SawStop Braking Mechanism

[Jester129]

I can remember getting my first (and only) table saw. No training, a quick read of the manual and how to set it up! That was it! Surely new saws somehow need, even if it's a video to watch regarding safe use, some kind of instruction? I'm too aware that I was very niaive, even if very wary, when I started using a table saw.

 

[Spectric]

A tempting belief, that one. Many humans, me included, indulge in the schadenfreude from time to time. It's difficult not to somehow enjoy seeing a dafty bitten by the consequences of a serious episode of daftness. However .....

Even nature gets things wrong and so to weed out the sub standard it came up with survival of the fittest which was supposed to remove anything that failed to meet the standard.

 

[MorrisWoodman12]

Just a couple of quick calculations tells you why demonstrators don't use their own fingers: well I certainly wouldn't.
If you assume the following, and you may want to argue details but the basis is still the same - OUCH!!
Saw RPM 3000rpm, 40 teeth, Diameter 254mm, stop time 1 msec (1/1000 sec). then the number of teeth passing through your finger in the stop time = 2.
TWO teeth through your digit. That's going to be a massive bruise even if you're not cut. And this assumes a stop time as aired above although it was also said that the detection time may increase that significantly. If it doubles to 2 msec that's FOUR teeth.
I, for one, am keeping my wiener well and truly hidden.
Martin

 

[Jacob]

Just a couple of quick calculations tells you why demonstrators don't use their own fingers: well I certainly wouldn't.
If you assume the following, and you may want to argue details but the basis is still the same - OUCH!!
Saw RPM 3000rpm, 40 teeth, Diameter 254mm, stop time 1 msec (1/1000 sec). then the number of teeth passing through your finger in the stop time = 2.
TWO teeth through your digit. That's going to be a massive bruise even if you're not cut. And this assumes a stop time as aired above although it was also said that the detection time may increase that significantly. If it doubles to 2 msec that's FOUR teeth.
I, for one, am keeping my wiener well and truly hidden.
Martin

Third obvious reason is that it's a machine and like all machines it will fail at some point.

 

[TRITON]

I would have left the braking cartridge stuck in the blade, added a simple quartz mechanism, a pair of hands, for a nifty workshop clock.

 

[Eshmiel]

I would have left the braking cartridge stuck in the blade, added a simple quartz mechanism, a pair of hands, for a nifty workshop clock.

Someone in the US even now may be buying up such embedded blades and readying a clock production line. $299 plus taxes, P&P. WARNING: Do not disassemble and install in a table saw!

 

[Sideways]

Someone in the US even now may be buying up such embedded blades and readying a clock production line. $299 plus taxes, P&P. WARNING: Do not disassemble and install in a table saw!

And here's me sacrificing that valuable asset in the interests of science amusement / my domestic harmony as my dear wife has been putting up with far to many tools in the house recently !

If anyone wants the blade (one careful owner, low miles, use at your own risk) you're welcome to it for the cost of postage.

I'm hanging onto the brake for more photos ...

 

[Spectric]

Third obvious reason is that it's a machine and like all machines it will fail at some point.

In any safety system failure is accepted but on two conditions, it fails safe and the failure is revealed. That is why a system that is designed to provide some safety function has to be tested end to end and initially a lot more frequently until you have enough history to support the stated SIL rating and that this system will perform on demand.

 

[Ed Weber]

Hers's the most recent survey of US table saw injuries I can find:

https://www.cpsc.gov/s3fs-public/statsaws.pdf

The figures are rather damning.

Two main factors seem to be in play: a macho attitude that rejects safety devices as somehow a nanny thing not for real woodworkers; the unisaw design which has for decades eschewed riving knife, effective guards, a blade brake and many of the other safety features long built in to European table saws.

It does seem to be a behavioural/cultural issue. I can't find the report now but I recall reading one that looked at various kinds of "accidents" across different nations. On many fronts, with various potentially dangerous machinery, the USA was pro rata a highly dangerous place to work with such things compared to other first world nations and even some rather less developed nations. Their traffic "accident" rate was reported as poor compared to many other nations too.

Sawstop is, from one perspective, a highly necessary development for the US, since a lot of users refuse to adopt safe operating procedures recommended by the likes of HSE as "not convenient". Sawstop is the unavoidable nanny in their tablesaw that stops them self-harming.

I seem to recall that riving knives are now mandated by the US government on new table saws sold in the US (but not on the millions of old/extant ones). Another necessary nanny. Will some remove them on principle, to regain their freedom to enjoy a nice kickback from a plank?

Your link is for 15+ year old stats.
This is even before riving knives were standard here in the states.
This is a bit more comprehensive and more current

My personal take on power tools is this;

 

[Ross Buchanan]

Portman Burtley's sawmill had one saw with what must have been an 8' Diameter blade. You could only see half of it.
The only safety sign said "Fresh milk is the best thing for transporting severed fingers"