Table saw issues

Woodshop
#1

Riving knife on Powermatic

I tried to rip some 2" thick hard maple on the Powermatic and the board got stuck on the riving knife. It’s either exactly the same thickness of the blade, or a fraction thicker. At first I thought the blade had gotten bogged down, so I swapped it out for the only rip blade I could find in the blade drawer, but I had the same problem with it. So I lowered the bladed all the way into the table and pushed my board which by now had a 6" kerf in it into the the riving knife and the real problem became immediately apparent.

Cut width indicator on the Sawstop off by 1/8"
Apparently, someone tinkered with the cut width indicator. It was way off when I used it today. I can’t imagine why anyone would mess with it. I adjusted it as close as I could, but I just wanted to give everyone a heads up. It probably needs to be fined tuned.

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#2

I never trust the cut width indicator, they’re like rough guidelines. Stuff gets abused too heavily for that. Easiest to pull a tape and measure the gap.

The riving knife issue is unsettling. I noticed there were two riving knives sitting on the powermatic the other day and one of them looked like it had been sanded down a bit. I wonder if that’s why. Anyone know any more about this?

@Team_Woodshop

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#3

It’s also possible that the board was pinching due to the release of internal stresses from cutting the board.

I had a ripped 2x4 Do that on my home contractor saw what didn’t have a riving knife. The board pieces pinched the blade itself and the kickback threw the board about 20 feet.

Be glad the riving knife was there.

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#4

A friend bought one of these and likes it. They say riving knife should be a little thinner than kerf width. We should probably do some test cuts with all of our blades and decide which riving knife goes with each blade.

If the board being cut immediately binds on the knife, it’s too wide,

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#5

See this post and thread:

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#6

@bertberaht This is exactly the point I was making in another thread. Unlike the Sawstop (and European saws) the splitter on the Powermatic was an afterthought. The Shark Guard is probably the best-known aftermarket splitter, but it is not perfect.

I know this isn’t the right answer for DMS, but on all of the tablesaws I’ve ever owned (Sears, Jet, Delta), it didn’t take long before the blade guard, kick-back cawls, and splitters got pulled off and tossed aside. American saws weren’t designed with these in mind, and I found them to be more trouble than they’re worth. On the other hand, I now have a hernia where I got hit in the gut with a board thrown back at me by my Unisaw with no splitter, so what do I know.

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#7

I have seen the pinching you speak of before, but mostly only with unseasoned wood, like southern yellow pine from a big box store. That was not the case today. I was trying to rip 2" thick hard maple. It was not pinching the blade. The splitter was simply too thick. I finished the cut on the Sawstop with no issues.

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#8

I understand what you are saying about the cut width indicator but in my opinion, it shouldn’t be that way. Once the blade on a table saw has been squared with the miter slots, and the fence has been squared up too, the next thing to set is the cut width indicator. And once set, no one should have to touch it. We have really excellent equipment in the Woodshop, and we should be able to rely on their accuracy once they’ve been set up properly. The only way those saws can get knocked out of alignment is by misuse or abuse, and we should to put a stop to that.

Another thing that I noticed today is that Kapex is not cutting square 90°. It wasn’t terrible, but on a 7" wide board it was off enough to matter. I’ve never thought much of sliding compound miter saws for this very reason, but I thought the Festool was expensive and fancy enough to have solved the problem. I switched to the cutoff sled for the Sawstop and it was actually worse, which was disappointing. The crosscuts weren’t that critical, so I went back to the Kapex and finished them up.

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#9

Oof that’s frustrating.

I’m sorry that happened to you.

Stay tuned for some committee discussion about how to work on this moving forward.