It happend again - table saw accident

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Niki

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From Woodnet forum

"My Father was just taken into surgery to repair two of his fingers, injured in a table saw accident a few hours ago. One of these will likely not be repairable (near complete amputation).

It happened in a moment of inattention, removing a cutoff from next to the blade without noticing that the blade had not yet come to a complete stop".


Maybe that's the reason for;
"The operator's hand shall never be less than 150 mm from the guarded blade" and
"The blade must stop within 10 seconds"

Safe work
niki
 
I believe recent legislartion requires you fingers are now kept at least 300mm from the blade or cutter, as I was taught at college.

So, a 300mm push stick wouldn't do, it'd have to be 450mm minimum.
 
Brian
Lately, in other American forum there was a post about the SawStop.
After all the WAW's and WOW's about it, I asked a simple question;

"I would like to hear from the guys that bought or intend to buy the Sawstop why they want to buy it...I mean...reasons like "I like to work without the guard and my hands are 1/8" from the spinning blade" or alike...in other words, give me some cases that the Sawstop will save your hands/fingers."

nobody replied directly to my question but...
Even if the Sawstop will stop the blade in case I touch it, I would not put the fate of my fingers, in the "hands" of any computer.

Let me tell you a story...you know the "Airbus 320", this airplane is not only fully automatically but also "Fly by wire" that means, that the pilot does not have a direct control on the Flight Controls but, he is giving command to the auto pilot vie a small "joy stick" that is positioned on the side and not in front of the pilot as usual.

This airplane crashed in the demonstration flight in front of the TV cameras and I remember the French reporter saying "Me no, me no..." BOOF and a lot of black smoke...

Not only but this airplane, "lost control" many times, once, they were in an "Holding pattern" and the airplane just got "stuck" and did not want to come out of this mod. They had to shut down both engines and switch "OFF" the battery to "kill" all the electric power and than, switch "ON" the battery and restart the engines in-flight (to "restart" the computers)...you would not like to be on that flight (me neither)...

One think is good about the Sawstop, if the system activates, it will cost you some $200 to change the mechanism and the blade and that, will cause you to be very careful NOT to activate the system...but that, you can do also while working on a "normal" table saw that is much cheaper.

I think that proper "table saw technics" are the answer to a safe work.

Olly
I took this information from here
http://www.hse.gov.uk/pubns/wis16.pdf

Regards
niki
 
Hi Brian

It is an interesting idea.
As I know, the inventor and the owner of the company is a lawyer and I believe that he "covered" himself (in the "small letters") in a way that nobody can claim if "something goes wrong"...

Btw, at the time that the A-320 crashed, we made the following joke;
The passengers are boarding the airplane and hear...(in a computer voice)

"ladies and Gentlemen, this airplane is fully automatically and nothing can go wrong...nothing can go wrong...nothing can go wrong...wrong...wrong...wrong...peeeeeeee game over" :)

Regards
niki
 
Whilst I agree with your safe working ethic, you are wrong about the A320, the crash at Habsheim was probably (has not been confirmed) caused by the test pilot disabling the automatic systems, they would have applied throttle and back stick to avoid an accident. The pilot deliberately disabled the system to perform a more impressive "lower and slower" fly past.
 
Oh ya, you are correct Paul (that's what happens when you get old) :)
But the "Holding pattern" story was correct.

Something similar happened to an A-600 at Nagoya airport, Japan, they were executing an "Auto-land" and for some mysterious reason the airplane pitched to 45° nose-up and at that speed (landing speed) not much of recovery can be done...

niki
 
brianhabby":1f2re9qu said:
Pity they're not available this side of the big pond

cabinet_saw_home.jpg


A pity that they choose to sell a saw with an at best incompetent design of rip fence (i.e. a straight-through fence without a dual height adjustable blade), no run-off table and then advertise it with illustrations showing no crown guard in place............... From their own website, "Given 60,000 annual injuries, then one out of every 100 table saws will be involved in a serious accident each year", but what they fail to point out is the high percentage of accidents caused by contacting the blade during run-down after powering off and also the number of accidents caused by kickbacks - both of which can be avoided by much cheaper "technology" which has been designed into European saws since the early 1980s. I'm all in favour of improved safety, but they seem to have their priorities completely wrong. I have to agree with Niki - I favour the idea of a car which handles better and will run straight in the event of a blow out rather than one which will run off the road then punch you in the nose with an airbag as soon as it hits something :roll:

Scrit
 
Niki":3vvtohdk said:
"I would like to hear from the guys that bought or intend to buy the Sawstop why they want to buy it...I mean...reasons like "I like to work without the guard and my hands are 1/8" from the spinning blade" or alike...in other words, give me some cases that the Sawstop will save your hands/fingers."

nobody replied directly to my question but...
Even if the Sawstop will stop the blade in case I touch it, I would not put the fate of my fingers, in the "hands" of any computer.

I think that proper "table saw technics" are the answer to a safe work.

Regards
niki

If you have difficulty with Airbus and it's computers then I suggest that you stay out of all the latest Boeing offerings because they have similar computer flight systems in them too!:shock: But you can be comfortable knowing that the pilot can turn them off to show off at an air show, or at any other time he choses to exercise bad judgment. :twisted:

I have had a very close look at the SawStop at a local woodworking show (waited two hours to see the hot dog get nicked) and in a local dealers showroom. That saw is more than worth the money they are asking strictly on quality alone. It is a slight bit bigger than the competitors in that category of saw and the trunnions are heavier and a lot smoother operating too. The riving knife and splitter guards that have long been standard in Europe were never supplied on saws here (unless they came from your side of the world) until SawStop came along and that has got the other makers starting to put them of their saws. (That and the fact that they will be mandatory in a few years anyway.) Even though the saw isn't perfect in every way, it it is still a leap forward.

I will soon plop down some of my hard earned cash for a SawStop of my very own. I have no intention of working dangerously just because the SawStop blade stopping mechanism is going to save me from myself. I want it because in the event that the once in a lifetime moment occurs and some part of me ends up contacting the blade, there will be one more level of safety that may still allow me 10 choices to pick my nose with. :^o
It will also give me a slight bit extra piece of mind if someone else is using my saw (an rare occurrence, I assure you) and makes a mistake.

You can say that with common sense and safe practices, the need for the SawStop mechanism is unnecessary but not everyone can be trusted to have or follow them. I can illustrate with a story from work. I will also add that I know that a SawStop wouldn't have been of any use in the following case but it shows how stupid and stubborn people can get, (managers) even when told otherwise.

We machine aircraft structural components for the big jets and we had a part that is machined from a plate of 7055 aluminium. 2 parts from each 1" thick x 1' wide x 45' long plate. When they first came up with the methods of machining they decided to leave the tooling lugs on the parts and cut them off using a table saw instead of installing clamps and cutting them off on the milling machine. They felt it would save time on the machine and at over $180 an hour they weren't going to waste any machining time. The Manager in charge of the Metal Finishers convinced them that it was safe because "they cut metal with hand held saws all the time and never have any problems." So they bought a cheap Asian contractors saw and planned to cut the parts when they were ready.

I found out about their ludicrous plan and tried to get the Plant Manager to give up the idea. (Wasted my breath!) Pointing out that the cheap carbide combination blade was not suited for the job and that that alloy was nearly as hard as mild steel and almost as strong. A few days later when I came in for my afternoon shift I found out that my concerns were warranted and came true.

They were cutting the tooling lugs off on the table saw with the Finishing Manager at the saw(to show how it's done) feeding the metal past the blade sans fence and guard. He had 6 finishers holding the part and as they ran out part to hold they would run to the out feed side of the saw to hold that end up. When they were at the stage where there were 3 finishers each, front and back of the saw, someone must have moved a little bit sideways and the blade stripped off 13 teeth, 3 of them hit the Manager in the left shoulder a few inches from his neck. He was taken to the hospital to have them dug out!

Oddly enough the company stopped sawing off the tooling lugs after that and went to doing them on the milling machine. For a while after, the Plant and Finishing Managers scurried off when ever they saw me approaching. Had they gotten away with that stupidity in the beginning, the Finishers would have had to do the same until one of them had been hurt in the same way. Perhaps with deadlier results.

Any safety device that operates without being obvious to the user should welcomed.
 
That "moment of in attention"!!!!

That's why you need belt & several sets of braces using machines with so powerful & quick amputation abilities.

Just push stick is not enough

Guards, pushsticks (usually two at the same time) , jigs on my homemade fence and (topically) minimal teeth above the workpiece for me.
I make my cut. switch off and don't move until the blade has stopped.
All this because I've analysed a few near misses I've had.

SWMBO used to work in A&E -you would be amazed how many circular saw accidents there are in an average town each year!
 
Well, its just 12 months since I managed to "do" my fingers on the table saw.

A bit of a warning here.

I was cutting some smallish planks into strips for a project I was working on, and I was being a good boy, using a push stick etc etc.

However, cutting one of the strips I attempted to pull the cut strip out from the end of the machine after the cut was completed (nowhere near the blade) and as it did it "whipped", broke 3 fingers and made rather a gory mess.

I'd done exactly the same thing 100s of times before but I havent done it since :)
 
Inspector":eaehvms2 said:
Niki":eaehvms2 said:
"I would like to hear from the guys that bought or intend to buy the Sawstop why they want to buy it...I mean...reasons like "I like to work without the guard and my hands are 1/8" from the spinning blade" or alike...in other words, give me some cases that the Sawstop will save your hands/fingers."

nobody replied directly to my question but...
Even if the Sawstop will stop the blade in case I touch it, I would not put the fate of my fingers, in the "hands" of any computer.

I think that proper "table saw technics" are the answer to a safe work.

Regards
niki

If you have difficulty with Airbus and it's computers then I suggest that you stay out of all the latest Boeing offerings because they have similar computer flight systems in them too!:shock: But you can be comfortable knowing that the pilot can turn them off to show off at an air show, or at any other time he choses to exercise bad judgment. :twisted:
.

The difference between Airbus and Boeing concept is;

On the Airbus 320, the pilot cannot "Override" the Auto-pilot (I mean, by force exerted on the control column or the control wheel because, there is no control column or wheel), he can only "Disengage" it but, if it does not disengages, like it happened that the computer was "stuck" at "holding pattern", the pilot cannot do nothing but to "kill" the computer (by shutting down the engines and battery) and "Restart" the system.

The Boeing concept is different, the pilot can Override the auto-pilot even if it is "Engaged".

Regards
niki
 
As I understand it, the sawstop works by 'stopping' when it measures too much moisture in the piece being cut. Does this mean it will 'stop' if you try to cut a piece of green oak? Be very expensive if it did!

Julian
 
No Julian,

It stops when it detects an electric current, such as the natural one in your body.
 
Slimjim81":1em31crd said:
No Julian,

It stops when it detects an electric current, such as the natural one in your body.

Actually it provides the electric current to the blade and constantly measures any changes as it cuts. (A sophisticated Ohm meter?) When the cartridge detects a change that matches the parameters of our flesh it sends a current through a wire holding a heavy spring. That burns up (like a fuse) and the spring releases its stored energy, jamming the aluminium block into the blade, stopping it. As the blade stops its energy throws the trunnion down, dropping the blade below the table. Much like running into a clothesline and catching it under the chin.

There is a test procedure if there is any doubt about whether the material (pressure treated or very wet wood for example) would set off the mechanism. A short cut is made in the test mode and the status lights will tell you if the SawStop would have fired. You can then disable the safety device and cut normally and when the saw is shut off, it resets back to the on mode. Conductive materials like metal will also set off the mechanism.

If you touch the blade at normal cutting speeds you'll have a small cut, maybe needing a stitch or two. If you slapped the blade (don't get mad at the saw) the wound will be worse. In both instances the damage will be substantially less than without the device.
 
Not sure what all this airbus stuff is about but back onto saw safety. One thing I often see less experienced workers (no reference to above made) made doing is using the rip fence as a length stop for cross cutting which normally causes a dangerous jam as the timber turns diagionaly- please beware!
 

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