One Cut, Two Results: One side smooth, the other torn out?

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Forum topic by thiel posted 06-24-2009 05:35 AM 1521 views 0 times favorited 14 replies Add to Favorites Watch
View thiel's profile


374 posts in 2713 days

06-24-2009 05:35 AM

Topic tags/keywords: cut problems tablesaw tool setup tuning


Any ideas for what’s causing this problem? The attached photo shows two sides of the same cut, and as you can clearly see one side is crisp and the other ragged. Thoughts?

Other details:
—Grizzly 3hp saw
—Forrest Woodworker II blade
—No splitter or guard
—I also get a lot of sawdust blowing back at my face while I cut. This is particularly prominent with plywood.

I had wondered if this meant my saw was out of tune in a particular way…. any ideas of where to look
first? (I recently moved and thought I’d successfully dialed in all my equipment, but then this started to happen).

Cut Detail

-- Laziness minus Apathy equals Efficiency

14 replies so far

View a1Jim's profile


115177 posts in 2998 days

#1 posted 06-24-2009 05:49 AM

Well David
It’s hard to believe it’s the same cut , the right side looks as if it didn’t quit cut all the way through with no evidence of the left having torn off from the left. It’s not a dull blade because you would have burn and its not a dirty blade for the same reason. I would say to try anther blade and see what it looks like. Perhaps it’s a bad or damaged blade or sharping job.

-- Custom furniture

View PurpLev's profile


8523 posts in 3069 days

#2 posted 06-24-2009 05:50 AM

looks like most likely one side of the blade has some dulled out teeth that are tearing one side of the cut. another though – since you mentioned you do not use a splitter – might it be that the side that is not running against the fence is pinching the blade on the back side as it passes it, causing the blade to shred it’s surface?

which side of the blade is the CLEAN side? the one running against the fence? or the cutoff side?

-- ㊍ When in doubt - There is no doubt - Go the safer route.

View thiel's profile


374 posts in 2713 days

#3 posted 06-24-2009 05:59 AM

I believe the clean side is between the blade and the fence. Not entirely certain about that though, but probably 85% confident.

I have a thin kerf freud blade I can try tomorrow, but it’s got 90+ teeth, so I’m not sure it’s a good comparison for diagnosis.

I was hoping one of you would say “oh yeah… your whozitz is out of alignment with your whatzis… happens all the time…”!

-- Laziness minus Apathy equals Efficiency

View Myron Wooley's profile

Myron Wooley

226 posts in 3317 days

#4 posted 06-24-2009 06:26 AM

This is an alignment issue. You need to verify that the blade and fence are both precisely aligned with the miter slot. The best way is to use a dial indicator mounted in a jig, either the TSAligner or the the A-Line-It. The straighter you can get everything, the better. I have my fence about .004” open to the blade at the back. Any more, and the teeth on the backside of the blade will frizz the offcut and throw sawdust in your face like you are seeing. Too much, and you are setting yourself up for a kickback.
If the fence is closed at the back, i.e. the gap narrows as you go, the workpiece will bind on the blade. Another dangerous situation.

-- The days are long and the years are short...

View thiel's profile


374 posts in 2713 days

#5 posted 06-24-2009 09:37 PM

Thanks. I’ll hunt down the alignment issues tonight and let you know!

-- Laziness minus Apathy equals Efficiency

View thiel's profile


374 posts in 2713 days

#6 posted 06-30-2009 03:34 AM

Turns out everything was in tune. The problem? The blade is warped! I checked against a flat reference surface because my dial indicator was giving me CRAZY readings.

Another blade on there and alls well. Now it’s time to send the first one back to Forrest!

-- Laziness minus Apathy equals Efficiency

View davidroberts's profile


1025 posts in 2907 days

#7 posted 06-30-2009 03:51 AM

forrest should be able to beat it back to flat. i have the same setup, WWII blade and Griz 3hp. now i’ll know what to look for, if i see it :)

-- Better woodworking through old hand tools.

View PurpLev's profile


8523 posts in 3069 days

#8 posted 06-30-2009 04:07 AM

interesting outcome – thanks for posting, another thing to consider in the future :)

-- ㊍ When in doubt - There is no doubt - Go the safer route.

View thiel's profile


374 posts in 2713 days

#9 posted 06-30-2009 04:14 AM

... now, of course, “everything was in tune” to a warped blade :-) So… now I’ll retune (again) with a flat one.

BTW… instead of an Aligner jig, I use a magnetic dialcaliper stand stuck right to the face of my mitre gauge. Works great :-)

-- Laziness minus Apathy equals Efficiency

View Don Newton's profile

Don Newton

714 posts in 3039 days

#10 posted 06-30-2009 04:31 AM

Warped blade…..who’d have thunk it!

-- Don, Pittsburgh

View jerryz's profile


164 posts in 2699 days

#11 posted 06-30-2009 05:57 AM

Well Well, that is indeed an interesting find, good to know if ever I come across something like that.

View thiel's profile


374 posts in 2713 days

#12 posted 08-04-2009 05:10 AM

FYI… I sent the blade back to Forrest and they replaced it no problem. I can vouch for their customer service level… they could not have been more reasonable and responsive. Class act there.

As far as I can tell, the blade has been warped for a LONG time. My saw is now running like butter.

-- Laziness minus Apathy equals Efficiency

View Innovator's profile


3584 posts in 2834 days

#13 posted 08-04-2009 05:25 AM

I am glad to hear they got it done for you, the problem is the pulling out your hair exercise you have to go through to find the problem.

Good Luck with the new one.

-- Whether You Think You Can or You Think You Can't, YOU ARE RIGHT!!!

View GFYS's profile


711 posts in 2892 days

#14 posted 08-04-2009 11:31 PM


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