If you are coming in to use the table saw in the wood shop anytime later today through mid-day Tuesday - this note is for you. (1/15-1/17)
The table saw is working, and is NOT red tagged
The brake has been tripped 3 times in the last two days, and the shop has run out of our normal table saw blades. More have been ordered, and are expected on Tuesday.
IF YOU NEED THE TABLE SAW IN THE NEXT FEW DAYS, I RECOMMEND YOU BRING YOUR OWN BLADE.
The goal here is for you to be able to complete your own work in the case of another tripped brake. As always, you are welcome to continue to use the blade that is on the saw when you arrive.
The shop does have a supply of brakes on hand.
As of the writing of this post, there is also a blade on the machine that is working.
Reminder: what to do if the saw stop trips.
Changing the table saw blade
Has the cause of the 3 tripped brakes been determined? User error? By 3 different users? This is disconcerting—if it is user error, is there an internal process to assist the user in reviewing safety and/or proper table saw techniques? I’m just thinking out loud here.
The first was definitely user error, resulting in actual skin contact! This member was new and took the Woodshop Safety class just recently. I believe a steward was on hand to counsel them about their mistake. (“And that is why we use push sticks….”)
Last I heard, the second person hadn’t reported back yet. But apparently the security camera view of the incident strongly suggests it was also a real skin contact event!
We hadn’t had even one happen in a while, so two back to back is a safety/training concern.
Also of concern is that the cause of the third is unknown, with no apparent skin or metal contact. That should be looked into carefully as well.
I was about to do a quick cut on a freshly glued piece of wood last week then reconsidered the decision. With the saw powered but not spinning you can watch the red LED on the switch and monitor circuit status. Touch the blade with your finger and the red light is illuminated. Touch the blade with green wood or a freshly glued joint and it MAY or MAY NOT be possible to see the light. Its not a perfect test but gives some idea of how the circuit functions. Don’t rely on this test to tell you if its ok to cut.
BTW, I am also a member of the SawStop cartridge club. Late last year the free end of my tape measure touched the spinning blade. I’m very conscious of the movement of my hands but the end of the tape got away from me. The saw put a small hole in the metal tape but its still usable. I was impressed.
I haven’t used it since last year so I can’t account for their current state, but there should still be a moisture probe on the side of the saw along with a metal detector
Ah, so many years ago I had a minor fight to put the Sawstop in not long after we moved into Dessau.
Actual arguments- it will lure people into a false sense of complacency, they stop thinking about what they’re doing and make mistakes (which somehow would be more serious than losing a finger?) and they aren’t learning. I’ve met more than a few woodworkers with less than the traditional full complement of 10 distal phalanges so I’m not really sure what that point even was.
And people actually proposed a second table saw for those who didn’t want the Sawstop. All I can say is, it was a different time.
Sawstop advised us that the flash/no flash test for conductivity while stopped is not reliable. At the time they said it uses a different algorithm while cutting, which actually doesn’t sound right.
I think the more important factor is that wet wood will likely be much drier on the outer 1/16" or so, making this test inaccurate.
There is a bypass mode which requires the key to set up. It electronically disables the brake trigger entirely. We don’t allow it to be used in this mode, but it can be used to test hypothesis because it will flash while cutting if it detects a trigger condition (which it will not act on). The only reason I mention this is it possible to explore just what “too wet” might be with samples being cut under controlled conditions with no possibility of finger contact
Regarding the testing of humidity levels of wood, there are so many quality meters available for under $80. I have a dual unit that has both pins and a sensor that reads deep into the wood. This may be a good investment for the wood shop considering the cost of a new blade and cartridge. Is there a way to get a consensus to adding one to the shop?
In my 3 years working at a community college woodworking program, we had 3 Sawstops and there was only one incident of a cartridge being engaged. That was from metal staples in the wood.
Only one brake tripped in almost a decade of combined table saw use is very impressive. Perhaps it is a cultural thing, maybe we need an actual penalty of some sort to encourage more care. Just having to pay for a new brake and blade isn’t really a penalty in and of itself, it’s just making it right. (Almost) all SawStop trips are completely avoidable. Of course, accidents happen, but three in one weekend is troubling
I think a $160 penalty for a new blade and brake is encouragement enough. Considering the number of people using the saw and the varied experience involved I don’t see much of a problem. Statistically speaking this may not be an unexpected occurance. The Saw Stop is doing its job.
While this is true, it mis-estimates things. We’ve gotten about one false trip a month for a while. Meh. That’s an acceptable tradeoff for being a real safety feature and $160 is enough of a pain that you remember what you did wrong.
The fact that we seem to have had two ACTUAL SKIN CONTACT SawStop trips close together is VERY concerning. We’re not getting through to people that the machines in the shop are dangerous.
Maybe watching that YouTube video of injuries and of the YouTube creators and their injuries together in the multipurpose room needs to be part of the Woodshop safety training to ensure that people take this seriously?
I will say that the one injury in that video that shocked me was the YouTube creator who got a kickback that impaled his right arm which distracted him enough that he put his left hand right onto the blade. A multistep failure like that is absolutely not a scenario I would have considered before that video. It certainly makes me think a bit more about “Is my other hand in a place where if something goes wrong it won’t get pulled into things and make the situation worse?”
Yeah, normally I’d think so but apparently it’s not disincentivizing that much; regardless, a higher financial penalty is not really what I meant. Maybe more of a strike system to put some extra pressure on you if you’ve done it multiple times. I just think that it really shouldn’t be happening, ever (besides the completely unavoidable false positives, as @buzmeg mentioned). I know “never” is an ambitious goal, but I don’t think that 10-20 a year or wherever we’re at is an acceptable place to stop trying to improve.
The saw stop is doing it’s job to avoid severed fingers, but I wouldn’t want to be the one who set it off – it can still cut you up well enough to need stitches.
I don’t think we’ve had anybody set off the SawStop multiple times. I don’t think that’s a problem looking for a solution right now.
We NEED to at least try to solve the problem of it firing even once on real fingers of newbies. The message isn’t getting through.
That’s good that no ones ever done it twice. In the words of President George W. Bush: “fool me once, shame on — shame on you. Fool me — you can’t get fooled again”
Again just thinking out loud here…one easy way to help new woodworkers and/or new table saw users is to require a shop steward to supervise them for X number uses before they given free access for future use. This additional “training” would be highly effective.
This is something we implemented at the community college and I can attest to its effectiveness. It proved invaluable not only for blade awareness safety, but also catching and preventing dangerous cuts that could lead to kick back.
Again, just some more pennies tossed in that no one asked for.
I’ve noticed a lot of people not using a push stick. I wonder if a lack of push sticks may be a factor. They are very easy to make on the CNC, so maybe would be a good project for the CNC intro class @jamesfreeman. If you would like, I can put together a .DXF file for you
We buy nice push sticks and blocks and they slowly disappear. I think we need to buy, or maybe make as Hanna suggests, a bunch more now; they’re becoming scarce again.
@buzmeg, Where does this statistic of one false trip a month come from? I’m not aware of any false trips on our machine. (The third recent trip has been identified as also a clear user error; they brought the metal stop block on the fancier cross cut sled into contact with the blade.)
Over time we’re in the ballpark of one non-skin trip a month. I consider that a false positive – the purpose of the sawstop system is to stop the blade on contact with skin. If it stops the blade on contact with something else, that’s a false-positive (even if it’s a known limitation of the system i.e. conductive materials)
@mgmoore Sorry. I was probably being insufficiently precise with language. As far as I know, we have never had a “false trip” in the sense that the machine went off for no reason at all.
I was using “false trip” in the sense of any trip that wasn’t a direct result of someone putting their hand in the saw. As for those, it feels like we’d get a “Tripped the SawStop” post about once a month or so.
However, the two most recent trips were the first I remember where someone actually got a SawStop fire on their actual hand. I don’t think we’ve ever even had one trip like that before let alone two.
Gotcha. We’re on the same page then. I also don’t recall a real skin trip before.