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Skin Sensing Table Saw

samzenpus posted more than 8 years ago | from the watch-your-fingers dept.


killabrew writes "Check out this article from Design News about a new skin sensing table saw technology that is on the verge of becoming a mandatory piece of hardware on every table saw. For years inventor Stephen Gass persevered in the face of legal, corporate and technical foes, he is forcing society to rethink its acceptance of saw blade accidents."

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Whats the problem? (0)

Anonymous Coward | more than 8 years ago | (#15902404)

I want to order one.

Re:Whats the problem? (5, Insightful)

LiquidCoooled (634315) | more than 8 years ago | (#15902460)

There are benefits and there are drawbacks to this method.

It works really well for none conductive materials (uses skin capacitance to make a circuit, then when made retracts the blade), however if your cutting up things which trigger it randomly you will disable the feature (yes its not all the time).

Each time it is triggered the blade is ruined and needs replacing, better make sure the wood you are sawing isn't damp or you will either remove the safety feature (to save money) or get pissed off because you have to spend 10 minutes to change the blade every few planks.

It would be better to concentrate whilst working than making silly mistakes every day, may be good to replace machines with this and for those silly enough to trigger it more than once disable the feature and let them learn a valuable lesson.....

Re:Whats the problem? (2, Insightful)

Rob T Firefly (844560) | more than 8 years ago | (#15902491)

Good points, I can't begin to count the carpenters and hobbyists who have boneheadedly disabled safety features on things for the sake of speed, myself included.

This may have a brighter future in heavy industry and the assembly-line type of stuff, where the material going in is fairly standard and conductive things aren't normally involved, making more sense for the machine to crap itself when something finger-like does find its way in.

Re:Whats the problem? (2, Insightful)

jonored (862908) | more than 8 years ago | (#15902630)

In heavy industry you are more likely to see a safety feature like "both of your hands must be in the boxes and you must press both buttons to activate the machine that'd make you into paste". I'd be surprised if there were still many machines requiring manual work while running; they're less efficient and harder to make safe. And to boot, the two-switch system is much, much simpler and more robust. Much more likely to fail in the nonfunctional direction than fail in the squish someone sort of way.

Re:Whats the problem? (1)

James McGuigan (852772) | more than 8 years ago | (#15902605)

Its not about the 99.9% of the time when you are concentrating and not making a mistake, but those few minutes on that one bad day in a blue moon when you attention slips.

Re:Whats the problem? (1)

LiquidCoooled (634315) | more than 8 years ago | (#15902658)

And your attention will slip when you have been battling with this softer wood and 4 blade changeovers and then get really annoyed and disable "the god damned trigger happy pile of shite" before slicing off your finger at a neat mitred angle.

I know 100% that this will save digits. But the best thing for those which need saving is lessons and knowledge.
You wouldn't go deep sea diving with an ear infection so don't operate dangerous machinary when your mind isn't on the ball.

Re:Whats the problem? (1)

johnny cashed (590023) | more than 8 years ago | (#15902638)

Yes, I think that someone will make a better blade stopping mechanism which doesn't trash the blade every time and also require the purchase of a new blade stopper after every trip. That hypothetical saw will probably sell better. I imagine a brake on the saw arbor, but I also imagine a table saw blade quickly loosening on the arbor and continue spinning. Maybe they need to make a arbor brake, and use special blade with a splined hole so it has a positive grip on the arbor. Either way, it is about time that the table saw was made such that it doesn't cut off your finger.

I work with metalworking machines mostly, and on a Bridgeport type mill, there is a brake on the spindle that can stop it virtually instantly, even with the motor running. This isn't so much a safety feature, as is speeds up production, because you don't have to wait for the spindle to coast to a stop.

Re:Whats the problem? (Go here) (2, Informative)

Pontiac (135778) | more than 8 years ago | (#15902603)

No Problem.. Get your $3,000 ready and go here []

Dupe from 30-Jun-04 (2, Informative)

Anonymous Coward | more than 8 years ago | (#15902405) 0/131241 []

Which was probably duped again earlier.

Quick, go steal some +5 comments from that one!

"Saw III" (5, Funny)

krell (896769) | more than 8 years ago | (#15902413)

Something tells me the next one will be G rated.

Re:"Saw III" (4, Funny)

ahem (174666) | more than 8 years ago | (#15902506)

Is that "G rated" as in "rated G by the MPAA", or "grated" as in shredded up?

Re:"Saw III" (2, Funny)

Orangejesus (898961) | more than 8 years ago | (#15902700)

When he loses the hotdog and flips his dick out on the table I'll be impressed.

Interesting Technology (4, Insightful)

Kranfer (620510) | more than 8 years ago | (#15902415)

At first I was very wary of reading the article, thinking how could it possibly sense that? Then I watched the video... very very nifty it barely cut into the hotdog they used as a test. Now, I would think this technology would be VERY welcome in all industries where moving parts like saw blades, robotics etc are used... Why wouldn't they want to embrace safety technology like this?

Re:Interesting Technology (5, Funny)

metasecure (946666) | more than 8 years ago | (#15902432)

didn't RTFA, but what if your skin is not made of hotdog ?

Re:Interesting Technology (5, Funny)

TykeClone (668449) | more than 8 years ago | (#15902500)

Perhaps hotdogs are made of fingers?

Re:Interesting Technology (4, Funny)

Junta (36770) | more than 8 years ago | (#15902577)

It's people. Hot dog is made out of people. They're making our food out of people. Next thing they'll be breeding us like cattle for food. You've gotta tell them. You've gotta tell them!

Re:Interesting Technology (1)

bcat24 (914105) | more than 8 years ago | (#15902597)

I thought that was Wendy's chili.

Re:Interesting Technology (1)

TykeClone (668449) | more than 8 years ago | (#15902622)

Nope - hot dogs.

Just watch "Naked Gun" for video proof!

Re:Interesting Technology (2, Funny)

sammy baby (14909) | more than 8 years ago | (#15902571)

didn't RTFA, but what if your skin is not made of hotdog ?

Then I'd say it's probably safe for you to pet my dog.

Otherwise, however, I'd be very, very careful.

Re:Interesting Technology (0)

Anonymous Coward | more than 8 years ago | (#15902692)

And who puts their lips and/or asshole on a table saw anyway?

Re:Interesting Technology (3, Insightful)

Rebuke (994145) | more than 8 years ago | (#15902448)

Why wouldn't they want to embrace safety technology like this?

The most obvious reason is cost. If a company hasn't been hit by an accident in the past, then if (like a lot of companies) they're purely looking at their bottom line, why would they pay more for this saw than the one they've already got...

Re:Interesting Technology (5, Insightful)

UbuntuDupe (970646) | more than 8 years ago | (#15902557)

That's true, but it's not nearly as malicious as you make it sound. Employers have choices: they can pay to eliminate the hazard, and then have to pay less to get workers to take the less risky job, or they can not eliminate the hazard, and have to pay more to get people to take the more risky job. Economists call this a "compensating differential". It's seen in the difference in pay between regular window washers and high-rise window washers, for example. It can also be negative in jobs that people enjoy doing (i.e., they make less than those of comparable skill and experience because the job is fun, like astronauts).

There is always going to be some level of safety below which people will say, "forget it, it's not worth it, I'd rather just take the cash than make myself 1 in a million less likely to die". For example, would you take a 20% pay cut to halve your risk of death on the job?

Re:Interesting Technology (2, Insightful)

plague3106 (71849) | more than 8 years ago | (#15902628)

Or, option three, outsouce the job completely to a country that wouldn't even consider using a safer saw.

Although I think your first two are options as well, you forget that not only do employers pay higher cost, if someone does get injured, they pay for the medical expenses related to the injury, likely for the life of the employee.

Re:Interesting Technology (2, Interesting)

cluckshot (658931) | more than 8 years ago | (#15902607)

Having worked as RN in a large factory which had Lost Time Injuries approximately every 3 days.... and which could have saved a fortune if modest changes had been made, I have discussed this with management.

The motivation of the management who makes the decisions is one of control and temper. It really does make sense to make things safer. This factory could have saved about $100,000 a week had it improved safety. They just didn't want to do it. You see a worker was only paid about $50,000 a year and as such these people didn't cost management enough to be worth anything to them.

I watched the expensive management employees get protected while the workers got nothing. This was a tire factory. They made $1,350,000 a day even with this injury expense. It may be strange to some but actually the workers were too cheap to be worth anything. The loss of a life about every year or so was an acceptable cost to management. So what if you pay off the family with a damage claim of $500,000 or so. Blow it off. These people are worthless in the eyes of management...

Saving $5,200,000 a year simply didn't enter their mind as worth that much effort. I proposed that we use the medical data to extract which machines should be fixed. I offered to observe the machines and look at what was going on. They had no interest. One major loss to them was hearing losses. The addition of a few minor changes could have nearly silenced the factory. They couldn't care less. Another major loss was loss of hands and fingers and intermittently a person in a machine. Simple design changes in jobs would have improved production and saved lifes. They didn't care because it might "bother" their situation. It was an attitude that the "Free Trade" advocates refuse to recognize. Burried in the true motivations of many rich persons is a hatred of other social classes and a view that they are property not people. This is why they will not embrace safety technology.

Re:Interesting Technology (2, Insightful)

radarsat1 (786772) | more than 8 years ago | (#15902455)

Why wouldn't they want to embrace safety technology like this?

Same reason safety is an afterthought in many industries: expense. New technology is always a bit expensive. They need to make this cheap for it to be widely adopted. Otherwise it will only makes its way into the high-end equipment.

Hopefully they will be able to sell a critical mass quantity to bring the price down and make it available to every tool maker.

Re:Interesting Technology (5, Insightful)

M-G (44998) | more than 8 years ago | (#15902457)

Because safety technology sounds good, but frequently doesn't hold up to heavy use, rough handling, dirt, etc. on the job site. Then the safety device gets in the way of getting work done, and it gets bypassed. And for all of that, you get to pay more for the tool.

Re:Interesting Technology (4, Insightful)

shawn(at)fsu (447153) | more than 8 years ago | (#15902567)

Then the safety device gets in the way of getting work done, and it gets bypassed
or it gets by passed because people are lazy and management looks the other way. For example the meat slicer at a restaurant/deli. I heard horror stories from my friends that started part time jobs in HS before me about how dangerous the slicer was they'd show me the cuts and the missing tips of fingers that would end up in tonight's bread pudding. So when I got a job that required me to use the meat slicer I was very careful and I found that if you would just keep your hand on the grip and behind the "shield" you were ok. I never cut myself or came close to it. So my point is even if the safety device is simple and it doesn't get in the way of proper use people will still find ways to hurt themselves in efforts to expedite their tasks.

Re:Interesting Technology (0)

Anonymous Coward | more than 8 years ago | (#15902458)

Why wouldn't they want to embrace safety technology like this?

This trusted computing idea is very very nifty, it prevents unwanted and malicious software from running on your computer. Why wouldn't they want to embrace safety technology like this?

Re:Interesting Technology (1)

jonored (862908) | more than 8 years ago | (#15902515)

The reasons I'd see are cost, added complexity, and a reduced respect for the machine. These machines will very likely be more expensive, they are more complex than a standard saw and therefore more liable to failure (no, I won't cut that piece of material, it looks like skin...), and they won't neccessarily tear you to shreds, so you'll be less scared of them, and more likely to get sloppy about safety. Not overwhelming concerns, but concerns.

Re:Interesting Technology (1)

dr_dank (472072) | more than 8 years ago | (#15902582)

Why wouldn't they want to embrace safety technology like this?

I would think that it would remove a very painful consequence to carelessness around the machine shop. Unless a saw is defective by design, many of these kinds of accidents are caused by human error. If you rely on a safety mechanism to keep your fingers rather than dilligence and common sense, accidents could increase if bad habits developed by a reliance on these devices are applied to the older machinery in the shop or a faulty safety mechanism.

Re:Interesting Technology (1)

christopherfinke (608750) | more than 8 years ago | (#15902593)

t barely cut into the hotdog they used as a test.
But what if I want to use my tablesaw to cut through hotdogs (or body parts...)?

Conspiracy theory: (1)

DeadSea (69598) | more than 8 years ago | (#15902699)

This device was designed to kill the hotdog cutting business. All "safety" benefits of this product are masking the true intention.

Re:Interesting Technology (1)

plague3106 (71849) | more than 8 years ago | (#15902604)

Because it will be forced to be implemented in all American manufacturing companies, which will raise prices of American goods even more, and push yet more jobs off-shore where they won't implement these measures.

Just to make it clear, I'm all for making things safer where theres a way. I think 'fair trade' should include provisions to make products more expensive if they are made in countries that do not have similar safety and workers rights law. Unfortunately we'll likely have to end up giving everything we worked for in regards to workers rights and safe work places to continue to compete in the 'global marketplace.'

Re:Interesting Technology (1)

MattHawk (215818) | more than 8 years ago | (#15902646)

The article addresses that, but to sum it up - the power tool industry has no financial accountability for table saw accidents. There's a longstanding legal precedent for saw makers not being accountable for table saw accidents, on account of the fact that anyone who would use a saw should be well aware of how dangerous they are and should be taking their own precautions as a result.

The rather outrageous licensing fees (8%) the guy was wanting for every saw produced with the technology couldn't have helped, of course. There's also technical issues with cutting conducting materials with it (metal, or even wood that's too wet) triggering false positives.

I tried to buy one. (5, Interesting)

RonTheHurler (933160) | more than 8 years ago | (#15902701)

I saw this demonstrated once, on the Tonight show, with Johnny Carson (yes, I'm that old and yes, this thing's been around that long!)

So, when I finally had a reason to go buy a tablesaw for my business, and I saw the horrible cost of insurance, I tried to buy the auto-shut-off table saw. Of course, I searched the web. Then I called the big saw distribution importers and distributors. It took some effort, but I finally got an answer why they were not, and probably would never be available.

It's not a perfect product. It is still possible to get your fingers cut off, and it is possible to have it "jam" on plain old wood too. When it jams, you have to replace the blade and the whole blade jamming mechanism- it can take most of a day to do that, if you have the parts, and it's expensive. It can cost as much as a whole new table saw each time it goes off.

All those things are solveable, but I was also told that the insurance companies hate the thing. It sounds counter-intuitive, but you know that a table saw is dangerous. If you believe that it's less dangerous, then you might be more careless too. The car companies had a similar argument against seat belts back in the 1960s.

There are better solutions in industry. CNC automated machines are used where lots of similar parts need to be made. There are very few, if any, one-off parts in manufacturing environments. So the only real market for this machine is the hobbyist or general contractor and cabinet maker, and the professionals have really good stafety rules anyway (at least the ones where I worked did).

But, as it stands, nobody has a case if he tries to sue the manufacturer because he cut off his finger. But put an auto-brake on the saw, and every time it fails the manufacturer and insurance company have a dismemberment case to settle.


Use your table saw today! Get catapult and trebuchet kit plans at []

Good product (5, Informative)

dave-tx (684169) | more than 8 years ago | (#15902421)

Here [] is a writeup of the saw's debut at the International Woodworking Machinery & Furniture Supply Fair (2000). I remember reading this back in 2000 thinking "great idea, but I wonder if it'll ever get adopted". Glad to see it's gaining traction - the table saw is the only piece of equipment in my shop that I'm nervous around.

Now if they can solve kick-back, I'll be a tablesaw fiend.

Re:Good product (2, Informative)

johnny cashed (590023) | more than 8 years ago | (#15902519)

There was a large table saw comparison review in Fine Woodworking recently. His saw was one of the top rated. It is good that he has built an excellent saw (one that is excellent, even if it didn't have the safety features) that can compete with the best saws in the industry. His was also expensive, but I imagine that having fingers re-attached costs a lot more. The saw blade gets trashed when the safety fires, but again, a saw blade is cheap compared to a trip to the hospital.

As far as kickback, a saw with a splitter helps a lot to prevent it. I'm nervous around the table saw as well. I also like those with the sliding table, I believe that that also makes a table saw safer.

Re:Good product (1)

johnny cashed (590023) | more than 8 years ago | (#15902672)

By splitter I mean a riving knife. Wikipedia calls it a splitter. I couldn't remember the name.

Re:Good product (3, Informative)

Anonymous Coward | more than 8 years ago | (#15902555)

They have solved the kickback problem. First, this saw uses a riving knife at the back of the blade. That is, it has a rather sturdy curved blade that stays fixed behind the rotating blade. The riving knife goes up and down with the blade and helps keep the wood from touching the back of the spinning blade, which is the root cause of kickback. Another think you can already do to reduce kickback is to ensure that you fence is exactly parallel to the spinning blade. In the alternative, you can have the back of the fence a few thousandths of an inch further out from the blade than the front. This keeps the wood from getting pinched between the fence and the back of the spinning blade.

For those that are curious (I can't get the article to come up, perhaps the server is melting) the SawStop works by sensing a change in the electical resistance in the blade when it touches flesh. (Since wood is, generally, of low moisture content, it will not set off the mechanism.) When the flesh is sensed, a heavy spring launches a sacrificial aluminum block into the blade and another spring retracts the entire mechanism. The aluminum block and your $50 to $120 blade must be replaced.


Re:Good product (1)

MikeB0Lton (962403) | more than 8 years ago | (#15902565)

"Now if they can solve kick-back, I'll be a tablesaw fiend."

Kick-back has been solved, in the form of that safety gear that comes with the saw. Use the riving knife and anti-kickback fingers on your blade guard!

The usual sources of kick-back are from the blade being dull/gummed up and/or the wood binding against the blade (keep it straight). Also try ripping with the wood going at a slight downward angle to the surface.

Solution... (1)

Khyber (864651) | more than 8 years ago | (#15902677)

Now if they can solve kick-back...

Keep your blades sharp and don't allow that cut measure to sit angled on the table, causing blade binding when you use it as a cutting guide.

Re:Good product (1)

MattHawk (215818) | more than 8 years ago | (#15902702)

>Now if they can solve kick-back, I'll be a tablesaw fiend. Hmm... optical sensors to track sudden acceleration of the workpiece across the table? I wonder if an optical mouse sensor could track fast enough - could make for a fairly easy hack. Of course, detecting the kick-back and stopping it are somewhat different matters - stopping the saw blade with a brake is probably easier then stopping the far less restrained workpiece. Stopping the blade still might reduce the severity of the kickback by giving the workpiece less time to accelerate before the blade stops feeding energy into it, though.

Oh, the humanity! (5, Funny)

Anonymous Coward | more than 8 years ago | (#15902429)

> For years inventor Stephen Gass persevered in the face of legal,
> corporate and technical foes, he is forcing society to rethink
> its acceptance of saw blade accidents."

Proof of why this technology is needed: the above sentence was horribly, tragically mangled in a comma splicing accident.

Saw this a few years ago (0)

Anonymous Coward | more than 8 years ago | (#15902433)

I saw this on TV a few years ago. It was amazing. He was using hotdogs as test subjects. He would have a hotdog on a piece of wood and be cutting the piece of wood, and evertyime there was even the slightest touch of the hotdog to the blade the whole thing would shutdown. It was pretty amazing.

Re:Saw this a few years ago, safe for hotdogs (1)

Sesticulus (544932) | more than 8 years ago | (#15902636)

I saw a similar review on one of the various wood craft magazines I subscribe to.

All we really know is that it's safe for hotdogs!

Transfering the momentum (2, Funny)

suso (153703) | more than 8 years ago | (#15902439)

Bret: "I only got a scratch from the blade, but I broke my foot when the whole table saw flipped over."

Geez... (1)

Sailor_Kashyyk (995187) | more than 8 years ago | (#15902442)

At first, I thought it would be a table saw that can sense our skins. That caused me to imagine what would happen to me in the wrong way with the table saw. That's a bad headline for the story.

weiners (0)

gEvil (beta) (945888) | more than 8 years ago | (#15902444)

Is this the one where the demo shows the weiner about to get lopped off?

Re:weiners (1)

tka (548076) | more than 8 years ago | (#15902467)

I guess it is but as you know, the site is down so I couldn't check it either. Tagged as oldnews.

Re:weiners (1)

winnabago (949419) | more than 8 years ago | (#15902651)

I'm not sure why this is news either. I recommended my company to put one in their wood shop last fall because we occasionally have high school kids in there as interns. Anyway, for $2800, it can be purchased direct [] . I'd rather replace 100 blades a year than have one table saw accident, but that's my risk manager opinion.

Whooops... (2, Funny)

Mad_Rain (674268) | more than 8 years ago | (#15902450)

It looks like it couldn't stop the slashdot buzzsaw - it cut straight through their server.

Re:Whooops... (1)

JoeBar (546577) | more than 8 years ago | (#15902533)


Re:Whooops... (1)

Reverend528 (585549) | more than 8 years ago | (#15902678)

Suddenly forcing readers to view a 300K ad before the article doesn't seem like such a good idea.

Foam-rubber coating the world (1)

Frumious Wombat (845680) | more than 8 years ago | (#15902456)

This is one place I certainly approve of it. Hopefully this will also be added to devices such as bandsaws, routers, circular saws, etc. I enjoy woodworking/construction when I do it, but I tend to try to find ways to get the same type of cuts with hand-tools, so that I don't have to handle powertools. This is a really great step forward.

Who do you sue... (1, Interesting)

Anonymous Coward | more than 8 years ago | (#15902459)

five or ten years later when the wiring for the mechanism fails and little Johnny Jr. cuts off his finger? Because you know it will come to that.

And if it is so great and reliable, why are they using hot dogs and not this guys hand?

Finally, they never show wet wood. We have to cut wet lumber sometimes. Does that make any difference with this mechanism?

Re:Who do you sue... (1)

raygundan (16760) | more than 8 years ago | (#15902481)

I would think the leading failure point would be the ultra-fragile fuse wire that keeps the whole thing from jamming a huge metal block directly into the blade to stop it dead.

You're more likely to wake up and find that you need a new sawblade, fuse, and blade-stopping assembly than you are to have it fail in some sort of finger-mangling way.

Re:Who do you sue... (1)

vortigern00 (443602) | more than 8 years ago | (#15902543)

That's the problem. My guess is that the sensor works about 99% of the time. Meaning it gives false positives often enough to render the saw utterly useless.

Moral: Buy a real saw today, because tomorrow the government will be outlawing the ones that actually work.

testing with hands (2, Insightful)

raygundan (16760) | more than 8 years ago | (#15902495)

As amazing as this thing is, and as remarkably fast as it stops the blade-- it's not going to eliminate injury. It will turn a finger loss into a nasty cut, though. And that, I suspect, is why the sales staff isn't karate-chopping the rotating blade during demos. The hotdog is always cut, just not cut in half.

Dunno about wet wood.

Re:Who do you sue... (1)

cecille (583022) | more than 8 years ago | (#15902561)

And if it is so great and reliable, why are they using hot dogs and not this guys hand?

If you look at the movie, you'll see that there is a little cut on the hot dog. It stops the saw from cutting right through, but I'm sure the guy doesn't want to sit there taking small chunks off of his hand every 30 mins.

they never show wet wood. We have to cut wet lumber sometimes. Does that make any difference with this mechanism?

Probably not - the article states that the mechanism looks for specific changes in the conductivity pattern - it is doubtful that wet lumber would cause those changes. Besides, skin is salty, not just wet. Water on its own really isn't terribly conductive in comparison.

Re:Who do you sue... (0)

Anonymous Coward | more than 8 years ago | (#15902568)

No, the blade uses capacitance to sense flesh. So you can't cut wet lumber, metal, etc.

The price tag puts a nice damper on the predicted wide spread adoption, as well. The author of the blurb is more than a bit misleading.

Re:Who do you sue... (1)

daranz (914716) | more than 8 years ago | (#15902588)

And if it is so great and reliable, why are they using hot dogs and not this guys hand?
For the same reasons for which you don't use humans in car crashtests. All the safety features put in today's cars decrease the probability of the passengers/drivers sustaining heavy injuries in case of an accident, but they do not guarantee that you'll survive driving your car into a concrete wall at 80MPH. In fact, even though such safety features are present, you are still supposed to drive safely and be careful, and they're there for emergency situations.

Same thing with the saw. You're not supposed to try to saw off your hand (unless some homicidal manaiac actually devised a complicated plan to get you to saw it off, but that's besides the point). The safety features are there in case you make a mistake, and they decrease the chances of you sustaining an injury in such a situation.

End of an era. (4, Funny)

Rob T Firefly (844560) | more than 8 years ago | (#15902464)

Gone are the days of charming high school wood-shop teachers who hold up two hands' worth of fingers when counting off their five years' teaching experience. What's next, forcing them to shave their woodsman's beards and stop wearing flannel?

Hey! (1)

RingDev (879105) | more than 8 years ago | (#15902516)

One of my tech teachers in high school only had 9 fingers you insensitive clod!

And scary enough, I'm not kidding (about the fingers)


Re:Hey! (1)

Rob T Firefly (844560) | more than 8 years ago | (#15902526)

I moved around high schools a lot, and each one had a tech/shop teacher with at least a small bit of a finger missing. I wondered if it was a traditional thing, like in the Yakuza.

Re:Hey! (1)

Scaba (183684) | more than 8 years ago | (#15902618)

Umm, I think that was the essence of the OP's joke - the woodshop teacher has too few fingers to count to five on one hand.

Re:End of an era. (1)

nizo (81281) | more than 8 years ago | (#15902694)

Even worse, how else are the shop teachers going to keep the lil' barbarians in line if they can't threaten to saw off body parts???

But what if I want to cut meat on my table saw? (3, Funny)

Anonymous Coward | more than 8 years ago | (#15902465)

But what if I'm trying to cut meat on my table saw? I guess I'll be stuck with the band saw and the wood chipper...

How does it work??? (1)

Abreu (173023) | more than 8 years ago | (#15902474)

I cant read TFA, probably slashdotted already...

Does it stop spinning once it tastes human blood?

Does it stop spinning once it encounters less resistance?

And what about slasher films? Are Jason, Freddie et al, going to have to look for vintage saws for their work?

I dont get it, please somebody explain

Change in Electrical Conductivity and Capacitance (1)

HighOrbit (631451) | more than 8 years ago | (#15902619)

Flesh has certain properties of electrical conductivity and capacitance different from wood. When the metal saw touches flesh, it senses the change in conductivity and sends a stop signal.

Re:How does it work??? (2, Informative)

jellomizer (103300) | more than 8 years ago | (#15902648)

Well our bodies give off an electical charge (which is very close to a hotdog) and the blade being metal. So when it hits our skin a low level electic charge is shot across the blade into a chip that determins if it is the same electical change as a human hand. If it is then it fires a stopping pin that breaks the saw very fast, and allowing it to only scratch the finger, mind you it will be a deep scratch, and will hurt like hell but it will heal in time and with a banage you can continue with work that day.
As for the slasher movies, I am sure they can just take out the breaking pin, and they will be all set. Heck it allows for 1 more minute of the movie to expand it plot.

Manditory? (0)

Anonymous Coward | more than 8 years ago | (#15902482)

So the free market didn't work, and now he's pushing the mommy-state on people?
If you're stupid enough to run a table saw in a dangerous manner, you deserive to get hurt.

always two sides to every story (5, Informative)

Anonymous Coward | more than 8 years ago | (#15902485)

As someone who was involved in evaluating this technology for a major US manufacturer of power tools, there are a number of issues which prevented early adoption. First and foremost was the inventor's demands for unreasonable royalties (including a percentage of the gross sales of table saws from preceding years!). I heard the director of the power tools group say that if the royalty had been reduced by 50%, it would have been a no-brainer. As it was, the proposed royalty structure was just unsupportable for a saw that sold for $500.

The second issue was that the product had great difficulty distinguishing the change in capacitance due to human flesh from that due to very wet lumber. This has undoubtedly been improved over the past few years, but people would have been somewhat unhappy to have false triggers that required them to a) replace the safety cartridge and b) their saw blade, which is consumed when the system triggers. Not to mention having the bejeesus scared out them when the system fires in error.

To talk about the inventor persevering in the face of corporate pressure is silly. This isn't a David vs. Goliath story. The inventor was a patent attorney that tried to bludgeon power tool companies with a 250+ page patent, and he could have sold his concept on day one if he hadn't been quite as greedy. There was no shortage of companies looking for competitive advantage in the power tool industry, which has been pretty stagnant of late.

This has been around for years (5, Insightful)

Pontiac (135778) | more than 8 years ago | (#15902488)

This guy has been trying to force his invertion on us for years..

After the saw manufactures refused to pay his unreasonable licensing free (3-8% of the saw sale price)for his patented tchnology he moved on to lobbying for a law to make it mandetory (and still pay his licensing fee)

I have to agree the idea is cool but I don't like having it forced down my throat.
He did go on to start his own saw company and makes one of the best saws on the market...

Re:Link to web site (2, Informative)

Pontiac (135778) | more than 8 years ago | (#15902540)

I forgot the link to the SawStop site []

Re:This has been around for years (3, Informative)

jsupreston (626100) | more than 8 years ago | (#15902657)

Not only that, but if for some reason the device acidentally trips, you're out a whole lot of cash replacing the blade, brake shoe and no telling what else. For someone who can afford a $2000 cabinet saw, this may not be that large of an expense, but for the average person doing this as a hobby, we tend to pinch every penny. Heck, I've been doing this as a hobby going on 10 years, and I can't justify to SWMBO why I need a dado stack for my saw. If I had to buy a new saw with this technology, I'd have to give it up, given the cost of the saw and repairs. Plus, a little common sense would almost reduce the need for this completely. Use a push stick when ripping narrow stock. Use feather boards where appropriate. Use a miter sled when cross cutting. If possible, leave the blade guard on (not previous saw was safer without the guard due to a crappy splitter on the guard). If you have to, paint a red line in front of the blade on the saw table showing where the blade is. Paint a perpendicular one showing where the throat plate starts. Don't stand in front of the blade if you don't have to. And, if you don't think it is safe to do the operation, then DON'T DO IT. And yes, before I am asked, I've not followed all the rules myself. I did get a very bad scare about 3 years ago. I was cross cutting something, and felt a really strange vibration on the tip of a finger. I looked, and somehow I had gotten the tip of a finger past the teeth on the blade, and my fingertip was resting on the side of the blade while spinning. Fortunately for me, I was not injured, and since then I have tried my best to make sure that I never have that situation again. I have found a great resource for all sorts of shop info, including safety. has several forums. The forum was created for owners of the Ryobi BT3x00 saws, but anyone is welcome. I have gotten lots of advice and inspiration from there. We all pretty much agree that the idea behind the sawstop is a good idea, but not that practical given its cost. Like I mentioned earlier, most of us would have to give up our hobby if we had to buy one.

Practical joke (1, Funny)

Anonymous Coward | more than 8 years ago | (#15902494)

This would make a great practical joke to play on a cannibal who uses his table saw to slice up his victim.

Yes! (3, Funny)

Geminii (954348) | more than 8 years ago | (#15902513)

Finally, I can saw naked!

No big deal. (4, Insightful)

WhatAmIDoingHere (742870) | more than 8 years ago | (#15902517)

Professional carpenters will just find a way of disabling this, like the blade guards on circular saws and the 'safety' on nailguns.

Honestly, you're not a carpenter unless you have a few battle scars to show off.

Re:No big deal. (0)

Anonymous Coward | more than 8 years ago | (#15902655)

or without one or two fingers... :)

I wanted to give it too thumbs up... (2, Funny)

B11 (894359) | more than 8 years ago | (#15902532)

but alas the technology wasn't around in my 9th grade shop class.

Bad Idea (0)

Anonymous Coward | more than 8 years ago | (#15902534)

If this thing gets installed on all table saws, where are we going to get our shop teachers from?

Hah! Take that Darwin! (1)

VendettaMF (629699) | more than 8 years ago | (#15902538)

Hah! Take that Darwin!

Just wait till representatives of the next generation of woodworkers accidentally trigger an older table... It'll be full slasher movie material. "Who could have expected this cursed antique would have such a thirst for blood? Who will it get next?"

Or, more seriously... "Accidents happen. Walk (hop) it off. If you foam cover the entire world then no-one will ever learn to cope with 'reality'" (Where reality is a dead chip in the machine for replacing dead chips).

NPR Covered This in 2004 (1, Flamebait)

HighOrbit (631451) | more than 8 years ago | (#15902549)

Here is the link from NPR Story in 2004 []

The interesting thing is that the power tool industry refused the technology because it was too safe. They were afraid anybody without the technology would get sued for unsafe products, so they they collectively embargoed the technology.

From the NPR write up:
Industry sources say the major manufacturers also worry that adding the safety brake to some table saw models but not others would make them vulnerable to lawsuits.

Soon will come a day (1)

lardbottom (537885) | more than 8 years ago | (#15902556)

Pretty soon, they'll take all the danger out of life. I wonder if they'll finally come out with that new foam-rubber hybrid? Or maybe it'll be illegal to own a real knife (we'll only be allowed plastic wear like on the plane - to go with our unwashed hair and unbrushed teeth). Well - here we go, FIGHT natural selection! Go go go.

I've got no problem with this except... (4, Insightful)

awing0 (545366) | more than 8 years ago | (#15902559)

The fact that this may be mandatory bothers me. It's like seatbelt laws, lawnmowers that stop running when you get off the seat, and coffee cups with warnings. I'd say, let the market sort this one out. Yes it's cruel, but feel free to give me a Nelson "ha ha" when I run my hand through a chop saw.

Table Saw Safety (4, Insightful)

clintp (5169) | more than 8 years ago | (#15902572)

I *have* had a finger get chewed through by a table saw.

I was cutting a piece of wood that was way too small for a table saw to cut safely and it got my index finger. An avulsion laceration about 1/8" wide, right across the fleshy pad of the finger, down but not quite to the bone.

My fault, I know. I didn't sue anyone, and wouldn't have thought to even if it took my hand. [For a cut that small and precise, I should have walked out to the workshop and used a band saw or built a jig. But I was lazy...]

This is a great idea, but like another poster said it has to be cheap, and it has to be non-obtrusive. The safety of the device is a trade off against its utility. If the saw stops working because of a faulty safety switch, the safety switch will get removed. If it's expensive to replace, it will probably not be replaced.

For example, my table saw has a kick-guard that goes over and behind the blade. It's an incredible pain in the ass because gets in the way, it's hard to see around, and makes some cuts damned-near impossible. It was removed.

Make it cheap and make it reliable, and then it'll actually save some fingers.

Just call me Butterfingers! (3, Funny)

frogstar_robot (926792) | more than 8 years ago | (#15902579)

Boy! Is my face red?!?

This has been around for years (5, Informative)

RembrandtX (240864) | more than 8 years ago | (#15902617)

Its been around for years, and has been shopped to the major power tool manufacturs [one of the largest, I used to work for, so i'm not talking out of my butt here.]

All of them turned it down due to legal implications, as well as adding to the cost per unit price.

Leagally, if a power tool manufacturer added this to their existing line of table saws, it *COULD* be taken as an admission of guilt that their previous models were not safe, any accident cases (no matter how stupid) would then have another chance at a successful suit.

Also, the inventor has been lobbying for *YEARS* to get his invention as a required component of table saws. He hasn't even had success in California - the most liberal state for passing stuff like this - let alone elsewhere.

I'm not knocking his invention, I've seen it pitched first hand .. the guy whipped a raw hot dog at the blade as fast as he could, and there was only maybe 1-2mm of damage to the hotdog before the blade dropped down into the brakes.

Destroying the blade of course. which .. at $50+ a pop .. kinda hurts.

Another reason this hasn't been adopted yet is that pressure treated wood also tends to cause the brakes to fire off ..

Re:This has been around for years (1)

dbmasters (796248) | more than 8 years ago | (#15902633)

"eagally, if a power tool manufacturer added this to their existing line of table saws, it *COULD* be taken as an admission of guilt that their previous models were not safe, any accident cases (no matter how stupid) would then have another chance at a successful suit." Isn't that what they said about seat belts in cars once too?

Re:This has been around for years (1)

RembrandtX (240864) | more than 8 years ago | (#15902676)

its also the same reason most airplanes still use engines that require leaded fuel.

SawStops and Hot Dogs.... (1)

Almonday (564768) | more than 8 years ago | (#15902631)

So is this more or less the same as a SawStop? I admit that their video documenting an attempt to saw a hot dog in half [] is pretty cool, although each use of the safety feature requires a new 40.00 cartridge. Worth a finger, sure, but I wonder how easily they're set off.

Please think of the Drafters! (0)

Anonymous Coward | more than 8 years ago | (#15902637)

Will someone PLEASE think of those draft dodgers, using table saw accidents to get out of Military service. Someone please think how "A Prayer for Owen Meaney" Would be without unsafe table saws.

Another example of patent BS (1)

duffbeer703 (177751) | more than 8 years ago | (#15902642)

There are two problems with this invention:

  - The inventor wants to extort 8% of the price of each saw
  - This opens the door for all sorts of product liability lawsuits

Its interesting that this idea gets universal acclaim, while software inventions covered by patent are almost universally reviled. The reason that you're hearing about this at all is that the inventory is a savvy patent attorney who is going to eventually use government regulation as a club to make a huge amount of money.

The product liability thing is a real issue as well -- you'll probably see some tools drastically increase in price, include onerous safety devices or disappear from the shelf entirely once the lawsuits start flooding in. Anyone who has purchased a gasoline can for their lawn mower in the last 2-5 years has seen this first hand... some anti-spill devices make it nearly impossible to pour gasoline, and cost double the price of their predessesors.

I'm not arguing in favor of making tools more dangerous. But the current system of torts and injury liability discourage safety innovation by sticking product manufacturers with the potential of massive costs.

This has been out for *years*. (4, Informative)

Chirs (87576) | more than 8 years ago | (#15902652)

For the non-woodworkers in the audience, this tech has been available for several years, and information on it was available for at least a year before the saw itself.

The "Sawstop" modifies the electrical potential of the blade, and can thus detect when skin hits the blade. Of course it also triggers if you cut metal, so it has a disable switch. Apparently wet wood doesn't trigger it.

When it detects flesh, it has an explosive charge that rams a chunk of aluminum into the blade stopping it within ~3ms. I saw it demoed in person at a wood show. The demonstrator slid a hot dog into the blade at a fair speed and there was a large bang. The hot dog had been cut into maybe 1/32" or so (a bit under a millimetre).

The main problem is that the inventor wanted huge royalties from existing tool companies, and tried to force through legislation making it mandatory to include the device on *all* table saws in the US. As you can imagine, people were less than impressed about having it rammed down their throats. Even now, the saw that incorporates this is a very nice saw, but they still charge about 30% more than for other comparable saws.

Wow, but needs work. (1)

goodmanj (234846) | more than 8 years ago | (#15902666)

Fantastic tech, but needs some improvement. It uses a fusible wire to activate the blade brake, which must apparently be replaced when it gets a "false positive" (which is apparently common when cutting wet wood). If this is to be adopted on a consumer scale, it needs an easily-resettable safety system, more like a circuit breaker than a fuse. Depending on the scope of his patent claim, there may be room for a number of competing improved safety mechanisms based on his idea, which could solve some of the problems with government's mandating use of an exclusive patented product.

Out of curiosity, can the government use an "eminent domain" style procedure to take control of a patent or force it into the public domain, in the interest of public safety or national security?

It's about time (0)

Anonymous Coward | more than 8 years ago | (#15902675)

This guy has a great product that will generate a lot of income. I don't understand why it's taken so long to get to market. But then what do I know? Maybe improving the safety of one's product is not a selling point.

Try it first ! (1)

Momo_CCCP (757200) | more than 8 years ago | (#15902684)

I want to see that guy try his own invention first. And no the hot dog is not convincing enough.
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