The saw is embedded with a safety system that detects when someone accidentally contacts the spinning saw blade, and then stops the blade in milliseconds. The system induces an electrical signal onto the blade and then monitors that signal for changes. Where wood has a small inherent electrical capacitance and conductivity, the human body has a relativity large inherent capacitance and conductivity which cause the signal to drop when a person contacts the blade. If two successive blade teeth touch a finger, for example, the detection system sees dips in the electrical signal and knows a person has touched the blade. An extremely fast-acting brake stops the blade when contact is detected by pushing a block of aluminum (a brake pawl), held in place by a heavy-duty spring, into the teeth of the blade to stop it spinning. When contact is detected a surge of electricity is sent through the fuse wire, which holds the heavy-duty spring in compression. At the same time, the angular momentum of the blade causes it to retract below the table an the power to the motor is shut off.

Damn remarkable. There were over 60,000 wood saw accidents last year...that should speak volumes for the need of this innovative technology.

Alaska18

Fierock

P.S. lmao@AlanIn4D ... try a knife! :)

Terp4Life

bigtimes

Damn replicants.

Dave!

Nkgneto

heyyou

BizarroBallmer

Darkest Daze

"Hey honeyyyy we need a table saw"

CEOself

vintagemxr

AlanIn4D

fastm3driver

vertigo

Bring in some wood from outside, and break your table saw for no good reason.

That said, this is thing is great.

photophile

MrSmoofy

Fierock

Since no manufactureres would get onboard with the technology. Sawstop folks started lobbying congress, and soon the technology will be mandated.

It's the American way.

Slack

urban_ninjya

A fence and all that stuff? What?!?!?!? What happens when I want to rip a piece of 4x8 plywood down the middle? All that stuff is just in the way then ;-)

Mainly, the kickbacks I have had is: table saws, which as you point out are pretty preventable, skilsaws (we always called them that even though they weren't "SkilSaw") with the obligatory shim to keep the guard outta the way :-|, and drills. And a damn drill came closest to f-in me really really good.

Done right, skilsaws and drill could prolly benefit from some kickback tech.

hypereric

Ultraorange

jmonty

Now all we need is a stupidity cutoff for preventing injury from hand tools =D

Xenobiologista

It doesn't ruin the saw, but it does ruin the saw blade.

There is a metal "stop block" that gets shoved into the teeth of the blade. The saw blade gets imbedded into the block. So you are out the cost of a new block (which I seem to remember costing ~$40) and a new blade. (which can cost some serious $$$)

Still, it's cheaper than a new saw or surgery.

Bender

I suppose you could throw some technological innovation to stop a kickback after the fact, but a riving knife prevents it from happening in the first place. Its like taking a sledge hammer to a penny nail. Yea, it works, but why bother.

BTW, you said "every time I have had a kickback"

I don't want to see a brotha take one in the gut. Check that fence alignment and be safe ;)

SgtBeavis

10 years, eh? I personally know a couple of fingers that could have benefited (not mine). I'll bet there are lots of other useful safety applications.

huygir

SrsRevo17

s017jrs

IMO it isn't responsible to expect and inanimate object to "respect" you. That saw will never respect you, no matter how much technology you throw at it. However if you fail to respect it, it WILL kill you.

SgtBeavis

kadtech

Gizmo

mrsalty

BigDanInTX

After an overly long three-minute cat-and-mouse chase, she managed to catch him in the back with a large double edged birch-handled axe that was conveniently left on a wood chopping block. Unsurprisingly, it only made him more angry as he knocked her upside the head with a sap-covered pine log. He had been going to someone for the past few months trying to get over his irrational fear and anger towards women, especially of the lithe female variety, but he thinks to himself that this only proves his fears were justified and it has just set him back at least another $2500 and two months of therapy.

He throws her stunned, but still conscious body onto the the table saw's rapidly whirring saw blade in a gruesome(and really rather over-the-top and dramatic) splitting of poor Brenda's pretty little forehead. Imagine his surprise when rather than hearing the familiar and comforting high pitched squeal of steel on bone like an oversized dentist's drill, the only sound heard was a loud thunk as the blade stopped suddenly and retracted back into the housing and subsequently with the motor grinding quickly to a halt.

Jason stares quizzically at the saw, wondering if the electricity had gone out at such an inopportune time for him but conversely, a serendipitous moment for Brenda. He then spots a small warning label on the bottom edge of the machine.

"This table saw is equipped with SawStop, preventing serious injury and loss of limb by stopping the machine when a person is in contact with the blade."

Jason thought about this for a moment, trying to grasp the implication of the warning. He looks again and spots another yet smaller warning label stuck a few inches below the previous one.

"Should not be used to bifurcate camp counselors.""

impliedsurprise

FlashSandbox

ysirotin

They need to get the dude from Saw I-III to endorse this stuff.

Or Lorena Bobbitt.

bunny_rabid

leetgeek

I've always wondered about preventing kickback, having my share of wallops from it. Couldn't you simply have a device that measures the amp pull from the saw's motor switch if off (and possibly a brake) if it jumped dramatically in a few milliseconds? Obviously, there would need to be leeway for knots. A knob for the type of wood could be responsible for choosing anything from balsa (hehehe) to ironwood, or if you are ripping sheet metal.

Seems like every time I have had a kickback, the saw first started to slow and "bind" (for lack of a better term) followed by amps surging and spinning the blade harder, which then whacks me across the head :-)

hypereric

I would totally love something like this for my chainsaw.

wanago

qhead7

watersketch

While you might think otherwise, the main cause of injury on a table saw is not cutting off digits. The primary hazard is kickback, which actually kills people. Kickback occurs when the woodstock binds against the sawblade while cutting. This causes the saw blade to "kick" the woodstock "back" at the user. A riving knife goes a LONG WAY in preventing that.

The SawStop mechanism itself is a work of genius IMO. However it isn't going to save the lives that riving knife will. That mechanism is the one that all saw manufacturers should adopt. The stopping of a blade to prevent lost fingers is something that is easily replaced by someone that actually respects the tool they work with. I started working with tablesaws when I was five years old and I've never even gotten a knick on my fingers because I respect my tools and the dangers they can possess. However kickback can occur to anyone no matter how skilled or careful.

SgtBeavis

Needs to come out with a retrofit kit then. And while we're at it, add a kickback detector so no broken bones or concussions. And only make porter-cable and milli-waukay kits. "Overseas" power tool owners get what they deserve (except, perhaps, makita owners).

And to those of you that scoff at someone losing a finger or whatnot; much like there are only two types of motorcyclers --- 'those that have fallen, and those that will' --- there are only two types of regular power tool users. Those missing a digit (or at least a very nasty scar), and those that will be joining them soon enough.

hypereric

Actually, I think they are afraid to get sued. And if you are wondering why all shops don't have these, its because they cost about double that of a good delta saw (which will probably last longer anyway). We have six of these at my school, and to be completely honest they aren't that great of saws for the exorbitant amount of money that you pay. Sure, they may keep an idiot from cutting their finger off, but if you don't act like an idiot in the first place, there is no problem.

spenc938

Litigation stopping innovation.. ain't it wonderful

zero_o

Eugene

Given the amount of idiots that buy power tools without reading the manual I'd say this thing will save quite a few fingers.

scoobydoo

dmenafro

Colonel35

ctthoqqua

Marshall