table saw tuning

I got a new table saw (Powermatic 64 Artisan) and I'm having a tuning problem. When I push the lumber past the blade, the piece starts to turn away from the fence toward the blade. As a result, the back of the piece can be 1/16" of an inch narrower than the front. I can "correct" this problem with a feather guide, but I'd prefer to tune it correctly. I assume the problem lies with a slight misalignment of either the fence or the blade. With my primitive measuring tools - namely a combo square - both the blade and the fence seem aligned with the table. Any thoughts?

BTW: The Accu-fence rocks! I can dial up 3" and it cuts 3". With my old saw, I could never trust the stupid guide. I measured each cut from blade to fence with my combo square.

Jeff

Reply to
Jeff
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This actually sounds like a feed technique problem or bad material that may be case hardened such that it bows after being cut. To eleminate that possibility og bad stock try cutting MDF or plywood.

As a result, the back of

The only place that you want to use a feather board is in front of the blade, NOT the back side.

I assume the problem lies with a slight misalignment of

You can easily check the blade to slot alignment with your miter gauge. Attach a piece of wood to the miter gauge so that the end of the wood is about 3/4" from the blade. Screw a screw into that end of the board so that it just comes in contact with the side of a tooth on the front of the blade. Rotate the blade so that the "same" tooth is at the back side, slide the miter gauge back and compare the measurement again. For the most accuracy raise the blade to its full up position and be sure to have the saw unplugged during this process.

Once you are happy with that adjustment adjust the fence to be dead on parallel to the same miter slot used to align the blade to the miter slot. You can simply use a piece of wood, thinner than the miter slot, to slide down the face of the fence into the slot. Check the clearance at several points if the fence is not parallel the piece of wood should hit the table surface and not go down into the slot. Make a test cut and adjust accordingly.

That is what a decent fence should do.

Reply to
Leon

You might want to seriously consider upgrading your 'primitive measuring tools'. There is an easy way to get your fence dead on balls accurate and you can then eliminate that as a potential cause of your problem.

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Reply to
Garage_Woodworks

Look into books by Kelly Mehler.

It's worth the $20. We could go over all the steps, but I think you'll find the book worthwhile.

Reply to
Kevin

I didn't specify it's location, but that's where I have it. See, cos I have this thing about taking a board to the mid section.

Reply to
Jeff

You have Jr.? I assume you think it was worth 133.00. How often do you use it?

Reply to
Jeff

I have a hunch either your blade is not parallel with the miter slot or the fence is not parallel with the blade.

Here's how you can fix that for WAY LESS than the prices of some of the tools recommended by others. Get yourself an adequate dial indicator (Harbor Freight has them). Cut a square end on piece of narrow hardwood and screw the housing of the dial indicator to it (it would be better of you bevel the hardwood so the indicator plunger touches near the bottom of your saw fence).

Clamp the assembly to your miter gauge (if necessary, shim the miter gauge guide bar so it doesn't drift in the slot).

Raise the blade to full height and mark a tooth with a marker. Check the blade by measuring the marked tooth nearest the front of the table, rotate the blade so the marked tooth is at the back and measure again. If the difference is more than .002-.003, adjust the blade to be parallel with the miter slot.

After aligning the blade, reclamp the dial indicator rig in the miter gauge so it will reach the fence (you can position the fence fairly close to the blade). Measure the fence along its full length from the front of the table to the back. It should vary no more than .005 and the back should be the longest measurement so the work piece won't bind when being cut.

Reply to
Chuck Hoffman

Ok then, Since you said, I can"correct" this problem with a feather guide,

If the feather board in the correct position solves the problem, your technique is probably the problem.

Reply to
Leon

Yep..that's exactly it.. for contractor type saws.. need to loosen trunion bolts and move it around. For cabinet type saws.. loosen top and slide it around. Loosen a very little and move in tiny increments. Remember.. we're talking about .001" here.

On your fence hopefully you have some parallel to slot adjustments and also perpendicular to table adjustments.

You might also want to look at the flatness of the top.

Also.. add in a homemade splitter if you need to remove the blade guard / stock splitter. Get a chunk of 1/8" wide metal, cut a hole then slot in the bottom to slip down onto the bolt that holds the blade guard inplace. Cut the metal off about 1" above the table. You can make one that sticks 1/4" and 2" if you want for thos times when you cut grooves. It's not as good as a riving knive, but pretty close... and can significantly reduce kickback.

If you can picture all this then you have the info.. if not.. like I said, see Kelly Mehler's books... I got one starting out and it's worth it.

Reply to
Kevin

"Jeff" wrote

If you pay the bucks for a high quality tool, why not spend a fraction of that to keep it operating at the peak of perfection? If you're really serious about woodworking, it's indeed a valuable instrument to have in the shop.

For high quality tools that hold their setting, probably not that often "per tool", but over the range of tools in the shop that benefit from tweaking for best performance, probably more than you think. (It's amazing how often a tool can take an accidental blow in a shop environment, necessitating a tweak, here and there, for even the best of equipment).

It's also a good feeling, when starting a new project, one you've been planning for months and just bought the wood for, to spend the time getting everything tweaked just right in anticipation of milling that new stack ... sort of a good karma, Zen, ying and yang, up your project chakra, kind of thing. :)

Hint: if you have a choice of dial indicators, consider upgrading to the highest quality one you can afford ... when you start dealing in ten thousandths of an inch, you'll probably be glad for extra little bit of accuracy.

Reply to
Swingman

That's certainly possible but I could rip straight without a feather guide on my last saw (a considerably crappier piece of machinery...) You can almost set your watch to the path each piece takes as it runs past the blade.

Reply to
Jeff

"Jeff" wrote

Hold a known straight edge across the length of your fence's face just to rule out that lack of flatness is not an issue ... little things add up.

Reply to
Swingman

I think it is worth it's weight in gold. I use it before every project session to check for alignment of various tools. My EB3 miter gauge usually hangs on my peg board. Before I use it I can check for square without making a single test cut.

I also make sure my jointer fence is square before squaring leg blanks.

You will be surprised how often you use it. For your case now it would be a huge asset. You could check your fence front to back and know how far out of wack (or not) it is (quickly and accurately w/o a single test cut).

Reply to
Garage_Woodworks

I should have added:

You can check for any bow in your fence with a dial indicator, too. Do the setup for the fence test as I described above then check the fence along its entire length. It should should not vary in flatness more than a couple thousandths from front to back. If both ends are very close in measurement and the middle has a deflection (one way or the other) of more than .003-.004, you should find some way to flatten the fence.

One way is to add an auxiliary face using birch ply or melamine laminated MDF. You may have to shim it (either on both ends or in the middle) to remove the bow.

Reply to
Chuck Hoffman

Sold. I'll get one in the next billing cycle...

Reply to
Jeff

Thanks. I used your method and found the blade is off by .02" The front of the blade is closer to the fence.

Jeff

Reply to
Jeff

I like that! (I had to look up chakra )

Reply to
Garage_Woodworks

"Garage_Woodworks" wrote

... I knew a whole bunch of hippy chicks back in the 60's and we were always trying to 'up our chakra', in one way or another. ;)

Reply to
Swingman

That's an error of 20 thousandths, or about 10 times the recommended amount. I'm surprised you don't get some binding or kick-back.

Just th>> I should have added:

Reply to
Chuck Hoffman

In the same vein...

Lots of times, the little things can add funky issues.

For instance, a bowed fence can show itself to varying degrees, based on the length of stock being ripped. Multiple rips from the same board can get really funky, especially if the board is short. On the other hand, a board of the right length will bridge the bow and come out skinnier in the middle. The short and long boards may exhibit different problems.

Reply to
Bonehenge (B A R R Y)

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