Consumer Product Safety Comm. to discuss proposed SawStop technology safety rule

[George Max]

And a full NASCAR roll cage and seat. With HANS device.

There has to be a limit.

[bremen68]

I stopped over at the saw stop site and took a look at their products. Interesting little gizmo, expensive, but very interesting.

I think if you're looking for an absolutely safe saw (from the blade anyway) this puppy just might be the ticket... Though I didn't see saftey bumpers on the corners, soft side cushions on the case, or an airbag type appliance incase of kick backs. And WHAT ABOUT THOSE BLASTED SPINTERS??

Ok I'll be serious for a moment, well as serious as I can be anyway... It looks like somebody put a lot of thought into this and if it works as claimed will save many a person from having to answer questions from their grandkids about why they have to take their shoes off to count to ten. However, with all new technology it's expensive. And anytime you ask a typical woodworker to lay out more cash...Well, let's just say it's not a good thing and leave it at that.

As for mandating that it be installed on all saws. That's an entirely different thing. Now you're encroaching on our rights to injure and maim ourselves in creative and painful ways as we see fit. I agree with everybody above who says "if it's that good a system, it will sell it's self and everybody will install it" The price will come down and like also stated above it will be just like any other feature "standard" on the saws.

Trying to mandate something in the US does tend to raise most folks hackles, we're a bit stiff necked about things when somebody comes up and says "This is how you're gonna do this, by the way you don't have a choice". Even if it's for our own good, we tend to be stuborn types.

I am kinda curious about a few technical aspects of the system. Not everybody keeps their shop in absolute perfect condition, some aren't weather tight, some are damp basements... How does this system handle adverse conditions. If it's relying on monitoring an electrical current through the blade will rust effect it?

What about nails? (I realize we should inspect our wood etc, but it does happen) Will hitting a nail in a piece of wood cause the safety to trip? I'm thinking hitting metal will cause a rather abrupt spike in conductivity and there by blow the stop. A block of aluminum hitting a spinning blade means that blade is toast, at $70 a reload plus $50 (or more) for a new blade, that's an expensive mistake. Does the saw function if you don't reload the cartridge?

For industry I'm thinking they're doomed to have to incorporate it. Insurance companies will make it happen if nobody else does. As with all things it will eventually trickle down to consumer level products. But just like the gaurds that are supposed to be on our saws now, how many are actually in place? I think that that will be the fate of this device as well for most of them.

My humbe two pennies worth of rambling... Take it as you will. :-)

[The Other Funk]

Finding the keyboard operational George Max entered:

coffee spray!!! Seriously the product warning lables are getting ridiculous. And not just the badly translated. I groan inwardly every time I see "caution contents may be hot" on a lid. If it isn't hot, I'm out of business. So it is with SawStop. As I see it there are two types of tabesaw acccidents. Being careful operator with an Opps and the careless operator. Both need the protection. Having reread the SawStop web site, I am very concerned about a third kind of trigger. If SawStop works by sensing a electrcal signal, what happens if someone is using a motor with worn brushes in the area or an arc welder? I know (hope) it's been tested for this but you can't test for everything. Bob

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-- Coffee worth staying up for - NY Times

[George Max]

You're in the retail coffee business? Sorta like Starbucks?

Moving onto the saw - this is what UL attempts to do. Test for everything. They say it senses the capacitance of a human body. I wonder if the amount of that capacitance is the same from individual is the same, and if not, does that make a difference? The electronics of the device can probably be shielded from interference, but the blade is part of the circuit, I don't think that can be shielded and in fact may act as an antenna. I'm also wondering about those teflon coated blades, but that might not matter since the teeth won't have teflon on them.

Since this is probably a new category of device for UL, they're going to have to dream up tests for it. Assuming it's totally new or at least nothing very similar.

There's going to be a heck of a lot of investigation on this.

[The Other Funk]

Finding the keyboard operational George Max entered:

If you are going to start talking dirty like that, I'll give you decaf. But yes I am in the coffee business. Check out the link in my sig.

The capacitance of the the human body, as measured to the saw blade (or where ever they are measuring it) will vary but I am sure they can cover the range. It's probably cheaper and easier to cover a range then a single value. The SawStop site doesn't go into any detail but I would guess the blade is a major part of the sensing part. If I get a chance , I'll look up the patent(s) and see what I can learn. Bob

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-- Coffee worth staying up for - NY Times

[CW]

[Brian Siano]

Actually, that _is_ the competitive marketplace at work. After all, if you had a product, and you saw an opportunity to ensure nationwide sales, wouldn't _you_ take that opportunity?

Look, people, the original article cited a _press release_ from the Sawstop people. All it said is that he's having a meeting with a government official. That's all. If there's any chance that this'll turn into a new requirement for table saws, we can expect to have a long period wherein the industry will debate the issue, lobby the government, argue back and forth...

And chances are, the deciding factor won't be the government, but insurance companies. They might decide that, if you don't have a Sawstop, you're not covered... and thus, it'd become practically mandatory because of the competitive marketplace.

[CW]

No, not like that. There still is a thing called ethics but, it seems that the current idea is that nothing matters more than money. Steal it, extort it, whatever as long as you get more of it.

[The Other Funk]

Finding the keyboard operational CW entered:

If a filter makes the device less sensitive, what is their legal exposure if that saw then bites someone?

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-- Coffee worth staying up for - NY Times

[The Other Funk]

Finding the keyboard operational CW entered:

Actually the SawStop folks have a legal responsibility to maximize profits for thier investors. Bob

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-- Coffee worth staying up for - NY Times

[CW]

It doesn't make it less sensitive. It filters out the static and voltave spikes on the line that are causing misfires.

[The Other Funk]

Finding the keyboard operational CW entered:

Well I believe you but I am going to have to do some research of my own. I thought that the trigger was a voltage spike. I'll get back to you. Bob

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-- Coffee worth staying up for - NY Times

[The Other Funk]

I don't want to fan the flames but this article has some interesting points

add on price quoted here is $150.00 not the $400.00 that has been bandied about. Since the controller is a TI part, it can't be too hard to build a competing product. The big trick is stopping the blade. Bob

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-- Coffee worth staying up for - NY Times

[lwasserm]

And on that note, there are proven, old tech methods of stopping electric motors using brakes or electrical methods. Years ago I worked at a plant that had among other things a "two roll mill." Without getting too specific about it's operation, it was driven by a 150 HP motor, and the business end consisted of 2 steel rollers, each about 4 feet long & 2 feet in diameter, rotating next to each other with a pinch point of about 1/2" or so between them. I'd guess that each roller weighed a couple/few tons. The whole setup had a safety bar above it that activated a braking mechanism. It was SOP for the operator to use this when he wanted to stop the mill for any reason, not just in emergencies. It would stop the entire machine, motor, gearing, etc, in less than a 1/4 turn of the main rollers without any damage to the machine, and could be reset by the operator, and the machine restarted, in less than a minute. (IIRC the rollers turned in the neighborhood of 100 RPM)

For that matter, just think how fast the brake on a CMS or router stops the tool (admittedly their reliability factor is not that high!) I'm no engineer, but it sure seems to me that it would be possible to stop a TS without a one-time-use cartridge.

[CW]

The amount of time for a CMS to come to a stop is sufficient to amputate a finger. Yes, there are ways of stopping a motor quite quickly but, even a partial rotation could be disastrous. In any case, stopping it that quickly would almost certainly unscrew the blade nut. A freewheeling blade will cut quite nicely.

[CW]

Capacitance change is the trigger. Likely somewhat more sophisticated but essentially like a touch lamp.

[The Other Funk]

Finding the keyboard operational CW entered:

I read it as a voltage spike caused by a change in capacitance. Guess I better read it again. Bob

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-- Coffee worth staying up for - NY Times

[Larry Blanchard]

And that justifies how many unethical and/or illegal practices?

[Joe Bemier]

I wondered about this as well. I read an article on the net that said it senses a *change* between the wood and say a hand/finger. But what if the accident happened before or after cutting. For example, and illustrative purpose only, what if one was to stick their hand directly into the blade? This would not result in a change of any kind. I don't know much about electronics.

Anybody?

[Leuf]

How is discussing your safety invention with a consumer safety board unethical or illegal?

Whether I like the guy or not, I'm not willing to increase my chances of losing a finger just to spite him. And seeing firsthand what otherwise intelligent people do with their saws, yes, as long as the cost isn't prohibitive there's no reason it shouldn't be on every saw.

-Leuf

[CW]