SawStop often breaks the saw itself, not just the blade. There's alot of energy being put into the saw all at once, and I've seen examples where it fractured the mounts of the saw itself when it engaged.

That's of course great, if you're in the business of selling saws, not so great if you're in the business of buying saws.

If it engaged incorrectly, absolutely. If it saved my thumb and I have to buy a new saw as a result, it's hard to imagine a price point where I'd call the outcome not so great.

If it saves your thumb, sure. If you're ripping a wet piece of wood, no thumb risk at all, then, yeah, not so great.

Realistically, I don't like the tech or the methodology at all. Battle bots had saws that would drop into the floor without damage, and pop back up even, also without damage, and that was decades ago. That's the right model, not "fuck up the saw".

>Battle bots had saws that would drop into the floor without damage, and pop back up even, also without damage, and that was decades ago. That's the right model, not "fuck up the saw".

Might be wrong, but my own amateur reasoning has me believe that a table saw has far more kinetic energy than a battery powered battle bot, and that the SawStop must likely move the saw in microseconds, vs a battle bot which may comparatively have all the time in the world.

No, I mean they had table saw rigs that would bring the saw up/down into the floor with an actuator as a 'ring hazard', ie, your robot could be subject to sawing at any moment if they happened to be there.

The question is, how fast does it need to be? Likely not that fast really, certainly not microseconds, and an actuator could easily yank the saw down without damaging it if it detected you were about to lose a finger.

There's also no reason you couldn't use the same actuator to do fancy things, like vary cut depth on the fly, or precisely set the cut depth in the first place. Can't do any of that with a soft aluminum pad that gets yeeted into the sawblade when it detects a problem.

Basically, SawStop exists to sell saws. Those saws happen to be safer, but that's a marketing point, it's not what ultimately makes them money. Look at the incentives, you'll find the truth.

>The question is, how fast does it need to be?

I don't know - the marketing material actually says 5 milliseconds. That's the crux of the problem and I don't believe you can actually move the saw fast enough to not cause serious damage to the human without damaging the saw. The problem, as I understand it, is stopping the saw. The saw actuator only makes sense if it moves fast enough and given the saw stop works on detection, I'm not convinced you have that much time.

I'm considering the physical reality here - if the saw must be yanked down quickly, how much force must be applied to the saw to move it, and then can that equal and opposite force be applied to stop it without damaging the saw?

>Look at the incentives, you'll find the truth.

This is true of any safety device? The SawStop inventor created his company after trying to license it and eventually won in the marketplace after nearly 30 years. Surely his competitors would have released an actuator based solution if it is was possible rather than ceding marketshare of high end saws?

Bosch did release an actuator-based solution. They got sued by SawStop for patent violations and lost and pulled it from the market. SawStop's main patent just covers the concept of a blade brake, not a specific implementation.

The actual contention isn't whether an actuator-based solution would work, its if an actuator-based solution could stop the saw without damaging it (and therefore not give credence to the claim that SawStop is intentionally designing a poor solution in order to sell more blades).

As far as I can tell, REAXX also damages the blade.

REAXX retracts the blade inside the table and lets it coast to a stop. It does not damage the blade.

>and therefore not give credence to the claim that SawStop is intentionally designing a poor solution in order to sell more blades

This is the most asinine argument I’ve heard yet, and I am not a fan of this regulation.

Blades are typically cheap and the ones that aren’t are often repairable after an activation. Also, Sawstop barely sells any blades - I don’t know a single woodworker or cabinet shop that runs their blades.

I think the speed that things can go wrong when using a table saw (or most power tools) is faster than some people, including some woodworkers, might expect. There's a good example video here (warning, shows a very minor injury):

https://www.reddit.com/r/Carpentry/comments/11s6zlr/cutting_...

While we're still not talking microseconds, I think it highlights that moving the blade out of the way needs to happen very quickly in some cases to avoid serious injury.

Sounds like you're perfectly positioned to start a SawStop competitor!

"Protect your equipment AND your fingers."

With the government potentially mandating these types of devices, you could be makin' the big bucks!

These incentives are clear, where's the truth?

(This is only somewhat facetious. I'm skeptical of your claims, but not enough to discount them out-of-hand. The industry honestly does seem ripe for disruption.)

> The question is, how fast does it need to be?

According to my calculations, on a 10in/ 30tpi blade you have a teeth passing every 8.3uS.

I think the other key variable is how fast is your finger being advanced towards the saw blade and how much total depth of contact are you willing to accept and claim a victory. In an aggressive ripping the material you're holding towards the blade that might be 10 mph (~15 feet per second), if you're willing to tolerate a 1/16" depth of injury, you have about a half a millisecond.

If the rate of advancement is much slower (like a normal pace of feeding the stock into the saw accident), you have several milliseconds before reaching a 1/16" depth of injury from first contact to last contact.

Bosch used to have a system called Reaxx that could pull the saw out of the way without damaging it.

Sawblades are consumables and cheap enough (some are ~10-12 bucks) that it's probably a worthwhile cost.

An entry-level Dado blade can run about $100. The $10-12 sawblades can't make finish cuts that are worth a damn, because they chew through the work and tear splinters out rather than making precise nips at the front and back of each grain of the wood. For a saw blade an entry level blade that doesn't do this to your work can run you more like $60.

I know this because I've had to buy a table saw blade to replace a $10-12 one on my wife's table saw that someone threw on there because they were doing framing work.

I'm sorry, but this is a bizarre take to me. I don't care what happens to a saw if it would have otherwise cut my finger off.

SawStop works by detecting electrical conductance, and there are many reports of it misfiring when attempting to cut wood that isn't fully dry (i.e., there is moisture inside the wood, increasing its electrical conductance).

I'm aware. I'm not buying that a new saw blade and a replaced brake is too much of a cost over the peace of mind that you're at a significantly reduced chance of losing a finger.

And they're pointing out it's not just those two replaceable components - it's the _entire saw_ that they're risking destroying off a false positive that some woodworkers will hit frequently.

That just means the tech is not ideal, not that I want table saws without it.

They are suggesting the blade retracted, broke the saw, in a situation in which there was no risk to the finger. Maybe there was a literally hotdog in the wood.

> If you're ripping a wet piece of wood, no thumb risk at all

How many expensive false alarms are you willing to accept, per serious injury avoided?

I'm no expert in this, but I'd say 'definitely way more than one'.

And many people have experienced those ratios.

Many older woodworkers lost fingers often multiple fingers in multiple accidents.

So, the risk is really quite high here.

The guys I've seen lose fingers were all sleep-deprived and working flat out. The biggest risk to site safety is sleep deprivation and physical exhaustion.

Most people would rather go bankrupt than lose a finger. Fingers are kind of important. If I can choose to keep my house or my finger, I’m definitely choosing the finger.

So just divide the average net worth of a saw operator by the cost of a saw to get how many saws a finger is worth.

Really? I would definitely rather lose a finger than go homeless. Homeless people have far, far worse life outcomes than people with missing fingers.

A specific person isn’t the average homeless person who tend to be dealing with addiction, physical or mental illness, past incarceration, etc.

So talking about the average outcomes of a random homeless person doesn’t really apply here.

Exactly, homeless people living on the street should really be called familyless.

If I went bankrupt and lost everything I have a social safety net of family members who would put a roof over my head until I got on my feet again. Only people without that safety net end up on the streets. Or they have addictions that mean their family can’t take care of them anymore.

StopSaw makes these. The saws, tables, and fasteners are beefy enough to survive.

It works on conduction and capacitance. It's not immune from false positives.

I do it so seldom and am so careful not to put my fingers within 3 inches of the blade that this is a non-issue for me. This is another one of those "let's put 6 extra buttons that all need to be pressed to start the saw!" kinda situations that doesn't do anything to improve safety because the stop is the first thing you disconnect if it throws a false positive.

If we're concerned about job site injuries then let's address the real problem, which is that a lot of people using these things do so as fast as humanly possible with little regard for set up, site safety, or body positioning because the amount of money they will lose by doing that eats so much margin out of their piecework that it's not worth it. As usual we don't want to solve the hard problem of reducing throughput to improve safety, but we're perfectly happy to throw a part that is as expensive as the sawblade on the unit just to say we're doing something.

"If we're concerned about job site injuries then let's address the real problem, which is that a lot of people using these things do so as fast as humanly possible with little regard for set up, site safety, or body positioning"

Solving that sounds a lot harder to me than legislating that saws have safety features.

How often do you use a saw? At $3500 a saw I care. I saw a lot of wood and inadvertently hit at least one staple/nail/screw per year. Over the last 20 years of using my saw that would be tens of thousands of dollars if even a portion of them damaged the saw. It would essentially price me out of doing woodworking.

Frankly, the biggest problem is that this makes it impractical to test the brake. How do I know the brake even works, if testing it is not practical?

The point is that there's a (>1) cheaper solution that still saves your thumb, but it's (they're) being regulated out of the competition.

I tend to agree, assuming there are no false positives. Admittedly, I’m not sure how often that occurs, nor if we even can know that based on all the various work environments the cheap table saws are being used in today.

This is true, it can also fracture the motor mounts and not be noticed, until you are performing a difficult and aggressive cut and the motor mount breaks with a spinning motor attached and your board shoots across the room or into your face.

Your board shooting into your face has always been a concern with saws. Hence why you don't stand in the line of fire when making cuts.

I have been associated with four hackerspaces that have SawStop's.

I have seen an average of about one false firing a month--generally moisture but sometimes a jig gets close enough to cause something. I have seen 4 "genuine" firings of which 2 would have been an extremely serious injury. This is over about 8 years--call it 10 years.

So, 4 spaces * 10 years * 12 months * $100 replacement = $48,000 paid in false firings vs 4 life changing injuries over 10 years. That's a pretty good tradeoff.

Professional settings should be way better than a bunch of rank amateurs. Yeah, we all know they aren't because everybody is being shoved to finish as quickly as possible, but proper procedures would minimize the false firings.

Part of the problem with false firing is that SawStop are the only people collecting any data and that's a very small number of incidents relative to the total number of incidents from all table saws. SawStop wants the data bad enough that if you get a "real" firing, SawStop will send you a new brake back when you send them the old one just so they can look at the data.

This is a good amount of data but is $100 really the right cost for the replacement of a table saw if the saw itself is actually damaged, as OP says? Is it your experience that the saw is almost never damaged and the replacement cost is almost always the ~$150 dollar blade, or do you know how frequently these false firings damage the saw as well?

Well, only SawStop sells these saws, and I haven't seen anybody need to replace the saw after a firing. They just replace the blade and brake and get back to work.

Replacement cost is always brake and blade.

The blade is always dead. These things work by firing what looks to be an aluminum block directly into the blade.

Thanks!

I ran woodshop at a makerspace with multiple SawStops. We went through lots of cartridges and blades but never experienced damage to the rest of the saw. I have no idea where OP is getting that information/FUD.

>That's a pretty good tradeoff.

Assuming of course, there is no possible way that you could otherwise reliably prevent those injuries that doesn't depend on a human's diligence. That is, of course, ridiculous, but, that's the nature of this regulation. You're also not accounting for the cost of the blade, which isn't salvageable after activation, and those can get spendy.

Realistically, SawStop wants the data so it can lobby itself into being a permanent player in the market, which will, of course, prevent anyone from innovating a no-damage alternative to SawStop, which is certainly possible.

> Assuming of course, there is no possible way that you could otherwise reliably prevent those injuries that doesn't depend on a human's diligence. That is, of course, ridiculous, but, that's the nature of this regulation.

Well, the saw manufacturers could have done that before this regulation. However, they didn't. Only once staring down imminent regulation have they been willing to concede anything.

Bosch even has a license to the SawStop technology and had their own saws with blade stops. They pulled them all from being sold.

Sorry, not sorry. The saw manufacturers have had 20+ years to fix their shit and haven't. Time to hit them with a big hammer.

> Realistically, SawStop wants the data so it can lobby itself into being a permanent player in the market

Realistically, SawStop is so damn small that they're going to disappear. They're likely to get bought by one of the big boys. Otherwise, the big boys are just going to completely mop the floor with them--there is absolutely zero chance that SawStop becomes a force in the market.

Bosch pulled their saws from the US market because SawStop sued and forced them to. Then SawStop started lobbying to have their own design mandated on all saws. It was only later that SawStop said they'd allow Bosch (presumably in order to collect patent license fees).

As to this proposed mandate... If it's mandating any safety device, and Bosch and others can freely compete without everyone paying SawStop, I'm all for it. But if it's mandating the SawStop design, or would require all competitors to pay SawStop, forget it.

You have the order wrong, first they lobbied (2011), then Bosch introduced (2015) and pulled their saws (2017). Then SawStop reached an agreement in 2018. And the reason Bosch hasn't reintroduced it is apparently interference from cell phone signals. https://toolguyd.com/bosch-reaxx-table-saw-why-you-cant-buy-...

Correction to my post: apparently SawStop already got bought. It is owned by TTS Tooltechnic Systems which also owns Festool.

> So, 4 spaces * 10 years * 12 months * $100 replacement = $48,000 paid in false firings vs 4 life changing injuries over 10 years.

Certainly reattaching fingers would be cheaper than $48k. That's a steal of a deal in the US.

Divided by four, right, so $12k? I would think the medical, rehab, lost wages/productivity, and disability costs of an average table saw hand injury would easily exceed $12k.

It is not that simple. Replacing a saw is a loss to the business owner, while an employee losing a finger by his own fault costs nothing to the company.

Apparently you've never heard of this thing called worker's compensation.

Fortunately, or unfortunately, depending on how you look at it, this is not true. If you are injured at the workplace while performing your work duties and you are not actively intoxicated on drugs or alcohol, then you are entitled to medical care and worker's compensation for that injury. It is absolutely something that has a cost to the company.

This is both factually incorrect and not funny at all.

In addition, last I checked, modern medicine cannot reattach nerves so you lose a great deal of functionality of your finger or hand even if you save it.

See: https://youtu.be/Xc-lIs8VNIc?t=1095

I hope I am simply missing the joke if someone would be so kind as to clue me in.

Yeah, you're missing the joke. The joke is the US healthcare system and how expensive it is.

A sense of humor might cost in excess of a finger reattachment, though.

N=few, but thank you for sharing this actual anecdata for those of us interests.

Similar background and experience with sawstop. I'm a huge proponent of SawStops but it's important to be as upfront as possible. It's $100 for the cartridge and then another $60-$120 for replacement saw blade.

Sweat dripping on the work piece (especially NoVA in summer with AC on fritz) was responsible for a fair share of the cartridge firing without contacting flesh.

> That's of course great, if you're in the business of selling saws, not so great if you're in the business of buying saws.

OTOH (literally?) keeping your fingers but having to buy a new saw seems pretty reasonable.

I ran the woodshop at a local makerspace. We went through a lot of sawstop cartridges...easily 10-15 a year. The saw was never damaged because of the cartridge firing.

We had one of these in my highschool woodshop - they would demo it once a year on the parents night because of the expense. I'd rather see this regulated in a way that says places like schools or production woodshops would need these from an insurance perspective, but home woodshops wouldn't be required to

https://www.grainger.com/product/DAYTON-Radial-Arm-Saw-120V-... here you go

You do realize you linked to a discontinued product that costs over $5k?

This is what I actually expect to happen to the table saw market - they all become expensive, and the sub-$1k market (which is huge) goes away. Yes, you can find an RAS but it's about 10x the price of what they used to be.

I found a RAS from Sears from 1995: $499, which is around $1000 with inflation. https://archive.org/details/SearsCraftsmanPowerAndHandTools1...

So I stand by my statement: they're effectively non-existent, demand is gone after the 2001 recall by Craftsman, and most of the major manufacturers have stopped producing them. I expect the same thing to happen to table saws.

They literally just updated the model number yesterday as they wait for new stock to arrive in July.

It even says so right under where it says discontinued. Specs are exactly the same.

I've seen all of the talking points, but a regulation probably is required simply to force liability.

The biggest "excuse" I have seen from the saw manufacturers is that if they put this kind of blade stop on their system that they are now liable for injuries that occur in spite of the blade stop or because of a non-firing blade stop. And that is probably true!

Even if this specific regulation doesn't pass, it's time that the saw manufacturers have to eat the liability from injuries from using these saws to incentivize making them safer.

As for cost, the blade stops are extremely low volume right now, I can easily see the price coming down if the volume is a couple of orders of magnitude larger.

Why are radial arm saws so dangerous? I have an old one and other than shooting wood into the shop wall when ripping, or holding the wood with your hand it seems pretty hard to hurt yourself. Circular saws seem way more dangerous, and the only injury I've ever had was from a portaband.

There used to be some pretty wild published advice on how to use a radial arm saw including ripping full sheets of plywood by walking the sheet across the cutting plane with the saw pointed at your stomach. They also travel towards the operator in the event of a catch because of the direction of the blade and the floating arbor. This makes positioning yourself out of the potential path of the blade critical and the one thing we know is that you can't trust people to be safe on a job site when they are in a hurry.

>There used to be some pretty wild published advice on how to use a radial arm saw including ripping full sheets of plywood by walking the sheet across the cutting plane with the saw pointed at your stomach.

So, similar to ripping plywood on a table saw, then? What makes one worse than the other here?

>They also travel towards the operator in the event of a catch because of the direction of the blade and the floating arbor.

So, like a modern sliding miter saw, then? What makes one worse than the other?

I have the original manuals describing how to rip using a radial arm saw. The blade is set at the level of your stomach and mere inches away from a spinning blade as you walk a sheet of plywood along it. There are so many ways for that situation to go wrong, and so few ways to make that situation safe. I have a beast of a radial arm saw, and I set it up to rip out of curiosity, and it would be insane to ever do it that way. It will cut your guts wide upon if you so much as slip.

And when that saw bites, and comes at you with enough force to be too much for you to react to. If parts of you are in the way, it'll rip right through them as it punches you in the jaw.