In the new Joinery book from Taunton, it states, “If work starts to ride up on the blade, hold it firmly in place while you dial the blade down and out of the cut. Don’t try to force the work down onto the blade.” p. 34
By “dial the blade down” does this mean crank the blade to table surface height? All while the saw is running and you’re holding the piece? (Sounds tricky.) Or does it mean carefully back out (or down) the piece without forcing it down?
I have seen reference to pieces coming up, and the reference to not forcing the piece down, but I’m still not clear how to properly respond. Thanks, Todd
Replies
A tough call, I'm sure you'll get a lot of opinions, but it isn't what I'd do. Off hand, if the wood has lifted off the table more than a fraction of an inch you're in serious trouble already with a very unstable situation that could go to south in a fraction of a second.
I'd be more inclined to duck quickly to the side, away from the blade path, turning my face away, and letting the wood go where it wants. You should already be safely off to the side to avoid getting hit by kickbacks anyway. Reaching down to turn the blade height crank, or even to reach the power switch, depending on where it is, would be inviting a potentially vicious kickback squarely in the face.
If you've got the cut set up properly, and have adequate control of the stock it is very unlikely that you'll ever have to decide what to do if the wood comes off the table, but I suppose it is worth considering.
John W.
Wood comes off the table generally because of stress.
Some times stress causes the wood to pinch the back of the blade and it is the back of the blade that does the lifting. A splitter of the same size of the kerf usually prevents that.
It is a good idea to have a "kill plate" that you can hit with your knee and shut off your saw.
C.
Toddhunter,
This has happend to me a couple of times. The first time I was able to hit the switch and just hold everything till the blade stopped. The second time the force was so hard I would not dare move my hand to the switch.....I just pushed down hard and held it there...the blade stopped and the motor tripped. I always use a long shoe now
I'd agree with John W. generally. If bad things begin to happen with any machine, move to the side and get out of the way! Let whatever happens to the wood happen; try not to be directly involved! Shut off the machine from the side or just pull the plug.
A related matter: educate everyone in the area (with a 2x4 if necessary) to STAY OUT OF THE PATH of the tablesaw when it's running. That way, you won't hit someone else if you let go and move out of the way.
By the way, you should discuss safety with everyone in the family. For example, I've impressed this on my wife and family:
1. If a machine is running, wait outside until it shuts off. I don't want to be startled.
2. Stay out of the path of kickback from the table saw when it's running. Wait! Don't hurry past!
3. NO COLD BEER BOTTLES ON THE CAST IRON!!
Seriously, safety is something that is best thought out before you need it, kind of like rehearsing a glue up.
Todd,
In this case, the best defense is a good offense. If the cut is set up correctly ahead of time, a climbing cut can be avoided, or at the very least, be more safely controlled if it happens. Foremost, the wood being cut must be face and edge jointed flat/straight, to keep the piece in contact with the saw's fence and table at all times, as well as using a sharp blade. If you don't want to joint the wood, cut it on the bandsaw where kickback and blade climbing isn't an issue.
Assuming that your saw is tuned up with the fence parallel to the blade (and it should be!), make sure that the splitter, guard, and anti-kickback pawls are in place and aligned.
Here's the easy part - as important as it is to have a feather board to hold the board to the fence, a hold down holding the wood to the saw top is almost equally important.
A hold down functions exactly like a feather board, with the exception that it is usually mounted to the fence facing downward. If you have T-track in the face of your fence, or if there is some sort of auxiliary fence, then mounting a feather board is straight forward (or can be easily fabricated). If on the other hand, you are just trying to hold down a narrow piece during a cut, clamping a short length of board to the fence face works perfectly. I use a 3"x7"x1/2" piece of UHMW, and clamp it to my fence with two small F-clamps. To line it up, move the fence away from the blade, and lay the wood (to be cut) up against it. Lay a piece of 3x5 card on top of the board next to the fence and place the hold down (wood, UHMW, etc...) against the fence and on top of the card. Use two clamps to attach the hold down to the fence. The hold down should be mounted so that the front end (the end farthest away from you) is approximately an inch and a half into the cut of the blade (e.g. if you were cutting wood and stopped after only an inch and a half was cut.) Now, remove your wood and the card, set the fence to the correct setting, and cut away! The card is used to allow space for the wood to slide under the hold down, but not enough to let the wood climb up. You will need a thin push stick to be able to pass under the hold down.
This procedure can be modified to accommodate wider boards as well.
If you have any questions, please feel free to ask!
Dan Kornfeld, Owner/President - Odyssey Wood Design, Inc.
Edited 8/11/2004 1:14 am ET by Jackie Chan
Edited 8/11/2004 1:14 am ET by Jackie Chan
Just lift the offending piece off the saw from the user end . Letting go & trying to duck out of the way is not a very good idea !
On a hill by the harbour
Todd,
Often the cause of a workpiece rising off the saw table is a less than sharp blade running into a knot, or an area of greater density in the wood. The key to avoiding this, is to be aware of any defects or crossgrain in the line of cut, and adjust your feed rate accordingly. Don't force the saw to cut faster than it wants to.
In a situation where the stock has pinched the blade, as John said, you should be standing out of the path of a kickback to begin with. My personal feeling is that lots of kickbacks happen when the operator is overly cautious, and is pushing the stock thru the blade while at the same time getting ready to let go. It is easy to lose control of the stock when you are just using your fingertips to push with, or if the push stick is held loosely, and pushed hesitantly. If you are holding the stock down as well as pushing it forward, it is less likely to rise off the table. I like a push board that's about 14" long, with a bump on top to hold onto, and a hook about an inch from the end to catch the stock, rather than a stick with a notch in the end. I try to position my hands so that if a kickback occurs, I'm not pushing directly toward the blade, but rather to one side or the other of it. Sounds like you have to be a contortionist to operate a table saw doesn't it?
My slant is more toward avoiding a situation where the stock is coming WAY up off the table. If I got that out of control, like John, I think I'd just let go and duck.
Regards,
Ray
You need a short fence for ripping. The Delta Unifence is excellent for this. You also need to use feather boards and you also need to rip with the guard and splitter in place.
If the wood starts to ride up on the blade the only thing you ought to do is stop advancing the lumber and reach down and shut the saw off. I wouldn't dare try to reach down and turn the wheel to lower the blade.
Some say a higher blade setting - the gullet at the level of the wood or higher - keeps the stock forced to the table. But that's a lot of blade showing. If you decide to try this, make damn sure your guards are in place.
Keep your blade sharp and clean. Wax the cast iron top and fence. Feed the wood at a rate the saw can handle. If the wood is misbehaving then rip it with the bandsaw and cleanup with a plane, or rip with a handsaw and cleanup with a plane.
Edited 8/11/2004 10:39 am ET by cstanford
"The Delta Unifence is excellent for this." So is a narrow piece of wood clamped to the fence. forestgirl -- you can take the girl out of the forest, but you can't take the forest out of the girl ;-)Another proud member of the "I Rocked With ToolDoc Club" .... :>)
I don't like clamps on the fence of a tablesaw, but if that's all you've got....
In last year's Tool Shops issue, a tip was offered by a reader who saw a cross cut sled rising as it began to fall off the end of the table after the cut. In other words, the near side of the sled rose after the cut and he feared it would be pushed back onto the blade. I wonder if this is what was referenced in the quote I mentioned. The tipster made a sled with a heavy near end. Another tip in a different magazine suggested a stop be installed on the side of the wing to prevent the sled from going too far forward. Todd
You're giving me nightmares just thinking of that scenario!!!!!!
Todd, sounds to me like the author is counting on you noticing the "rise" when it very first begins. I dunno, I've never cranked down the blade -- I just hit the switch, and can't see any reason to do it differently. A good knee-operated off switch would make that even more efficient.
Letting the stock fly sounds dangerous to me, especially with sheet goods. While a regular board may shoot straight up and forward, a piece of plywood can and does spin during a kickback event.
If I'm ripping off a couple narrow pieces that might climb, I'll just place a couple of Quick-Clamps on the fence, one in front of the blade and one just short of the back of the blade, with the rubber tips just barely touching the stock. That gives me enough help to feel pretty safe. Wouldn't work, though, with a wide cut on a piece of ply.
forestgirl -- you can take the girl out of the forest, but you can't take the forest out of the girl ;-)
Another proud member of the "I Rocked With ToolDoc Club" .... :>)
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