Sawstop Brake Fired

[Prashun Patel]

Stupid move: forgot to reset my Incra miter fence and it just grazed the blade.

BANG!

At least I know the SS works, now. Man, when I saw how deep the blade dug into the brake, it really made me shudder...

[John Lifer]

Well I guess you need a plastic miter gauge/fence. Kind of an expensive lesson. :>
I could get rude, crude and nasty, but I'll let everyone else pile on.

[Myk Rian]

I could get rude, crude and nasty, but I'll let everyone else pile on.
Pile what on? He knows what happened.

[John Kali]

Pile what on? He knows what happened.

I was thinking the same thing....I don't see a need to be rude or crude...

[Prashun Patel]

I have NO problem if anyone gets rude and crude about this. I'm humble enough to know I'm the most dangerous kind of woodworker: an intermediate who is comfortable with a tablesaw. So, the more reminders I get to save my fingers, the better.

In fact, the fence was set properly - had the blade been set at 90 degrees. But I was cutting a dovetail, so the blade was angled at about 8 degrees. Just enough...

Can never be too careful.

[Glen Blanchard]

They say there is strength in numbers, so let it be known that I have made this very same mistake..........twice.

[Victor Robinson]

Despite reading this thread, I am sure I will make the exact same mistake any day now...

[Don Alexander]

exactly! rudely , crudely piling on serves no useful purpose at all in fact there is absolutely no call for angst on anyone's part

glad that you weren't injured Prashun that type thing can easily happen to anyone

[John Coloccia]

Man, when I saw how deep the blade dug into the brake, it really made me shudder...

Just wait until you compare it with a new brake and see how much it deformed too :) There's a lot of energy in that that saw blade. It may not be a complete loss. If it's not trashed and if it's worth it, send it back to the manufacturer for straightening and sharpening.

Now this brings me to a point I made some time ago. Before I make ANY cut, I always do a test run. Why? Because I'm always lining stuff up so that things that shouldn't go into the blade go into the blade, or interference from a clamping mechanism, or the realization that I need to remove the guard to do a non-thru cut, etc... You obviously can't dry run the actual cut, but you'd be surprised how much stuff you catch just doing a quick shoving back and forth of a jig (or miter gauge), or whatever. ANY cut, including just using a router with a flush trim bit. Oh how many times I've done the dry run only to find that if I didn't move something I would cut right through my power cord. When I'm working, my focus is right on the cutting edge of the tool so I would absolutely never notice something like that on the fly.

Anyhow, you used up your stupid allowance for the month early, so stay on your toes. I used mine up this morning. Piece of wood went flying out of my hands courtesy of the router table and a moment of distraction. Gosh dang lucky thing I went through my mental checklist before starting the cut and got my hands into some sort of safe area in case of a catch. Mind wandered, wood trashed, but fingers ok :)

[JohnT Fitzgerald]

Prashun - I'm glad it was the fence and not your hand!

New cartridges should also come with new boxer shorts. I haven't had mine fire yet but I know it will eventually, and it'll probably scare the heck out of me.

[Dan Hintz]

I could get rude, crude and nasty, but I'll let everyone else pile on.
If this wasn't a SawStop and he just destroyed the blade or the miter, would you have even considered such a comment?

Something about SawStop really seems to polarize people... if they hate it, all too often they seem willing to be nasty about it just so the world can acknowledge their hate of it.

[Paul McGaha]

Prashun,

Better the fence than one of your fingers.

Hopefully that is as close a call as you will have.

Glad you werent hurt.

PHM

[Peter Stahl]

Saw stop would be nice if they had the blade on a axial that had a disk brake that rotated on the same shaft as the blade. This way when it triggered it would clamp the disk brake and lower the blade without destroying the blade, of course SS wouldn't make a bunch of money on brake cartridges. Is the setup on the contractor SS the same as the cabinet saw ones.

[Marty Paulus]

Saw stop would be nice if they had the blade on a axial that had a disk brake that rotated on the same shaft as the blade. This way when it triggered it would clamp the disk brake and lower the blade without destroying the blade, of course SS wouldn't make a bunch of money on brake cartridges. Is the setup on the contractor SS the same as the cabinet saw ones.

No but it may be worth a read of SS Patent. Interesting idea....It may be that you can't get the blade to stop as quickly by just clamping down on it. Hmmmm.

[Dan Hintz]

It may be that you can't get the blade to stop as quickly by just clamping down on it.
You would have to clamp very hard... by working on the teeth of the blade, the SS has the highest moment force on the blade, as well as absorbing power directly in the aluminum honeycomb. A disc brake would have less of a moment force (being closer in to the center), and it would have to rely on friction.

It may be fast enough with enough clamping force, but without doing the calculations I can't say... getting the pads onto the blade quickly enough and with enough force is the major issue with that design.

[Prashun Patel]

"...of course SS wouldn't make a bunch of money on brake cartridges."

Having owned one for a year and having re-read the manual, I highly doubt this is their intention.
In fact, if the brake fires because of contact with an operator, they pay to have the brake shipped to them for analysis, and send you a new one for free.

[Ben Hatcher]

Prashun, glad to hear that you're ok. Does SS supply a back up brake with the machine? I'm sure that if I had a ss, I'd want a back up brake just in case something like what happened to you happened to me.

[JohnT Fitzgerald]

I have thought about this approach often. I would design it so that the disc brake had a sacrificial rotor. better to replace a $20 rotor than a $100 blade....

however, to get good 'leverage', the rotor might have to be large enough such that it would interfere with the table top, reducing how high the blade could be raised. I'm sure there are different ways to avoid this issue (gearing, etc).

[John Coloccia]

"...of course SS wouldn't make a bunch of money on brake cartridges."

Having owned one for a year and having re-read the manual, I highly doubt this is their intention.
In fact, if the brake fires because of contact with an operator, they pay to have the brake shipped to them for analysis, and send you a new one for free.

Exactly.

The blade digs into the brake because it is the blade's own momentum that allows the brake to work. The harder the blade digs in, the harder the brake clamps.

Prashun: I've finally learned just to ignore the inevitable SawStop peanut gallery. It's like when you're concentrating on something, and someone starts yapping in your ear: "Blah blah blah blah, blah blah, blah blah.....".

[Prashun Patel]

They supply it as an option. The retailer from whom I purchased the saw told me that I should buy a backup brake and a dado brake, but of course, I did neither.

[David Giles]

Welcome to the club. My blade grazed the holddown bolt on the miter sled. One moment everything was fine and the next moment all was quiet and the saw blade was gone. I stood there totally bemused for a few moments. The $200 lesson taught me that a) it works b) keep a spare cartridge c) things that I don't intend to happen still happen.

[Todd Bin]

Prashun, If you do a search you would probably find a lot of posts where people have done this exact thing. I bet it is the most common reason for firing the break. Wasn't it awesome how fast that thing fires and stops the blade. Can you post a picture of the "damage" it did to your miter guage. I bet it barely nicked it.

~Todd

[Prashun Patel]

It did insignificant damage to my fence. The thing is, I've done that kind of thing before on my previous saw, so the tip of the gauge was already scratched. I can't tell how much worse it is now, but it's certainly not any damage anyone would notice.

[Ken Fitzgerald]

I feel sure that if you weigh cost and reliable function, the current SS basic method is the best method to achieve blade stoppage in the quickest time.

So what if it ruins the cartridge or the blade? It functioned as designed and intended.

...and we are all human........we all make mistakes.....

[Mike OMelia]

Prashtun, good on you for ignoring the ignorables. And thanks for sharing your story. I got to believe that the instant that thing goes off, there HAS to be a serious pucker factor! I like the saw stop concept. Maybe one day they will figure out how to recognize the "signature" of a finger vs the signature of wet wood, and of the saw itself. :)

Mike

[Howard Acheson]

>>>> It may be that you can't get the blade to stop as quickly by just clamping down on it

I believe that is correct. I seem to recall that this issue was discussed by Gass a couple of years ago.

[Kevin Stricker]

I was in Rockler a few weeks ago and there was a Sawstop demo. Although I have a PCS and have seen the video demos I didn't expect the noise of the brake firing. Serious pucker factor. Keep an extra pair of shorts with your spare brake cartridge. I have a full Incra setup and know I am going to blow it some day. Need to make some good aux fences before I ruin my Woodworker II.

Thanks for the reminder!

[John Coloccia]

I was in Rockler a few weeks ago and there was a Sawstop demo. Although I have a PCS and have seen the video demos I didn't expect the noise of the brake firing. Serious pucker factor. Keep an extra pair of shorts with your spare brake cartridge. I have a full Incra setup and know I am going to blow it some day. Need to make some good aux fences before I ruin my Woodworker II.

Thanks for the reminder!

At the local Woodcraft, they demo it on the contractor saw. Now, even the contractor saw is a HEAVY saw...I mean, seriously heavy for a contractor saw. When the brake fires, the whole saw jumps and moves a little bit!

[Neil Brooks]

I guess ... if you're truly *committed to* sawing a piece off your miter gauge ... you can always use the "wet wood" or "bypass" setting.

When my time came, and NOTHING was going to stop ME from putting MY mark on MY Incra 1000SE .... I was glad NOT to have the braking technology :rolleyes:

[Jerrimy Snook]

Prashun, I am glad that you are Ok. This may be an expensive reminder to be on your toes but at least you still have your fingers.

I service saw blades for a living. A customer recently brought his Woodworker 2 saw blade stuck in the Saw Stop brake. He was cutting wet cedar with the safety off, quit for lunch and forgot to disarm the safety after lunch. There was virtually no damage to the blade. We checked the blade for flatness, gave it a touch-up sharpening and gave it back to him.

A local high school student was also using a Saw Stop in the Woodshop. He was making a dado cut using questionable technique ( I don't know the details). Anyway the thing fired and the dado hit the stop as it should. There was more damage to the dado set because the side plates were swapped than there was from the brake.

My point is that the technology does what it should regardless of the politics of the manufacturer. And, just because the blade hits the brake doesn't mean that the blade is shot.

[Kevin Womer]

I am glad nobody was hurt, machines can be replaced but fingers cannot. I am reminded of this everytime I see my brother-in-law and his missing fingers on his left hand. This was caused by a miter saw not a table saw, all machinery can be dangerous-be careful out there.

[Marty Paulus]

You would have to clamp very hard... by working on the teeth of the blade, the SS has the highest moment force on the blade, as well as absorbing power directly in the aluminum honeycomb. A disc brake would have less of a moment force (being closer in to the center), and it would have to rely on friction.

It may be fast enough with enough clamping force, but without doing the calculations I can't say... getting the pads onto the blade quickly enough and with enough force is the major issue with that design.


Dan,

I thought more about it after posting. Using the teeth is prob. the best as you and other point out. If there was anything on the blade like wax or a non stick coating it would defeat the disc style brake system. While both will stop the blade, using the teeth if definately more effective and faster.

[Alan Schaffter]

Ah, waiting for the day that a Sawstop brake firing is no longer newsworthy unless there is something new to learn!

[Chris Tsutsui]

I wonder if Incra can insulate their fence so that sawstop owners can cut through them without the brake firing? They can call it the Incra SS miter... heh

Sucks to hear about mistake. I don't know why but I always click on the SS threads wondering if the thread will be about SS saving a finger or a hand.

[Rod Sheridan]

Prashun, glad to hear that you're fine, and so safety concious that you test your fail-safes.....LOL.

It's one of those OOOPS moments, good to be able to joke about it..........Regards, Rod.

[Prashun Patel]

Alan, sometimes I post just for moral support, not because I want to teach or learn.

[Chris Padilla]

Maybe Gass will figure out a way to distinguish between aluminum/metal and a hotdog. :)

[Alan Lightstone]

Prashun - I'm glad it was the fence and not your hand!

New cartridges should also come with new boxer shorts. I haven't had mine fire yet but I know it will eventually, and it'll probably scare the heck out of me.

True, dat. I triggered mine once. Scared the crap out of me. Still look at it with awe.

Of course, I was using my most expensive blade - my dado stack, at the time.

[Andrew Pitonyak]

How close can the fence be before the brake fires?

In other words, is it fine if your aluminum fence is 1/4" away from the blade? In the hot-dog test, it seems that the blade hits the hotdog before it fires. I assume that it is the same for the fence...

[Prashun Patel]

I've pushed hundreds of cuts with the fence 1/16-1/8" close to the blade. It only fired when the blade actually touched - and I don't mean rammed into - I mean shaved/grazed.

[Joe Mioux]

did the same thing 3 years ago

[Alan Schaffter]

Alan, sometimes I post just for moral support, not because I want to teach or learn.

I understand, just making an observation.

All news is good news. Every thread, good and bad, helps SS. Just wait- if the industry ever gets on the ball and another manufacturer comes up with a viable alternative or close copy- then we can see an entire new round of XXX is better than YYY or "that wouldn't happen with an XXX", etc., etc. threads.

Anyone have an authoritative answer to when the SS patent runs out? Typically it is 20 years from the date of application. Since it can take as much as 3 or more years to issue and if a Provisional Patent Application was filed first it may be an additional year less, so only 16 + / - years from when it finally issued.

[Myk Rian]

Anyone have an authoritative answer to when the SS patent runs out? Typically it is 20 years from the date of application. Since it can take as much as 3 or more years to issue and if a Provisional Patent Application was filed first it may be an additional year less, so only 16 + / - years from when it finally issued.
December 21, 2012. All patents will run out on that date. But then again, so will the universe.

[Aaron Berk]

I wonder if Incra can insulate their fence so that sawstop owners can cut through them without the brake firing? They can call it the Incra SS miter... heh

Sucks to hear about mistake. I don't know why but I always click on the SS threads wondering if the thread will be about SS saving a finger or a hand.

LOL, I like this one. It needs to be done!

[Andrew Pitonyak]

I have thought about this approach often. I would design it so that the disc brake had a sacrificial rotor. better to replace a $20 rotor than a $100 blade....

however, to get good 'leverage', the rotor might have to be large enough such that it would interfere with the table top, reducing how high the blade could be raised. I'm sure there are different ways to avoid this issue (gearing, etc).
I expect that stopping the motor is not sufficient because the blade is simply held in place using friction. If the spindle stops turning suddenly, I expect that the blade might not stop completely with the spindle unless there is something other than just friction holding the blade in place. A custom blade with say a square arbor or a pin (or two) that go through the blade would likely suffice.

[Tom Willoughby]

Don't quote me on this but I believe that the SS firing mechanism is a drop in voltage. Wood doesn't conduct electricity well so it doesn't set off the brake but as soon as the blade hits something that causes a drop in voltage (i.e. conducts electricity), the brake is fired. If my logic is correct, the blade would have to actually touch the fence before the safety mechanism was fired.

I inadvertantly set mine off when sawing through some wood with brad nails. I was 3/4 done when all of sudden the saw stopped and the blade was gone. I should have used the bypass but didn't think that I needed to. I didn't have a spare and had to wait until the next day to continue sawing. The only good news is that I was using a cheap blade but it was unusable afterward with a few carbide teeth missing.

I still don't have a spare brake because it will never happen to me... again ;-)

[Prashun Patel]

Tom-
If the brad nails are embedded in the wood and not touching the table, and therefore don't have a path back to ground, then how does that conduct? This has puzzled me.

[John Coloccia]

Tom-
If the brad nails are embedded in the wood and not touching the table, and therefore don't have a path back to ground, then how does that conduct? This has puzzled me.

It's not like Steve Gass sent me a memo on how the saw works, but if I dig into my engineering background and think about it for a minute, my gut instincts tell me that I would try capacitive sensing to detect contact.

[mreza Salav]

You are right John. Here is what Steve Gass said it here:
http://www.sawmillcreek.org/showthread.php?131016-SawStop-blade-touch-detection&p=1325710#post1325710

[Mike Henderson]

My reading of the Gass post is that he said a conductive connection is mostly what the system senses. He points out that the capacitance to a body part from the teeth of the blade would be quite small.

Mike

[Brian Penning]

I hung my 2 fired brakes( both due to hitting the miter gauge) up near my SS as a reminder to not forget to reset the gauge.
Hasn't worked so far. Then again, sometimes I forget what I went into the shop to get in the 1st place.

Anyone have a tough time getting the embedded blade and brake off the saw? Took me over a 1/2 hour to get the 2nd one off.

Remember to specify which cartridge you have. There are 2 different styles. Has to do with the connector pin quantity.

196935

[Mark Blatter]

I inadvertantly set mine off when sawing through some wood with brad nails. I was 3/4 done when all of sudden the saw stopped and the blade was gone.

I was cutting some wood with 23 gauge pin nails in it. After the third little 'pop' it hit me what I was doing and I stopped cutting, but the saw never did fire. Learned a good lesson though....Always stop and think about what you are going to do before doing it. Sort of like measure once and cut twice.....

Only had the saw fire one time. It was while cutting a thick piece of foam packing. During the quiet time immediately after firing, the gentleman running the saw noticed that there was a very thin layer of aluminum running in the middle of the foam. Lesson learned needles to say.

[Tom Willoughby]

Tom-
If the brad nails are embedded in the wood and not touching the table, and therefore don't have a path back to ground, then how does that conduct? This has puzzled me.

Others will have more knowledge than I about the technology but that was exactly my thinking. I cut through a number of brad nails with no problems but it was either a larger brad or a connection to multiple brads and the blade that dropped the voltage enough to set off the blade.

As Mark mentioned, that event made me think about what I am about to cut so that I don't trigger the brake needlessly.

Tom