I know, I know. No more Saw Stop Threads!!!! I just have to because of what happened today.
This morning first thing I set up the Saw Stop to rip down some strips of 1/2″ CDX plywood that had been fire treated . The material had been left outside covered in previous days but brought inside yesterday in prep for this morning. The material was NOT soaking wet. It was damp at best and no where as wet as P.T. would be straight from the lumber yard. So you can imagine my surprise when the mechanism tripped while into my second cut. My hands were no where near the blade at the time and all guards were in place.
I cannot believe the saw was tripped as a result of the stock being as damp as it was. I tend to think it was a false trigger. Either way I believe there could be a flaw in the design of the tool. We cut all kinds of wood and plastic with it and this is the first time this has happened. I can understand not cutting metal but what happened today seems extreme. We intend on contacting the company for more info on why this happened.
Beware out there……Think twice before you cut anything that is even a little damp, never mind wet, with this tool. As a side note- it took me about 5 minutes to change out the blade and cartridge after this happened.
-Paul
Replies
I hope you have contacted SawStop about this. They will want to examine the parts. They definitely do not want false triggers, and my understanding is they persue likely problems vigorously. It's only fair that you call them and find out what they're wanting to do, and what they might do to make things good.
forestgirl -- you can take the girl out of the forest, but you can't take the forest out of the girl ;-)
Forestgirl,
Yes I have an e-mail into the Saw Stop folks. I will report back any info.
-Paul
What you say all sounds reasonable, however In their defence if you had any idea that the material could have been on the wet side all you had to do was bypass the electronics. I'm not saying you should have, I wasn't there. But the option to bypass the electronics is there, and with what I spend on blades and the cost of the cartridges I would be cautious.
Pardon my spelling,
Mike
Make sure that your next project is beyond your skill and requires tools you don't have. You won't regret it.
Hey Mike,
It didn't even occur to me to by-pass the mechanism. That's how un-wet the stock seemed. I had heard the wet might be a problem. In this case I guess I mis-judged how wet was too wet.
-Paul
That is understandable. I can't imagine that CDX straight from the yard would trigger it. When you said something about fireproofing and leaving outside I thought that was too much. But I understand that didn't think it was too wet. I may have made the same call.
If I understand the Saw Stop electronics it dosen't measure moisture, rather it measures the magnetic (inductive) properties of the material and compairs its signature to a reference that would trigger the brake. So it is possible that it wasn't the moisture content but the combination of the "fire proofing" and moisture and ??? Well you get the idea. I bet Saw Stop will be very interested in the properties of the material you cut.
By the way did the brake scare you when it triped? The first Demo I saw scared me and I knew it was going to happen. I imagine it would really scare the crap out of me if I wasn't expecting it.Pardon my spelling,
Mike
Make sure that your next project is beyond your skill and requires tools you don't have. You won't regret it.
Hey Mike,
I am looking forward to correspondence with the Saw Stop folks to get to the bottom of this episode. The technology fascinates me.
I have to say when it fired I had no idea what was going on. It was a loud slamming noise that clearly lets you know that something is wrong. It happens very quickly. There was a lot happening in the shop at the time so it probably didn't startle me nearly as much had I been alone. I hope to never hear the noise again.
-Paul
Do you have a moisture meter with which you can check the moisture content of the wood? It'd be interesting to know this information.
I don't have access to a moisture meter. Perhaps I can persuade management to invest in one. It would never actually occur to me that I would need to meter plywood. I guess I assume its dryness as a manufactured product. Perhaps I will need to re-adjust my approach when utilizing this new technology.
-Paul
Uncle,
It was damp at best and no where as wet as P.T. would be straight from the lumber yard
If you had an idea it was damp, why didn't you bypass the safety feature? Damp will trigger the mechanism. CDX is nowhere near as dry as kiln/air dried hardwood. (Probably in the neighborhood of 15% moisture content). I would definitely invest in a moisture meter.
Lee
Hey Lee,
Just didn't seem like I needed to meter the plywood at the time. Nothing about the operation raised any red flags with me. After I had time to go back over what happened I'm leaning in the direction of a false trigger. I'll wait to see what the Co. says before I make any final judgements, though.
-Paul
Just curious, what was the extent of damage to the blade?
Hey Mike,
Not sure of the full extent of the damage just yet. We left the blade embedded in the alum. block as a bit of "show and tell" with folks that are in and out of the shop. Have had a lot of interest in the saw since we got it so we figured we could show what happens when it goes off.
My suspicion is that it warped it judging by the "crumpled" look of the block it is embedded in. In the manual it says to dislodge the two with a block of wood before removing from the saw. I was able to remove the two while still attached. One other note here. After it trips and you have replaced the parts, you have to wind the blade height adjustment all the way down to re-set that assembly. I couldn't figure out why I couldn't raise the blade like normal until I read the instructions.
-Paul
"Not sure of the full extent of the damage just yet."Paul,Thanks for your reply. That's interesting, and it's what I would expect, but a local dealer told me he saw a demo and the blade needed only couple of teeth replaced after the cartridge deployed. I have no reason to doubt his word, but can't see how a blade could withstand that kind of trauma without some distortion. I know the cost of a cartridge and blade is small in comparison to the loss of a digit, but the guy who finds a way to spare the blade will sell a ton of saws.Anyway, thanks for the information. I'll bet that even without physical contact with the blade, a sudden "incident" like this can get your attention.MikePS. I see from your profile that you're in central Florida -- Gator fan?
I'll report back on blade damage. One thing for sure, that thing stopped that blade dead cold. There is no indication of any spin past the point of contact. It was a brand new blade so I hope it can be saved.
I am a transplant to Fla. from New England. My boss bleeds orange and blue so when he's around I am a Gator fan! LOL! Go Patriots!
-Paul
"I am a transplant to Fla. from New England. My boss bleeds orange and blue so when he's around I am a Gator fan! LOL! Go Patriots!"You're killing me! I'm a Connecticut guy who loves the South (Valdosta Rebels '72), not just Connecticut, but Hartford, so you'll understand why I'm not a Pats kind of guy. Go Gators -- Go Jags! I won't rat you out to your boss, but in your heart, you know he's right, and someday Uncle Steve WILL be back. So thanks for getting back to me and glad the "blade stoppage" was not more damaging than it was.
I received an e-mail back from SawStop president Stephen Gass about the saw triggering episode. He wasn't aware of fire treating ever causing a saw to trip and indicated that the moisture would need to be pretty high for that to be the cause. He said to send him the spent cartridge for analysis to try to determine what happened. I plan on doing just that. His advice on cutting stock that you aren't sure about is to make trial cuts with the mechanism off. The status lights on the switch module would indicate whether or not there would be a problem had the system been engaged. An easy way to tell if a trip would occur.
I will update this story as I get more information.
Thanks,
-Paul
Paul,
Overall how has this affected your sawstop "experience"? Were you a fan of the technology before, and are you still?
I think the technology is cool, and I'd gladly trade my $100 blade for my finger.
Buster,
I am and continue to be a believer in what the SawStop folks are trying to do. It is an excellent saw. I would expect a certain number of hiccups in technology as new as this. I was pleasantly surprised that the president and founder of the company personally responded to my e-mail.
I look forward to seeing this technology advance and hope that the vision here will usher in a revolution in tool design.
-Paul
One thing I always say is that if you took the emergency brake off the Saw Stop you would still have the best american style 10" cabinet saw on the market.
Pardon my spelling,
Mike
Make sure that your next project is beyond your skill and requires tools you don't have. You won't regret it.
Absolutely.
-Paul
I love the idea behind the Saw Stop and can't wait untill i can afford to trade in. But i have always wondered, when stoping a blade that fast the energy has to go somewhere. I wonder about it twisting or fracturing some of the trunion and other things underneath. Does the machine still seem perfect? balance, alignment, ect....Tmaxxx
Urban Workshop Ltd
Vancouver B.C.
cheers. Ill buy.
I think thats whats behind the holes in the brake shoe. They act as crumple zones and absorb the bulk of the energy.
Since the house is on fire let us warm ourselves. ~Italian Proverb
It is exactly as dgreen said. The aluminum block crumpled at the holes. Also if I understand it correctly, the power is cut simultaneously so I would think any left over transfer energy may go away as belt slip over the pulleys. The mass in the trunions probably compensates for the shock anyway.
I have noticed no residual problems or misalignment after the trigger.
I believe a contractors saw is coming at a lower starting price.
-Paul
I believe the act of pulling the blade below the table dissipates a lot of the energy.
George
I work for a store store that primarily sells tools, supplies and equipment to the cabinetmaking, woodworking and costruction trades, as well as to hobbyists. SawStop is one of our product lines, which also includes other quality cabinet saws such as Powermatic, Jet, General, Delta. Most of recent our sales of SawStop saws are to schools or larger shops with multiple semi-skilled employees who are not dedicated, mature and cautious woodworkers. Some home shop hobbyists and small woodworking shops are also beginning to buy the SawStop, but we still sell lots of other brands of cabinet saws. I have seen a live "hot dog" test, and we have the video running continuously on a small laptop in the store. If a prospective customer comes in without a specific brand preference, I point them to the video, and tell them about the features and benefits of the SawStop cabinet saw. If they are not interested for whatever reason, I move on to other brands. We have a spent cartridge sitting on our floor model that a customer brought in after forgetting to set the bypass switch when cutting wet pressure treated lumber. They bought a new cartridge plus a spare, and were aware that the safety feature should have been switched off. Everyone discussing the merits of the SawStop should should understand some of the basics of the triggering of it's safety feature. (If I am wrong about the details, corrections are welcome.)- The system senses changes in conductivity/capacitance, and a material must be conductive to trigger the brake. - Since pure distilled water is not conductive, wet wood without ionic salt or metallic particles present should not trigger the SawStop. The above party who bought the replacement cartridges said that they have cut lots of wet lumber with no problem.- By touching a workpiece to the blade and reading the SawStop's indicator lights before turning on the saw, you should be able to determine whether or not you should turn off the safety stop feature. - If the saw blade touches a small staple or other tiny bit of conductive material in the wood, it would probably not trigger a firing of the shoe.- It is a sophisticated electronic circuit, not just a simple detection of conductivity or capacitance that makes the SawStop safety mechanism fire.- When the brake shoe slams into the blade, the blade is not "pulled" down, but rather the significant energy in the rotating blade (angular momentum) is instantaneously transformed into a powerful linear motion that slams the blade down below the table with a very loud BANG.I have talked to several customers recently who could have benefited from a SawStop cabinet saw. Two tablesaw accident victims came into the store last month and told me about their accidents. One had cut off a finger, and and the other one, a thumb. They were both able to retrieve their digits and have them reattached, but permanently lost feeling and mobility, and a bit of length. One of them said that he had slipped on the sawdust on the floor at the front of his table saw. He immediately wrapped a cloth over the bleeding stump, retrieved his thumb, and got his son to drive him to the hospital. (When he came back home from the hospital the next day with his re-attached digit neatly bandaged, he discovered that his shop lights were still on and the saw was still running!!) A couple of days ago, another customer told me about two friends in the business who had suffered serious tablesaw accidents recently. He said that in both cases, the victims had looked backwards while working at their saws with the blade running, and run their hands into the blade.I won't get into the arguments for and against the SawStop. I'm glad that the technology is there for those who want it, but I absolutely do not want to see legislation mandating this proprietary technology.Dave van Harn
Hi Dave,
Your post was very informative. I have seen the SS at a shows and my local supplier. When you said.
"Most of recent our sales of SawStop saws are to schools or larger shops with multiple semi-skilled employees who are not dedicated, mature and cautious woodworkers. "
It seems to imply that those who are dedicated, mature, and cautious don't need the added protection. I don't know if that is really what you meantm, or simply that is who is purchasing. I just want to say that it is the profesional with years of experience that is most likely to make a mistake. I know that I have spent 6 or more hours cutting ply down or ripping lumber and it only takes a second to have an accident. Pardon my spelling,
Mike
Make sure that your next project is beyond your skill and requires tools you don't have. You won't regret it.
Hi Mike,I was just talking about who is buying SawStops, and making a casual observation based on my experiences talking to people in the store. Interestingly, it is often long-time woodworkers in addition to students and "lower-skill" employees who happen to work in a wood shop who hurt themselves. It can happen to anyone. The guy who told me about the two friends who had recent tablesaw accidents did not buy a SawStop, but he is thinking about it.All it takes is a split second - before you realize what is happening part of your hand is gone! Just like other statistics, even if you are cautious, the longer you do something dangerous, the more likely you are to have an accident. And yet, as in gambling, the odds do not change for an individual instance or event, but accumulate over time - a concept the few actually understand. No matter how many times you roll the dice, a particular number is never "due" to come up on a given roll. But unlike the statistics for rolling dice, accidents while working with tablesaws are more likely under certain conditions. Accidents are more likely to happen if you are tired, stressed, careless, sloppy, and distracted. I do not work in the shop if I have had any alcohol, or if I am drowsy or really tired.Who "should" own the who saw and who choses to buy it is a difficult question with no clear choices. We can debate the issue forever, but that's not why I posted. Dave VH
I agree completely. Working at a retail store with all these machines side by side, how would you compaire the SS to PM66 or General. Forgetting about the brake technology I think the SS is still superior to the others in castings, machining and fit finish. Pardon my spelling,
Mike
Make sure that your next project is beyond your skill and requires tools you don't have. You won't regret it.
"Most of recent our sales of SawStop saws are to schools or larger shops with multiple semi-skilled employees who are not dedicated, mature and cautious woodworkers. "
I suspect a primary reason such institutions are buying the Saw Stop has to do with liability insurance. Such technology could equal a big insurance discount for those large enough to think on such a scale.
Certiantly that is a big motivator. But as a owner of a pro shop let me tell you workmans comp in this industry is no joke. Luckily my shop is small enough that my premiums aren't that bad. Some of my friends are paying 5+ thousand a year and their shops are not very large either.
As far as liability, in my shop the machinery makes little difference because my customers or non-employees are never going to use them.
Pardon my spelling,
Mike
Make sure that your next project is beyond your skill and requires tools you don't have. You won't regret it.
"Some of my friends are paying 5+ thousand a year and their shops are not very large either."
Mike - Precisely my point. If owning a Saw Stop will save you 10% (theoretically) on your insurance, in the above example you've paid back the higher price (compared to a Powermatic, say) in 2 or 3 years. No brainer if you have the resources, and if the saw on it's own is everything I hear it is.
Richard
Oh I agree completely.
I thought you meant that those schools and the like needed them more.
My origional observation was that the first poster noted it was mostly inexperienced users and schools that were buying them at his store. I find that interesting because my local distributer (pro sales only) is selling them so fast that they keep 4 or 5 in stock. I wondered if he thought that a Pro or "mature" wood worker didn't need the Saw Stop. But he did not mean that.
Unfortunately there is not a "discount" if you have a Saw Stop. My insurance agent called me a while back to ask if I had one (I don't know why he already has a detailed list my machinery) but he said there was no real discount as of yet. And I've been around enough to know that there will never BE a discount. They might charge MORE if you don't. But there is never a lowering of insurance rates. heh heh.Pardon my spelling,
Mike
Make sure that your next project is beyond your skill and requires tools you don't have. You won't regret it.
I tripped mine about a year ago, I was doing something stupid for SWMBO and cut through a nail that I knew was there, the item was an old household window frame that was painted. the nail may or may not have made contact with my fence, which is aluminum. My hands were 2 feet from the blade.
they asked for the cartridge back, so the could read the data out of it., even emailed me a graph back if the incident. I need to replace a tooth on the blade (thin kerf freud 50t), but it is otherwise OK.My theory is that the cost of the saw is less than the cost of 1 trip to the ER, minus the pain and crippling injury, of course. I also get the best darn saw ever made, I get pleasure every time I use mine, nothing like a quality tool!Edited 9/11/2006 3:15 pm ET by michael503
Edited 9/11/2006 3:17 pm ET by michael503
His advice on cutting stock that you aren't sure about is to make trial cuts with the mechanism off. The status lights on the switch module would indicate whether or not there would be a problem had the system been engaged. An easy way to tell if a trip would occur.
I must not understand this correctly. This idea seems counterintuitive to safety. If I'm running a cut, I'm looking at the blade. I don't want to be looking at the status lights by the switch... ESPECIALLY if the safety mechanism is overridden. Is there a way to get those lights to stay on AFTER you turn the saw off and indicate whether it would have triggered?
Edited 9/10/2006 5:47 am ET by Muzhik
A little confusing, I know. There is a green light and a red light on the switch box. There is a menu on the side of the switch box of different red/green flashing and not flashing combinations that give you the status of the saw.
The lights continue to blink or stay on/ off depending on the reading for a time after the cut is complete. Actually, as stated elsewhere, with the saw not running you could put the work piece against the blade and get a reading as well. An example: take an ordinary scrap of lumber and place it against the blade at rest and you'll get no change in the status lights. Place a scrap of aluminum against the blade and you get blinking red lights.
Hope this helps.
-Paul
Hey Mike,
Just a follow up to your earlier question about damage to the blade. We removed it from the block so we can send the block out for analysis. I carefully inspected the blade and found no damage. There is no chipped or missing carbide and when laid it flat on the jointer table there appears to be no distortion in the form of warpage.
The guy that does our sharpening was in the other day and he also found no damage. Did we get lucky? Was it a perfect shot? Maybe just a really good blade? (A 60T industrial grade combo we get from the sharpening guy at about $100 a piece). I just don't know the answer. I hope we lucked out and there isn't damage we can't see. Haven't used it again-yet.
Stay-tuned.......
-Paul
"Just a follow up to your earlier question"Paul,Thanks for the follow-up. That's good news for you and encouraging. As I said earlier, my local dealer saw a demo where the only damage to the blade was a couple of missing teeth. Another reason to like the saw. I love my 66, but if I were buying today, I'd probably jump into a Saw Stop. Mike
"I hope we lucked out and there isn't damage we can't see. Haven't used it again-yet."If you want to be sure take the blade to a Non Destructive Testing Company and have them do a Magnetic Particle Inspection of it. It's a crack inspection process for ferrous metals. They can find cracks that you can't see. Many trade schools, engine rebuilding shops, heat treating companies also have them. Small price to pay for piece of mind.
Thanks for the suggestion.
-Paul
I've seen two blades, both good quality, that were halted by a Saw Stop, and both of them had half a dozen teeth broken off. I wouldn't run a blade, no matter how good it appeared, without replacing the teeth that were actually embedded in the aluminum block.
There is an excellent chance that the brazing was damaged, and will eventually fail, turning the tooth into a scary little bullet. It would be a shame to save your fingers only to be shot in the chest or face by a broken off tooth.
John White, Shop Manager, Fine Woodworking Magazine
I'd be scared to just replace the teeth precisely because of the hidden damage you referred to in your post.
Hard to imagine out of the entire scenario of tripping the SawStop that a commercial shop, at least, would get hot and bothered about the cost of the blade. Save a thumb and lose an eye to a tooth that flies off months later due to hidden damage?
Besides, the old blade has some bad MoJo on it.
Get a new one.
The blade stops so quickly that only a few teeth ever strike the brake, the rest are untouched and wouldn't be damaged, so I think that just replacing the involved teeth would make the blade safe again for use.
Of course replacing a number of teeth probably gets you close to the cost of a new blade anyway. Personally I would just chuck the blade (easy to say since, at the moment, I'm not paying for them out of my own pocket) and that's what Saw Stop recommends.
I've been thinking lately that I would probably use cheaper blades on a Saw Stop for work that doesn't require the best blades, just to cut the financial pain of triggering the brake. Tearing up a $100+ blade really hurts, especially when the trigger was caused by a non skin contact, such as brushing against a poorly placed clamp on a jig (don't ask).
John White
Just out of curiousity, how many times has the saw triggered since FWW has had it?
Since the house is on fire let us warm ourselves. ~Italian Proverb
Twice, first time the day after we hooked it up months ago, an aluminum miter fence touched the blade, barely scratched the aluminum, chucked the fence to prevent a recurrence.
Second time just last week, clamp on a tenoning jig got a bit loose and shifted just low enough to for the blade to graze it. No mark on the clamp. The saw just went "thump" and the blade wasn't there anymore. Since the tenoning operation was low risk, I disabled the Saw Stop brake for the rest of the cuts to prevent a second false trigger.
I'm sorry to have wasted two blades and two cartridges for non finger threatening incidents, but I love this saw none the less.
John White, Shop Manager, Fine Woodworking Magazine
...and that's what Saw Stop recommends...[replacing blade after tripping the mechanism]
Good advice IMO.
As a guy who has a comercial shop let me tell you $100 is $100 is (yep you guessed it) $100. The $100 I DONT spend on that blade can buy me all the things it will buy you. In fact I suspect most high level hobiest have more disposable income than most shop owners. Before someone mentions it, certiantly the risk of hurting an employee or ones self is most often worth more than $100. Pardon my spelling,
Mike
Make sure that your next project is beyond your skill and requires tools you don't have. You won't regret it.
John,
Thanks for your insight. I was a little leery about using it again and a couple of posts here have helped me to make up my mind. It's tough, you don't see damage on a blade that was really only a few cuts old go in the trash. Definitely a better scenario than an injury, every time.
-Paul
"a couple of posts here have helped me to make up my mind"Paul,Are you saying that you won't replace the teeth and continue using the blade? I think that if you determine that the blade is flat and undamaged, other than the missing teeth, it's probably safe to replace the teeth and use the blade. I have a blade that came up missing a tooth once. Don't ask me when it came off -- my undertaker will probably find it in my spleen. I replaced it long ago, and many sharpenings later, it's still fine. As I understand it, the probability of a carbide saw tooth or cutter bit tip letting go on its own is greatest at start up. I don't do it on the table saw, but whenever I start my router (in the table) or a shaper, I hold a scrap piece of stock between myself and the bit/cutter until it's up to speed just in case. I'd give your blade a second chance, but in the end, if you're not comfortable using it, you should probably toss it. 100+ bucks down the drain is worth the peace of mind, but still; maybe just fire it up, let it run a bit, rip a 2" piece of maple, and then make a decision.
Hey Mike,
Sorry I wasn't more clear. I tossed the blade in the dumpster this morning. I work in a place that is VERY safety minded which I feel is a good thing. After reviewing with my supervisors what we know about the blade and more importantly what we don't know, trashing the blade really became our only option. We would be more inclined to replace the blade rather than a few teeth though I understand this would be an option for some. The money it costs becomes a lesser concern if it is a safety issue. I know folks will balk at the $100 blade in the dumpster but in this case it is a cost of doing business.
-Paul
Good decision. BTW, the first time you run your own flesh into a saw blade not on a Saw Stop, you will spend WAY more on the treatment of the wound and rehab than $100 for a blade. Not to mention the pain and anguish of a terrible accident. Like you said, the $100 is the cost of doing business--whether you are a hobbyist or pro. Tom"Notice that at no time do my fingers leave my hand"
Couldn't agree more , Tom.
"I work in a place that is VERY safety minded which I feel is a good thing"Safety is a good thing. The Saw Stop device is a huge leap forward, and hopefully just the beginning. Thanks for your reply, and take care of that new blade.Mike
Mike,
I believe they may have a bandsaw in the works. Can't wait to see a full product line.
-Paul
I would put the blade in a vise and take a big hammer to it to bend it over before tossing it just to make sure some dumpster diver doesn't find a "treasure" and end up hurt.The Professional Termite
I would take the blade and make it into a clock to hang on the shop wall. Nothing like a Forrest sawblade clock to get 'em talking. The Rolex of shop clocks!
Sound advice. I wrapped it inside other trash so you would need to be a serious diver to find it. Regardless, the dumpster was emptied shortly after.
-Paul
I share your pain, just chucked a dado set.
John White
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