Saw stop

[pettyconstruction]

I was making some shaker style doors for my old kitchen and triggered the saw break.
Good news is it worked , the bad news is it  went off.

My own fault as I had a dado stack in the saw and got the fence to close.
I should have put a sacrificial fence on the saw but didn’t .

Two things that are interesting,
1- The whole thing was way less violent than I had expected , the dog wasn’t bothered until I started to swear. Lol
2- The blade ran and had no problem until I had put the wood through with a crosscut sled.
I think my flesh had completed the circuit and triggered the mech.

Anyway,just a reminder of how fast things can change and could be bad.

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[Alanbach]

So did your flesh contact the blade?

 

[RKA]

1 - good to know, my dog does not like swearing (or loud noises).
2 - huh?  You triggered it twice in a single night?

 

[pettyconstruction]

No flesh contact, I think my hand on the wood did the trick.
Also , I did not trigger it twice in one day,just once.

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[Alanbach]

I’m just glad that you were not hurt! Could there have been any metal contacted when the blade touched the fence?

You can send the cartridge into Sawstop and they will read the data. If they detect any sort of human contact they will send you a new cartridge for free.

 

[Gregor]

You can send the cartridge into Sawstop and they will read the data. If they detect any sort of human contact they will send you a new cartridge for free.

Strange policy.

I would understand it would they replace ones that misfired...

 

[RKA]

Ah, I misunderstood.  I thought you were suggesting the blade to fence contact caused it. 

As far as what triggered the brake, it’s most likely the crosscut sled or the material you were cutting.  Even high moisture content wood can cause it to misfire.  I would sort that out before you try again.  I don’t think your hand on the wood was a factor unless it came in contact with the blade.

 

[Birdhunter]

You said you were using a Dado stack. Did you have the Dado cartridge in place and the SawStop Dado specific lock down throat in place? Did you adjust the cartridge-to-Dado blade clearance?

 

[cpw]

You can send the cartridge into Sawstop and they will read the data. If they detect any sort of human contact they will send you a new cartridge for free.

Strange policy.

I would understand it would they replace ones that misfired...

It makes sense in terms of: (1) they don't want to subsidize mistakes when you contact metal, (2) having data that shows a confirmed "save" is good for them marketing wise.

 

[RKA]

What's interesting to me is there is information stored on the brake cartridge that helps them discern a flesh activation vs. some other cause.  The question that raises is...if they can figure it out, why can't the saw be set up to make the same distinction.  The only thing that comes to mind is it's not quite black and white, but shades of gray and they set up the saw to activate the brake nearly 100% of  the time when exposed to flesh at the expense of some unwelcome activations?  So maybe they know what data to expect with steel, aluminum, high moisture wood and other common triggers.  And if the data is inconclusive, they give you the benefit of the doubt?

 

[usernumber1]

i suspect sawstop wants the human accident data in order to have more leverage. there's a political battle still ongoing with saw safety, Consumer Product Safety Commission (CPSC) and their opposition at Power Tool Institute (PTI)
Bosch also has a saw since 2015 that infringes on two sawstop patents.
i could not find either company publishing actual numbers of accidents prevented due to their technologies specifically

"intensive lobbying" in 2017 -https://en.wikipedia.org/wiki/SawStop

What's interesting to me is there is information stored on the brake cartridge that helps them discern a flesh activation vs. some other cause.  The question that raises is...if they can figure out it, why can't the saw be set up to make the same distinction.  The only thing that comes to mind is it's not quite black and white, but shades of gray and they set up the saw to activate the brake nearly 100% of  the time when exposed to flesh at the expense of some unwelcome activations?  So maybe they know what data to expect with steel, aluminum, high moisture wood and other common triggers.  And if the data is inconclusive, they give you the benefit of the doubt?

 

[jeh]

I don't care about the data or misfires. I bought my PCS at a sharply discounted rate in order to provided feedback prior to it shipping. I have never had a misfire and have never bypassed the system. The misfire issue is being overplayed.

 

[ChuckM]

Not counting the dozen or so of hotdog tests that I witnessed, I have not come cross any activation (misfires or not), having been a sawstop user (later owner) since 2007 or 2008. I did know of one misfire caused by someone where the mitre gauge fence touched the blade.

My go-to blades are Woodworker II, and I will do everything humanly possible to keep them from getting wrecked. The cartridge is cheap in comparison. I have bypassed the system two times all these years.

 

[Alanbach]

I am friends with the Manager at the local Woodcraft. In his experience most “misfires” aren’t misfires at all. He sold a bunch of saws to a large University. A week after installation they had a “misfire”. They were unhappy as they had been concerned about the possibility of multiple misfires and the associated expense. He drove out there and had a meeting with their people including the person that was using the saw. They were sure it was a misfire. The employee described the incident move by move. As he simulated passing his right hand through the blade zone my friend asked why he had a bandaid on his thumb. He said that had a little scratch there and he did not know where it came from. Mystery solved.

Sometimes the contact is so slight that the user doesn’t even know. Either with skin contact or metal or wet wood or some other conductive material.

 

[pettyconstruction]

So to clear up some stuff.
At no time did my saw blade contact my flesh ,
The saw fence triggered the cartridge .

I had run the saw  to see if the blade was clear of the fence, and it seemed to be clear.
When I ran a board through , it went off.
I had only started cutting when it happened .

I think the blade flexed into the fence , or my hand on the table did it. At no point was my hand near the blade.

A small bit of metal was shaved off the fence ( 1/16-1/32”) very small.

At no time did I want people to think it was skin contact and I apologize if that’s what was thought.

Just a stupid mistake by not adding a sacrificial fence.
Thanks for all the comments ,
Charlie

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[Alanbach]

Ok, in the original you had said that you thought that your flesh on the table had triggered so that is what caused me to suggest you send the cartridge to Sawstop.  Based on your last post I have drawn 2 conclusions:

1. IMO, The small metal contacted in the fence was definitely what caused your event.

2. Clearly your dog is smart and has faith in the Saw Stop tech. That is why he was calm and cool!

I do have one more important question. Even though you said the whole thing was way less violent than you thought, did you still have to go change your pants? I know that would have had to!

BTW, my theory on why it was less violent than you expected is because the whole event takes place in a few hundredths of a second.