Article on Skin sensing table saw

[Alan Anderson]

Originally Posted by sanddrag

No invention should ever replace simple diligence when it comes to using power tools.

But I don't think that argument should be used to naysay a safety feature. If a power tool can be made more benign when simple diligence is trumped by accidental circumstance, I consider it a good thing.

The point of inventions like this is to make systems more fail-safe. That means they're more safe when existing practices fail -- which they obviously do.

[Richard Wallace]

Originally Posted by Alan Anderson

I know first-hand that a simple capacitive detector is discriminating enough by itself to tell the difference between flesh and damp plywood, ...

First-hand? I hope you still have both hands intact!

This reminds me of a classic lampoon book titled Fixit And Be Damned by Lawrence Lariar (Prentice-Hall, 1955). It contains numerous how-not-to cartoons, including one showing a guy who has just severed his hands while using a table saw. Above the saw there is a sign reading "Hands Off!"

I found the SawStop claim of "52 saves" interesting. Apparently, SawStop customers report incidents in which they were saved from injury. Other table saw users just report the injuries.

[Mark McLeod]

Originally Posted by Richard

Apparently, SawStop customers report incidents in which they were saved from injury. Other table saw users just report the injuries.

SawStop has a built in measure since the satisfied customers have to order a replacement for each incident. The customers without hands probably have trouble placing any orders and can't be counted.

[Alan Anderson]

Originally Posted by Richard

First-hand? I hope you still have both hands intact!

I built a touch-sensing light switch about thirty years ago, using a 60 Hz probe signal (instead of the much more sensitive high-frequency signal employed by SawStop). My sisters and I had fun trying to see just what would trigger it. Keys, coins, and coat hangers did. Wet wood did not. Pencil lead was hit or miss.

[KenWittlief]

I had a TV set with a touch sensor channel selector.

Every once in a while a fly would walk across the buttons, and change the channels. I guess the fly didn't like my choice in programming.

As hard as it may be to accept, it is not possible to design power tools and powerful equipment that nobody can get hurt on (by accident). How many injuries per year are acceptable? Zero if you are the person who lost body parts.

But the reality of our lives is that we control powerful machines everyday, for some people its all day long. If you take a zero-accident approach then everything has to be very expensive, time consuming to use, with double redundant safety features. ( the ultimate system would be fully automated, you have a stack of boards and the machine saws them for you, with no human intervention - you stand outside the perimeter guards and push the start button).

Even then, if you stop a person from sawing off his fingers they may very well step in front of a bus an hour later, choke on a hot dog, fall down the stairs, get struck by lightning, or hit by a marble size meteorite (or all of the above at the same time )

I know there is a balance to be struck. To me it seems more reasonable to find ways to keep fingers away from saw blades, than to design saw blade/finger contact systems that jam blocks of aluminum into spinning blades.

We have to accept that emergency rooms will not be put out of business anytime in our foreseeable future. We should do everything reasonable to keep people safe from harm

but everything about this system looks wrong to me. Esp the fact that it is being mandated by lawyers and elected officials, not by people who work in the industry to ensure worker safety.

[sanddrag]

Darn "You must spread some Reputation around before giving it to KenWittlief again."

Anyway, well said Ken.

[Alan Anderson]

Originally Posted by KenWittlief

...but everything about this system looks wrong to me. Esp the fact that it is being mandated by lawyers and elected officials, not by people who work in the industry to ensure worker safety.

I'm not sure whether the problem is with the small font size in the article or what, but you don't seem to have comprehended what it says.

Originally Posted by Charles J. Murray, Senior Technical Editor -- Design News

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.

[Richard Wallace]

Originally Posted by KenWittlief

... We have to accept that emergency rooms will not be put out of business anytime in our foreseeable future. We should do everything reasonable to keep people safe from harm

but everything about this system looks wrong to me. Esp the fact that it is being mandated by lawyers and elected officials, not by people who work in the industry to ensure worker safety.

Hard to argue with this. The inventor/petitioner is a lawyer, albeit one with a Ph.D. in Physics. I don't know if the CPSC people are elected, but they're certainly public servants -- and some of them are engineers, as Alan pointed out above..

My reservation about those opposing the petition is that parts of their argument, that safety features are expensive, inconvenient and imperfect, can be used generically against almost any safety feature.

Market forces might eventually impel adoption of safety features. Is that our standard for doing "everything reasonable to keep people safe from harm"? If so then our public servants should simply make rules requiring 'economic' safety; i.e., make us safe enough to avoid spending more on post-accident treatment than we would on pre-accident prevention. By this standard, the issue raised by the petitioners amounts to asking who should pay. Clearly the cost of treatment is paid by those who are injured or by all of us in the form of taxes, insurance premiums, etc. And if the regulations don't change, the cost of prevention will remain optional.

[joshsmithers]

Originally Posted by Alan Anderson

But I don't think that argument should be used to naysay a safety feature. If a power tool can be made more benign when simple diligence is trumped by accidental circumstance, I consider it a good thing.

The point of inventions like this is to make systems more fail-safe. That means they're more safe when existing practices fail -- which they obviously do.

i can relate to this because i have personal experience with the said table saw. my school's shop has one and i was in the cabinet making 1 class last year. our teacher was not the least bit less concerned when we used the saw stop. usual precautions were always taken not matter what.

still, i gotta say that i somehow felt safer while using the sawstop. that quick "stop and drop" feature was like an angel over my fingers. most of the other students in my class prefered it over the old table saw we had, too. though we didn't need it, the technology and safety was more relaxing condition to work under.

[Andrew Rudolph]

We have one of these saws here at ULL, I was talking to the guy incharge of the shop today about it. He really likes it, esp since its more powerful than the last saw. He also said that sometimes the thing would trip if you put a metal ruler into the blade, no big deal though since its not spinning the aluminum wouldn't bond into the blade. He says its overall a really well made saw even barring the stopsaw part, he said it rarely ever kicks and whatever other things master cabinet makers like about saws.

He did say however he was having issues with certain blades not having the correct diamter so you have to be pickey with your choice, and as he said to us today,"if i can save you finger for the $70 it costs for the new cartrige i will pay it out of my pocket" for anyone having unexperienced (and overworked/undersleeped design students) using a table saw its the way to go.

[DonRotolo]

I agree with some posters, that the issue here is whether to make such a device mandatory or not. I, for one, hate mandatory things (most of the time).

This is much like chain brakes that were developed for chain saws. In many models they are required, and in fcat they are a darned good thing to have. Certain high-end professional saws are exempted, but the people using them are usually quite experienced.

Would I retrofit this device onto my table saw? Probably not. Is it worth the money? Absolutely.

The bottom line is taht if it costs $25 million per year and saves just a single damned finger, it's worth it. Especially if that's MY finger there.

But, give me the choice.

Don

[Mike Schroeder]

Originally Posted by Ben Piecuch

So, is the extra money and the time delay worth a finger? That's up to you. Would I recommend a product like this in every school system that has a woodshop? You better believe it! A trained woodworker should have the experience and the know-how to protect himself. Unfortunately, I can't say that about most students, or even myself.

BEN

Ben as a college job i work at Home Depot, i worked in the Lumber Department, until..... anyone who has seen my left arm knows what comes after the until...
Let me tell you something, I will honestly admit, I made a mistake, i wasn't paying attention, and i put my arm in front of a spinning saw blade...

as a result, The Home Depot, fined my store, 200,000 dollars, because after the lawsuits and medical bills and what not, thats the approximate cost to the company, if an employee hurts is seriously injured on the job... never mind if a customer is hurt, and subsequently if you have been to home depot near the saws in the past year or 2, you probably have seen what the My store managers have affectionately refereed to as "The Schroeder Maneuver" on the Radial arm saw

[FourPenguins]

Originally Posted by Ben Piecuch

Would I recommend a product like this in every school system that has a woodshop? You better believe it! A trained woodworker should have the experience and the know-how to protect himself. Unfortunately, I can't say that about most students, or even myself.

BEN

I agree.
However, I think that pushing for legislation in order to sell your product compromises the free market economy. The best solution for this product would probably be to change it so that it can be used as a "retrofit" instead of a factory-installed-only product.
A salesman going to a school wood shop teacher with the hot dog video and a low enough price to retrofit the school saws would probably have enormous success.

It'd also be nice if the stopping solution was a bit more...innovative for lack of a better word. Destroying the blade and destroying the brake mechanism in the course of a normal deployment isn't a very good design IMO. I'm not saying that I'm prepared to present something better, I'm just saying that it shouldn't be mandatory for a table saw to eat itself. Sandrag brought up GFCI devices, which are an excellent model of an easy to reset and non self-destructive safety device. What we have now is a fuse, but we need a breaker. (To continue the electrical analogy.)

[sciencenerd]

I agree with those who have said this should be available but not mandatory. I firmly believe that once customers begin realizing that there is a safer product available, they are fit to make the decision themselves whether it is worth it. I know if I were purchasing a table saw I would want this technology, but to each their own. Just don't ask me to pay for it when someone cuts their own finger off with their own table saw that doesn't have this technology included.

My school's wood shop just upgraded to a sawstop table saw, and as a new user most at risk of an accident with this thing, I applaud their choice. Of course, I'll be sure to stay on guard while operating the machine, sawstop or no sawstop, I feel better knowing that it's there in case of an accident.

Originally Posted by KenWittleif

If you take a zero-accident approach then everything has to be very expensive, time consuming to use, with double redundant safety features.

It is true that a line between safety and efficiency has to be drawn somewhere. But for me, this technology doesn't cross or even approach that line. The only thing distinguishing this saw from any other table saw is a slightly higher initial cost; it still operates like all the others - until it hits your flesh. At that point, it may have just saved your finger. And even if in so doing it destroyed the entire apparatus, I'd consider the save worth it. I'd say a $70 easily replaceable cartridge is a good bargain for a priceless, irreplaceable finger.

Again, I'm not in favor of forcing this on anyone, but I think the technology definitely has promise.

Edit: Missed spell-check.

[MrB]

just to throw in some info I found out. I know someone in the wood working industry and saw this saw at a trade show, he said it puts on an awesome demonstration, but they don't come out and tell you it costs over $200 per catridge. I think he said it was some type of a block that gets jammed into the blade to stop it from spinning.

That is great if it saved soemone's fingers, but in a high school, i could only imagine how many times it may accidently be set off (costing $200 each time). Assuming no one is dumb enough to try it with fingers, but what about a wet towel, wet wood, food, etc...

Soudn sgreat, but from what i've heard it is a bit overpriced.

And NOTHING beats proper safety practices..