SawStop inadvertent brake activation causes


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On 2/27/2021 at 8:54 AM, Mark J said:

Still non-flesh triggers happen.  It would be a nice development if they could figure out a way to pull it off while preserving the blade.  Or if Felder could make their system cheap enough for people to actually buy.

Bosch figured it out sawstop served them with a lawsuit. Remember the reaxx contractor saw? I don't think sawstop has much intention of making their system better or they'd have done it by now.

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I'm not sure the Bosch system would work properly for the greater mass of a cabinet saw driveline. Portable jobsite saws are pretty low mass, so their explosive cartridge (compressed gas, wasn't it?) had enough power to drop the blade below the table, but SS would need a significant rework of their patented system to manage that without using driveline inertia as part of the motive force to drop the blade. I'd like to see how Felder does it, I'm guessing there is a massive spring involved, somehow.

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15 hours ago, wtnhighlander said:

I'm not sure the Bosch system would work properly for the greater mass of a cabinet saw driveline. Portable jobsite saws are pretty low mass, so their explosive cartridge (compressed gas, wasn't it?) had enough power to drop the blade below the table, but SS would need a significant rework of their patented system to manage that without using driveline inertia as part of the motive force to drop the blade. I'd like to see how Felder does it, I'm guessing there is a massive spring involved, somehow.

I haven't dug through engineering drawings to see how they work. My gut instinct is that it's not that different. I could probably figure out a way to make it work. Man now i want to examine how they are both built. The sawstop contraption looks like it'd work easily with the gas cylinder as it's quite light looking. Using springs and a sear it'd be pretty easy to offset the weight of a swinging component and the spring would help keep the blade below the table....

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Drew, it may just be that the brake reduces injury a bit more. There is a slow-motion video floating around, of a SS tripping. You can clearly see that the blade stops long before it drops. And is clearly under high stress, I would not try to re-use it. Of course, at normal speed, the blade disappears in maybe one frame of video, so the added time is relatively short.

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Seen the video multiple times. I still stand buy the brake being unnecessary. The Felder and Bosch design were retracting the blade fast enough to only leave a scratch (very similar to the SS) but neither damage the saw blade.

I don't think that Gass intended the brake to retract the blade. The brake was the main function and the retracting was a secondary result because the energy is easier to deal with if it's redirected. Though I doubt very few people will truly know the answer to this question. The evidence is the blade comes to a complete stop before it retracts. If retracting the blade was his main goal i strongly feel the design of the saw and safety system would be dramatically different EG Felder and Bosch. Also the blade would still probably have some rotational motion as it's retracting. Again I haven't had a chance to closely examine the Bosch, Felder, nor sawstop system in person.

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  • 2 months later...

I had an inadvertent brake activation the first time I went to use the saw. I was testing out the power on procedures and had no wood touching the blade when the brake activated. (The k-chunk is not a sound you want to hear). I just sent in the brake to SS, so I'm not sure why it activated. The engineer I talked to on the phone from SS said they encounter a lot of folks who were plugged into an outlet that had a "brownout" or a large electrical draw as the saw powered on and that will cause the brake to activate. My blade had barely begun spinning, it was so quick to shut down right up front. My best guess is that my activation was caused by the outlet, but I'm anxious to see what the SS engineers find. My brake was the one that shipped with the saw (it's all brand new), and when I removed the activated brake, there was a loose piece of metal jangling around inside it. I don't know if this happened when the brake activated or if it got this way during shipping (it shipped installed in the saw). 

The owner's manual does guide you through testing to see if you should use the override feature, so I will definitely use that. It hurts to have to buy a new brake and blade before I ever got to use them. 

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On 5/14/2021 at 6:59 PM, HeidiM said:

I had an inadvertent brake activation the first time I went to use the saw. I was testing out the power on procedures and had no wood touching the blade when the brake activated. (The k-chunk is not a sound you want to hear). I just sent in the brake to SS, so I'm not sure why it activated. The engineer I talked to on the phone from SS said they encounter a lot of folks who were plugged into an outlet that had a "brownout" or a large electrical draw as the saw powered on and that will cause the brake to activate. My blade had barely begun spinning, it was so quick to shut down right up front. My best guess is that my activation was caused by the outlet, but I'm anxious to see what the SS engineers find. My brake was the one that shipped with the saw (it's all brand new), and when I removed the activated brake, there was a loose piece of metal jangling around inside it. I don't know if this happened when the brake activated or if it got this way during shipping (it shipped installed in the saw). 

The owner's manual does guide you through testing to see if you should use the override feature, so I will definitely use that. It hurts to have to buy a new brake and blade before I ever got to use them. 

I think they will ship you a new break for free when it triggers like yours did. Did you ask? Bummer that it did it upon first startup. I installed a new 220 circuit in my shop last Summer and that is what I used. It only has one 220 piece of equipment on it at one time. 

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  • 9 months later...

I was cutting a piece of Osage orange and it went off. The humidity here in Texas is between 25 and 36% most days so it being wet is not even possible. I do not know what caused the thing to inadvertently fire, but I am really unhappy. 

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If you don’t know why it triggered, you can send the cartridge to SawStop for their analysis. They pull data from the cartridge and can typically say why it triggered. They have been reported to replace cartridges if it was determined to be a misfire. 

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On 3/9/2022 at 4:53 AM, Joe Faia said:

I was cutting a piece of Osage orange and it went off. The humidity here in Texas is between 25 and 36% most days so it being wet is not even possible. I do not know what caused the thing to inadvertently fire, but I am really unhappy. 

I would absolutely send them the cartridge.  That way you would have a definitive answer.  Not necessarily one you may like but, definitive. 

As to staples and bullets.  I have sawn right through embedded material.  Small items don't seem to have enough conductive effect on their own.  I have triggered the saw when I have accidentally cut something conductive while I am touching that conductive thing by holding the material against a miter gauge.  The system is made to detect the skin that wraps up us big ole bags o' water :).

After my first dumb-guy move of trying to saw conductive (anti-static) UHMW I became real careful.  If there is any suspicion I make a cut in safe mode.  The thing that'll tick you off is if you had no reason to suspect or bother to test in safe mode and you fire the system :angry:.

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I always keep a spare cartridge because you just never know when it might go off, and I don't want to be interrupted in the middle of a project for more than a few minutes. I also bypass the safeties when I am cutting something I think is too wet or a non-wood material. It seems in your case the wood should have been dry and not triggered it. I would be curious what SawStop says if you send in the cartridge.

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On 3/9/2022 at 8:51 AM, gee-dub said:

...After my first dumb-guy move of trying to saw conductive (anti-static) UHMW I became real careful.  If there is any suspicion I make a cut in safe mode...

This is what I do as well.

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There would have to be competition for SS to dump money into an updated system. I love the idea of making the world better but greed really hampers progress for the spirit of mankind. More Elon Musks would be good.

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On 3/10/2022 at 7:19 AM, sjeff70 said:

There would have to be competition for SS to dump money into an updated system. I love the idea of making the world better but greed really hampers progress for the spirit of mankind. More Elon Musks would be good.

A system that sometimes fires when it shouldn’t is always better than a system that sometimes doesn’t fire when it should. 
As their patents age, you can guarantee that SawStop is heavily investing in R&D to significantly improve their current system or to develop new/different systems. They would be foolish not to.

Elon is a wacko but does push the competition and development curve forward. I love my Tesla and made a lot of money from Tesla stock, so I do have some bias.

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On 3/10/2022 at 7:33 AM, JohnG said:

A system that sometimes fires when it shouldn’t is always better than a system that sometimes doesn’t fire when it should. 
As their patents age, you can guarantee that SawStop is heavily investing in R&D to significantly improve their current system or to develop new/different systems. They would be foolish not to.

Elon is a wacko but does push the competition and development curve forward. I love my Tesla and made a lot of money from Tesla stock, so I do have some bias.

That would make good business sense for SS to take that approach.  

I think there's more to Musk than his cars. I don't believe anything the media puts out without fact checking (propaganda).

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