Tablesaw Issue

[Jack Frederick 135]

I have a Grizzly G0771Z. I love the saw but this is the second time I have had an issue ripping hardwood, so I have figured I would ask what I am doing wrong.

Both times it was 4/4 - 5/4 hardwood. Happened once with oak and once with walnut.

While ripping the wood, the wood pinches SO tight around the riving knife that I cannot push the wood any further. One time I had to shut the saw off and pry the riving knife out of the cut. This does not happen all the time while ripping hardwood, just some times. I ripped a piece of walnut tonight and it got VERY tight on the riving knife. Once I finally worked the piece through the blade, right before the cut was complete, the two pieces split very aggressively, like they where under pressure. Kinda freaked me out. My last cut with walnut I got smart (i think?) and once the board got tight on the riving knife I shut the saw off and wedged a flat head screw driver in the cut to separate the two pieces significantly more. Once I did that, the board went through the rest of the cut like butter! Is this safe? It felt safe, but it felt unnecessary... is there a better way? What am I missing.

I am running a general purpose diablo blade.

[Mark Hennebury]

Your wood is not properly seasoned and is under stress.

[Jack Frederick 135]

What’s the fix? The moisture content is 8%. How better to season it? How do I relieve the stress? Whiskey? Beer? Lol.

[David Eisenhauer]

The wood is what it is at this point. You can make a less-than-a-through-ripping cut on the wood (sometimes from each side if it is thick) and finish it up with a handsaw if you want to. Inserting wedges for either a power or hand cut works to help out as you have noticed. I have a bandsaw and tend to go to it when I encounter this condition, but it can happen there as well. I like my handsaw for final ripping when I encounter this. Slower, but not so hard on the equipment and way less exciting.

[Rick Potter]

Agreed. I am finishing my kitchen, and cannot help noting that the lumber I buy today from the same dealer has more stress in it than when I last built a whole kitchen over 20 years ago.

Assuming the fence is not set wrong, today's wood is more likely to either pinch at the riving knife or spit part way through the cut.

No expert here, but what I do is cut my wood a bit long, then rip my pieces about 1/8 to 1/4" wide. Then I let them sit a couple days in the shop before planing, or sanding all to finish thickness. This helps with making good joints. Then joint one side, and cut the pieces to size. It has made a big difference for the cabinets I am building for my house.

Hope this helps.

EDIT: A couple thoughts.

1. Are you running a thin kerf blade with a full kerf riving knife?

2. With wood that thick you should be using a real rip blade.

EDIT 2: I use a wedge also, as others have said. I have an assortment of plastic shims from Ace Hardware, and keep a couple handy on the top of my fence. I shut off the saw, and tap one in with my push stick, then finish.

[Andrew Hughes]

I do most of my ripping down on my bandsaw for this reason. Sometimes I can see the kerf opening and closing.If the wood is thick and unruly it will split the last three inches.
My tablesaw is for sneaking up to my final cut.
I also know no one really cares.

[Bill Space]

It happens sometimes.

I ripped a lot of wood (for me) recently, all ash from the same tree, and all kiln dried at the same time and stored together. I had one or two boards do exactly as you experienced. Had to turn off the saw and wedge something in the end of the cut to separate the pieces. Then proceed to finish the cut.

This is happened twice in several hundred rip cuts ( probably, did not count, but a lot).

Luck of the draw in my opinion.

Bill

[robert wiggins]

I do as you when that happens, shut the saw off as quick as possible for safety and by that time I have already determined that piece is under so much stress so I don't need it in a project so into the wood stove it goes.

[glenn bradley]

What’s the fix? The moisture content is 8%. How better to season it? How do I relieve the stress? Whiskey? Beer? Lol.

Beer for the wood and whiskey for you . As mentioned, the material has the characteristics brought on by the handling from tree to retail and it pretty much is what it is. This sort of material is sometimes called "lively" and pops up now and again even in properly prepared and handled material. Since you have only seen it a couple of times it may well be within what folks would call "normal". The riving knife should help with this but, I too have had the grip of lively material be so tenacious that I had to stop the saw. Keeping the riving knife clean and waxed can help.

I have seen this tip and done it once or twice but, the pucker factor is greater than I prefer to subject myself to. If you notice the wood start to grip the riving knife, jam a wedge (that you just happen to have handy, right) into the kerf to hold it open in order to complete the cut. Although this works, there are many things wrong with it. You need to know when it is going to happen so that you have a few wedges within safe reach. You then have to throw caution to the wind and reach over the blade to insert the wedge behind the riving knife. I'm OK with that whole operation as long as I stop the saw first ;-)

[David Kreuzberg]

Jack,

I agree with everyone else, but I would advise against wedging a metal screwdriver in the saw kerf. If that screwdriver were to work loose and come in contact with that blade....

[Ben Zara]

Several people have asked this but I'll repeat it: What is the thickness of the riving knife compared to the blade?

[Jack Frederick 135]

David - good point in the metal screwdriver. Now that I know this is an acceptable fix, I’ll build a purpose built wedge that is safer for use.

To all - I will double check, but I am 99% sure the riving knife is sized correctly.

[Orlando Gonzalez]

Have you checked that your fence is aligned to the miter slot. The front and back of the fence need to be the same distance from the miter slot. If the back is angled inwards then you will be pinching the material against the riving knife. Some adjust the back of the fence outward by 1/64" to make sure it doesn't pinch. I have the G0833P and have had to realign it a couple of times but not by much. The instructions how to do it are in the manual. By front I mean the part of the fence closest to the operator and back is the one furthest away. You will be aligning the face of the fence to the miter slot. There are many ways of doing this and Youtube is a good source. I use a 12" ruler and pick either the right side of the miter slot (nearest to the fence) or the left side of the slot to take my measurement. I then adjust the fence, if needed, as shown in the instructions.

[robert wiggins]

For those that are inclined to use a wedge, ACE Hardware has 6 pks of plastic wedges. May be in the plumbing section.

[Marshall Harrison]

Most likely it is the wood as others pointed out. But my first thought was is the riving knife the proper size and aligned correctly.