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This may be a bit too broad for this site, but I hope that it's specific enough to stay. If not, I'll close it.

I started on a project this weekend, and some (most) cuts on the table saw did not go as well as I had hoped. The edges show burning, the cuts aren't straight or true, the wood didn't feed smoothly, and I could feel the table saw tipping a bit towards the end of a cut.

I was cutting 1/2" and 3/4" plywood (blondewood from Lowes), had Lowes make a few cuts to get it into more easily-managed sized pieces, and had my father-in-law helping to wrangle the wood during the cut. I ripped a 1/2" off a 76" long, 40" wide piece of 1/2" plywood, and cut a 40"x56" piece of 3/4" down to 35 1/2"x37 1/16". My tablesaw is a 10" Craftsman Evolv, which has a ~24"x18" table, with the blade approx 10" from one side and 14" from the other.

So, my overall question is: is it poor technique leading to those problems or is my tablesaw not up to the job of ripping down larger pieces of wood?

Some related follow up questions: is it just that my blade needs a cleaning or sharpening? Or maybe I need a different blade (I'm using the stock 24T blade it came with)? Should I not even use the tablesaw for breaking down plywood, but a circular saw instead (I had similar burning problems previously with my circular saw)? I suspect that the tabletop is just too small to work with big pieces of wood, but short of buying more wood to try it, I'm not sure.

mmathis
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    It's often best to start breaking down plywood using a circular saw to cut slightly oversize pieces, then use the table saw to trim it to final size for accuracy. When handling large pieces, in feed and out feed supports are important for safety. Burning usually means you are cutting too slowly. – keshlam Sep 06 '16 at 03:14
  • If you have a circular saw it would be highly advisable to use it to do the initial break-down cuts on large pieces of ply. They're difficult to manipulate even on a full-size table saw with infeed and outfeed surfaces, nearly impossible to do it properly on a small saw. To do long cuts with your circular saw, clamp a straightedge (a straight piece of 2x material is fine) to the ply, run the saw carefully along it and you should be getting much straighter cuts than you're currently getting. The ply can be laid directly only styrofoam insulation for doing this sort of cut on the floor. [contd] – Graphus Sep 06 '16 at 07:13
  • To get the most out of your table saw you should prioritise making an infeed and/or outfeed table for it that's exactly level with the bed of the Craftsman. Even an additional 18" would make a massive difference. – Graphus Sep 06 '16 at 07:14
  • I'd also be suspicious of the stock 24" blade. It's probably either a rip blade or a combo blade designed for ripping and crosscuts. Neither will do a particularly great job cutting plywood, especially if it's a nicer veneered plywood. Those blades will tend to rip and tear the veneer. A new blade shouldn't be burning the wood, though, so I suspect either blade sharpness or feed rate. I use a clean, sharp 80 tooth blade for cutting plywood cleanly. As others have said, it is hard to feed plywood through a table saw, and since the blade is new, feed rate would be my first suspicion re: burning. – Katie Kilian Sep 06 '16 at 14:56
  • @CharlieKilian The blade isn't brand new - I've used it previously to rip down some PVC exterior brickmold, maybe 10 cuts. – mmathis Sep 06 '16 at 15:22
  • @Graphus, keshlam In this particular case, Lowes did the initial breakdown of the plywood (couldn't fit in the car otherwise!), so the tablesaw was used to do the final cuts. In the future, I guess I'll do any "big" cuts with my circ saw and use the table saw to rip off the last inch or so – mmathis Sep 06 '16 at 15:32

2 Answers2

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Although I have not seen your tablesaw, I have used other portable contractor saws and they tend to have several problems. First the fence is not substantial and may have some give when the wood piece applies pressure against it. The fence is also very short and the sheet can easily get off track against the fence. It is also possible that the fence and the blade are not fully parallel and the wood can bind a bit as it is moved passed the blade.

In addition the table top is very small relative to the plywood. I use a table extension to support the full width and run-off length of the plywood I cut and have clamp on legs that attach to the fence guide to provide support on the front of the table. The only force I apply to a piece I am cutting is to push it through the blade with a light pressure to keep the plywood against the fence.

In short, it is very difficult for anyone to cut plywood that large on a such a small table. to make the cut you must 1) provide much more level support before and after the blade position, 2) verify the blade is parallel to the fence, 3) make sure the fence is secure, 4) provide a fence extension by adding a longer board securely clamped to the fence to provide a longer guide surface.

Ashlar
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    Good answer. Just to add, the stock blades that come with saws are pretty notorious for being, well, crap. Getting even a mid-priced one (say, a 40-odd tooth diablo) should improve matters. – Aloysius Defenestrate Sep 06 '16 at 03:50
  • @AloysiusDefenestrate How well do the "combination" blades work, especially for cutting plywood? I realize it'd be best to get two (or three) blades for ripping, cross-cutting, and maybe plywood, but of course the budget doesn't always allow for that :) – mmathis Sep 06 '16 at 18:16
  • Lots of people would have opinions on this one... I'd even suggest you form a question out of it... but having said that, combination blades are the ultimate compromise -- they neither rip nor crosscut excellently. Since ply is both, the combi blade isn't bad. If I knew I wanted a fine finish, I'd go to a crosscut blade. – Aloysius Defenestrate Sep 07 '16 at 01:29
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I have a similar table saw and have done a few things to get better results.

First, get a better blade. A sharp blade will cut faster, a faster cut means the wood can move through the area where the blade is rubbing on it quicker, which means the wood will heat up less and lead to less burning.

Second, find something, anything that will help you support those large pieces. I have used a stack of scrap wood on a nearby picnic table to build up something close to the height of the wood on the out-feed side, this will help you to concentrate on the wood as it goes through the blade. I understand if you don't want to invest in the time/space to make/use a dedicated infeed/outfeed table, but a roller stand (folding legs, roller on top) is a good helper. Also, learn to think with both sides of the wood. If you can only set the rip fence out a foot but want a 18 inch wide panel and your board is 20 inches wide, set the rip fence to 2 inches and rip off the waste with the part you want to keep on the far side of the blade to the rip fence. While not as nice, this trick has saved me a time or three.

Third, and this was the big one for me, cheap tools have a problem in that they are not built to the same tolerances as more expensive tools. To that end, you need to spend a bit more time calibrating and dialing them in. On my table saw, I need to reset the blade angle every 3-4 cuts, or it will slip from 90 degrees to the table to maybe 85 or so. Also when setting up the rip fence, I have to check that the distance is the same at the beginning and the end of the blade. I also typically do this using the same tooth to make absolutely sure. Another issue is that the miter gauge is ok, but does have a tiny bit of play in it. As a result it needs to be squared up every few cuts (when I have the square in my hand already to re-position the blade angle). Finally, after a blade change, I run the saw for a minute or so with a sacrificial reference edge close to the blade to make sure the blade does not wobble. I have looked at the uber-fancy ones at various stores when killing time/dreaming, and from what I see, it has none of these issued. The rip fence and miter guages slide easily in their slots, but not enough to have any play in them. The mechanism that handles the blade height and blade angle are two separate controls (changing height ALWAYS skews my blade angle a bit), and are built much more solidly, so they don't wobble on their stand nearly as much.

Pulsehead
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