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SawStop Nusance Trips

14K views 91 replies 45 participants last post by  rob2 
#1 · (Edited by Moderator)
If your SawStop break has tripped and it didn't touch your finger, Please share what did trip it.

I trripped mine with a carpenters pencil lead. I had turned the saw off, it was coasting and I was using a pencil to move small pieces of maple away from the blade. POW. Fastest $200 i ever spent.

Hopefully we can help each other avoid the expense. If your finger has been saved please share that also.

Thanks.

Rob
 
#3 ·
I agree with Sharon. You might want to forward that info to SawStop. I would think they could add a section to their manual (or web site) to alert folks of what can cause an accidental trip.
 
#5 ·
I don't know anything about Saw Stop, but it probably works on the electrical capacitance of the blade. They are probably using very sensitive electronic to sense any change.
Anything you touch it with is probably risking a trip. The carbon in the pencil lead would probably do it. Really green wood would probably do it. Just my wild guess. Been electrician for 40+ :=))
 
#6 ·
I've heard a small brad or even wet glue in a fresh joint will stop it cold. The local plastic shop has one and they found out that foil backed plastic sheet sets it off. It has bypass mode for cutting wet wood or anything else known to be conductive but that bypasses the safety also.
 
#8 ·
I work at the Marc Adams School of Woodworking and we have 8 SawStops in the building. In the 2 1/2 years we've had them the brake pad has been tripped by brads, wet glue. Also riving knife we forgot to take out when we cutting a new throat plate; in raising the blade through the plate the knife got pushed down and just touched the blade. A couple brake pads went off on their own. Supposedly there is "black box" in the brake pad that SawStop can examine. I believe that in that manual is mentions that the brake will activate as long as the blade is spinning (even after you push the stop switch.)

We've not had any finger incidents since we use the "3inch / 12 inch rule" for our machinery.
Keep your fingers 3 inches or more from guards, shields, pullies, and pinch points. Use pushsticks or jigs to maintain that distance when needed.
Marc created a series of articles on safety that were published by Popular Woodworking and were in issues starting about a year and a half ago.

The 12 inch rule means that if your stock in less than 12" long, you need to consider whether a piece of machinery is appropriate for the operation you want. Stock under that length needs attached to a bigger piece of wood or the use of a jig, etc that makes the small piece behave like a bigger piece of wood.
It sounds like you were either crosscutting with the mitre gauge or ripping a short length. Most of the time we dont crosscut on the table saw unless we use a crosscut sled. If you are using a mitre gauge, you need to screw a long and tall scrap board to the gauge to create a long fence that extends past blade ( this supports your stock on both sides of the cut. ALSO, screw a fat wooden block to the back of extended fence where the cut will be. This will create a blade shield on the back of the fence. What this set up will let you do is make your cut, pushing your stock past the riving knife, and with the blade safely covered by the shield you can remove your cutoffs ( or ignore then since they are safely past the blade and riving knife).
For ripping some (NOT ALL) short pieces you can use a wide push block. Some of our's are 2 1/4" wide. By raising the blade about half a tooth above the stock and using just the riving knife ( the one without the blade shield.). What you will be doing with your push block is placing it so as to support both sides of your cut and pushing it right over the blade( your riving knife should be set just under the height of the blade; check your manual). This will cut into the push block as you push both sides of you stock past the blade AND the riving knife.
Again there are many ways to safely do things. Safety is a skill that needs regular practice, so take the time to think things through. You'll be rewarded with better cuts to.
 
#12 ·
I wonder if this is going to be like Ground Fault Circuit Interrupters (GFCI) when they first came out and were required on all construction sites? So many nuisance trips nobody could get any work done.
 
#13 ·
I tripped the brake on my saw over the weekend. It ruined my brand new freud rip blade. I only had it for two weeks. I was lucky that I decided to take out the Forrest WoodWorker II to clean it. It destroyed a $60 dollar blade versus $115.

Here's how it happened. I made the mistake of gluing a metal tape measure to my cross cut sled. I don't know what I was thinking. It just brushed up against the blade and bang, there went $140 dollars (new blade and cartridge).

I think it was a lesson well learned though.

- First lesson. The brake works and is very sensitive

- Second lesson. The brake won't work if the blade is dirty. Pitch will break the electrical current between the blade and your finger. How do I know? I had my WW2 on the saw for months and didn't have a problem. The minute I switched out to a clean blade and it touched the metal tape measure attached to my cross cut sled, it fired off. Suffice it to say, I will keep my blade clean from now on.

Hope other people learn from my mistake….
 
#15 ·
Is it possible that you were touching the other end of the pencil lead when the blade hit?
The saw might have been sensing the your hand through the pencil.

On TV they like to use the eraser tips on those cheap yellow school pencils to move small parts away.
I personally use the the tip on my push stick, since we always keep those close by….right?
 
#19 ·
Chucky,

Both blades have teeth which are 1/8" in thick. In fact, thin kerf blades don't work with this saw because of the riving knife. You could remove the riving knife, but I think I read somewhere that there are more kickback accidents than accidents where hands come in contact with the blade.

Cr1,

Where do you see stats on how often the brake gets tripped? I've only seen this forum here, but haven't seen a lot of published data. If it does get tripped often, I would consider selling my saw, but its such a good it would take a few trips before I am convinced that its flawed.

On a similar note, last week Finewoodworking announced that the courts upheld the ruling against Ryobi, and apparently it's a big deal because the saw manufacturers may have to develop their own version of the safety device.
 
#20 ·
Certainly any finger is a finger worth saving, but the SawStop method seems a bit over the top. I suppose if one can afford to replace blades and cartridges, not too mention the premium for the saw, then it makes good sense, but….

When will someone come out with a overhead-mounted device that projects a solid, blood red beam of light onto the workpiece that matches the outline of the blade insert plate ? That would get my attention.
 
#21 ·
KBX500,

My portable craftsman saw had a laser mounted on the blade guard that pointed a light on the cut line.

Topamax,
There was an article a few weeks back where someone invented a light activated safety device. He demonstrated it in a video, but didn't explain the engineering behind it.
 
#22 ·
From when I looked, the same SS cost about the same as the comparable Uni …. FWIW.

If we do the typical Internet thing, and judge from the people who post what DID happen (ignoring, by definition those for whom a thing did NOT happen), we'll be screaming that the sky is falling.

We don't read about airplanes that don't crash. Let's keep this in perspective ;-)
 
#23 ·
breaknrn, I saw that on here, I think. I'm not exactly sure how they do the motor stop on a single phase motor, but it has to be an electronic signal similar to dynamic braking on a dc or 3 phase motor. Even with saw stop, I think that braking system would be a lot more serviceable than the braking cartridge and destroying the blades.
 
#26 ·
Makes sense that wet glue, even a pencil lead touching the blade would set it off…anything that changes the capacitance of the blade is going to fire the cartridge. Foil backed plastic..that's a no brainer….It's too bad that it ends up costing so much…..I would be seriously bummed if I had to throw out one of my cherished Forrest WW2 blades due to a misfire….but I would take the "hit" if it saved me from a trip to the hospital..
 
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