# Miter saw issues - cracked blade?



## Yodaman (Mar 9, 2015)

if there is any question at all that might be a crack, don't use it. Toss it out. Your hat wont fit right with a 12" disc sticking out of your forehead.

Any chance the blade was on backwards? I have no problem taking very light cuts with almost no deflection useing a 15 yr old Dewalt 12" with no defection. Something is very wrong. New blade first


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## ddawg16 (Aug 15, 2011)

Go buy a Diablo or Freud.

It doesn't bother me to spend $50 or more on a blade.


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## del schisler (Aug 22, 2010)

LanterDan said:


> I have 12" Ridgid compound miter saw (non-slider) (R4121) that has been causing me trouble. When I complete a cut the blade seems to jump to the right , ~1/8" or tad more, and then wobble as it spins down. At full speed, at least by eyeball, it the blade seems to run true. I can get a straight cut provided I'm cutting off more than a full saw kerf. Trying to "nibble" off a hair of something slightly over sized results in large blade deflection and curved cut (which I realize can be a bit of a problem with miter saws, especially 12" ones, but its really shouldn't be this bad). In retrospect, I think this saw has been causing me trouble for a while, but it has definitively gotten much worse of late.
> 
> Searching the internet on miter saw wobble seems to narrow the problem down to four possibilities: bad blade, loose arbor nut (or worn flange washers), bad bearings, or bent drive shaft. The arbor isn't loose and their is no sign of wear on the flange washers. I don't think a bent shaft is consistent with the blade appearing to run true at full speed. I can't seem to detect any play in the bearings in pulling the blade by hand.
> 
> ...


unplug the saw , now see if their is any wobble in the blade , like where the arbor goes into the saw head their should be no movement their , if their is bad beiring , that probly is the problum , but try a blade first


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## LanterDan (Jul 3, 2006)

I was looking at the the Diablos, but I was reading several online reviews of people complaining that it deflects horribly. I was also looking at the DeWalt Precision Trim line. Same reviews. Most praised the blades, but a significant minority were very unhappy (I can't help wonder if they have bad bearings and are blaming the blade). I have a co-worder who swears by Forrest. Not likely to happen. There is the Freud Industrial line which supposedly better than the Diablos for another $20 or. I could do that if I thought it was worth it.

I think I'm over thinking this and any blade is likely to be better than what I have now.

The previous blade was installed in the correction direction, and I definitely won't be using it further.

Thanks.


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## Thurman (Feb 9, 2009)

Putting money into a good saw blade will be worth the expense many times over. The photo does show what appears to be two (2) radial cracks in your saw blade. Try this: Place something like a wooden pencil, or dowel, through the hole of the saw and hold the blade up so noting is touching it. Using any piece of wood strike the blade as if striking the outside of a bell. IF you get a ringing sound, and I bet you won't, then the blade is _probably_ not cracked. But IF you get a sort of dull thud metallic sound then the blade is cracked. As stated in post #2, just go get a good blade and trash that one.


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## woodworkbykirk (Sep 25, 2011)

diablo blades work fine its just when your cutting thicker materials or making bevel cuts in wide stock the thin kerf blades are more prone to warping.

as forcing cuts with a dull blade will cause deflection. the issue with dewalt blades is that they arent resharpenable like the freuds are


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## shaftmaster (Mar 30, 2015)

I had problems in the past with cheap 7.25" circular saw blades that would go from flat to dish-shaped when they heated up. I think the heating was caused by the blades becoming dull after just a few rip cuts of 5/8" plywood. Won't make that mistake again.


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## Yodaman (Mar 9, 2015)

Thurman said:


> Putting money into a good saw blade will be worth the expense many times over. The photo does show what appears to be two (2) radial cracks in your saw blade. Try this: Place something like a wooden pencil, or dowel, through the hole of the saw and hold the blade up so noting is touching it. Using any piece of wood strike the blade as if striking the outside of a bell. IF you get a ringing sound, and I bet you won't, then the blade is _probably_ not cracked. But IF you get a sort of dull thud metallic sound then the blade is cracked. As stated in post #2, just go get a good blade and trash that one.



The ring test! Yes that was my first thought too, and I know it is conclusive with grinding wheels but wasn't sure about a steel blade. Most grinding wheels have a glass bond which causes the ring. Are you sure steel wouldn't ring anyway?


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## LanterDan (Jul 3, 2006)

It appears to have been the blade. Replaced it with a new Diablo tonight and much much better. Unfortunately I have to do most of my work outdoors, so I want to try again tomorrow when I have better light, but from what I can tell now it seems to be perfect. 

FWIW I tried the bell test and the old blade seemed to pass. Obviously I will be permanently taking it out of service anyway. 

I'm still not sure if I should be concerned about why the previous blade failed or just chalk it up to a manufacturing defect. I'm not sensing any bearing play, so I figure I'll just watch it closely and if it continues to work well I'll just stay happy. If the problem develops again, you guys will probably hear from me again.

Thanks all.


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## Yodaman (Mar 9, 2015)

Dan, glad the new blade has helped. Looking at your pic again it appears that you had a heavy build up on the teeth. Not abnormal with a blade that has significant use. Usually from the natural resins in the lumber. But as it builds up, it makes the cutter seem dull and starts to generate excessive heat _and deflect_. If you clean that off now and then the blade will cut free-er and stay sharp longer. Mineral spirits softens it a little. But leave this old one in the trash!


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