A cautionary tale, or how to pay your dentists kids tuition

[smorris]

I've been debating since it happened if I was going to post this and decided maybe it will prevent someone else from getting hurt but then it was a kinda bizarre kickback accident. Feel free to tell me how dumb I was, it won't be worse than what I've told myself.

I'm not sure exactly how it happened that I ended up spitting teeth at the table saw. I was crosscutting a 6" piece of white ash taking off about 4", yes the stock 3100 guard was on the blade. I had just finished the crosscut a couple seconds before and I was reaching for the power switch when I heard a bang and my head snapped back. Then the pain started.

Once I could see straight again and was catching the blood in a rag instead of down my shirt front I saw that the guard was now upright and the cutoff was missing from the deck. Apparently the cutoff edge was still under the guard and when I was reaching down for the power switch it worked its way into the back of the blade and just launched at full force upward into my mouth. I lost one tooth on the spot and the dentist had to remove another one that was broken off. I go back in 10 days to see if he is going to have to extract the other 2 which were loose after this. Hopefully they'll settle back with the splints he put on them. Who knew you could splint teeth. Vicoden and I were friends for a few days.

What will I do differently in the future?
1) I am going to mount a power switch on the left of the saw up by the rail so I don't have to bend down towards the firing line in the future. Any recommendations of switches you have had experience with are welcome.
2) Had i been working with one of the woods that effects me I would have had my Triton respirator on and the face shield would have taken the hit. I will be more inclined to use that in the future.
3) NEVER, EVER again will I put major body parts into the firing line of any power tool regardless how many times nothing happened.

My safety glasses are still MIA somewhere in the shop.

[jackellis]

I'm sorry to hear you were hurt and at the same time, I'm relieved to hear it wasn't worse.

The lesson for me is to keep a push stick handy and get cutoffs out of the way before reaching over to turn the saw off.

[dlminehart]

smorris, how'd you set up the crosscut? Using the SMT? If so, I'd assume you left 4" on the SMT, taking 2" off the end of the wood. You didn't, by chance, have the tip of the wood touching the fence during the cut?

[smorris]

smorris, how'd you set up the crosscut? Using the SMT? If so, I'd assume you left 4" on the SMT, taking 2" off the end of the wood. You didn't, by chance, have the tip of the wood touching the fence during the cut?

The fence was well away from the cut at the limit of its right most travel. I was using the SMT as I have done many times.

I see now my explanation was unclear. The board I was cutting was 6" wide and about 14" long, I was removing about 4" so I had 10" to the left of the blade on the SMT. Sorry about that.

[cgallery]

The scary thing about this cautionary tale is I think it is something we've all (more or less) done. It sounds like a freak accident, so while we may be able to protect ourselves with your warning, you have to wonder what freak accident could happen next.

I hope you feel better. Sounds terribly painful.

[softop41]

Two Words....
SHARK GUARD!!!!!!!!!!!!!!!!!!!!!!!!!

[Ed62]

Sorry to hear about your accident. It could have been worse, but my guess is that you think it's bad enough. I wrote an article about how I handled the problem of having to reach down for the shutoff switch. You can find it here http://www.bt3central.com/showthread.php?t=29215 . Someone else also has an article on his approach, somewhat different than mine. You can find it in the same place. His idea might be better than mine, but I've never been sorry I made mine like I did. I use it every time I use the saw. If you have any questions, send me a PM.

Ed

[Wood_workur]

I have the router table switch from rockler hanging on my rail, and I love it. I have a fear of that happening to me, so I'm always paranoid of crossing that line.

Glad to hear you are okay, even though a few teeth didn't make it (hey- that's less cavities to worry about, right?)

[jon_ramp]

Two Words....
SHARK GUARD!!!!!!!!!!!!!!!!!!!!!!!!!

While I don't dispute that the Shark Guard is superior to the stock guard, I fail to understand how it would have prevented an injury in this instance as it seems the stock guard was properly in place. Can someone please explain?

[leehljp]

I can easily see how that happened. If you did not use a push stick - As you finished the cut, the guard was holding down on the cut-off part. I am going to assume that it was NOT behind the blade, but beside it. In this case, I can see the guard holding the cutoff part next to the blade. The rear of the blade caught the edge of the cutoff, pushed it up and into the guard and then forward toward you.

Blade guard's purpose is to prevent the hand from touching the spinning blade, not to prevent kickback.

It is the riving knives' purpose to prevent kickback - but they don't always work on cutoff parts that are left beside the spinning blade. The riving knife keeps the cut open and from closing or pinching the rear of the blade - where the majority of kickbacks start.

Four safety parts to a TS:
1. Guard to protect the hand from a spinning blade
2. Riving knife to prevent kickbacks due to pinching
3. Push sticks to get the cutoff out of the path of the blade as quick as possible.
4. Quick cut-off switch.

Rethinking this for this particular case:
In your case, the 6 inch wide board had finished being cut, but the cut-off was probably sitting totally beside the blade, and was not beside the riving knife itself. And - trapped next to the blade by the guard, the rear of the blade caught the back edge of the cutoff and fired it forward.

I doubt that a quick cut-off switch would have helped prevent the kickback. As blades go through their slowdown, they also go through a stress vibration release in which the runout usually exceeds normal "stop / full speed" runout. This wobble often picks up a piece near the back of the blade and fires it forward. (This is only one scenario of many for kickbacks.) IMO, it is always good to make sure the piece has cleared the blade altogether.


I always use push sticks and make sure the cutoff is past the back of the blade or at least out of the way to the side. I learned from experience more than once - that blade guards can trap a small piece that is next to the blade.

Another thing that I do with push sticks - on smaller pieces, I do not always use the little hook/notch to push the front edge to the back. Sometimes, placing the notch of the push stick on the leading edge of the cutoff - can cause the back edge to lift or twist. I often use a rubber tipped push stick near the center of the cut off so that the cutoff stays FLAT on the table as it is pushed through. VERY IMPORTANT. A push stick used improperly can lead to kickbacks too! DAMHIKT.

[RayintheUK]

Sorry to hear of your incident - thanks for posting it, though, it reminds us all of the dangers to our hobby. Regarding moving the switch - I've done this (see picture below - click to enlarge):



It's the same switch, removed from the normal position, then re-positioned by mounting on an MDF bracket. There was enough cable, so no problems or need to re-wire anything. Have a look inside the carcass and you'll see what I mean. HTH

Ray

[Stytooner]

Ouch! I know that had to hurt. I usually use a push stick to both push the offcuts on through and then to smack the switch cover without bending down much. I generally hit it on the first hit.
Usually the guard would help prevent stuff from vibrating into the blade, but not always as you know.

In this case, the offcut was sitting in the worst place possible. Unattended right next to the blade.

Now would a shark have prevented this? Surely not in every case, but perhaps and for two reasons I can think of.

First the shark weighs a little more than the Ryobi guard. It may have keep the part in place due to this.
Second, the Ryobi guard doesn't have a lot of room for air to escape. The right side of the guard is also shorter than the left. The saved part was on the left and therefore the guard may not have been putting much pressure at all on the offcut. This coupled with the air circulating from the blade may have just been enough to move that offcut the wrong way putting the rear corner in touch with the rear teeth.

The Shark is designed first as a finger barrier, but it is also intended to help stop or at least slow down very small parts the the guard won't sit on when severed. With the newest design, it can take a few of these kinds of punches. Most are normally designed kinda like air bags or the older 5 MPH bumpers. Once they are used in an accident, the usually need replacing or at least some work done to bring back to operating condition.

There are types of hits that even the shark can't sustain though. While the shark is one of the strongest designs I have seen, the Brett Guard is likely the champ for extreme protection and being able to take the biggest hits without damage.

I hope you heal up fast and regain a smile again.

[cabinetman]

I can easily see how that happened. If you did not use a push stick - As you finished the cut, the guard was holding down on the cut-off part. I am going to assume that it was NOT behind the blade, but beside it. In this case, I can see the guard holding the cutoff part next to the blade. The rear of the blade caught the edge of the cutoff, pushed it up and into the guard and then forward toward you.

Blade guard's purpose is to prevent the hand from touching the spinning blade, not to prevent kickback.

It is the riving knives' purpose to prevent kickback - but they don't always work on cutoff parts that are left beside the spinning blade. The riving knife keeps the cut open and from closing or pinching the rear of the blade - where the majority of kickbacks start.

Four safety parts to a TS:
1. Guard to protect the hand from a spinning blade
2. Riving knife to prevent kickbacks due to pinching
3. Push sticks to get the cutoff out of the path of the blade as quick as possible.
4. Quick cut-off switch.

Rethinking this for this particular case:
In your case, the 6 inch wide board had finished being cut, but the cut-off was probably sitting totally beside the blade, and was not beside the riving knife itself. And - trapped next to the blade by the guard, the rear of the blade caught the back edge of the cutoff and fired it forward.

I doubt that a quick cut-off switch would have helped prevent the kickback. As blades go through their slowdown, they also go through a stress vibration release in which the runout usually exceeds normal "stop / full speed" runout. This wobble often picks up a piece near the back of the blade and fires it forward. (This is only one scenario of many for kickbacks.) IMO, it is always good to make sure the piece has cleared the blade altogether.


I always use push sticks and make sure the cutoff is past the back of the blade or at least out of the way to the side. I learned from experience more than once - that blade guards can trap a small piece that is next to the blade.

Another thing that I do with push sticks - on smaller pieces, I do not always use the little hook/notch to push the front edge to the back. Sometimes, placing the notch of the push stick on the leading edge of the cutoff - can cause the back edge to lift or twist. I often use a rubber tipped push stick near the center of the cut off so that the cutoff stays FLAT on the table as it is pushed through. VERY IMPORTANT. A push stick used improperly can lead to kickbacks too! DAMHIKT.

I agree with Hank's explanation and suggestions. Inattention can be a culprit. Fortunately you lived through the ordeal...a close call. Unfortunately it was severe being just a warning. Those instantaneous happenings are scary. As for remote safety switches, Ed's switch is clever. This switch can be effective.
.

[Hellrazor]

I have tuned my saw off with my right knee more then my hand over the years. Not the best way to turn the saw off, but it works when your hands are full or you need a quick stop.