I have more than 25 years of experience pushing things through saws and saws through things...take this as you wish.
It's mostly down to experience levels...properly identifying the
potential danger of a particular operation you're performing, on the particular machine you're using. The other major contributor is overconfidence on the part of someone with "time in", who (for whatever reason) chooses to ignore what their gut is telling them.
Then there are situations where no amount of caution/experience would have changed the outcome one whit.
Case in point?
An extremely experienced flooring installer I know was freehand ripping a piece of "engineered" hardwood to close to a crooked wall. This particular product uses nylon cords in the core sandwich (kind of like post-tension cables in concrete) to increase the stability.
Somehow the saw blade grabbed one or more of these cords and in a split second, the saw sucked the board and one of his hands down through the front of the blade.
Even if the splitter/guard assembly
had been installed it would not have changed the outcome.
In such a ("one in a million") situation? Yes, the saw stop would be a benefit.
I rip freehand all the time; many times it's the quickest way to get the bulk removal in a particular operation done (i.e. scribing wall fillers in a cabinet installation). Critical to safety in operations like this (where you're "pushing the envelope"), are
high quality blades/cutters, sharpened/maintained
properly. Using the proper blade (tooth count/removal pattern) for the material
and the rated horsepower of the saw you're working with is also paramount. Above all is the
experience to guide such a cut through the tool manually, without running off line and creating forces that
will cause a "problem". Equally important is recognizing the onset of
anything "out of the ordinary" and stopping the tool to re-evaluate the operation. Knowing how to use simple jig and temporary fence techniques to perform dangerous operations in the safest manner possible.
All of this taken together? This is what I mean by "experience".
Ignorance/indifference in
these matters are where many, many of these "accidents" start. It's amazing how many "pro's" know little about basics like this...let alone all of the "handymen" out in the garage with their brand new Ryobi, garbage blades, eastern hard maple, and a six pack of beer.
I carry a half-dozen different tooth/chipout patterns for my 10" site saw
alone and maintain/replace them rigorously. It's just another cost of doing business that goes into the price when I quote a job.
I have all of my fingers, although back when I was a young buck with a bit of "time in", I "felt the wind" once or twice...
The recent boom in the "DIY mentality" (and the resultant availability of "cheap" tools that have the potential to cause serious injury in unskilled hands) has contributed greatly to the need for such devices. IMO...they should absolutely be required on all the "cheapo" saws marketed to weekend warriors by the box stores.
In the "real world" I don't think they should be required, even if one
would have saved my friend's hand. I know that it would only take one or two "false trips" (trashing a $100-$200 blade in the process) before experienced guys would toss it aside or disable it anyways.
OTOH, "Mr Handyman" will just go back to the box store for another 2 pack 10" Samona combo blade set...
...on sale all this week for only $39.99.
, etc.) so it was a pretty stupid lawsuit.
