2 x 4 Rocket

[Kfbeal]

Ok, here's another one. You folks are going to think I'm dangerous but growing up on a farm and still working with it and cattle part-time I've done a lot of things in my life.

A few weeks ago I decided to make a saddle rack and I decided to rip 2 x 4's into 1 x 2 slats. I ripped several of them and almost enough to complete it. The design was half-moon shape with the belly up top.

The table saw is a tabletop which I had to put on the floor due to space this time. On one of the last rips, I guess the fence moved somehow, but for whatever reason the full 2 x 4 got in a bind, shot out and pegged me on my inner thigh. I jumped up, said a few choice words and limped into the house. After about 10 minutes of cooling down, I went back out there and finished ripping the boards in pain of course.

The next day I looked at the damage and it was a softball + size bruise where you could actually see the outline of the 2 x 4 within it. Had it been about 2-3" to the right I would have had a very high pitched voice.

I've never had my fence move on me so I'm not real sure what happened here. I'm just glad that my leg was there and I was not standing directly in front of it with my chest or face. I normally stand off to the side on everything I do. Being on the floor I had my left leg forward for balance.

All in all, I thought I did everything I could to be safe other than having the table saw up higher on the stand. If I had done that I probably would have put a hole through my garage.

 

[petegoud]

Sometimes when you rip a board the internal stress will cause the pieces to bend quite a bit. This is probably what happened here. There are safety devices built which are designed to reduce kickback, but has you, and others know, they are routinely removed because of the hassles involved with using them. To me, the bottom line here is to know how your machine will react under such conditions, and try to practice some safety. It's a minimal price to pay in order to walk away from pieces of equipment with all your digits intact. And yes, I can say "been there, done that". Doug

 

[Tig]

Glad you are relatively ok, and the accident didn't "steer" you into a more serious condition.
Brings back memories of highschool woodshop mayhem.

 

[JB4310]

Had it been about 2-3" to the right I would have had a very high pitched voice.

:O I've shot stuff out to, never hit any vitals though. :O

 

[actionaj]

The spliter/antikickback/gaurd on my portable table saw is hassle to use. I end up taking it off when ripping if I am doing a lot of cross cuts I will leave it on. I think the problem is it so large you can not see what your doing. Needs a better design.

 

[J_J]

Kfbeal. I am sorry about your misfortune. Just curious, but did you have your hands on the board at all times, and was the 2 x 4 flat on the table? If you did, and it was, the blade should have stalled out. Then you reach down and hit the cutoff switch.

 

[WBWI]

I remember wood shop days in high school. I was ripping something on a table saw when it kicked back. It hit the tape measure I was wearing on my belt an sent it flying across the room. It certainly left an impression on me but like you all vital body parts were left in tact.

 

[JB4310]

I don't use a table saw much but the worst for me is when I'm cross cutting some 1x, just trimming off an inch or 2, then that little pc is just sitting there floating around on the table getting closer and closer to the blade, it's like slow motion, you know it's gonna launch but your not sure what to do, try and get it off the table or take cover.

 

[Flatheadyoungin]

When you are ripping a pc. of wood on the table saw your blade makes an 1/8" (or so) kerf (wood turned in to sawdust where the blade cuts). What happens, many times, and especially with pine from big box stores that is improperly dried, not dried completely or dried too quickly, is that the grain is under tension. When you cut through some of this, sometimes, it causes the grain to move and when it does, it closes the kerf. Basically, like taking the palm of your hands and putting them on both sides of the blade and trying to make it stop- something has to give when the kerf closes. Either the blade stops spinning, or it thows the wood back at you. Very dangerous and it happens in the blink of the eye.

When I first started teaching wood shop about 6 years ago, I used the machines we had in the shop. A good ole' Delta Unisaw with no guards whatsoever. Well, it got me one day. I was making a cut for a student- one that I didn't want him to make and before I understood very much about kickbacks, etc. That pc. of wood came out of there like a rocket and tagged me a few inches away from my youhaha. It dropped me to the ground and freaked out most of the students. It didn't break skin but like you, I could see the imprint of the corner of the board. I was black and blue for 3 months, literally. I joked that, "Well, I already had kids........"

One of my better students was making a cut and doing everything he was supposed to (guard, splitter, push sticks, standing to the side of the blade, etc.) A board kicked out and flew clear across the room and hit another kid in the back. The kid it hit was just getting ready to make a cut on the radial arm saw (that could have been bad!). He let out a few choice words but was ok.

Right next to the radial arm saw, in my old shop, was a large garage door that had many pcs. of plywood screwed over broken windows. I had always thought it was from vandals but after those two situations, I knew it was from years of kickback on the table saw.......the door was about 30ft away but in direct line of the table saw.

Be careful, use a splitter/anti-kickback device (they work WELL and worth EVERY penny as you now know). Stand to the side of the work, if you can. AND MAKE YOURSELF SOME PUSH STICKS AND USE THEM!!!

I took a pc. of pine and made a cut about half way through it. I held it down and shut the machine off. I had to use a screwdriver to pry the board off of the blade. It can have an unbelievable grip on the blade. Anyway, you can see where it closed up the kerf you and can't open it back up with your hands. I keep the pc. of wood as a demonstration to my students as to what can happen. If I had a camera, here, I'd take a pic of it for you and post it.

edit: check this out, it's not me....

http://www.metacafe.com/watch/910584/table_saw_kickback_demonstration/

**I've seen more kickbacks or possible kickbacks from the kerf closing up on the blade......so there are several ways....

http://www.youtube.com/watch?v=sVpGi85HfnY

This is an inexpensive splitter.......see the kerf/cut in the board........imagine if the little plastic splitter wasn't there and the kerf began to close up and grab the blade with a lot of force...

http://www.rockler.com/product.cfm?page=10889

sorry i keep adding to this but the thoughts keep coming..

when you are cutting and it gets hard to push for some reason, that is the kerf closing up.....sometimes you cut past the tension and all is fine......sometimes the tension increases to a point where you can actually feel it pushing back against you......at that moment, you either need to press the board down with your hands and turn the maching off with your knee or use one of you hands (keep holding lots of down pressure) OR in a worst case scenerio, step to the right side, let go (if you can safely) and let her fly....i've had to do both of these, many times...

 

[PILOON]

My worst weapon saw was an old radial arm saw when used to rip planks.

It had an anti kick back little thingy that needed adjustement for every change in thickness so naturally did not get used often.
That darn radial would shoot boards clear across the room at the slightest missalignment.
So many pieces got me that I was soon trained to stand to one side whenever ripping.
Being as that you feed into the blade the the stock had to be perfectly flat on the table however with a warped or twisted board a radial being overhead would 'grab slam' the stock downwards and launch it!
Also because of the motor/mechanism being overhead you have to hold the stock from far away and chattering followed by launching is the norm.

Give me a large heavy cast iron table saw anytime!
At least you can use push sticks or board buddies to prevent kick back.

 

[Kernopelli]

KFBEAL, Sorry to hear about this but thankfully this story didn't follow your previous posting.
My best friends father retired 2 years ago. He had talked about it for years and how he would be able to fish, play on his TO20 and work in his wood shop. One month after being retired, he was ripping a 4x4 (he has a very sturdy professional table saw that runs on 220V that he bought from a cabinet making shop and apparently is quite powerful). The way my buddy tells it, it kicked back and hit him in the chest hard enough that it "stunned him" and he fell forward across the saw and cut all four finger off at the knuckles and half the thumb, on his dominant hand.
You can imagine how traumatic that would be in its self but the fact that this happened so soon into retirement has devastated him emotionally. When he was down to visit my friend before this happened, he would never miss an opportunity to come to my place and fish all afternoon. Now when he's here, he is like a different person and appears to have no desire to do any of the things he used to love. It is very sad.

 

[Kfbeal]

I'm a die hard fisherman and hunter also and not sure what I would do if it had been worse. My biggest fear is the burden it would put on my family such as picking up my 2 children, etc. I've worked on combines, cotton pickers, hay balers, etc. as we farmed growing up without any injuries. Maybe I'm just getting older and a lot slower than I used to be.

On how I was doing it, I always use a push stick and I belive I had a stick on top to keep it from rising as it passed the blade. I was in a cramped position and shouldn't have done it there to begin with. I normally don't like my hands close to the blade so I try to avoid that at all times.

 

[DWCox]

Many of you may have seen this saw demonstrated before, but I still find it fascinating to watch. While its safety feature will obviously not prevent kickbacks, etc., it is pretty amazing in its ability to detect and prevent serious cuts to the skin:

SawStop

 

[Redneck in training]

My brother is an owner of cabinetmaking business and coincidently we were taking about internal tension in wood before I read this thread today. He said that it all depends how the wood is dried. If they dry it too quickly it might bend and jammed between the fence and the blade when ripped. Some wood such as oak is more prone to internal tension than other. I personally prefer hand circular saw when ripping 2X4.

 

[kidr]

You guys probably already know.....but I have to remind myself every time I rip , to keep the cupped side of the board down on the table. When I don't, I get into trouble.

 

[Kfbeal]

What do you mean cupped side? The grains of the wood possibly? U facing down?

I know I always do that when putting board on trailers so they bow up and now down.

 

[Kfbeal]

Many of you may have seen this saw demonstrated before, but I still find it fascinating to watch. While its safety feature will obviously not prevent kickbacks, etc., it is pretty amazing in its ability to detect and prevent serious cuts to the skin:

SawStop

I saw this a few weeks ago on one of those shows on the Discovery Channel. I can't remember which one.

The inventor tested the hot dog, etc. then used his own finger. As he slowly moved it in, as SOON as it grazed it the blade stopped. You couldn't even see anything on his finger, and I thought that was the most amazing thing.

 

[Willl]

Did the saw come with 'anti-kickback pawls' ?

 

[sixdogs]

What a great thread. It has made me think anew about tablesaw safety. We tend to forget how to be careful.

I once saw the partial imprint of a sheet of plywood in the metal sliding door of a pole barn where I guy I knew was making cabinets. He had made them for many years and is a sharp guy. I didn't ask and he didn't volunteer.

 

[kidr]

What do you mean cupped side? The grains of the wood possibly? U facing down?

I know I always do that when putting board on trailers so they bow up and now down.

Yes.exactly. Ripping with the U up usually results in binding for me.