Article on Skin sensing table saw

[Alan Anderson]

Originally Posted by KenWittlief

...Making a saw that will sense fingers may not be the best answer (the power tool companies seem to agree, or they would have jumped at the chance to buy his patent)...
the idea that engineers in the power tool industry care more about law suits than user safety is absurd, and down right insulting. If your invention is a good idea you dont need a plane full of lawyers to force people to implement.

It's people in the power tool industry who pointed out the liability aspects if this invention were to be widely adopted. They're not engineers, they're "liability experts". You can dismiss their idea as absurd if you want, but the explanation seems entirely plausible to me.

Whether or not a flesh-sensing saw blade is the "best" answer is not important. The problem at the moment is that table saw manufacturers are not obviously taking any steps to advance the technology of user safety. SawStop has a proven technology. The only compelling reason the manufacturers give for not licensing it is economic, and I don't blame them for balking at an 8% royalty demand.

[KenWittlief]

I dont know how proven it is. I found it interesting that they did a hot dog demonstation at a trade show at 30 minute intervals, and there was mention of a replaceable 'brake cartridge' in the system. Was there some significant cost, or down time involved, so that they only did a demo once every 30 minutes at a trade show?

I dont know the specifics of how it works, but I do know that basement inventors often design systems in a way that they work 'once', and they dont really care what it takes to get it to work again.

Do you have to replace some nail-gun-like brake cartridge every time the thing stops the blade? What is the down time after it triggers?

If Im sawing wood at 5pm on sunday afternoon, and it triggers on a damp piece of pressure treated wood, am I shut down till Sears or Home Depot opens the next morning?

If so, guess what Im going to do to my table saw?

I got a portable MPG4 video recorder and player about a year ago, that wont let you record a DVD if its copy protected. So you buy a DVD, and you want to copy it into your MPG4 player to watch it later on a trip, and you cant.

It took me about 30 seconds on Google to find out how to over-ride the copy protection system (you let the player record for 10 seconds with the input unplugged, after that it will record anything).

This will be the same deal. If someone wants to over ride it, they will. (esp after the 7th time it goes off on a damp piece of wood).

[Stu Bloom]

How many consumers want to pay the extra cost for implementation of a system like this? Before using any tool you should understand the proper operation of that tool, which includes proper safety precautions. If I cut my finger off using a power tool I suspect I will be at fault for ignoring and/or shortcutting safety procedures (guards around cutters/blades, push sticks, feather boards, anti-kickback devices ... etc ...).

How does that joke go ??
What is the difference between a Lawyer and a Catfish ?

[Peter Matteson]

The article mentions a fuse that gets burned up to spring the brake. I believe that this is what needs to be replaced. A task like that wouldn't be much different than an ordinary replacement fuse on a consumer product.

[Ben Piecuch]

If you download the user manual, it goes into great detail about replacement of the brake system.

First, you have to understand how the brake works, then you can understand why it's a bit more complicated that just replacing a fuse or resetting a spring. The brake is basically a piece of aluminum that is forced into the teeth of the blade. When the system senses a step change in the control voltage, this curved aluminum block gets rammed into the blade. The blade embeds itself into the block and is stopped in a few milliseconds. (The slo-mo video is wild to watch...)

So, what needs to get changed? The entire brake system, which looks to be one complete module. However, since the blade is being forced into the aluminum, they recommend changing out the blade as well! So, can the blade and module be changed out in 5-10 minutes? Probably. The toughest part is probably extracting the blade from the aluminum block, nothing a block of wood and a hammer can't take care of.

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

[Peter Matteson]

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,
You reminded me of why I posted this originally. It immediatly made me think of your former Hydrogen Source coworker who cut off 3 fingers on his table saw (all reattached). Also the number of people around our shop who are missing part or all of a finger. To me adding the price of the device up front and replacement parts is worth it no matter how careful you think you are. If the device is retro-fittable to older saws I'll be buying one for my father, an avid wood worker, asap. Otherwise he may have to wait a little longer until we get him a new saw.

Pete

[KenWittlief]

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

Give me an hour and I'll bet I can come up with 5 ways to design a table saw type of machine that will prevent you from pushing your fingers into the spinning blade, and none of them will involve destroying the blade or jamming blocks of alumimun into spinning machine parts.

[sanddrag]

Dean Kames once said something along the lines of "Every engineering project is a solution to a problem, but not every engineering solution is something the public needs."

I believe this invention is a marvelous idea, but it just isn't practical in the real world. Once you (a company) start claiming things to be safe, all it takes is one equipment malfunction and you're really in trouble.

The problem I have with things like this is that the easier you make it for people to do something, the lesser skilled they become. I think technology like this would put power tools in the hands of people who really have no business using tools. Power tools are nto for everyone, there's no changing that fact.

I mean seriously, what are they going to do, safen every dangerous tool out there? Put a compressable sleeve over dril bits? Permanently affix a shield into a welder's head? Make an oxy-acetylene torch that you can't point at yourself?

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

[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.

[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.