Just for openers I didn’t get badly hurt. And now the puzzling begins! I’m looking for help because I DON’T want a repeat… and I stayed up half the night thinking about it. Comments very welcome.
So since I started woodworking and aspiring to Woodworker around three years ago I haven’t had a kickback that hit me (or really a note worthy kickback)… until now. I was trimming the waste off the cheek of a tenon (like I always do with block clamped to the leading edge of the fence) and the cheek waste (3″x3″x1/4″) caught in the blade, hit the fence, hit the stop block, and somehow winged into me (small welt WAY to close to, uh, ahem). In retrospect I’m amazed it didn’t embed in the stop block considering the dent it left. The block I was using was 4″ wide so I thought it would have left room for the waste to not bind against the blade and fence- hasn’t before anyway. So the only things I came up with last night are:
– That the block should be wider than the diagonal of the largest waste?
– Maybe a crosscut sled would fix the problem all together? (Never used one)
– Is my saw blade seriously messed up? My insert is, and if my blade went that far into the insert it must have deflected a LOT.
– Maybe I should just use a dado blade to make tenons like Norm does sometimes? It just seems like it wouldn’t be smooth enough.
Anyway ANY advice would be welcome. I have my first kid about to show up, well, any day now, and against my nature thus far I’m become super extreme nut. Or maybe it’s just if I’m missing a finger my argument that bike helmets are a must just wont carry weight.
Thanks for any help- just writing about it makes me feel better!
Replies
What you were doing can be done safely, but obviously some details of the set up need to be changed.
To be sure about what happened and why, can you provide a few more details: how thick was the stop block, that is the distance between the face of the block and the face of the fence. What was the overall size of the stop block, length, width and height? Third question: where was the stop block in relation to the leading edge of the blade? Just to be sure of what you were attempting: were you cutting the shoulder of the tenon after having cut the cheek earlier?
You might have bent the blade, rotate the blade by hand while holding a scrap of wood next to the teeth. If the blade is bent, you'll see the gap between the scrap and the teeth vary as you turn the blade. If there's a slight wobble the blade won't be dangerous to use but it won't cut as smoothly. If there is a large wobble the blade should probably be retired. Also check the teeth, you may have broken a few of them. It's also possible that youve knocked the fence out of parallel with the blade.
John W.
Edited 3/16/2004 6:42 pm ET by JohnW
Chipper:
Here is my guess as to what happened: As the waste came off the cut, it got caught by the blade, and spun. Since your block was only 4", the waste got caught between the blade and the fence, resulting in the kickback.
You are right with regards to the fence setting. If I remember my geometry right, the minimum fence setting (with 3" square waste) must be 3 * squareroot 2 = 4.25". Your blade deflected by about a quarter of an inch.
Your method could be done safely, just move the fence out further. A crosscut sled would be good too.
Glad to hear you weren't badly hurt...just got a badge of experience.
You'r right about the diagonal of the off cut and the distance to the fence. The more room the better. Sometimes "bleep" happens. I learned long time ago to watch the off cut like a hawk. it usually doesn't matter what the other things are doing, it's that loose off cut that that will get you.
Another thing that you might consider. You mentioned a new arrival at your house soon. Could it just be that you were a little over tired at the time? Think about that one as well. Also, not to go scapegoating, but were you distracted by anything. There not kidding when they say power tool opperation needs 100% of your attention.
Now that you have learned that small blocks of wood propelled at very high rates of speed really CAN do damage, you will be a safer worker just from having had the experience.
Chipper,
Like John W., I am not exactly sure how you had your set up. It sounds like you were cutting your shoulders after cutting your cheeks, leaving your waste between the blade and the fence. If I am gathering things correctly, you left a little extra space between the blade and the fence by using your stop block. My suggestion to you would be to cut your shoulders first, then your cheeks using the tenoning jig so that you are not using your fence when the waste comes off.
A good rule of thumb is to never have a set up where waste is left to dangle between the spinning blade and the fence for any operation.
Cheers
Kyle
I use either a radial arm saw with a dado blade (all cuts go the rear); or a hand saw for those small cuts. The main shoulder cuts are made on the table saw with a tennoning jig or preferably on a radial arm.
Thats the way I do it. Don't be afraid to take out a hand saw now and then for smaller cuts.
I had a picture frame kick back on a 5hp Unisaw once right in the same place. The darn things swelled up the size of grapefruits and I couldn't walk for a week. I stand well astride of the blade now.
Regards,
Boris
"Sir, I may be drunk, but you're crazy, and I'll be sober tomorrow" -- WC Fields, "Its a Gift" 1934
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