# Whirlwind--add-on blade brake for your existing table saw



## intelligen (Dec 28, 2009)

Is anyone familiar with this safety accessory for table saws?

http://www.whirlwindtool.com/

I just stumbled upon it when trying to look up the SawStop. Supposedly it stops the blade even before flesh contacts the blade, and it doesn't destroy your blade the way a SawStop's brake does. At first glance, it looks like it could be a bit clumsy to use since it's even bigger than a normal blade guard, but you can install it on any existing table saw.


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## DIYaholic (Jan 28, 2011)

I took a guick look at the link, it looks very interesting. I bookmarked it for further review.

Thanks for sharing this.


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## ruel24 (Feb 14, 2012)

It's a technology they are not interested in producing, but looking for a buyer. I wouldn't look for one anytime soon. Besides, it doesn't work on any saw. It can be MADE to work on any saw, meaning a model will be needed to be produced for each saw specifically, from what I read. Probably doesn't cost much to adapt to different saws. So far, they have not found any takers.


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## toolie (Mar 16, 2011)

that thing has been kicking around for a while now. lots of teaser info and no production yet. i'm beginning to think you'll see the loch ness monster before that safety device is put into production.


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## Viktor (Jan 15, 2009)

The greatest disadvantage of this design is that it works on contact or very close proximity to the blade guard around entire perimeter of the blade. This defeats the purpose of the device. If you already have the blade completely enclosed like that the break mechanism is mostly redundant.
You want the break to engage when your hand touches or better yet approaches exposed blade, not the guard. Touching the guard is not dangerous, touching the blade is.

If you really want to go flash detection route, a motion and proximity recognition device (think Xbox Kinect and alike) could be used. Very sophisticated devices of this type exist and these days they are within the reach of common consumer. If not, just design a sturdy blade guard for a change that is convenient to use. The latter is not rocket science.


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## ruel24 (Feb 14, 2012)

Touching the guard was probably the only alternative *not* patented by sawstop, and therefore why it was done that way.


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## IrreverentJack (Aug 13, 2010)

Probably needs to activated so far from the blade because it stops so slowly. How much would you pay for it? $200,$300,$400? Real flesh sensing technology will probably be available or on all new saws soon and the estimates are that it will only increase prices $50-$200. I'd wait. I wish the guy the best but I don't think this will ever be in production. -Jack


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## Viktor (Jan 15, 2009)

Given a choice I would very much prefer controlled, albeit slower stop when my hand is still at some distance from the blade to fast violent crash on contact a la SawStop.


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## intelligen (Dec 28, 2009)

I had previously searched for Whirlwind using this website's search box, but didn't find anything. However, it looks like someone else did post about it about a year and a half ago.

I like the fact that the Whirlwind doesn't damage your saw blade, but after doing the math, (5000 RPM / (60 sec/min) * (1/8 sec)), the saw blade still rotates almost 10-1/2 times after the brake is triggered. Your hand can slip a foot or more in 1/8 sec, and what happens if the brake itself or something else startles you to the point that you jerk your hand right across the path of the blade? I guess the plastic guard would have to be fixed very well so you couldn't bump it out of the way. You might be more likely to trigger the Whirlwind than you would be to trigger the SawStop, just because triggering the SawStop is going to cost you $100+ every time to replace the cartridge and repair or replace the blade.

IrreverentJack, I guess I would pay up to $200 or maybe even $300 for an aftermarket solution, but if the gap between saw+aftermarket brake vs. SawStop closes enough, I'd jump up to the SawStop. Did the legislation pass, or have other manufactures announced flesh-sensing technology in upcoming models? How long are we talking before those other saws hit the market? If any blade brake technology only increases the price of a table saw by $50-$200, I'd think it's a no-brainer for any saw that already costs $600 or more MSRP, and maybe even for lower-priced models, since it costs $300 just to check in at the ER. I guess if flesh-sensing technology becomes mandatory, the $89 table saws at Lowe's the day after Thanksgiving will soon be a thing of the past.


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## HorizontalMike (Jun 3, 2010)

AND neither the blade NOR a sacrificial $100 brake are harmed! That alone is a $200 save each and every time it is activated!


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## Alexandre (May 26, 2012)

Well, My dad is a electricion, and I'm sure he could wire one as well….. Like I could add a siron to it


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## DavidWW (Jan 5, 2010)

Hello lumberjocks woodworkers. I've not been here for a long time but a friend just asked if I might provide you folks with a littler more insight into what inspired me to invent the table saw safety device which we now call "Whirlwind," and I am happy to share some thoughts and reflections on that experience and maybe answer a few questions from readers. Most of this was taken from another blog posting I was asked to make. This week we here are so happy to have been informed by USPTO that our Black Box patent will issue on Christmas Day, 12-25-2012. The sun never sets on USPTO.

To those who suggest we've been around a long time and it will never happen, take heart. I put up our website in 2009 when my first patent was first pending. That mean pendency period for US patents is 36+ months. The patent office was very kind and helpful to honor my "Senior Citizen (Geezer!) Petition" and my first patent issued in less tha two years in 12-2011. Only one year later our second patent will issue as the "Black Box" device as I call it to retrofit millions of existing and future machines and we still have a couple in the PTO Mixmaster. We are asking the machinery industry to simply BUY our patents, special research knowledge, and any required support in order to bring improved safety to machine tools, especially table saws. Some background:

I was enrolled in the Cabinetmaking program at Boston Trade High School at the age of 14 where I formally learned the craft. That early high school four year education schedule was a week of academics followed by a week of shop time. The shop was huge and basically divided into a mill section and bench work section. I immediately gravitated toward the mill section with the noise, the dust and excitement where perhaps a half dozen machines were running at any given time. This place was a throwback to an earlier time, still equipped with an overhead line shaft driving a 36" thickness planer, and a 16" jointer among the many other independently powered machines. There were a couple of bad accidents while I attended, but I personally witnessed only one, which was not a table saw injury.

Upon HS graduation the US Navy accepted me and provided several months of electronics training and I became an Electronics Technician working both ashore and shipboard. In a few short years, I left the Navy for civilian life where I was fortunate to be offered a job with IBM. After more months of classroom and lab training I was assigned to work on the huge prototype SAGE air-defense computer which was still under development by MIT, IBM and the Air Force. I was indeed fortunate and spent most of my professional career in computer related electronics and developments.

Over the years as time, work space and budget allowed I built up a home woodworking shop and acquired a few machines. During that time I did much carpentry and built many small things and occasionally would build a reproduction of an American classic furniture piece. When we moved into this house about a decade ago, I finished the new basement with my office a den and a good sized shop with proper power and lighting and very important dust control. Sawdust is really very bad stuff to breathe over an extended period. All species of wood dust are now recognized internationally as a Class 1 carcinogen. I hope I dodged that bullet, but I do seem to have minor chronic sinus problems.

I was looking into improved dust control for my Delta Unisaw when I began to think about the work of Steve Gass and SawStop which was occasionally in the news. I thought the SawStop idea was just great and would soon be widely available. However, at that time I was concentrating my work on a whole new above the table blade guard or enclosure design which would do wonders for dust control. 
It wasn't long before I was experimenting with a rapid, but non-destructive emergency stop of the blade upon sensing the operator's hands becoming too close and this was the genesis of Whirlwind. My early prototypes that are shown on www.whirlwindtool.com we now call the legacy design and the newer models represent most of what we have up on the website.

An absolute key feature of the Whirlwind design is a fixed-in-place blade guard or blade enclosure. This fixed design harkens back to Boston Trade where we had a fire-breathing 5+hp shaper that was suddenly fairly docile when its fixed guard was properly positioned. Today, our Whirlwind fixed guard makes the table saw operation safe without requiring use of a splitter, riving knife or anti-kickback pawls. However; a riving knife may certainly be used with Whirlwind. This guard/enclosure is so effective that we have used the saw backwards; that is feeding stock from the rear to the front of the saw. Why would anyone ever want to do so? Because your saw is now also a scoring saw for clean cutting expensive veneered sheet goods without the damaging tear-out that results on single blade table saws!

I see many comments on woodworking forums that Whirlwind safety might be okay, but it would often have to be removed for some operations. I respectfully disagree, so let me explain. The Whirlwind design is intended to improve dust control above the table and guard the operator from placing hands too close to the spinning blade. If that should occur and the operator contacts the bottom edge of the enclosure the saw will shut down and emergency stop, thereby serving as a lesson and a warning. The saw may then be immediately restarted.

Now if the operator is performing an operation where the guard/enclosure must be removed, such as cutting sheet goods or cross-cuts where the cut-off is too long to fit under the overhead support arm, then removing the blade enclosure (simply lift and twist) is not likely to require the operator's hands to be placed near the spinning blade.

Besides these inherently safer operations I can think of only three rare cases where the blade guard/enclosure must be removed. The first and second are when using a tenoning jig or making raised panels on the saw. In my 60 years experience, I've never performed either of those operations. I make precision tenons with the stock lying flat on the saw table. Raising panels on a table saw is very dangerous and messy and much better left to a shaper, router or hand tools. The third case I can think of is when a large assembly must be trimmed on the saw and in that case also, the operators hands need not come too close to the blade. If there are other common operations I've overlooked that require the removal of this blade guard/enclosure, please point them out to me. That's the beauty of this type of forum and we can all still learn from each other.

If there are questions and or feedback presented here for me I'll do my best to answer.

WORK SAFELY

David Butler
[email protected]


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## HorizontalMike (Jun 3, 2010)

Good for David. What has been hoped for, since the A-hole Gass has insisted on copyright and on contracts, I have to say that I am DEEPLY disappointed in your efforts to do the very SAME BS! We all had our hope in YOU, and you are just doing the very same BS as Mr Gass! I originally thought your idea had hope, however your method sucks just as bad as Gass. get off your Ass and build it! That being said, GO FIND OTHER SUPPORTERS.

I hope that is clear enough without being offensive. NO pun intended,... I really do want to see this as it is stated. Build it, and you will have supporters. Market it for others to take the risk,... and you will be as vilified as Mr. Gass is. Period.

I like your invention, but get off your butt and do something with it, OR QUIT.

Just my 2-cents… 
Michael


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## pierce85 (May 21, 2011)

Viktor's earlier assessment of the disadvantages of this design are precisely the point. The issue here isn't about saving the blade or saving a couple of hundred dollars as Mike so mistakenly suggests. The issue is about saving your appendages on that one in a million chance when you've let your guard down… or not. So far, the only proven technology capable of consistently preventing direct blade contact injuries is SawStop.

I think the introduction of David Butler's Whirlwind design is essential in moving these sorts of technologies forward. It means that alternative ideas and technologies are being explored and tested. It creates innovation, forces improvements and will ultimately result in safer tablesaws as an industry standard.

SawStop detractors, however, have already lost the war - sorry Mike. There's no need for government regulation. SawStop is kicking ass in the marketplace and will continue to do so. The question is when will the PTI wake up. By the time the CPSC gets around to making SawStop-like technology mandatory on all tablesaws, the vast majority of them will already be there.

No need for invoking penny disclaimers.


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## intelligen (Dec 28, 2009)

Do the newer Whilrwind designs do a better job of enclosing the blade? Because if the blade is exposed as seen in the videos, I could see someone reaching from the side and getting their hand pulled in before the blade brake can even activate, and certainly the 10+ rotations of the blade afterward would be enough to cause some damage.

Am I understanding correctly that the Whirlwind's guard is fixed such that you can't accidentally push it up and out of the way? Does it still work if you're wearing gloves, or does bare skin have to contact the guard? How is it that it doesn't require anti-kickback pawls-does it have an equivalent built into the blade guard?

The only thing that irks me about Steve Gass is that he has lobbied to try to make technology like SawStop required by law-something from which he will personally profit. I don't have a problem with him competing in the free market as long as he's just doing a good job of selling his product, but trying to force the entire market to license your technology via legal means, such that you personally benefit, is crossing a line that takes you from hero inventor and entrepreneur to self-interested, greedy sleazeball.

If you invent a piece of safety equipment that you think is essential to the industry, then you have every right to get your investment back and maybe even make a little money. But if you want people to take you seriously on your word that your one and only goal is to make the woodworking world a safer and better place, then give away your invention for free or next to nothing after you've recouped your original investment. Or donate your share to some worthy cause.

On all other counts, I respect his Gass' ingenuity and the fact that he did go out and build his own line of saws when existing saw labels turned him down. And from a commercial standpoint, his invention is near-perfect-not only does his invention work well (not to mention, the saws built around it are high-quality), but it will undoubtedly require consumables over time, even if you don't stick your finger in the blade brake. Just as you have to change your smoke detector every 5-10 years, you'll have to change your SawStop cartridge every so many years to guarantee continued proper operation. This may eventually become an artificially-enforced requirement, but a valid argument will be that the electronics degrade over time and cannot be guaranteed to function properly after, say, 10 years.


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## Viktor (Jan 15, 2009)

Just a technical note. Contrary to statements from several posters here and elsewhere the blade does not take 10 turns to stop. It comes to full stop in 1/8 sec, but keeps decelerating during that time. Assuming linear deceleration (most likely) and initial speed 3600 RPM (most induction motor saws) it will take 3.8 turns to stop.

David, it appears from the video that the device is capable of detecting flash at some small distance without contact. If that distance could be increased to several cm (i.e. your finger can't slip under the guard without being detected) I think then your invention will easily challenge SawStop.


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## intelligen (Dec 28, 2009)

Viktor, thanks for the correction; I hadn't thought about that. But 3.8 turns over 1/8 second still seems like there's still a lot of room to do some damage. It's certainly still better that nothing, and as I mentioned before, I like that activating the brake is pretty much inconsequential, but it seems like there's a lot of room for improvement.


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## Redoak49 (Dec 15, 2012)

I like the idea that someone is working on a safety device for the table saw in addition to the SawStop.

However, I want to see more of it in action. The amount of time that it takes to stop is a concern of mine. The SawStop seems to be much faster. Do I really like the marketing of the SawStop safety mechanism…not really but it does work.


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## intelligen (Dec 28, 2009)

The great thing, advertising-wise, about the SawStop system is that its results are so dramatic, it makes a really great demonstration:

1. The blade vanishes!
2. There's just a little nick on the finger or hot dog
3. The damage to the blade brake makes you go, "Holy $%@#! That could have been my hand!"

It certainly seems like the most effective way to stop the saw blade, because…
1. You have the most stopping leverage at the tip of the blade
2. The energy of the spinning blade is transferred in such a way that it pulls the blade down beneath the table

But it does have its drawbacks:
1. only engineered to work on specific blade thicknesses and diameters (no thin kerf blades, no thick 10" blades, no 12" blades, must use different dado cartridge for dado blades and thick 8" blades)
2. triggering an activation is expensive (though still less expensive than a trip to the ER)

Still, I wonder if there's a different way to achieve almost the same braking power without damaging the blade, or if this really is the only practical way to stop it that fast. I also wonder if SawStop is only willing to license its patents as a set, rather than licensing, say, the "retract blade below table" patent alone.


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## SCOTSMAN (Aug 1, 2008)

I figure the best way to stop a blade instantly is to use a three phase motor and use one of the phases to reverse causing the motor simply to stall instantly neither going forward nor back just stalls the motor but does so instantly it was being talked about but then nothing from what I understand.Alistair


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## DrDirt (Feb 26, 2008)

Alistar - I think it would might stop the blade, but where does all of the inertia go? There is a lot of energy spinning the blade at 3600 RPM, and to take it instantly to zero the energy has to be dissipated…. otherwise it would be like driving you car down the freeway at 110 Km/Hour and throwing the transmission into Reverse …or Park.

The Saw Stop has the brake cartridge of aluminum crushes like the crumple zone on a car, and the entire arbor swings the blade down below the table. Much like catching a baseball, you have that "recoil" built into your arm motion.

Not sure there wouldn't be a lot of damage to just stop the motor instantly.


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## Nate1 (Aug 21, 2013)

Has anyone heard anything since 2012 about the Whirlwind technology? Looks like this is another of the many competing technologies to SawStop that seem to come out with lots of hype but are not coming to fruition.


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## intelligen (Dec 28, 2009)

Nate, I haven't seen anything else new about it outside of this thread. What are some of the other competing technologies?


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