I was crosscutting 5/4 walnut boards this past weekend when suddenly the blade started binding about midway to 3/4 of the way through the 7 inch boards. I was using a crosscut sled for this operation. I pulled the sled and made sure the blade was 90 degrees to the table. It was.
Later I started ripping the boards down to fit my 6 inch jointer and.. again the binding.. only worse. Tripped the circuit breaker. Rechecked the blade.. and the fence. Everything straight and square. Still binding the blade to a complete stop in the wood.
Stopped everything.. went to the bandsaw and finished the ripping.. still unsure what was happening with the TS. (I know many of you prefer ripping on the BS but it’s too slow going for me.)
This morning I went back to the shop and metered the boards. 10% to 11% mc. And glancing at my TS I realized that when I put the sled away to begin ripping.. I hadn’t replaced the blade guard and splitter.
I think the high mc together with no splitter was causing the binding. At least I hope that was the reason.
I have everything rough milled and stickered for the blanket chests I’m planning to make when the humidity drops a bit and I have a more decent mc to work with.
Replies
I had this same problem on my Jet 3HP cabinet saw when I had a 80T crosscut blade. I put in a 40T combo blade and no problem.
As a matter of fact I was using an 80T crosscut blade. And when I began ripping I switched back to my WW11 thin kerf blade.
using a thin kerf blade in unstable wood will definately contribute to binding...
I should have used my bandsaw to begin with for the ripping operation..
.. and I'm now in the market for a 10in slider to perform those crosscuts my current chop saw can't reach.
the mc has nothing to do with your wood binding. neither does the splitter, unless the kerf is closing up after the cut.
are you using the fence and the sled at the same time? this would definitely cause it.
there are other possibilities but this is the best place to first check.
I'm thinking the kerf is closing up during the cut and trapping the blade.
I'm editing now because I just realized you suggested I might be using the crosscut sled and the fence at that same time. For the life of me I can't imagine why anyone would do such a thing.. can you?
Edited 9/19/2006 4:50 pm ET by billballeza
"For the life of me I can't imagine why anyone would do such a thing.. can you?" Because they don't know any better....when making repetitive cuts, using the fence to set the length of the piece. Instead of using a short little block attached to the fence.
Common enough that tablesaw "how to" books warn against it, and Norm demo's how to do it right periodically.forestgirl -- you can take the girl out of the forest, but you can't take the forest out of the girl ;-)
Okay, now I see. I remember about four years ago it was you who finally got it through my dense gray matter what a stop block is.. and how to use it.
I was just getting started back then.. and you and Sarge and other generous souls helped and encouraged me more than you'll ever know.
Thanks again!
"...who finally got it through my dense gray matter what a stop block is.. and how to use it." Hah, too funny. Not a blatantly intuitive thing, is it, LOL?!forestgirl -- you can take the girl out of the forest, but you can't take the forest out of the girl ;-)
Bill, 10%- 11% MC is not a figure I would consider wet for working solid wood. I wouldn't expect that sort of MC% to cause problems such as binding during ripping. That's at about the top of the MC range internal furniture will normally experience in a Houston house with decent insulation and A/C, plus a hint of heat in the winter, not that it's ever really needed, ha, ha. Wood in a Houston house might go down to about 7% MC in the winter if you do run the heating quite high.
So I'd discount the MC as a cause of the binding during ripping. From your description I'd be more suspicious of case hardening of the wood-- some kind of stress induced by the drying process. Case hardening can sometimes cause problems during cross cutting, but this is somewhat rarer in my experience.
From what you've said I'm not sure what's going on to cause the problems you experienced. But I would certainly monitor your partially worked up pile of timber for signs of excessive distortion. Excessive and rapid distortion in stick could suggest that the wood is stressed, e.g., case hardened.
This leads to, "What is excessive?" If planks bow significantly in the length, perhaps 1/2" or more over 3', cup perhaps 1/8" or 5/32" over a 4" width, or go into winding very noticeably, then there may be significant stress.
Incidentally, the lack of a splitter and crown guard during ripping wouldn't cause the timber to pinch after the cut but, as you are obviously well aware, it could help to reduce the chance of kickback. Slainte.
Richard Jones Furniture
Thanks, Richard. In a bit more detail.. I was crosscutting 8' long 5/4 walnut timbers.. reducing them to just over the lengths needed for the tops, rails and stiles for the blanket chests I'm fashioning for my children.
Most of the crosscutting was completed when I began having the problem. I had the timbers supported on the left side of the saw.. and using my sled was taking 24" to 42" lengths off the timbers. It was in the final three or four cuts that the blade began binding and altogether stopping.. once tripping the breaker. Devil of a time extricating the board from the blade each time.
Then I removed the sled.. added the fence.. and began ripping the boards down to width for my 6" jointer. Immediately.. on the first board.. the blade froze at about 20" into the cut. I had made sure to recheck the blade for 90 and square to the table.. ditto the fence.
Whereupon I forsook the TS for the bandsaw.. which I dislike using for ripping because of the time it takes.
I suppose I'm going to have to check the TS arbor and bearings next.. but something has definitely gone awry.
Whoa, something just occurred to me. The timbers are rough and therefore did not have straight edges to reference against the sled nor the fence. Could that be the problem?
In any event, as mentioned to someone else earlier.. I definitely need a 10" slider since I lack the space for a radial arm saw.
Hope all is well with you and thanks for weighing in. We had a nice day in Houston.. 80's with 24% humidity. About as good as it gets here this time of year. Cheers.
The timbers are rough and therefore did not have straight edges to reference against the sled nor the fence. Could that be the problem
Most definitely. All stock should be squared up before using the tablesaw...
Sawing up rough timber without any straightened reference surfaces wouldn't help Bill, especially if you have quite a small (and perhaps low powered) saw. That could possibly be your problem, and hopefully that's all it was. But checking up on the saw's alignment is probably a good idea too.
I'd still keep an eye on the wood that's cut up and make sure it doesn't distort significantly just in case there was some stress in it.
80ºF and 24RH in Houston during September! That proves global warming is a myth, ha, ha. Slainte.Richard Jones Furniture
Yep. Guilty on call counts. Probably most guilty on the low powered saw.
Wood is looking fine so far.. and I tuned the saw (such as it is) today.
And.. we're back to 90F and 86RH. The garage was like a sauna.
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