor assembly back to working position. According to Bosch, it takes about a minute to perform the operation. The cartridge is double-sided so it can be triggered twice before needing to be replaced (see video below).
The mechanism used by Bosch to swing the blade below the table is a variation on a design the Power Tool Institute (PTI) patented in 2009. Bosch, DeWalt, Makita, and several other tool manufacturers belong to this trade group, which has taken the lead in fighting SawStop’s efforts to convince the CPSC (Consumer Product Safety Commission) to require SawStop-like technology on table saws with blades 12 inches or less in diameter.
The most obvious difference between the Bosch and PTI design is the source of energy used to bring the blade below the table. The PTI design relies on the kind of charge used in powder-actuated fastening tools. Bosch relies on technology similar to what’s used to deploy air bags in cars. It is able to access to this technology because the company has a huge automotive division.
An important issue not addressed in the announcement by Bosch is what replacement cartridges will cost. Presumably, they will be less expensive per use than the cartridge and blade that must be replaced whenever a SawStop is activated. If it is not less expensive, Bosch loses a major selling point for its saw. [Author's note: Bosch has since announced cartridges will sell for approximately $99. Each cartridge is good for two firings so the cost "per incident" is about $50. This is less than the cost "per incident" with the SawStop, which includes the replacement of a $69 single-use cartridge and possibly the blade—should it be damaged or destroyed by the brake.]
That the Bosch can be reset faster than the SawStop only matters when the mechanism is activated by cutting overly wet lumber or by hitting a piece of metal. In the event of a near miss—a serious accident averted by the triggering of the safety mechanism—a tradesman with any sense will be too shaken up to go back to work right away. And he might also need to change his drawers.
In daily use, the only tipoff to the presence of the safety mechanism is the on/off switch, which contains color-coded LEDS that display the status of the system:
Green means the saw is ready for use
Yellow means the system is set in bypass mode by the operator; this mode is used for cutting conductive materials that could trigger the safety device.
Red means the saw is not ready and will not function until the user corrects an issue
Blue means the saw requires service
Up until now, I’ve talked about functionality that relates to protecting your body should it come into contact with the spinning blade. But during day-to-day use, the tradesman operating a saw is more focused on how well it works. I haven’t tested this saw so I can’t say for sure how well it functions. But it’s from Bosch, which is known for producing excellent portable table saws. I’ll be able to tell you more about the performance of this saw after we lay our hands on one and test it. The features and specs below should give you some sense of its capabilities.
Blade: 10-inch diameter
Motor: 15 amps; soft start
Max depth-of-cut at 90 degrees: 3 1/8 inch
Arbor: 5/8 inch
Weight: 78 pounds; 123 pounds (with stand)
Includes: blade, cartridge, wrenches, and a Gravity-Rise Stand
MSRP: $1,499 (US); $1,699 (Canada)
Available: fall 2015
The video below was produced by Bosch so it’s essentially an ad. I’m including it here because it shows the safety mechanism in action and what it takes to reset the saw. If you don’t feel like watching the entire thing, view the portion between 0:30 and 1:06.