Update on Bosch’s New Finger-Saving Portable Saw
Last Wednesday, Bosch announced that it had developed a flesh-sensing tablesaw meant to prevent the finger-amputation injuries that are so common among carpenters and woodworkers. Although the saw won’t be available until the fall, I got a chance to see a preproduction model at the Northeast JLC Live trade show on Friday. Like SawStop’s line of saws, Bosch’s REAXX ($1500 list) uses the principal of capacitance to trigger the finger-saving technology. What’s different is that the REAXX doesn’t attempt to stop the blade, but instead forces it below the saw table within milliseconds after the safety device is triggered. It uses a small piston-shaped cartridge with an explosive charge much like those in automotive airbags to force the saw below the table. Each cartridge can be used twice. Replacement cartridges cost $99.
The new saw is based on the popular Bosch 4100 model and shares many of the same components, including the table, the fence, and the universal motor. Unlike the 4100, which has the motor’s transmission connected directly to the saw arbor, the REAXX has a belt drive connecting the blade arbor to the saw’s motor. According to product manager Craig Wilson, the belt drive, which is necessary because of the safety system, is similar to the setup used on modern miter saws and requires no maintenance. Bosch declined to give me a specific date when the saw would go on sale (the company wouldn’t even commit to early or late fall), but I’ve already requested a saw for testing as soon as they’re available. To see a video of the Bosch REAXX’s safety system being demonstrated, click here.
Bosch product manager Craig Wilson uses a hot dog to demonstrate the Bosch REAXX tablesaw's safety system. Like SawStop's finger-saving saws, the Bosch uses the principal of capacitance to trigger an explosive cartridge (like those used in automotive airbags) to force the spinning blade below the table. Unlike SawStop's system, the blade is not damaged by the activation.
When the hot dog hits the blade, there is a loud bang, and the blade immediately disappears below the table. There was only a small nick on the hot dog when it was passed around following the demonstration.
When the safety system is triggered, it locks the blade below the table until you reset it. After swapping the spent cartridge for an unfired cartridge, free the locked trunnion by pulling up on the saw arbor with the blade wrench while holding a small button in front of the blade.
To return the saw to operation, remove the guard and throat plate to access the explosive cartridge, which is mounted in a red plastic cylinder behind the blade. Each disposable cartridge has a pair of charges mounted side by side. If one side is triggered, you can switch it to the other side. Once both sides are spent, you need to replace the $99 cartridge.