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Table-Saw Kickback on Camera (2012) [video] (youtube.com)
159 points by MagicPropmaker 46 days ago | hide | past | web | favorite | 144 comments

I'm a hobbyist woodworker. After meeting so many craft store employees with missing fingers (vast majority from table saw accidents) I will never operate anything other than a SawStop [https://www.sawstop.com].

The origin of SawStop is quite a cool story. The founder and inventor created this auto-stop saw, and tried to sell the tech to all the major saw manufacturers. No company would buy it because they didn't think there was a market, so he started a company around it which is disrupting the entire market.

As a fairly experienced woodworker, I have another angle on this: the SawStop is a band-aid on the typical American "cabinet saw" design. Cabinet saws (and worse, contractor jobsite table saws) invite doing really dumb things re: workholding. That is, how the workpiece being cut is secured before, during, and after the cut. Most of these dumb things are essentially invitations to secure the work using your hands anywhere near the blade.

In contrast, variants of sliding table saws are the norm in Europe and elsewhere. These are common in the US as panel saws for cutting sheet goods, but also come in much smaller sizes which are often better for smaller shops and solid wood-based applications. The workholding is different: a slider and a few standard accessories eliminates the need for crosscut sleds, common jigs, and a whole display of gripping-things at your local Woodcraft. The operator stands to the left of the slider, and the blade is to the right – if kickback happens, the operator is entirely out of the line of fire. Likewise, the operator's hands are pushing the slider, not near the blade. Since the work is moved with and/or fixed to the slider this eliminates entire classes of errors that lead to injury. The design difference is profound, akin to the coding philosophy of "make bad states unrepresentable".

I'd absolutely prefer a SawStop if I were using a cabinet or contractor saw again, but IMO a sliding table saw is intrinsically safer than a cabinet saw, even with excellent workholding discipline.

I am all for SawStop and their invention.

I am also all for the Consumer Product Safety Commission doing their fucking job and requiring this to be part of any table saw sold in the US, without paying SawStop any patent fees. This is a consumer safety issue; the exact kind of thing that the CPSC was created to manage, and they've done nothing to reduce or limit the number of appendages being cut off in saw accidents.

I think there's a difference between tools used by industry/hobbyists and products used by the general public. People who buy table saws are either professionals or at least have enough of an interest in woodworking to know the risks and know they need to learn safety tips. As opposed to products like cars or toasters, used by the general public who usually have no interest in how they work.

At the end of the day, it's really not hard to prevent table saw injuries. Use a riving knife, don't twist the wood and you'll pretty much never get a kickback. If something does go wrong you won't get injured if you keep your body out of the way. So don't stand directly behind the saw and use a push stick (I love my GRR-Ripper) so your fingers are never close to the blade. I'd guess the majority of woodworking injuries are due to people who know these rules but break them out of laziness or rushing. Table saws also aren't the only risk in a workshop. You can injure yourself just as easily on any other type of saw, jointer, planer, etc. It doesn't make sense for the CPSC to only require SawStop tech on table saws and putting it on every other tool would put the price of woodworking out of reach for most hobbyists.

From a quick Google search, 93% of table saw injuries are to the users' hands. The only actual deaths I could find were suicides. Yea it sucks to lose a finger but I'd argue that it's not the worse thing in the world. Pretty much everyone could still do their jobs minus one finger.

The one exception I would make is high school woodshop classes. Based on most teenagers lack of judgement, I think it does make sense to mandate that these woodshops only use saws with this technology. I'd be surprised if most school insurance policies don't already require it.

This makes no sense. We mandated airbags and safety belts in cars and we should mandate SawStop or similar in tools like this. To me that's what "advanced" societies do and I call it progress. The cost will also go down with higher volumes.

I used to work for a chainsaw manufacturer and we had devices on all saws without exception that would prevent injury in case of a kickback. Once this is part of all designs the cost is negligible.

My brother is a Joiner, and had laboriously educated me (usually by being shouted & screamed at) when I'm doing dumb things on his panel saw.

I asked him one day about saw stop and his comment was surprising.

1. Good workshop behaviour is always safe.

2. The blade is all but destroyed in stopping so quickly. (A small price to pay, really)

3. He cited places that used saw stops had the highest levels of work place accidents... Which increased after having them installed... I think he mentioned that yes, no fingers lost though.

So, i think this device is wonderful, but can have nearly equally dire consequences, because it seems to breed poor safety.

I don't know how good SawStop is exactly but destroying a blade is probably better than losing a finger. Otherwise we could argue that airbags are bad because we need new steering wheels after.

When I was in wood shop a million years ago they didn't have table saws and didn't even want us using the one band saw in the shop. We made all our cuts using jigsaws. You'd have to work really hard to seriously hurt yourself with one of those.

> At the end of the day, it's really not hard to prevent table saw injuries. Use a riving knife, don't twist the wood and you'll pretty much never get a kickback.

isn't this just another way of saying "don't make mistakes"?

If you're about to remove the riving knife, or making a cut that may twist the wood you should immediately ask yourself if there's a more appropriate tool to use or way to make the cut. If you continue anyways I'd see that as negligence as opposed to a mistake. (To expand on twisting the wood, the longest side of the piece should always be held against something while cutting. So on a rip cut it should be held against the fence. And on a cross or angled cut it should be held against either a crosscutting sled or miter gauge)

Not saying mistakes don't happen. I'm sure there are instances of people doing everything right and still getting injured. But as I explained I don't think it happens often enough and the injuries aren't serious enough to make the risk so unacceptable that we need to add $500 to the price of every new tablesaw.

I generally agree with you.

Wood often has hidden stresses within its structure. An apparently straight length of wood can cup/bow/curl quite markedly when cut. So you can't always know if a particular rip cut will result in the wood binding between the fence and blade leading to kick back.

On the price difference point, I have a portable Dewalt table saw that cost about AUD$1100 with a stand. Saw Stop didn't have a portable version when I purchased. Now that they do have a portable version, it is about AUD$2000, roughly twice the price of similar models from other manufacturers (at least here in Australia). That's quite a price difference for hobbyists and home gamers who aren't deriving an income from the tool.

It's a little more complicated than that. Even with a riving knife, you can still get kickback if your blade isn't aligned properly -- and most cheaper saws need a tune-up before being used.

Someone was working on an alternative where they switch the motor to DC current, which causes the magnetic fields to stop rotating and hence the blade as well. That gets around the patent and has the potential to not require repairs after triggering.

Edit: and it looks like Bosch has a cheaper system involving tech from airbag firing hardware that’s $50 per charge, that retracts the blade instead of catching it.

The Bosch system has been banned from the US for patent infringement.

Detecting a finger touching metal through change in electrical resistance doesn't seem novel, but the stopping mechanism does. Do I have that right?

I've never really understood patents, but none of this seems really "novel" to me.

I take it you said that backwards on purpose though as sarcasm?

Applying braking technology to a blade doesn't seem like that novel of an idea compared to detecting a finger touching metal through change in electrical resistance.

> without paying SawStop any patent fees

That'd be a great way to stop any future safety innovation that may benefit many people.

It isn't benefiting many people now. Look at these prices


True, they are not cheap tools, but SawStop makes high quality equipment. Their prices are a bit cheaper than Powermatic [1], and the saws compare favorably in performance-oriented reviews.

SawStop isn't really a homeowner tool, but it is certainly within an accessible price range for enthusiasts, schools, and professionals.

[1] https://www.toolnut.com/power-tools/saws/table-saws.html?man...

Sure, you'll find a premium on top of commodity tool prices to add the sawstop technology. No doubt about it. What you won't find is anyone who says "sure, I lost my finger/hand/arm to a sawblade, but look on the bright side, I saved a thousand bucks!"

That $1000 difference wouldn't even cover most insurance plan deductibles for one ER visit. Not to mention specialists, surgeons, reconstructive surgery, physical therapy, etc.

Their jobsite and contractor saws are expensive, but the cabinet saws are priced pretty similarly to other high quality cabinet saws (and SawStops are high quality).

Ask the person with missing appendages how much money was saved by not buying the tool with the safety features.

I don't believe that is really true. Most woodworking stores pretty much only have Saw Stop in the stores. Sure, lots of people have the super cheap Dewalt's or whatever from Home Depot, but Saw Stop sells a lot of table saws. I won't use anything else.

You literally can't buy a Saw Stop outside of the US. And even if you import one, after paying $$$ for the saw and $$ for shipping, you'd need to install a big hunking $$$ 220V-110V transformer in your shop. I've never seen one over here.

The European philosophy seems to be that the Saw Stop isn't worth it, because if you get in a situation where it kicks in, it means you've done something stupid like not using a riving knife and not using a crosscut sled or other pushing device.

I think also the fact that you don't get the system on other types of saws (band saw, mitre saw, circular saw, etc.) says something about the efficiacy.

>I think also the fact that you don't get the system on other types of saws (band saw, mitre saw, circular saw, etc.) says something about the efficiacy.

No, I don't think it says that at all, and you should reconsider your statement. I think it's a matter of geometry more than anything else.

The technology works. People do stupid things all the time. Having a backup safety device is a good idea, not a poor one. Or would you argue that safety belts and fire extinguishers are also unnecessary for "responsible" people?

What is in question, is the ability for an explosive block to stop a blade in single-digit milliseconds, before it can travel far enough to cut the user.

On a spinning saw blade, firing an aluminum block into a spinning blade and dropping the assembly away from the user is a matter of geometry.

How would this work on a band saw? If you can come up with a way, I believe a very lucrative patent is in your future.

Same goes with the other saws you've mentioned.

SawStop has stopped all competing attempts for patent violation, so I'm not sure it not being sold elsewhere is a clear sign it's not wanted.

AFAICT SawStop's patents (seems to primarily hinge on US patents 7,895,927 and 8,011,279) are only valid in the US. Also, when Bosch tried their "Reaxx" branded competitor, it was only launched in the US.

The official reply from Bosch when people asked on their forum about bringing the Reaxx to Europe was

""" There are currently no plans to bring the Reaxx to the European market simply due to differences in health and safety regulations across the two continents. """

My reading of this is that as long as people in Europe follow local H&S regulations, this technology is redundant. And they're not going to sell tools with features that enable people to disregard H&S regs.

American-style table saws (that you see in literally every YouTube video involving wood) are fairly rare in professional woodshops in Europe. Almost every larger shop has a format / sliding table saw, which avoids several (but not all) "classes" of kickback and other safety risks in the first place. Even small shops often have scaled-down sliding table saws (which have been around for many decades, usually using round steel bars for guiding the table instead of the more complex double-roller designs used by Altendorf & Co.). A Sawstop-like system could still be a useful addition, though.

I agree that simply invalidating the patent would have serious repercussions on future safety innovation. But if we decide that it's beneficial enough to require, maybe the government could buy the patent from SawStop for a fair market value.

Honestly, I think that this is <i>not</i> the best option- requiring some certain solution is not the best option, as it stifles innovation and there might be something better around the corner that won't even get looked at. For instance, the Bosch Reaxx saw retracts the blade down below the table as fast as possible, instead of embedding it into a chunk of metal the way that SawStops do (they both have their merits, but Reaxx is more universal, and universal safety is important- humans, in general, are more likely to mess up when they're doing something new, and standard cutting blades have been around forever, but that new Rockler kit you bought not so much.)

Instead, I'll argue something similar, but different: the laws should require some level of safety, but not require any specific implementation of the feature, as long as it's safe and dependable (per legalese specifications, no doubt). However, there are many other <i>equally important</i> safety features to think about, such as (the term escapes me at the moment) inrush-detecting limiters that keep the saw from blazing to life when you plug it in [1], or saw blade covers that are actually usable and don't impede work.

If you were to invent, build, and manufacture something life-changing, would you want the government to socialize it and not compensate you at all for it? Part of the problem with the SawStop was that the inventor wanted an inane amount of money for the license, so Bosch, who saw value in the feature, worked around them. Do something like mandate that all products of type X include exact part Y leads what you see in the defense industry- parts that aren't priced competitively, and might not be the best thing for the job. (Yes, I know there are holes in this analogy, and that building stuff costs money.)

[0]Link to legal fight between Bosch and SawStop: https://www.protoolreviews.com/news/sawstop-vs-bosch-reaxx-l... [1]AFAIK, the general mode of operation for these is to flip the switch to off when it loses power (like a GFCI, I would guess).

>I am all for SawStop and their invention.

>requiring this to be part of any table saw sold in the US, without paying SawStop any patent fees

I don't think you are for SawStop or their invention. Sorry, you don't get to cheat someone out of their work just because it's a good idea. It's pretty much the exact opposite of that.

I do not understand patent laws.

SawStop invented a thing. Does that mean nobody else can ever produce a similar thing?

Ford created the first mass-production automobile. Did that stop other companies from developing their own cars with their own internal-combustion engine? I don't think so.

Where do you draw the line on what is patentable and what is not? If I have designed a new pharmaceutical compound and it is patented, does that mean other companies can not synthesize their own version of the same compound and sell it under a different brand name? I suppose if we apply this logic to mechanical devices, you pretty much kill all competition for the life of the patent.

> SawStop invented a thing. Does that mean nobody else can ever produce a similar thing?

No. SawStop patents (there are many) begin expiring in 2021.

> Ford created the first mass-production automobile. Did that stop other companies from developing their own cars with their own internal-combustion engine?

As you say, Ford wasn't first to the ICE car game. They did have patents on the Model-T, though.

>Where do you draw the line on what is patentable and what is not?


> If I have designed a new pharmaceutical compound and it is patented, does that mean other companies can not synthesize their own version of the same compound and sell it under a different brand name?

That is correct.

> I suppose if we apply this logic to mechanical devices, you pretty much kill all competition for the life of the patent.

This logic does apply to mechanical devices, but it doesn't "kill all competition" because companies can design around existing patents. If you can find another way to achieve the same effect that's not covered by the patent, then you're fine. In practice, this happens all the time.

For the unfamiliar in this thread. The SawStop on it's own will not prevent kickback as seen in this video. That said there are other types of anti-kick guards available.

I've been waiting for somebody to say this. The SawStop would ideally prevent his hand from being cut by the blade, but it wouldn't stop the wood from flinging back from the machine at high speed which is incredibly dangerous on its own and could cause (and has caused) severe injuries to people.

I'm not against SawStop saws, and in fact I own one, but I would not feel any danger using any other type of table saw in good working condition. Understanding how the machine works and taking the proper safety precautions is much more important to your overall safety than something like SawStop technology.

Sawstop is a great invention but has known to false trigger and you then need to replace the blade and the gas cartridge. I believe wet wood is an issue.

If you use a Sawstop you should know what can cause it to trigger and not use those materials. Let your wood dry before cutting and never use something with foil on it.

Also, Sawstop has a bypass if you have to use it on something mildly conductive.

Such as slightly damp wood (think portable jobsite saw for framers or finish carpenters) or aluminium (yep, you can easily cut aluminium with most wood working tools).

It's too bad SawStop saws are incredibly expensive (and going up in price Feb 1st.) They are definitely worth it compared to the cost of an injury, however many people are priced right out of owning one.

They've also used their patents to stop competitors entering the market. So we're stuck with them for 20 years or however long their patent is.

I believe the patent expires in 2021, however I'm sure their lawyers will likely find a way to extend it well into the future.

On the one hand, that guy shopped his technology around for years trying to find someone to work with... on the other hand, I find it weird to see a useful safety technology hidden behind patents.

Competitors only tried to enter the market after SawStop validated the market's existence. Something that never would have happened without the assurance of profit that the patent provided. The company tried to license the technology, unsuccessfully, for years, before going into manufacturing themselves.

I don't remember the details...

A trauma doctor invented a new helmet for motorcyclists. Reduces neck injuries. Couldn't get any mfgs to bite. So he started his own company.

Gotta love the innovator's dilemma. (The opportunities are insurmountable.)

It's fun to see this one pop up on HN. I'm a programmer making a career change to woodworking.

A useful contextualization for how powerful most stationary power tools are (table saw, but also jointer, planer, chop saw, shaper, and, yes, band saws too) is that they're usually rated for continuous output of several horsepower. Go do an image search of people getting kicked and or thrown by horses. Now think about how much that must hurt.

Now, remember each of those machines is as powerful as one or more horses, and has a commensurate ability to injure you[0].

Can't stick around to discuss this now, but I'll check back this evening.

[0] Yes, I know the history of the horsepower and exactly how much power a horse develops is imprecise. For getting a rough idea how much you can get hurt, it's immaterial.

Another thing e.g. with bandsaws is that their wheels have large diameters, are heavy (~10 kilos for a 500 mm saw), with most mass concentrated on the rim, and spinning at fairly high linear velocities (10-30 m/s), i.e. they are perfect flywheels. If a bandsaw has neither mechanical nor motor braking (absence of which has been banned for decades here), they'll typically take several minutes to come to a stand still, and they're perfectly capable of cutting through hardwood at slow speeds - not to speak of flesh or bones.

Format table saws used in most carpenters shops here have 5-7.5 kW motors (7.5 kW are ~10 HP). Impressive power. Though format saws are far safer by design than regular table saws (and better for both your back, and accuracy, too).

That being said kickback is almost always caused by making a cut that simply can't be made safely on a table saw. With suitably sized work pieces the next major concern is binding; a riving knife helps with this but naturally cannot prevent it -- it just gives you more time to shut the saw off. (Larger workpieces are also somewhat -- not much -- less problematic when caught on the blade, because they won't fly as fast or far as a small, light workpiece).

As a US woodworker, I'm unfamiliar with how the Euro-style sliders are actually used in practice. If you have a video you could post a link to that shows some of the things that are done with them with safe technique, I'd be really interested.

I think part of the appeal of a table saw for woodworkers here is that if you can set up a jig, you can do a lot of pieces with good repeatability. I cut bridle joints to make seat frames yesterday, for instance, and once I set up the jig, I could cut them quickly and accurately. Ditto cutting tenon cheeks.

This is definitely one of the sketchier things you can do with a table saw, in large part because the workpiece is standing on end (supported by the jig, of course), but if you cock it out of vertical, you've set up a situation where kickback is quite likely. This is something I'd love to hear about a safer alternative.

As it happens, I have an old Unisaw, and I have an original sliding table for it. I would really like to see what I can do with that above and beyond the obvious.


The larger manufacturers (Altendorf, Felder) probably have videos. Marius Hornberger has a really cute Felder saw and shows some stuff.

Jigs are normally mounted to the sliding table (which has T-slots for this), which pretty much constrains both jig and workpiece to a single degree of freedom. (And if you clamp the workpiece to the jig you can guide the cut with one hand on the sliding table and still have another hand free to support e.g. a long workpiece that's mounted vertically -- and both hands stay well clear of the saw blade).

Basic operation would be e.g.

- having a panel with one straight edge, cutting a panel of given dimensions with square and straight edges out of it. Straight edge goes against the cross-cut fence that's mounted on the sliding table, first cut, turn 90° and use stop on the cross-cut fence (they usually have two independent stops) to cut it to width, turn 90°, cut to height.

- Rough sawn lumber with live edge, clamp it to the table, trim live edge off, use rip fence to trim the other side off.

- Unlike a miter gauge / cross-cut slider on a normal table saw, the sliding table can be used together with the rip fence safely. This makes it very easy and safe to rip narrow strips from a wide panel or board. This also makes it easy to e.g. cross-cut square-ish things off a board or panel, something which is pretty much impossible to do safely on a normal table saw. The rip fence on an F45 goes to well over a meter, so if you have many parts with the same length this is a real time saver.

- There are very accurate miter gauges that use fixed stops to mount to the sliding table (e.g. Altendorf Duplex). These allow to cut "into" the miter in both directions with basically perfect accuracy + repeatability (even when removing the jig from the table, as long as you don't touch the stops on it, it will cut the same miter when re-mounted). All miters I have ever made on the Duplex came out perfect, except a few that I screwed up during glue up.

- For edge mitering using the swivel-function of the blade works very nicely because even older models have digital readouts which are accurate enough that you can set them to 45.0° and get a perfect joint. Some never saws can swivel the blade in both directions (+45° and -45°). Swivel and cut depth are adjusted by foot-pedal (which I think is pneumatic) or electrically.

- Some rip fences can go to a few centimeters negative, zero included, which means you can use the saw as a sort of big flush cutter.

Scales are adjustable and use magnifying readouts, (mirror) vernier scales or are digital. When adjusted correctly, they're very accurate and repeatable. Rip fence on an Altendorf has a fine adjustment that works after clamping, so no measurement change due to tightening the clamping.

Overall it's just very nice to work with because you don't have to move the workpiece around by yourself, and when using the rip fence you're always standing a good bit off to the side.

Thank you! I'll look up some videos from the manufacturers.

I had never heard of sliding table saws. Beautiful machines

Felder: https://youtu.be/LVYUss6pJqQ

Altendorf: https://youtu.be/L8JR_fD-dMI

I’m sure there are innumerable options and configurations but these gave me a good idea of basic operations

1 horse-power is not the full power of a horse.

And when said horse kicks you with one leg, horse hasn’t exerted his full power. Yet somehow it stills hurts like a mofo.

There are some good videos on this by Matthias Wandel as well (who used to work at RIM, and has a great channel filled with technical/nerdy woodworking videos):

Table saw kickback experiments https://www.youtube.com/watch?v=xFkHmgRIkOI

Effects of table saw misalignment, and kickback https://www.youtube.com/watch?v=Fbca0Km8Q5E

Even a very experienced and meticulous guy like Matthias Wandel recently got his finger bit by a spinning saw blade:


It's very easy for anyone to drop his guard which leads to injuries. Since a lot of people admire his skills, he provided a great public service to the community by showing how his small moment of carelessness lead to an accident.

One thing that I will note is that Matthias often makes somewhat risky cuts and is known to joke about what the "safety police" will think of it.

He obviously has a very deep understanding of his tools (since he built most of them) and where the danger lies, but I would say that he also intentionally accepts a little extra risk with cuts to save time. In his specific case I think he does have enough experience to make the trade-off safely, but if you were a new woodworker I would not learn any safety techniques from his videos.

Another nice kickback video is this one, which uses a foam block to illustrate the principle --


I actually like this video better than the one we're all discussing. He does a fantastic job of safely illustrating the problem of kickback: how fast it happens, how little movement it takes to trigger, and how to prevent it all together.

Great recommendation, thanks for sharing! I've just recently been getting into woodworking and have been getting my zen on with Chris Salomone's videos (https://www.youtube.com/channel/UC1V-DYqsaj764uBis9-UDug) which are also very educational and a bit nerdy. I love the pure educational aspect I'm seeing here in Matthias' videos.

If you enjoy chris' videos, and you enjoy the zen of watching someone make things, check out this channel https://www.youtube.com/channel/UC7FkqjV8SU5I8FCHXQSQe9Q

Speaking of folks operating with no safety devices other than that which is between his ears.

I love that channel.

Awesome, thank you.

I like Chris's stuff, and I really like Andy Rawl's "No Talk...Just Work"[0] series of videos. I actually like _all_ of his videos, but that series is great for relaxing.

[0] - https://www.youtube.com/watch?v=7Yo6ALeIfF4&list=PLPCaXyAa7W...

When my father-in-law was a college student he was using a table saw to cut aluminum stock to make a 2" cube. He had the fence on. As he finished the cut, the 2" cube turned between the blade and the fence and launched at him, hitting him right on the lens of his safety glasses. He never saw the cube--it went out a window after bouncing off his glasses. His safety glasses were crushed, and he had pretty deep cuts and bruises around his eye.

He tells that story when he thinks people aren't having enough respect for power tools. He could have been much more severely injured. If he hadn't been wearing safety glasses he definitely would have lost his eye and could have had brain damage as well.

Human strength and reaction times are so insignificant compared to these machines. It's purely an illusion that we are in control of them, and there's no reason not to use all of the safety measures and precautions available to us.

I can't imagine how cutting a cube would not involve a crosscut as the final cut e.g. perpendicular operation of the material. This type of cut would ideally be done with a sled not a fence, so unless I'm really misunderstanding it was probably a major error in technique selection that caused this incident.

Yes, that is also true, and my father-in-law readily admits that he was simply misusing the tool in a very dangerous way. I believe he was starting with 2"x2" bar and cutting off a 2" segment. The fence should not have been on the saw for this, and a sled would have been ideal.

Always remember, you are the softest thing in the shop--softer than plastics, even.

I have a lot of respect for the table saw when I do my hobby woodworking. Stupid me didn't think a jointer was that dangerous; I tried to joint a small (2"x3"x2") piece of mesquite using just my hands. The piece flew off and my finger dropped into the spinning blades. Luckily, while it did slice off the tip of the finger, it hopefully won't be permanent damage. It did make me realize though how dangerous things really are.

Videos like this help me to remain vigilant. The longer I work with power equipment without any accidents, the easier it is to forget the risks.

For better or worse, I'm unable to forget a picture of the victim of a lathe accident.

Heck this is even making me think twice about my habits around the soldering iron.

That warning at the end, to always read and follow the directions of your tools, will be burned in my mind now. I bet this video will prevent some bad injuries.

Wood working newbie here. I recently learned about table saw kick-backs and ordered a Grr-Ripper push block[1] after seeing it being recommended on several YouTube videos. I’m quite happy with it but I’m not really experienced enough to make a fair judgement of the product. Is these kind of things something that more experienced wood workers are using/recommending?

[1] https://www.microjig.com/products/grr-ripper

Depending on the type of cut, I'll either use my hand, a push block, a push stick or something like the Grr-ripper to make a cut on the table saw.

The Grr-ripper is what I use the least, but it is one of the options that is really irreplaceable. For example if I have a long thin piece of wood (say 2' long x 2" wide x 0.25" thick), and I want to rip it into 0.5" strips, then the only way to safely make this cut is with something like the Grr-ripper. It is the only way to get grip on a thin piece of material and allow me to put pressure in the appropriate places (downward, towards the fence and through the saw).

But keep in mind in this specific example that the stock is not very wide. If you have a 6" piece of stock and are cutting off 0.5" strips, then by far the safer way to do it is to keep the bulk of the material between the fence and the blade and have the off-cut be the thin strip (and there are a variety of ways to setup your saws to do this cut repeatably). In this example the wood is also very thin, which is important. If the wood is thicker then the danger of ripping on the table saws increases, because there is more surface area between the blade and the wood, and at some point I'll just go over the bandsaw, rip things to rough size and then clean them up on the drum sander.

I'm also a huge fan of the grr-ripper rip block for the jointer. I use it all the time for thinner stock where I don't feel there is enough distance between my hands and the blades.

How do you do that cut repeatedly? You have to move the fence each time?

(very amateur woodworker who makes repeated cuts like that with the bulk of the wood on the other side of the blade so he doesn't have to move the fence each time)


Thanks for the detailed write up!

I'm a reasonably experienced woodworker and I couldn't agree more. The Grr-Ripper is a fantastic way to keep constant forward movement on your work piece and avoid getting your fingers too close to the blade. I use mine for the tablesaw, bandsaw, and router table.


That's just not true though that a miter/band saw are any replacement for a table saw.

Let's say I pick up some 2x4 and want to get rid of the round edges so it's pretty darn square. Are you suggesting to run an 8 foot 2x4 through a band saw to remove the 1/4" edges? First you need a damn good band saw to even attempt this.. you wouldn't have any decently long fence really. And even if you set this up all perfect, there's no way it's going to be even close to a straight cut.

Handheld jig like you saw could kind of do it, but my god that would be an awful cut even with a straight guide.

Ripping boards is basically impossible to do well without a table saw.

I agree a lot of other stuff can be sort of done with alternatives, but no where near the speed/accuracy. And if you do any woodworking, you know how much that matters.. if you don't get good cuts you end up taking forever trying to fix everything.

Anyway.. I hate using table saws, and do try to avoid it. But there are some tasks where it would be ridiculous to not use one.

Despite being well trained, I've had one kickback. It put a hole in my garage door and I had to drive to the emergency room in shock to get a partially detached finger reattached. Expensive lesson.

Somewhat off-topic, but...

IIUC, fixing severed nerves in the spinal cord is beyond the state of the art in medicine.

So when someone goes to the ER with a cut-off finger, how is it possible for the finger to be reattached, and for the proper nerve connections to be re-established?

Not a doctor, but it was explained to me thus:

The peripheral nervous system can regrow nerve tissue but only if it has an intact pathway. So when they sew on a finger, if they can repair the myelin sheath, new nerves will grow down the old conduit at a rate of about an inch a month.

So they sew your finger on and you have to wait a few weeks to see if you're going to get any feeling back. That waiting would drive me nuts.

I'm not a doctor, but your fingers are operated by tendons attached to muscles in the arm. So possibly the nerves don't need to have the exact proper connections, and the finger can still move.

Not a doctor but my experience was that there was no feeling at all on one side for about ten years afterwards. Feeling it just now, it seems normal to me. There's still a scar though.

I had this happen to me once with a bigger piece of wood I was cutting. He's right you have no time to react and the board is gone and flew 30 feet into the wall behind the saw. My hands were no where near as close to the blade as his were since it was a 12" wide board, but certainly freaked me out. He is lucky though that he didn't get cut.

There was a guy last year trying to post a video like this and he used a high speed camera.

When he went to edit the footage, he discovered to his horror that when the board kicked, it nearly sucked his fingers into the blade. Missed by less than an inch. The final edit ended up being mostly a message of "learn from my mistakes". Basically I learned that there's never a good time to have a kickback, even if you're trying to make an educational video.

Are you sure that’s not this video. That happens here too.


Yes this might be the one. Somehow on mobile I missed the big scare banner at the beginning.

This exact thing happened to me as well in High School "woodshop" class. The entire class and even the teacher called me "kickback" for rest of the year.

I don't think any of us realized at the time just how close I was to injury.

The blade of a standard 10" table saw rotates at very close to 100mph (150 fps). Of course, the teeth of the blade point such that they will maximally engage the wood if it gets loose. So anything of small-to-moderate size will accelerate to as much as 100mph. Using 150 fps, it will depart the 2-foot table of the saw in about 15 milliseconds, so (like the author of the video, and me, once) you will only understand what happened after it's over.

The usual reaction is to stare dumbly at your hands, and then stock up on push sticks, push pads, and work holding jigs ;-).

Yeah, it's crazy. I would never have imagined a table saw being able to throw large pieces of wood with such force. I had kickback on an 8-foot long 2x4. It wanted to throw that thing like it was a golf ball.

I probably avoided a broken rib thanks to having all the safety features of the saw on. Beam ended up jammed into the guard instead of jammed into my chest. So many people leave those things off because they're inconvenient. Glad I didn't.

I had a lighter board kickback on me while cutting a grove. It hit me in the side of my gut and then proceeded to fly back another 25 feet into the street in front of my house.

The kickback happened because the blade was so shallow. As I pushed the board into the blade, it rode up on top of the blade. The answer is more downward pressure, but I was using two push sticks to guide it through and didn't have the leverage to provide that pressure. Luckily, I was in a completely stable position and at no time were my hands anywhere near the blade, but it was still pretty scary.

I had a small bit of my finger removed by the table saw. It was actually a great lesson since I'll never forget it, but it wasn't permanently damaging (other than feeling slightly numb on the tip of that finger). Now I always think twice about the blade path and what things could go wrong.

For a more humorous take on workplace safety, I heartily recommend "Shake Hands with Danger" [0].

[0] https://www.rifftrax.com/shake-hands-with-danger

A table saw should have a riving knife installed. AFAIK it is mandatory for CE.

Thank you. I didn't know what this part was called, although I have a pretty good idea what it does. I really wish they had itemized the things you should have as well was what could go wrong and how.

There are also saws that can be used from the side.

I'm trying to get into bigger wood projects, and I'm on the fence about getting a circular saw or table saw since they scare the crap out of me. I'll probably get a bandsaw and hand held router, but I don't think I could ever have the courage to use a table saw (even a saw stop). I've used circular saws in the past and I was pale white afterwards. I'd prefer to just use hand tools but I'm getting more ambitious with my work and I'm starting to lose patience with the hand saws especially - it's really hard to make perfect straight lines at exact angles on large boards. I have no problem planing down to size by hand. I've seen track saws being used on YouTube and they seem lower risk for me - which might be the closest I'll get.

You're not wrong to be afraid of the circular saw. Whenever it comes up I introduce it as "and here's the most dangerous tool I own". However I look at my table saw this way: getting the table saw allowed me to use it instead of the circular saw, for most jobs. So it's dangerous in itself, but a net safety win. Nevertheless I have nice 2" x 4" x 0.25" dent in my Craftsman toolbox from one time when my table saw decided to conduct an impromtu ballistics test at it from across the room. Thankfully I was standing to one side of the board I was feeding through.

Imho a router is way scarier than a table saw. Mostly because you can pretty easily go to cutting a different grain direction when doing a curved cut and stuff can go awfully wrong very fast if you don’t know what you’re doing.

You're going to have a pretty hard time being serious as a woodworking hobbyist if you're afraid of table saws.

Yes and no. Some things take longer and require more practice and skill. I just need to decide if it's worth the time and effort or not. Believe me, if there were an easy way to overcome my fears, then I wood.

A lot of hand tool craftsmen would disagree with you. Chris Schwarz, Paul Sellers...

You can do a lot with a circular saw. It takes a little more imagination for some cuts but they're perfectly safe and doable. If you either buy a track saw or make your own track you can make repeatable, long, skinny cuts pretty well. Now you're not cutting coves or the like on a circular saw though.

I have had a kickback ripping 2x4s on a table saw when in a professional woodshop with my dad. That one luckily didn't cause me any injury, but my paychecks from my summer job for the next two summers went directly to the woodshop owner to pay for the damages. The 2x4 flew with such force from the saw that it hit a shelf of tools behind me, destroying several and deflecting slightly before going THROUGH the side of the building, which was a steel shop building from the 60s. Just imagine what it would do if you'd been standing there.

You always see those pictures of a hurricane taking a piece of grass and embedding it into a telephone pole, well a table saw can take a 2x4 and put it through just about anything. Crazy powerful tools.

The reason people don't think it's because in their mind they don't understand a Watt is.

Your average gasoline gallon has 33kW worth of energy in it, which can drive your car for about 35 miles or around 1kW / mile.

Look at your average table saw running at 600W of consumption and consider that piece of hardware is using up enough power to move your 3000 pound car a little over half a mile.

> ...gasoline gallon has 33kW worth of energy in it...

kW are a unit of power (energy/time, 1 W = 1 Joule/s), which is not relevant to measure energy content (for a gallon of gas). You'd want plain Joules for that.

If anyone wants to go (much) deeper, or works with wood themselves, I made a table saw safety compendium: http://sawsafely.org/

Fellow product geeks might enjoy the design tradeoffs that different countries made, and injury statistics: http://sawsafely.org/#understand-design-decisions-&-trade-of...

Isn't his push block already broken @ 4:19? He was suggesting it got cut because of the the actions shown in the video but it appears to already have been mangled...

Maybe, but if you slow down the video to 0.25x, @4:30 you can definitely see the blade bite into it and yank it away.

The scariest part is how his fingers get pulled towards the blade:


I had a kickback happen in high school woodshop, broke the saw guard and the piece of wood flew right past my head. I knew I dodged a bullet that day.

It’s nice to see that Harry S. Plinkett has a constructive hobby these days.

Thank you, now I know.

A european sliding table saw is even safer since you dont have to use your hands that often.

I have a very hard time understanding why do people cut corners and do not follow safety instructions to the T. They're there for a reason, so why ignore them? Same thing why I'll never understand why people bitch about OSHA. They exist to save your limbs/life, why on earth would you ever berate them for that? It's literally the best thing workers have to protect them, because their employers would value money over safety a lot more if OSHA didn't exist.

So as someone who has spent some time with and around physical workers - because all of this safety stuff takes time, and time is money, so if you can trade a little bit of safety for some extra time, then it seems like a good trade off.

Like, I worked with people who climb industrial chimneys professionally(for inspection, cleaning, etc). Now, in the UK the safety code requires that they have to clip in to the ladder they are climbing with a safety harness every 2 steps. So take two steps, attach one clip to the step above you, remove the clip from the step around your waist, repeat until you are at the top. Now - this might be a safety procedure, but literally no one follows it - simply because if you wanted to do that, it would take you 30 minutes to climb a 100m tall chimney. And these guys have absolutely zero fear of heights so for them cliping in is stupid anyway.

I imagine the same logic applies here - sure I could mount the blade guard....or just cut the plank carefully like I did 1000 times before already...."what am I, an idiot?".

Those are good points - and match what I've seen with arborists who climb trees, prune, and do full removals for a living - chunking trees down from the top, oftentimes while they're in them.

A lot of safety procedures and best practices diverge wildly from those in other industries. I get the impression it's probably the same way with chimneys in the UK, given that industry's long history. [1]

In arboriculture, the following weird things are acceptable(-ish, depending on the country):

- The climber is often supported by a single non-redundant rope, unlike rope access in other fields where two ropes are required.

- "Riding the ball", or using a crane to hoist a human load, is done in exceptional circumstances.

- Some critical PPE gear is often hand-made, it's very common for climbers to splice their own ropes.

- Even the most die-hard chainsaw-safety advocates will grudgingly acknowledge that sometimes situations call for one-handed use.

Some of these industry practices are in direct-conflict with more broad OSHA and/or EN safety standards. It isn't that the industry disregards safety - most climbers and crews I know are very safety conscious. Rather, the situations are different enough that the risk-mitigation calculus arrives at different answers.

Where a ladder climber may be not-always attached to the ladder, in the tree-care industry, that's utterly unacceptable.

[1] eg, one of the many Fred Dibnah videos on YouTube https://www.youtube.com/watch?v=3R3-YwDZrzg

So, weird/dumb question, I don't know if you have the answers to this, but why don't ladders have round tubular hand rails? Like, no residential or commercial ladder i've seen has hand rails, so I'm always gripping tightly to the sides or the steps.

But this seems stupid. Anyone with hands will realize that sliding your gripped palm around and up a round tube in a neutral position (that is, with your palms facing each other, not facing down) feels more secure then hand-over-hand on the steps, which don't give good grip anyway because the lip of the step faces down, not up.

Unless the ladder is anchored to something, it’d probably just fall over backwards if you put any weight on such a rail. They get unbalanced if the load isn’t kept forward.

At least over here, in maintenance ladders over a few stories high there's a central C shaped track where you attach a metal car about the size of a fist. Then you attach your harness to the car. The car can't come out of the rail. It also has a mechanism that it only moves if you pull it outwards.

Makes climbing really easy and safe. Technically you don't even need to use your hands for anything .

There are many types of fall arrestor systems for ladders, so you can climb a ladder without stopping, but still be caught in a fall.

Sure, but not every chimney/antenna/building in the country is fitted with those. Quite often it's just a straight ladder with no extra safety rails going straight up 100-200 metres. In that case the basic principles(clipping in every 2 steps) should apply - but like I said, are frequently ignored because of the time they would take.

Yes this is a huge issue. The solution really is to make safe ladder-climbing more convenient and inexpensive, so that people can and will choose to use it.

I do not do work-at-height, but my (unoriginal) proposal for a simple solution is to run a steel cable from bottom to top, anchored at both ends. This is cheap and low maintenance. Then a worker can bring their own cable-grabbing fall arrestor with a progressive-tear lanyard. Attach yourself to the cable at one end of the ladder, and climb up/down as you would normally until you reach the other end.

Obligatory reference: Fred Dibnah, steeplejack.


I grew up cutting firewood with a 1m diameter buzz saw driven by the power take-off of the tractor via a long belt that would be more than happy to consume your loose clothing or hair with you still attached. The single safety guard for that whole contraption was barely worthy of the word (it was mainly to give you something to put the wood against). Cord after cord was cut with that saw, and both my father and I still have all of our limbs and fingers.

If that buzz saw didn't kill me, I'm not fiddling with that stupid safety guard on the table saw/lawn mower/high-amperage device; I've got shit to do, I know what I'm doing.

(In reality, I personally use every safety feature of every cutty/stabby/choppy powered device I own. I'm not getting any smarter or attentive in my old age.)

Speaking of complacency around giant spinning blades, I was putting on cedar shingles last year, and wondered how they were made: https://www.youtube.com/watch?v=B3HBfj423cc

I so regret watching this video, made me sick in the stomach.

It's absolutely insane, and what's worse, the person posting it considers this a positive advertisement of their company.

Oh man heavy machinery(esp tractors and PTOs) are a whole nother class of things that can kill you in the blink of an eye.

PTO Guards, ROPS, 4WD(almost no tractors have brakes on the front wheels, so running a loader downhill can be really dangerous). All things I'm incredibly thankful for.

I can answer that I think, although I certainly don't agree with the reasoning.

The answer is twofold: number one is 'oh, these instructions are overly cautious, my expertise trumps them', and that is compounded by the fallacy of 'well, I've done it and seen it done for x years this way and have never had a problem'.

Because risky behavior doesn't always lead to disaster, and people get complacent. You cut a corner on safety one time, and nothing happens, so you do it again. Eventually it catches up to you.

Humans naturally have varying degrees of patience, and thus varying degrees of regard for safety measures.

This is an absolutely unreal level of professional grade ignorance.

no safety shield on his face

no gloves

baggy sweat pants

not even a shop apron

its just ONE GUY in a...garage? no safety spotter or anything. Its sheer luck that this guy didnt end up live streaming a suicide.

What thintz12 is also not considering is the blade itself is likely carbide tipped. the tips are hard, so if you crash the tool into the steel frame of the workbench, those bits can fly off like a bullet. a kickback that crashes a tool or jams the machine will also trip the breaker youre plugged into. If that breaker controls your garage door, and you're badly injured, you will not be able to make a simple and quick exit for help.

> no gloves

Wearing gloves when you are working with spinning things (table saw, lathe, etc) is a huge no-no. The glove may initially protect your hand, but as the blade shreds it, it will get tangled up, and will pull your hand into the blade.

This is a pretty controversial sentiment, and ive heard plenty of woodworkers tell me this. at 3450RPM, no glove is going to draw a persons hand into a rotating blade. The glove would need an almost cartoonish amount of strength to resist the physics involved. conversely, specially designed chainsaw pants are intended to do this to stop the blade as a safety feature, but the risk of entanglement is much greater in a metal shop where speeds of 600-1000 RPM definitely will grab loose clothing, gloves and jewelry.

I'm really confused... You criticized him for not wearing gloves, then when someone suggested that gloves could be sucked in, you countered by saying that gloves would simply fall apart against a machine going "3450 RPM."

So either the gloves are pointless, and your original critique was wrong, or gloves are worthwhile and could get pulled into the machine. Pick one position or the other.

I've had my glove pulled into a regular rotating drill, breaking 2 of my fingers in the process. (recovery was extremely annoying)

It was a cut-resistant glove, made from kevlar with a rubberized palm. Lesson learned that day.

But obviously, do whatever you want, YMMV.

No sane woodworker wears gloves. They are completely unnecessary and there is plenty of stuff slower than a table saw blade that will suck them in. Go over to the /r/woodworking subreddit and I doubt you'd find a single person who would say they wear gloves with their power tools.

If you want to see what happens when a glove catches a table saw and other spinning tools, do image search for "degloving" (NSFW).

There's no good reason to wear gloves when woodworking with machines.

To quote the guy in the video: "This shows just how stupid this was..."

After the fact he realized the magnitude of how dumb this demo was.

I'm grateful he shared it. It's valuable for others to learn from his foolishness, and brave of him to recognize this and tolerate the embarrassment for the benefit of strangers.

Second this. It’s super hard to imagine in what ways things can go wrong before you have seen or experienced them.

Kick-backs would never even have been on my radar, even though I’m seeing myself as a careful person, if it wasn’t for YouTube and people like him taking their time to educate the rest of us.

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