Stumpy Nubs - Table Saw Bevel Kickback Goes Thru Wall
#31
That kickback happened because he tried to remove the piece away while the saw was running. Not just kickback, but many fingers or hands have been injured or maimed or lost exactly because many people are impatient, including accidentally touching the blade when it is coasting down.

Simon
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#32
(02-13-2021, 07:36 PM)Handplanesandmore Wrote: That kickback happened because he tried to remove the piece away while the saw was running. Not just kickback, but many fingers or hands have been injured or maimed or lost exactly because many people are impatient, including accidentally touching the blade when it is coasting down.

Simon

This impatience is a ubiquitous modern habit induced in us by the queer "time is money" mantra drummed into we wage slaves from early schooldays.  Personally I've come to appreciate the alternative mantra "more haste less speed", which is true at the minor but also the major level, since you can waste years by losing your fingers, an arm or even your life by being so impatient you let a table saw or a spindle moulder eat your appendages.

But for those of us who have acquired a habit of impatience so ingrained that even being a free individual in America can't change it .... I recommend once more a European table saw gubbins, which is the electronic or mechanical blade brake. On the Scheppach TS I have, for example, pressing the red button stops the motor doing it's usual thing and puts it into a light reverse. This stops the blade spinning in just less than 2 seconds.  I believe the mandate for European TS is a maximum of 10 seconds to stop the blade spinning on switch-off but all the European TS I've ever seen stop it in a couple of seconds or thereabouts.

Now, this has taken the freedom of the individual woodworker to have a blade that goes on spinning for 5 minutes after the red button is pressed, as well as the freedom to cut off his fingers should he feel like hurrying to get the workpiece out of the way ready for the next one. His "responsibility" to deal with the predatory nature of unisaws, thus proving he is at least as brave as Davy Crockett, has been removed by some dang health & safety bureaucrat! The cheek!!

Still, ten digits on two hands at the end of two arms is better than .... less than those numbers, eh?  :-)

Capel
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#33
I am sorry about the red in my last response. I didn't have it in there when I wrote the response and I have no idea how it got there. But then I somehow turned off the sound on my computer also.

In my trade when someone was talking about a subject it is because he had some important information he wanted to pass on. Like what to do to tap, so that tapping bronze was as easy as tapping mild steel. I listened and learned from what he had to say.

I watched the video and heard and saw what caused the kick back. I heard, saw and am paying attention so that it won't happen to me. As far as not following through the cut I don't do that. I had a friend do exactly that and almost lost his thumb. I learned for that incident also.

Although a Saw Stop was used in the video and it alone didn't stop the kick back I am still hoping to replace my General 350 with a Saw Stop by the end of March. Protecting what I can't replace is not a rule to be observed, it is is a way of life

Tom
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#34
(02-13-2021, 02:26 PM)Capel Sion Wrote: Heh - I notice that bit above in red and, taking it with the rest of your post, I have decided never to get in a car with you, young man!  Since my safety during the journey would be "my responsibility alone" I would need to wrest the controls from you as you broke the speed limit to avoid being passed by others or ignored all the other rules of the road in favour of your personal judgements.  I mean, what if you decided to drive on the left hand side to please me, because I am British!?

But I feel you aren't up for a change of mind on this subject, despite my handy picture of all those safety gubbins on a TS that you might try. Of course, none of them will deal with a deer leaping in to your shed when you leave the door open.  :-)

Capel, feeling righteous but without the indignation. (Better than feeling wrongeous, bach, look-you).

How the red got there I do not know, and am sorry for it being there.  Like I also wrote that I somehow got the the sound turned off on my commuter also. At 75 A lot of things happen on the computer I don't have a clue about. You missed the point, If I follow the letter of the law I get past because others are braking it. If I speed up I will still get passed because even at a an increased speed there are more that brake the law.. I merely stated the truth. I never said I did so to avoid being passed. and ignored all the rest of the laws. You just accused me of a lot of everything I didn't write.

Because I did not agree with indignation over the braking of a safety rule, when there were no safety rules were broken I get personally attacked? It seem to me that you have what you are a cussing me of written all over you.

You can respond but I will not look at the post ever again so I won't know one way or the other. I will also never read any of your responses ever again, I do not need the heart ache.
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#35
Social media being what it's, I always know views opposite to mine exist and can be expressed. I may feel the need to respond to statements or opinions that I don't agree with, but I don't get upset by any exchanges, even if protracted.

Some forums allow you to "block" (ignore/disregard?) members you want to avoid or ban. Not sure if this feature is available here. I always welcome anyone to "block" my posts since I don't practice groupthink in my professional life or personal life.

Simon
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#36
This would have been a bandsaw cut for me. 

Also, a sawstop wouldn't stopped this as it is a kickback.
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#37
(02-10-2021, 10:20 PM)Teak Wrote: PSA. I apologize in advance if this video has been posted and discussed here before. I just saw it on YouTube and it blew my mind. Had to watch a couple of times to fully understand how a minor little oversight on the table saw can have devastating consequences. Highly recommended.

 https://www.stumpynubs.com/caught-on-tap...-happened/

IIRC Stumpy Nubs was a member here. Not sure if he still posts but I really appreciate this particular one. Work safe everyone & stay healthy.
The math is pretty simple. At 3450 rpm the teeth on a 10" blade are moving at about 150 fps. If just 85% of that energy/velocity is transferred to a small remnant cut you have a projectile moving at about 87 mph. Imagine standing on the freeway and a car is coming at you at 87mph - and it is ONLY 2 feet away. You will NOT be able to get out of the way - its over before you can say "aw s...."
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#38
In my life, I have been a mechanic and an automotive machinist, working with huge machines(Army tanks/etc.), switch engines, and all kinds of electrical utility equipment as well as some quite dangerous tools in the machine shop.

The tool that injured me the worst? A retractable blade utility knife.

Why? Because I was not paying attention. Period.

I've had several kickbacks while using a table saw. Only one hit me. When I was not paying attention.

I've sanded off finger/thumb nails on a OSS---not paying attention.

However, there is one more important factor about using machines/tools. The immutable laws of physics and the relation of object interaction. 

Best way to get hurt or worse when using a tool/machine is to not understand the operation and possible consequences of misuse of the tool/machine. 

I've made lots of mistakes with tools/machinery use, but seldom was I hurt because I understood the tool/machine use and used the safety methods. Like standing out of the path of a kickback.

I see folks talking about fearing a machine. Not a good idea to use something you are afraid of. Instead, respect the use/power of the machine and understand the possible problems that could happen if it is misused.
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#39
A good way to avoid this situation is to bevel with a dado blade. The potential wood rocket gets turned into chips.

Doing this cut on a shaper would also solve the problem.

Having off cut sticks litter the shop floor is itself a safety hazard. The stories I could tell. OK, I'll tell one.

When I new to woodworking, in 1985, I worked in a shop making wooden sun rooms. Crazy idea, isn't it. Wood heats up, goes full pretzel, glass lifts out, roofs leak, customers get upset, company gives out free buckets with company logo on them to catch drips.

But that's not what I wanted to tell you about.

Offcuts. on. floor.

We were making sills for the greenhouses. The 2 3/4" x 8 1/2" sill required a 1" x 1" rabbet on the exterior edge. Molder? no. Shaper? no. Dado blade? no. (the saw sitting there could take a 1 5/8" dado set.) 10 hp table saw with 18" blade? check. Inboard? check.

The saw was set up to make the cut in two passes, with the blade 1" high and 1" off the fence. At the end of the second cut, there would be a 13/16" x 13/16" x 6' stick left between fence and blade. That's OK, there was a kid catching out of the saw, and he would grab the stick. Until he didn't.

This work piece had some twisty grain, the off cut bowed as it was cut, and caught in the blade. The kid was paying attention to anything else, and the wood went flying. It missed the operator, shot though an empty foreman's office, shot though a window, and penetrated the rear quarter panel of the company owner's Lincoln Town car. That was bad.

Even worse, it also punctured the gas tank. We found out when we pulled the stick out, hoping Boss Man wouldn't notice the new hole in his car. The gas came streaming out, pooling on the ground beneath the car.

From here, dear reader, you could see this misadventure going in two directions. Does Table Saw Kid throw his cigarette in the pool, and burn down our shop? Or do we all step up, take a collection, fix the car, and try to work in a safer way.

We put gum in the hole.

Lesson Learned: kickback stories are the ones we remember, and, like a tree growing too close to a fence, get fairly twisted up as the years go by.
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#40
Lots of good replies here. The video was thought provoking to me because my offcuts are always left there gently touching the spinning blade and I also have that habit of nudging it away from the blade with my ripped piece. The bevel did have an influence on the kick back but I can see how it could happen just as easily at 90*.

I cringed when I saw the left hand in there too. I was taught that the only place for your left hand when nearing completion of a rip cut is in your back pocket. Only when it's there, can you be reasonable assured it won't get cut. A kick back can't drag it over the blade (ouch!). If anything goes wrong, your ability to instinctively react and reach has been eliminated; it happens way too fast. I've been bitten twice by the T.S.. Both times, the damage was over and done with before my nervous system had sent a signal to my brain. The first was right index finger in the cutting path. My first thought; "Why is my arm raised over my head?" There was an 1/8" kerf in the nail. I felt dumb. "There's a spinning blade right there. How could I actually touch it?" Slow down. Pay attention.

 The second was my left hand. Yes, I broke the rule. Even though I was looking right at it, I did not see it happen. It was over. The off cut twisted and the blade cut a spiral through the foam-board with total disregard to my appendices on top. My thumb took four stitches and the pinky needed only a Band-Aid. The rest were pretty well mangled but healed well. However; my ring finger did donate about 3/4" to the lesson. Now, I can say that it only happened because there was a 2" drywall screw concealed in the foam, but it could never happen if that hand was in my back pocket. Consciously putting my hand in my pocket also reminds me to step out of the path of a possible kick-back. I once had a kick "up" that would have left a nasty impression on my face if I was standing behind the rip.
Sign at N.E. Vocational School Cabinetmaking Shop 1976, "Free knowledge given daily... Bring your own container"
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