Hey all, going to be buying a table saw soon, and I haven't used one since Highschool woodshop. I remember getting some stinging fingers from a kickback, but it's been so long I don't really remember what caused it. I do remember that using the table saw after that was quite intimidating.
What are the main things I need to be careful of when using a table saw? As a software engineer, my fingers are important to me. :)
This has been addressed in a number of places online. Some places to read:
Finally, you might consider the "Sawstop" saw. It costs more, but will bring the saw to a stop very quickly if the blade touches part of your body. There are some caveats though, a google search in this newsgroup will give some discussion threads.
Chris
A Google search of "table saw safety rules" yielded this site:
- Never use rip fence and miter gauge together (kickback)
- If it feels dangerous, don't do it
- Use a blade guard
I've heard varying arguments regarding the height of the blade. The URL I cited says keep the blade just slightly above the workpiece to minimize injury if you slip. Other sources I've read say raise the blade as high as possible. This makes the cutting action *downward* onto the table versus *sideways* into the direction of the cut. I tend to keep the blade high. Good luck, have fun and be safe. I used to be a software engineer, now I'm just overhead :-) But I *do* have all 10.
~Mark.
Thanks, I did some looking and turned mostly the information that is in the first link you gave, information that anyone with common sense should know. I am looking for more specific information about what can cause kickbacks and obviously how to prevent them.
I'm a develoepr also. The table saw scares the daylights out of me. I'm considering getting a full face shield for the table saw just in case of a kickback.
I experienced a kickback from my benchtop saw when I had it. It was a piece of laminate floor maybe 12" long, 6" wide, and 1/4" thick. I'm still not quite sure of the chain of events. The entire experience was over in a fraction of a second. The board hit me low in the chest. It caused a shallow gash that I still have a scar from. It was enough to cause me to bleed, but did nothing to my shirt. After hitting me, the board came up and smacked me in the face. It was enough force that it felt like someone was pushing the board in my face. No injuries there, but it sure felt strange.
Now I have a 1.5hp contractor's saw. I haven't had any kickback on it yet. I think the day is coming though. Here's what I do:
Use a splitter. I'm not currently using one since the one that came with the saw was so bad that I felt it was more dangerous. Boards kept hanging up on it. I have a new splitter that I just bought, but havn't put on yet.
Stand to the side of the workpiece so that if it does go, it goes past you instead of in to you. This may not always be feasible, but when cutting skinny stuff, it should keep you from getting impaled.
Similarly, have extra people in the shop not stand behind you while you make a cut.
Don't cut thin stuff. In other words, if you have a 24" wide board and you need to cut 1" off, put the remaining 23" between the fence and blade while letting the 1" fall off. If you put the 1" between the fence and blade, that's a kickback hazzard.
Don't reach behind a running saw blade to get a piece you just cut. If you bump the loose piece, it can catch the blade and force your hand into the blade on the way toward you.
Always wear eye protection. I think it's far more likely that you'll have a little cutoff piece propelled back at you than the entire workpiece.
Use a zero-clearance throat plate. If the opening is too big, the little pieces can cat caught and thrown back.
If it's taking too much force to cut, stop.
If it feels wrong, stop.
Dado blades add to the danger so be extra careful when using them.
Board buddies or a power feeder probably help the situation a lot.
I'm sure other people can suggest other things.
brian
Brian, thanks for the exccellent reply, this kind of info is what I was looking for.
Speaking from experience, be absolutely certain that any wood that you use does not have a foreign object in it - such as a nail.
Kickbacks are caused by the blade teeth catching in the work, grabbing it, and flinging it at you. Generally this occurs when the teeth at the back of the saw catch on the cut.
This in turn can be triggered by any number of things:
1) not holding down the back of the board (helps to use a push block, not just a push stick, can also use a featherboard on the fence to hold the wood down) 2) the wood warping and pinching the blade at the back (use a splitter/riving knife the exact width of the blade, or even a hair wider) 3) offcuts catching on the back (don't use the mitre guage and fence together--if the offcut pivots slightly it can catch between the fence and blade and get flung)Chris
You've had and will have some good responses. However, here is my rule of thumb (So I can keep mine!) Have respect, not fear of the machine. Learn how to adjust it and how to know when it needs adjusting. Keep the wood down and tight against the fence. Don't have anyone help you control the feed or support the outfeed. (Make or buy an outfeed table.)
Dave An old solid oak tree is just a nut that refused to give up.
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See the first chapter of Ian Kirby's book "The Accurate Table Saw" for discussion of how to keep extremities attached.
One simple additional way to get a kickback- workpiece and waste not completely separated, and pinch the blade. (Lotsa ways that can happen, and when the "kick" causes them to pinch tighter, bada-bing ...) Definite tummy-tucker.
J
Yep, mine too as a Sysadmin/Programmer. Depending on the kind of woodworking you want to do, you might want to consider a bandsaw. I sold my tablesaw, mainly because of lack of space when we bought a new car. I now have a bandsaw and really love it. Don't miss my table saw at all. Have to find different ways to do some things, but I am going more neander (hand tools) all the time. Course, you can still get badly hurt on a bandsaw. But I love the added versatility.
HTH
jim
Yep, mine too as a Sysadmin/Programmer. Depending on the kind of woodworking you want to do, you might want to consider a bandsaw. I sold my tablesaw, mainly because of lack of space when we bought a new car. I now have a bandsaw and really love it. Don't miss my table saw at all. Have to find different ways to do some things, but I am going more neander (hand tools) all the time. Course, you can still get badly hurt on a bandsaw. But I love the added versatility.
HTH
jim
If you write software you probably are good at solving problems. Not sure how many engineering courses a software engineer is required to take but just in case you didn't take physics, statics or dynamics this may provide many of the parameters of kickback - with diagrams with colored arrows and all.
charlie b
Jim, thanks for the advice. I can't imagine ripping stock with a bandsaw?
Manufacturers of table saws are so gun shy of lawsuits that might result from"failure to warn" or "failure to guard" that it would surprise me if you didn't have pages of both general and specific warning information in your instruction manual when you purchase your saw. Read it.
Frank
The root cause of kickback is the workpiece getting pinched between the blade and the fence. There are a couple of reasons why this happens:
The most common reason is that the workpiece turns slightly (i.e. doesn't stay tight against the fence) while pushing it through. Keep in mind that the teeth on the blade are slightly wider than the rest of the "meat" of the blade. This means that during an ideal cut, the only parts of the blade ever to contact the workpiece are the teeth. In reality, however, if you're not careful to constantly push the workpiece up against the fence, it can turn a little, and the front corner can come into contact with the inner part of the blade. The friction between the blade and the workpiece causes a force which wants to further turn the workpiece which causes the workpiece to bind even harder, causing more friction which causes even more turning and binding until, a fraction of a second later, the piece comes flying back at you at mach 10. Inevitably, despite rotating rapidly through the air, it will strike you in the gut with its sharpest point every time.
This scenario happens almost exclusively when you are cutting something which is wider than it is long. It's also the reason why you should never use the miter gauge at the same time as the fence, unless you're VERY careful to apply pressure to keep the piece between the blade and the fence pushed tightly against the fence or against the miter gauge. This also happens fairly frequently when cutting very large pieces of plywood. Despite your best efforts to keep the piece held tightly against the fence, it's way too easy to torque the workpiece and bind it against the blade. On large sheets of plywood, once it binds on the blade, it usually rides up on top of the blade where it gets hurled at you at high velocity, leaving a nice rustic scarring pattern (and possibly some blood stains) across the face of the plywood.
Note that in opposition to Brian's advice, ripping a 1" strip off a 24" piece is LESS likely to cause binding (and, hence, kickback) by keeping only 1" between the blade and the fence. The larger the ratio of length:width of the piece between the blade and the fence, the better.
Another common reason for kickback is improper use of a pushstick. If you're ripping a piece 2" or wider, you can pretty safely push the piece through with your fingers. When the piece is narrower than that, however, you'll want to use a pushstick or scrap of wood to push it through without getting your fingers too close to the blade. If you don't use a pushstick and simply guide the piece along from outside the blade, the part between the blade and the fence will most likely be shot backwards once you finish the cut. This is a lot less violent than the other scenario, however. Depending on it's length, the piece usually only flies 5 or 10 feet.
Kickback can also occur when cutting warped boards. Sometimes even straight boards will warp once you cut them and release the tension from the grain. This warping can sometimes cause the piece to push away from the fence and bind into the blade. In most cases where warping is an issue, you'll be talking about ripping boards that are at least a couple of feet long. That usually means that the length:width ratio is high, so you're not that likely to experience kickback. You may, however, experience enough binding to burn the wood or even bring the blade to a screeching halt. This can be a dangerous situation, as you don't want to remove you hands from the workpiece allowing the blade to start back up and throw it backwards, but you also need to shut the power off as soon as possible. Often, the circuit breaker on the motor or in your breaker panel will trip in this case. A splitter can help immensely to avoid this problem.
You can also experience kickback (and rough looking cuts) when the blade isn't perfectly parallel to the fence. You'll want to make sure your saw is adjusted to keep the blade, fence, and miter slot all parallel to each other.
Last, if you try to cut pieces that are exremely small, especially without a zero clearance insert, you're almost guaranteed that the piece will kick back at you. The good news it that the pieces are light enough not to break any ribs when they hit you. The bad news is that such pieces are sometimes small enough to penetrate the skin rather than just bruise. They also tend to ricochet in random directions adding to the fun and sport.
Charlie, excellent link!
Let alond trying to do a rabbet or a dado.
Thanks for the smug answer, but I was looking for more personal experiences and opinions that you can't get from manual.
Thanks to everyone who took the time to share your thoughts and experiences.
Proper cure for that problem was not to remove the splitter, but to adjust it so that boards would not hang up.
Put it on before you use the saw again. Using a TS without a splitter is just asking for trouble.
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