Blade or table saw problem ?

[Robert Hayward]

A new PM2000 table saw, new Ridge Carbide 40 tooth blade and what was a new Powermatic zero clearance throat plate.

Each time the saw is started I get a little flutter, waver or what ever you want to call it causing the fresh cut in the zero clearance plate to widen ever so slightly. The widest being wherever the blade teeth are, then tapering back to the normal 1/8" wide kerf closer to the arbor. The happens for only a split second then the blade runs smooth and true. The plate is being cut slightly less than a 1/32" wider at the teeth. Each time the blade position is changed the plate gets cut again upon startup.


What are your thoughts, blade problem or PM2000 problem ? Or maybe normal ?

[Matt Day]

Did you check the arbor for runout and make sure the arbor flanges are flat/true?

[Myk Rian]

You need to check the blade, arbor, and flange with a dial indicator. HF has one that is suitable. Get the magnetic base for it also.
Is the raising mechanism locked?

[John Lankers]

If this only happens when you turn the saw on then I would check the drive belt/s also, if they are too tight it could cause the the arbor to twist ever so slightly. 1/2 thou on the arbor could translate into 1/64" at the saw teeth..
Btw., try a different blade first and see if that's the problem.

[David Kumm]

I don't know the probability but it could be mediocre bearings with too much internal clearance. Old English direct drive saws ran self aligning bearings of large size. Blades wobble slightly at start up until the bearing centers and then gets tighter as the bearings warm up. The little radial bearings used in new saws should not do that but if the clearance cold is too loose, you could get the same flutter until the bearing seats itself. If all else fails, that could be the problem. Dave

[lee cox]

I would buy a gauge which fits in the miter slot. I have both and prefer the miter slot version. I am no expert but I restored 3 Delta table saws. The arbor bearings have already been mentioned. Also the arbor plate. I had to have an arbor plate turned on a lathe to be square to the arbor shaft by chucking the arbor shaft in the lathe. Is that blade a thin kerf? Maybe your aero insert is a little off and bending the blade. Lots of things to check.

[Jim Dwight]

My saw is very different from yours, a BT3100, but it does this too. I think the blade goes through a harmonic during startup that causes the flutter. I haven't calculated the speed of the outer diameter but I think it's above the speed of sound. So it could just be passing through that. I don't think it's bearings or the blade. I suspect all saws do this. Bearings will not prevent all movement of the outer portion of the blade if the system vibrates. It only takes a split second to impact the zero clearance plate a tiny amount.

My "solution" is to use one zero clearance plate for normal work where it isn't critical that it really have zero clearance and to use a new one for the rare situation where I really need it to have zero clearance. I make them of scrap so it isn't a big deal. (I use a zero clearance all the time after having a cutoff fall into the little belts of the BT3100 ruining them - they are a pain to change)

[Tom Ewell]

Kinda agree with Jim, I use a glueline ripper so my 'divots' are a little smoother but still there.

Since a normally preset the hgt of the blade then turn it on, the wind up to speed usually causes some 'tinging' in the insert slot unless I'm spot on at a preset hgt which ain't going to happen.

Fresh cut inserts stay pretty good for a while but after many hours of use at different settings the slot shows some wear.

Definitely check out the specs with a gauge and make sure the blade looks good, could be even a tooth slightly miss ground or bent kicking the blade side to side too.

[David Kumm]

Jim could be on to something but I don't get anywhere near that flutter on my 18" blades. Your picture shows what I consider to be a massive flutter. I agree that all saws should have their flanges trued up. makes a huge difference. Dave

[glenn bradley]

I'll assume you have already confirmed that the blade is clean, the flanges are smooth and well machined and other blades do the same thing. I you have not checked these things If would do that first.

While the blade is off you can take ahold of the Arbor and try to move it laterally to see if there's any play in the bearings, any sort of a ticking feel. Let us know how that turns out and will move along.

[Van Huskey]

I haven't calculated the speed of the outer diameter but I think it's above the speed of sound.

The tip speed on a 10" saw on the average table saw is probably going to be less than 20% of the speed of sound.

[Lee Schierer]

One work around would be to lower the blade below the insert until the blade is up to speed and lowering it again before shutting off the power.

[Robert Hayward]

Cannot say positively it is not run out, but I do not think it is. I will pick up a dial indicator and mag base this weekend and check the run out anyway. Reason it does not look like run out to me is because the blade can be raised up through a fresh piece of wood and the resulting kerf/slot is dead straight with smooth sides. This problem occurs only when the saw is turned on and then for only a split second.

I have checked for play in the arbor, by hand, and the arbor feels tight like you would expect a new saw to be.

In a few minutes I am going out to the shop and check the belt tension. Over the weekend I had my head inside the cabinet adjusting the 90° stop bolt and casually squeezed the belt together, or tried to. It felt really tight, but that was just a touch while I was on the floor. Not a real tension check.

Do not know why, but I am thinking this is a blade problem. I have a WW11 full kerf ( 1/8") on the way, but will not be here until next week. The Ridge Carbide blade on the saw now is brand new and also 1/8" kerf. Good solid blade, in my opinion.

I will do a Google search for this, but what is the proper way to check for arbor shaft and flange run out ?

[Tom Ewell]

Needless to say, but I will anyway, remove the zero clearance insert before going to a blade angle other than 90°

Sometimes during a busy day this little tidbit goes forgotten when setting up for an angle rip...... BTDT :)

[Ronald Blue]

It's much more likely that the saw is causing this than the blade. That blade isn't so flimsy that the torque of start up is going to cause it to deflect sideways. I would check the drive belt tension as John suggested and maybe even experiment with it and also make sure no play is evident in the arbor bearings. Also there is no harm in truing your arbor flanges up as Matt suggested. As much as it appears it is moving I would suspect something is not as tight as it should be in the trunnion and arbor area.

[Robert Hayward]

Stopped at Harbor Freight on the way home this evening and used my 25% Super Coupon, good only until Sunday. :D The dial indicator did not clamp tightly to the mag base arm, but I fashioned a couple washers from some gasket material. That allowed the dial indicator to be fastened to the arm without moving.

I measured the arbor flange run out about 3/32" to 1/8" from the outside edge of the flange. Super flat, less than .0002. Probably closer to .00012 ~ .00015. Hard to say with certainty as the dial indicator is marked only to .001.

The blade is a different story. I did the measurements just below the bottom of the gullets with the blade raised to its highest position. I picked a random spot, marked it and zeroed the dial. I was getting variations from + .003 to - .005~6. In my opinion that is way too much for an expensive blade. Still not as much variation as I am getting in the throat plate. Can this blade flex upon start up ? I bought the blade earlier this year at the Tampa wood show and it has a thirty day return policy. So no sending it back. Can the blade be straightened ? Is it worth the money for shipping both ways and the charge to fix it ? I guess I will call Ridge Carbide and see what they say.

I need to do the measurement on the teeth again. I was getting tired and sloppy, but the teeth edges are out also. Maybe due to the disk not being flat.

I also took a bit of tension off the drive belt, it was really tight. I will try loosening it a bit more, as I think it is still tight enough that it will not slip while cutting wood.

[Ronald Blue]

So your saying the needle didn't move at all on the arbor flange? .0002 on an indicator that is graduated in .001 is going to be hardly a wiggle. I have difficulty believing the arbor is that perfect. Is this like your indicator?
https://images-na.ssl-images-amazon.com/images/I/61HCJh-VCgL._SL1024_.jpg

[David Kumm]

Run out should be tested at speed. Bearing causes won't show up with hand turning. My worst 16" blades will typically make a kerf .004-.006 wider than the tooth so the runout is half of that. The flanges are 5" and ground so the deviation is all blade. Dave

[John Neel]

Speed of sound is about 767 mph. Outer edge of 10 inch blade @3450 rpm travels at about 103 mph. Some 10 inch models have a blade speed faster than this, but none come close to the speed of sound. A 10 inch blade would have to spin over 25700 rpm for the outer edge to reach the speed of sound.

[Jim Dwight]

The measurements are interesting but does anybody have a zero clearance insert they have used for awhile that shows NO areas where the teeth touched at startup or shutdown? Absolutely straight sides with no nicks? If you do, maybe not all saws do it. If there are no examples, then I think you have to just say this is normal. Magnitude maybe varies for the reasons discussed (blade looks a little suspect but I like Ridge for resharpening blades and I think they come back better than Freud made them).

[Van Huskey]

Speed of sound is about 767 mph. Outer edge of 10 inch blade @3450 rpm travels at about 103 mph. Some 10 inch models have a blade speed faster than this, but none come close to the speed of sound. A 10 inch blade would have to spin over 25700 rpm for the outer edge to reach the speed of sound.

That is what I as saying earlier, the PM 2000 spins 4300 rpm but still in the 140 mph range.

[Curt Harms]

My saw is very different from yours, a BT3100, but it does this too. I think the blade goes through a harmonic during startup that causes the flutter. I haven't calculated the speed of the outer diameter but I think it's above the speed of sound. So it could just be passing through that. I don't think it's bearings or the blade. I suspect all saws do this. Bearings will not prevent all movement of the outer portion of the blade if the system vibrates. It only takes a split second to impact the zero clearance plate a tiny amount.

My "solution" is to use one zero clearance plate for normal work where it isn't critical that it really have zero clearance and to use a new one for the rare situation where I really need it to have zero clearance. I make them of scrap so it isn't a big deal. (I use a zero clearance all the time after having a cutoff fall into the little belts of the BT3100 ruining them - they are a pain to change)

I was thinking harmonic as well. Pretty good sized hunks of steel can flutter if the right things go wrong, I know of a solid steel shaft about 1/38" in diameter with high precision machining that if it runs for any period of time at certain RPMs will flutter and me$$ the bearings up. Actually that's more like me$$$$$ things up.

[Frank Pratt]

I've had 3 table saws & many blades & all have done that to some degree. Looks pretty normal to me.

[Greg Peterson]

Does every blade do this?

[Robert Engel]

Yes you need to do measure the teeth. I don't think 5 thou is that bad for any ww'ing machine.

Personally I wouldn't consider Rigdid a high quality blade.

My suggestion is pop a Freud blade in there and see what you get.

[Robert Hayward]

The measurements are interesting but does anybody have a zero clearance insert they have used for awhile that shows NO areas where the teeth touched at startup or shutdown?

I am interested in seeing answers to this. I have been wondering to myself if I am expecting too much from this new saw. It absolutely is leaps and bounds above my prior saw, a Bosch TS3000.

Robert, This is not a Ridgid blade, rather a Ridge Carbide blade. Different companies and products.

Greg, every blade that has ever been on the saw has done this. :rolleyes: One blade is all that has ever been on this saw. I have a WWll on its way to me, but will not see it until next week. I have three Diablo blades hanging on the pegboard from my Bosch saw. They have a thinner kerf than the Ridge blade though and I currently have only one zero insert. If I was not playing on the computer I could be out in the shop making homemade throat plates right now to test other blades with. :) Maybe tomorrow morning. I have a 30 amp 220 circuit to run today for my yet to arrive dust collector.

[Joe Kaufman]

I had a similar situation a few years ago with a new Freud Premier Fusion Blade (1/8 curf), but it would occur on deceleration, when the centrifugal switch closed and the motor decelerated abruptly. Talked with Freud and their response was that the anti-vibration technology slots are designed allow considerable lateral flexibility to the plate so it runs true at speed providing a polished cut by their improved tooth geometry. Freud exchanged the blade and the second one wasn't quite as bad.

[Jim Andrew]

I have had a defective blade on a hand held saw that when it started to heat up, would behave like a wobble blade. I like the Tenryu blades from Carbide processors.

[john bateman]

A new PM2000 table saw, new Ridge Carbide 40 tooth blade and what was a new Powermatic zero clearance throat plate.

Each time the saw is started I get a little flutter, waver or what ever you want to call it causing the fresh cut in the zero clearance plate to widen ever so slightly. The widest being wherever the blade teeth are, then tapering back to the normal 1/8" wide kerf closer to the arbor. The happens for only a split second then the blade runs smooth and true. The plate is being cut slightly less than a 1/32" wider at the teeth. Each time the blade position is changed the plate gets cut again upon startup.


What are your thoughts, blade problem or PM2000 problem ? Or maybe normal ?

I have a Ridge TS2000 blade that makes those widened kerfs, except it happens randomly while cutting wood. It even occurs on flat, smooth MDF which has no grain or internal tensions which could cause a blade to wander. Worst blade I ever bought.
Even though many people recommend them, I won't based on my experience.

[Robert Hayward]

The WWll blade arrived with Mondays mail and I could not make the time Monday evening to put it on the saw. I did not have much more time this evening but did manage to put the blade on the saw, do a very quick run out check and another very quick run of the blade.

From a low spot of -1 off reference to a high spot of slightly less than +3 for run out. Pretty good in my opinion, .004 variance. I put the chewed up zero clearance plate on, cranked the blade up and down while hand spinning the blade to check clearance against the Ridge blade kerf in the throat plate. No problems so I put the new blade in a fresh spot in the plate. Pushed the switch and got just a momentary whisper of a kiss against one side of the insert. Tried the same in two more fresh spots on the throat plate with the same results. I will do a more thorough test this weekend, but as far as I am concerned the verdict is in. The problem was the Ridge Carbide blade.