How do these cuts not cause kick back?

[TRITON]

I watched a video of someone demonstrating dropping on to a spinning sawblade and lifting off with neither a back or forward stop, so in that case those 'always present' stops were absent. Demonstrating is one element of teaching, and those that watch to learn often try to replicate the actions of the demonstrator. In my case demonstrating to learners has always been in my teaching arsenal. Slainte.

I'd question as to in what capacity that 'demonstration' was being made.
But either way can we examine the mechanics of laying on.

The action of the blade is driving forward, in that anything in contact is being pushed backward. You agree ?
So from a safety point of view, it is hand pressure only keeping the movement from flying back, in a kickback scenario
That action alone would have the HSE sweating. There is no way on gods earth they would allow that action to take place in a teaching environment. Given the actions of what happens in an accident are what is being examined by HSE in a logical manner. They aren't just guessing, they're looking at it and the mechanics of long understood scenarios from their decades of experience.

But anyway.
In the vid, he is laying on, and the action of pressure from his hands are inward towards the fence, in line with the blade, and also holding it stationary to prevent it from moving backward beyond the point of the intended cut. Agree ?.
In effect the operator is using his right hand as an improvised back stop,but one that can move, so not really effective should he mis-align or the saw catch and try to kick out the component.
I would say that isnt a safe way, but if we replaced the right hand with a backstop, the action would effectively be the same. Dropping the component onto a moving and unguarded blade.
But thats not the dangerous part. The dangerous part is lifting it off. At this point it is at risk of snatching it as you need release inward pressure and at the same time lift the leading edge of the component, which risks coming into contact with the back and upward direction of the blade, which facilitates a kickback.


In my humble opinion, the choice of using a saw to make this cut is the wrong one, and it should probably be made on a spindlemoulder, using a slitting saw(or wobble saw) thats coming through a zero clearance fence(as in a sub fence of say 6mm ply and its been broken through)
Failing a moulder, then a router table with the same set up, or failing that a router and jig. But onto a saw no way.

30,000 saw bench injuries each year in the US, of which 4000 involved amputations.
OK the operator in this might be Canadian, but the statistics given lack of hse incentives is the same and will be proportional, in that its going to be a hell of a lot.
It's actually hard to find the data for Canada and the UK, but I'l hazard a guess out of all three the UK scores best with fewer accidents per head etc etc.

 

[Kicked Back]

I`ve seen how one of those big cutters can grab and throw wood (in my case an electric guitar body grabbed the end grain and threw the body into just below the trouser belt line (you all know where) luckily it wasn't me)

That happened to me on my very first time using a router table, electric guitar body and everything, using one of those large Radian flush trim bits. I'd watched a video by Crimson Guitars (who I love) where Ben essentially free hands removing a mm at a time before finally having the guide bearing sit on the template. I tried it and it just ripped one of the horns off and sent the body flying...

Now I never 1. start the cut with the workpiece unsupported by the fence or starting pin and 2. not have the template in contact with the bearing at all times. This usually means I bandsaw/disc sand much closer to the line before taking it to the router.

 

[Doug71]

I would make those cuts using a plunge saw/track saw, it's what they are designed for. Much safer as any problems or kickback and the guard springs back over the blade plus your fingers should be well out of the way.

Can't see why anyone would do it on a table saw, it's just plain stupidity ☹

 

[TRITON]

That happened to me on my very first time using a router table, electric guitar body and everything, using one of those large Radian flush trim bits. I'd watched a video by Crimson Guitars (who I love) where Ben essentially free hands removing a mm at a time before finally having the guide bearing sit on the template. I tried it and it just ripped one of the horns off and sent the body flying...

I watched a joiner using a large panel raising bit freehand. I had to look away.
He worked really slowly,and probably lucky for him had forearms like tree trunks, but still it was one of those EEK moments

 

[Blaidd-Drwg]

One of my favourite furniture restorers on YouTube has many decades of experience and does excellent work. But every time he goes near his table saw I cringe. When I first started watching him his table saw practices almost made me stop, but I have just resigned myself to cringing once in a while in order to watch the rest of his work. There are quite a few comments about his practices in the comments sections and he has talked about it a bit, but it's been more about, "I was taught this way and I'm too old to learn a new way."

I don't use a table saw myself anymore, so he isn't teaching me the incorrect way to use one, but it is still irresponsible of him because I know from the comments section that there are quite a few newbies who are looking to him for guidance and follow him step by step.

 

[Sgian Dubh]

I'd question as to in what capacity that 'demonstration' was being made.
But either way can we examine the mechanics of laying on.

Your response is interesting. Without commenting specifically to your discussion of the mechanics and procedure of dropping on and lifting off to make a limited length cut on a table saw, we're both evidently in agreement that what's shown isn't particularly safe.

As to the question of "in what capacity that 'demonstration' was being made", I'd say it's simply out there for all to see with the unspoken message, as far as I can recall, of 'this is how I do it, and it works for me'. That's all there is to it and it's up to the viewer to decide if they want to copy the procedure in some form. I wouldn't do it nor demonstrate or teach it because I'm fully aware of the risks that specific procedure involves; I also know safe ways to make essentially the same item as he made if I wanted to, but have no desire to do so. I don't know how other viewers of the video evaluate it from a safety aspect, or even if they do, and it's really neither my responsibility nor any of my business. In this case I simply found the subject piqued my curiosity, interesting enough anyway to cause me to comment, not something I do in many a thread. Slainte.

 

[transatlantic]

...but it is still irresponsible of him because I know from the comments section that there are quite a few newbies who are looking to him for guidance and follow him step by step.

And there lies the problem.

Some things are obviously dodgy. Others ... not so much. A good example is climb cutting using a router. If you're new to using a router, it's not obvious that what the operator is doing goes againts the recommend techniques, and you might attempt to copy it in other scenarios where it is not applicable (e.g a much deeper cut).

But then again, you could argue that you shouldn't be learning to use a tool by simply watching someone else make a project. You should seek better, more imformative literature.

I don't know where to draw the line, but I know that the video in question is on the wrong side of that line. There is absolutely no reason he could have not just demonstrated the cut using the jigsaw, and then used his prefered approach off camera. Although personally, I think he does it for other reasons...

 

[Spectric]

When I asked about the guarding, the American supervisor said, "If they're so stupid to put their hand in there, then they can!". It's clearly their mentality, as it is ours to put guards everywhere to protect the stupid Brits from themselves. That's our HSE working.

The person using any machine must take their share of responsibility, in a home workshop you will only ever have yourselve to blame and HSE is not involved but in a place of work then it is both you as the employed and the company, so if you use a machine in a dangerous way and hurt yourself and in the process impact the companies output then you can be held responsible for all loses. I do not know how the system works in the states but watching some of their reality programs the workforce out there do look like they take more chances, maybe because getting the job done is number one.

Life is never going to be safe, there is no such thing as safe and all measures taken in a working enviroment can only reduce the probability of a hazard occuring to an acceptable level, to make a machine fully safe would mean removing the actual hazard, ie the cutting blade or implementing high level safety control systems at SIL 4 which in a home workshop is not feasable. As for online videos does it mater how dangerous the person is, if they show you an easy way to cut a few digits off then are you really going to follow suite, if you cannot make the judgment whether the practice is safe then you should look at doing something else. Ok there are some right idiots out there and you will never protect them from themselves, but is that not just natural selection, survival of the fittest.

 

[Spectric]

Some things are obviously dodgy. Others ... not so much. A good example is climb cutting using a router. If you're new to using a router, it's not obvious that what the operator is doing goes againts the recommend techniques, and you might attempt to copy it in other scenarios where it is not applicable (e.g a much deeper cut).

It might just be my age, but before I even purchased a router I looked at books, yes those paper things that do not rely on the internet and did my homework for several reasons, one to purchase the right tool and also to learn the fundamentals. Training is a fundamental aspect of any safety culture and I trust a book more than you tube videos simply because you need a certain level of ability to write a book but can be a complete nuumb nuuts and still produce a you tube video. From a book you learn the basics like direction of cut and enough knowledge to progress further, and when looking at you tube you can decide on it's credability and some authors have moved online so you have trust, people like Bill Hyton, Alan Holtham and Ron Fox.

 

[Spectric]

For interest some good router info.

https://www.wealdentool.com/kb/rons-tips/

 

[Bojam]

It might just be my age, but before I even purchased a router I looked at books, yes those paper things that do not rely on the internet and did my homework for several reasons, one to purchase the right tool and also to learn the fundamentals. Training is a fundamental aspect of any safety culture and I trust a book more than you tube videos simply because you need a certain level of ability to write a book but can be a complete silly person and still produce a you tube video. From a book you learn the basics like direction of cut and enough knowledge to progress further, and when looking at you tube you can decide on it's credability and some authors have moved online so you have trust, people like Bill Hyton, Alan Holtham and Ron Fox.

Totally agree with this. Books are invaluable and can help assess/verify the credability of other sources. Also paying for DVDs or downloadable tutorials from credible sources - like e.g. the wood machining series by @Peter Sefton (of this parish) - is also worthwhile if taking training courses in person is not possible due to cost, time, location, or whatever. We need to assume responsibility for educating ourselves, especially when using dangerous machinery in our own workshops.

 

[transatlantic]

It might just be my age, but before I even purchased a router I looked at books, yes those paper things that do not rely on the internet and did my homework for several reasons, one to purchase the right tool and also to learn the fundamentals. Training is a fundamental aspect of any safety culture and I trust a book more than you tube videos simply because you need a certain level of ability to write a book but can be a complete nuumb nuuts and still produce a you tube video. From a book you learn the basics like direction of cut and enough knowledge to progress further, and when looking at you tube you can decide on it's credability and some authors have moved online so you have trust, people like Bill Hyton, Alan Holtham and Ron Fox.

Absolutely, I made that point.

But let's not forget, times are changing, and people are getting their information from different sources. There is no reason youtube cannot be a good source of information. The difficulty is assessing what's good and not so good before you're very familiar with the subject itself.

I'd also say that books can be just as bad as youtube videos. I have plenty of woodworking books showing questionable cuts on the tablesaw.

But I agree, publishing a bad video is FAR easier than publishing a bad book.

 

[Kayen]

If anyone thinks they can instantly become a safe and accomplished woodworker after watching a couple of youtube vids, they shouldn't moan if they end up injured. If they want to become a woodworker, they should do what most woodworkers before them have done - train for many years!

I think most have the sense to realise that machines have to be understood before using them, and if they want to learn correct practices, they should seek out those specific videos, or better still, sign up for some proper training.

I personally enjoy seeing an individual's own way of doing things.

In answer to the original post - a piece will only kick back if it rotates, there was no way a reasonably large, square (ish) piece of 18mm ply was going to rotate in that particular situation. Having said that, I would have raised the blade into the workpiece, rather than dropping it on, but each to their own.

 

[Jacob]

.........
In answer to the original post - a piece will only kick back if it rotates,

Not really. It just takes a little movement for a piece to skew sideways and be pressed against the fence / blade teeth and propelled forwards and/or upwards. Believe me I know from having made many basic mistakes over the years!

there was no way a reasonably large, square (ish) piece of 18mm ply was going to rotate in that particular situation.

If very large it might just have a big bite taken out, but still alarming and unpredictable.

Having said that, I would have raised the blade into the workpiece, rather than dropping it on, ...

Not viable unless the workpiece was held very firmly down and in by power feed or similar, and the saw could be cranked up easily. Mine couldn't - its a lever with a locking knob and a 2 handed operation. You couldn't adjust it whilst it was running - perhaps designed to make dangerous ops more difficult.

 

[transatlantic]

In answer to the original post - a piece will only kick back if it rotates, there was no way a reasonably large, square (ish) piece of 18mm ply was going to rotate in that particular situation.

But you can still have pieces fling back if they catch the teeth at the back of the blade as it rotates towards you. Like when you have a small offcut that isn't immediately removed after it has come free.

So seems like a similar thing could easily happen here. I.e the piece rotates by a tiny fraction, and catch the teeth at the back of the blade.

 

[Kayen]

Not really. It just takes a little movement for a piece to skew sideways and be pressed against the fence / blade teeth and propelled forwards and/or upwards. Believe me I know from having made many basic mistakes over the years!

I would consider a "skew" to be a rotational force. If you're making many mistakes, I would suggest you seek some professional training before you sustain a serious injury.

If very large it might just have a big bite taken out, but still alarming and unpredictable.

I wouldn't suggest dropping a very large piece of anything on to a moving blade.

Not viable unless the workpiece was held very firmly down and in by power feed or similar, and the saw could be cranked up easily. Mine couldn't - its a lever with a locking knob and a 2 handed operation. You couldn't adjust it whilst it was running - perhaps designed to make dangerous ops more difficult.

A firm pressure down with one hand (nowhere near the blade of course) whilst the other hand slowly winds the blade up - it's definitely viable, I've done it many times, but absolutely not if the saw in question requires two hands to raise the blade .

 

[Jacob]

......

A firm pressure down with one hand (nowhere near the blade of course) whilst the other hand slowly winds the blade up - it's definitely viable, I've done it many times, ......

Definitely possible, definitely dangerous. A really bad suggestion. I would suggest you seek some professional training before you sustain a serious injury.
PS I should add - I have done this very occasionally, to make a zero clearance insert, but with thin material and with very careful holding down - the insert already located in the opening for starters.

 

[Kayen]

But you can still have pieces fling back if they catch the teeth at the back of the blade as it rotates towards you. Like when you have a small offcut that isn't immediately removed after it has come free.

So seems like a similar thing could easily happen here. I.e the piece rotates by a tiny fraction, and catch the teeth at the back of the blade.

The off-cut should always be to the free (left) side of the blade, in other words, not trapped between the blade and the fence. Off-cuts in the correct place don't come flying towards you, trust me.

 

[Jacob]

The off-cut should always be to the free (left) side of the blade, in other words, not trapped between the blade and the fence. Off-cuts in the correct place don't come flying towards you, trust me.

But then the non off-cut piece is the risky one, as it would be with the OP's example at the start. His offcut is bobbing about loosely and unlikely to get snatched. Trust me.
What you are saying is self evidently true but misses the point completely.

 

[Kayen]

Definitely possible, definitely dangerous. A really bad suggestion. I would suggest you seek some professional training before you sustain a serious injury.

A bad suggestion, but one that you have done yourself! The alternative is to drop (controlled) the piece onto the moving blade - if you prefer that option, then go for it.

I have been professionally trained - I used to teach. I hated it, and only did it for five years but never had an accident on my watch.