As featured recently on Toolmonger, the SawStop table saw features a safety system that starts by inducing an electrical signal onto the blade. If your fingers (or any other part of your body) come in contact with the blade, the signal changes and the blade retracts within milliseconds, leaving your fingers with only a scratch. SawStop currently offers only one product, the table saw, but they’re working on some other stuff. These two quick videos give a first look at future SawStop products.

Note to viewers: imagine that the hot dog is your favorite finger.

SawStop [Corporate Site]

There’s no doubting SawStop’s technology and its ability to keep your fingers attached to your hands — especially after watching the “hot dog demo” video — but a big question remains: would you shell out the cash to own one?  And if you did, are you pleased with the quality of the saw besides the brake?

We’ve seen lots of words about the SawStop — both good and bad — but we wanted to put it before our most trusted group: Toolmongers.  Have some experience with one — or opinions on the price/quality balance?  Let us know in comments.

We mentioned SawStop’s skin-sensing auto-stop table saws a while back, but we weren’t aware of the ongoing legal wranglings in the industry as a result of their product introduction until today.

According to this article in Design News:

Vindication arrived for Stephen Gass on the afternoon of June 28, 2006, when someone finally agreed with him. It had been nearly seven years since Gass invented his skin-sensing table saw, and in that time he’d begun to wonder if anyone would truly see the wisdom behind his device. Over the years, the responses he received from the power tool industry graduated from indifference to hostility. He’d gone from being a rejected outsider to a festering industry sore. And by 2006, Gass himself had considered quitting many times.

But on that June day, everything changed. Someone understood. Acting on a petition from Gass, engineers at the U.S. Consumer Product Safety Commission recommended that the government begin a “rulemaking process” that could result in mandatory safety standards for table saws. Days later, the agency’s commissioners shocked the power tool industry by concurring with the recommendation. They saw the wisdom in his petition. Suddenly, the ultimate outsider joined the game, and now he was holding a strong hand.

We were under the impression that high cost and lack of brand-recognition was limiting SawStop’s sales, and we wondered why other more notable manufacturers hadn’t licensed the technology.  Apparently liability concerns — and, of course, Gass’ request for an eight percent royalty on each mechanism — factor into the equation.

Now it seems each side is seeking federal legislation to require/not-require the safety technology on all applicable products.  Design News’ writers suggest that such regulation may mean little to SawStop in the short run, but could help to firmly polarize the industry toward developing or not developing the technology.

Personally, we’d like to see SawStop’s gear — or a similar, non-patented technology — made widely available.  Maybe our kids’ll grow up to believe shop teachers really do have 10 fingers.

“Man on a Mission” [Design News via Slashdot]

From Reader Comments: Michael, a cabinet maker, points out that he sometimes cuts wet wood on his saw, which would trigger the SawStop.  (And as the SawStop’s cartridge has to be replaced after each incident, that’d get expensive.)  He also sagely points out, “Nothing will compensate for lack of common sense on the part of the operator.”

When we first heard about the SawStop, we were doubtful.  A table saw that actually stops when you get a finger caught in the blade?  Impossible. 

Well, apparently not.  The SawStop induces an electrical signal onto its special blade and then monitors that signal for changes caused by contact with the human body.  SawStop says:

The human body has a relatively large inherent electrical capacitance and conductivity which cause the signal to drop when a person contacts the blade.  Wood has a relatively small inherent capacitance and conductivity and does not cause the signal to drop.

When the SawStop detects such a drop, it sends a surge of electricity through a fuse wire, which burns and releases a spring-driven block of aluminum (a “brake pawl”) into the teeth of the blade to stop it from spinning.  Simultaneously, the system shuts off power to the motor and the saw’s angular momentum causes the blade to retract below the table. 

The result: the blade stops in 3-5 milliseconds, turning what could have been a severed finger into just a nick.

The whole brake and fuse mechanism is contained in a cartridge which must be replaced  — along with the blade — after each “emergency stop.”  Pricing for the SawStop 10” cabinet saw is $2,799, and replacement cartridges run from $60 to $89.  Sure, that’s not cheap, but compare it to a trip to the ER and possibly lost fingers.

There’s a lot more information about this system on the SawStop website (including a cool video of them simulating finger contact with the spinning saw using a hot dog), and we’ll definitely bring you more on this subject soon.

The SawStop Table Saw [SawStop]