Can a dull tablesaw blade lead to out of square cuts?

[Greg Woloshyn]

I'm having a difficult time making square cuts using my delta 10" contractors tablesaw with a freud 10" combination blade. The fence, miter gauge, and blade are all square to one another so I cannot figure out why I'm having so much trouble. The blade on the saw is fairly dull and needs to be resharpened soon, could this be the cause of my problem?

[Sam Murdoch]

Yes especially if it has been burning through stock thus overheating and now not truly flat.

[John Coloccia]

If your Delta contractor was anything like mine, the whole motor mount design is truly awful. Unplug the saw and grab the arbor. Wiggle it back and forth. When your blade is dull, it will push everything out of square. When the blade it sharp, it only pushes it a little bit out of square. Eventually, it loosens up enough that the saw becomes useless, like mine did.

[Greg Peterson]

The miter slot is your reference point. The blade, fence and miter gauge should be parallel and square to this first.

A dull blade, like a dull knife, is a bad thing for a number of reasons. The cut won't be as clean as it could be. With a dull blade, you have to force the stock through the cut which heats the blade, dulling it further, stresses the arbor/trunnion assembly as John points out, and is unsafe for the operator.

If in doubt, get the blade sharpened. It's an inexpensive procedure.

[Greg Woloshyn]

Thanks for the replies. My saw is in fairly new condition, its the type where the motor leans out the backside. My arbor is solid with no play.

Greg, I'm guessing you meant inexpensive right? My local shop charges $16 and I'm going there tomorrow. I just can't figure out the problem. Maybe the stock delta miter gauge sucks?

[Lee Schierer]

A common problem is that the miter gauge bar fits sloppy in the miter slot. There should be no side to side movement. Also, Blade height can affect cut quality. Make sure the gullets of the teeth are above the top of the wood as you cut. You may also be sliding the wood to one side as you make the cut. Place some adhesive backed sand paper on your miter fence to help keep the wood from sliding as you push it through the cut. Slick surfaces on miter fences can make holding the piece still more difficult. If you know the blade is dull, it is also dangerous as you will have to force feed the cut. Do yourself a favor and get it sharpened or get a new blade. If this is a combination blade, try a dedicated crosscut blade, you won't believe the improvement in cut quality. Freud makes a number of blades that give excellent cuts for a modest price.

[Greg Peterson]

Thanks for the replies. My saw is in fairly new condition, its the type where the motor leans out the backside. My arbor is solid with no play.

Greg, I'm guessing you meant inexpensive right? My local shop charges $16 and I'm going there tomorrow. I just can't figure out the problem. Maybe the stock delta miter gauge sucks?

Fixed it. Thanks.

Don't trust it to be set up square out of the box. You can get a contractor saw squared up fairly easy, and if you have not set the blade to parallel that would be the first thing I would do.

[Greg Woloshyn]

Well I had my blade sharpened but still no luck. Does anyone have any other ideas I can try? I ran an indicator through my miter slot to the blade and was right on. It has to be my miter gauge, which is the stock Delta miter gauge that came with the saw. I have an auxillary fence attached to the miter gauge which is straight. When I square this against my blade it shows square!

[Chuck Dienzo]

I've had a few friend's with similar issues with their contractor's saws. From your description (motor leans out the backside), I'd say that you've got a contractor's saw as well. Here's a cut & paste of my solution, which I posted a while back on a different forum.

I had a similar experience with my PM64. Look under the saw and locate the 2 long bars that “join” the front and rear trunions. Those bars should be parallel and co-planar to each other. To check for this, I laid a small board (known flat & square, a mirror or piece of glass will work, too) across both of the bars, then checked for “wobble” at the board. Mine were not co-planar by ~1/16” or so.

To adjust, you need to loosen the screws for those bars (mine were located at the ends of the bars, at the rear of the saw) and twist the bar assembly until the board lays flat, with no wobble. Tighten the end bolts carefully, then carry on with squaring up the blade.

Hopefully, this helps you out.

Regards,
-cd

[Sam Murdoch]

If you haven't done this already I would suggest clamping your sample board somehow to the miter square so that you will eliminate the factor of your "technique" pushing stock through the saw. Not being a wise guy here. I have found myself that as I crosscut with a miter gauge on a table saw I sometimes creep the wood. Maybe due to my height or strength relative to the feed rate? Don't know for sure but clamping will help insure a steady feed and that might result in a more square cross cut.

[Curt Harms]

I don't know if this will help but it doesn't cost much to try. I made a fence for my miter gauge - Incra 1000. A flat piece of 3/4" ply then glued some 220 grit sandpaper to the face of the fence. That keeps the piece from moving along the face of the miter gauge. IMO the Delta style miter gauge is fine if you take the time to get it truly square to the blade then never move it. If you angle your miter gauge, a miter gauge with more accurately repeatable stops is a worthwhile investment.

[John Piwaron]

Long ago I was having a similar problem with my contractor's saw. I finally realized in was that the workpiece was slipping on the miter fence. I glued some fine grit sandpaper to the face of the miter gauge fence and no longer had a problem with out of square cuts.

That, of course, is dependent on everything else being correctly adjusted as the other posters point out.

In case you're wondering, this problem doesn't go away with better equipment. These are the basics of making things right. Sometimes I still have to work on some of them. Regrettably, I have not yet attained perfection. Though I work on it every day.

Good luck.