Saw blade vibration

[pelligrini]

Every once in a while I will get some vibration from a saw blade on my 21829. More often than not it will be with my thin kerf 30T Forrest WWII. By vibration I mean that during a cut the blade will wobble slightly leaving some nice teeth marks and an uneven edge. It won't vibrate all the time, just intermittently during a cut. I've tried different feed rates, heights, etc. and I still get it on occasion. It happens very rarely with my full kerf Olshun 24T, or the stock TK blade, or my 60T Dwalt crosscut blade. It'll happen in hardwoods and softwoods, more often in hardwoods though; either rips or crosscuts too.

My Forrest probably needs sharpened, but it happened a few times right out of the box too. I'm wondering if a pair of blade stabilizers might help. They seem like they would be a PIA when I go to to tall cuts. (I hate stopping and changing blades). Any suggestions?

[SARGE..g-47]

If what you say is the case... you are left with little choice but to go with a stiffner. There is a difference in a stiffner and stabalizers which are sold in pairs. The stiffener is flat and thicker and only goes on the outside. The draw-back is the height lost but what ya gonna do? BTW.. you might look at the price and if close to the same as a newer blade well...

Good luck...

[poolhound]

I know it may be stating the obvious but...

1. are your abor washers/spacers OK?
2. do you ensure they are clean when you change blades sawdust trapped in there could cause wobble.
3. have you measured abor/blade runout, especially just after you notice this problem occuring.

[pecker]

I had the same thing happen on my BT, for many years. Quite frustrating.
Unfortunately, it also occurs on my Ridgid TS3650, using a nice, thick, Ridge TS2000 blade with a stiffener on it, though not as severely. Even on something as flat and uniform as MDF.

The things I've found that really helps is to slow down the feed rate, and try adjusting for a different blade height.

[pelligrini]

The washers & spacers are flat & very clean. I haven't done a whole lot of checking on runout. Last check was about .002 when I got done tweaking. http://www.bt3central.com/showpost.p...56&postcount=5

Every time I go shopping online I'll add a set of Forrest stiffeners to my cart, I always end up removing them too. I'm thinking about getting a 40t full kerf, and maybe a set of stiffeners for my other TK blades. Which will mean redoing my ZCTPs, riving knife, rail/tape position, etc..

[pecker]

The washers & spacers are flat & very clean. I haven't done a whole lot of checking on runout. Last check was about .002 when I got done tweaking. http://www.bt3central.com/showpost.p...56&postcount=5

Every time I go shopping online I'll add a set of Forrest stiffeners to my cart, I always end up removing them too. I'm thinking about getting a 40t full kerf, and maybe a set of stiffeners for my other TK blades. Which will mean redoing my ZCTPs, riving knife, rail/tape position, etc..

The Forrest stiffener is not a "set", but a single plate that goes on the arbor nut side of the blade. It won't change your ZCTP's or anything else, except you can't raise the blade as high.

I don't think it will completely solve the problem, as it hasn't solved mine...2 different saws and many different blades. However, my Freud Glue Line rip blade has never exhibited this problem.

I think many folks have it happen without thinking it's a problem...you often see someone mention that he'll clean up a cut on the jointer. To my mind, one should never have to do that.

[pelligrini]

OK, I always thought those Dampener/Stiffener were in pairs, one for each side. Not having to change the position of the blade makes using one more palatable.

[pecker]

OK, I always thought those Dampener/Stiffener were in pairs, one for each side. Not having to change the position of the blade makes using one more palatable.

The ones by Freud are like that...you can't use just one of their's.

[cabinetman]

A good stabilizer will help prevent some of the vibration. The TK blades are prone to be less stable than full kerf. As it was said, it's less of a problem to some.
.

[LarryG]

It'll happen in hardwoods and softwoods, more often in hardwoods though; either rips or crosscuts too.

It sounds like this won't be the case, but does the problem mainly occur when you're trimming to final size, either just shaving the edge or cutting off a very thin sliver? Saw blades, thin-kerf blades in particular, perform best when they're running in a kerf, with adequate material on both sides to help hold the spinning disc flat and keep it from deflecting.

If that's when the problem most often occurs, it may be a function of your 21829's power. With my BT3100 I would occasionally get a very slightly beveled cut when shaving off an edge, especially at the first few inches of the workpiece. With my cabinet saw that doesn't happen, using the exact same blades. I have always assumed that the cabinet saw's more powerful, higher torque motor is what makes the difference.

[pelligrini]

Just trimming the edge is when it irks me the most. I don't think it happens more often at those times, but that is the time I really hate it when it happens. This last time it was towards the end of a cut shaving off a 1/16 or so. It was a crosscut in what probably is mahogany (recycled end table), a 2 1/2" thick glued up piece.

I'm thinking about getting the full kerf 40T WWII from woodcraft for fathers day. They've got a version with a #1 grind for flat bottomed cuts. I'll probably pick up a stabilizer too.

[cabinetman]

Just trimming the edge is when it irks me the most. I don't think it happens more often at those times, but that is the time I really hate it when it happens. This last time it was towards the end of a cut shaving off a 1/16 or so. It was a crosscut in what probably is mahogany (recycled end table), a 2 1/2" thick glued up piece.

I'm thinking about getting the full kerf 40T WWII from woodcraft for fathers day. They've got a version with a #1 grind for flat bottomed cuts. I'll probably pick up a stabilizer too.

Thin kerf blades give underpowered (or less powered) saws an advantage. As for removing less waste, I don't feel that's such a big deal. If you are using a TK blade, you may try using a stabilizer (single, on the nut side), and/or elevating the blade higher. This procedure will make the angle of cut to be more perpendicular (less blade to wood contact) and positioned closer to the center of the blade.

If you use a full kerf blade, with especially thick or hard wood, use a slower feed rate.
.

[LarryG]

I'm thinking about getting the full kerf 40T WWII from woodcraft for fathers day. They've got a version with a #1 grind for flat bottomed cuts.

That may be counter-productive (although I understand the appeal of having a flat-grind blade in the arsenal). A recent test in Fine Woodworking Magazine compared regular and thin-kerf blades from the same manufacturers (i.e., they were not testing one brand vs another, only the different kerfs of the same brand). A power feeder was used to eliminate the human variable. The two principal findings of the exercise were summed up thusly:

"I discovered that thin-kerf blades do save power, allowing a small saw to cut big timbers, and saving motor life on tablesaws large and small. But I also found that thin-kerf blades cut just as good an edge as standard-kerf blades."

In some of the test cuts with a low-powered saw, the regular kerf blade caused the saw's motor to bog down whereas the TK blade got through the cut okay. The tester also concluded that modern TK blades are just as stable as and don't vibrate any more than their full-kerf counterparts.

If you're a finewoodworking.com subscriber, you can read the entire article here (if you're not, that link won't work).

[poolhound]

Just trimming the edge is when it irks me the most. I don't think it happens more often at those times, but that is the time I really hate it when it happens. This last time it was towards the end of a cut shaving off a 1/16 or so. It was a crosscut in what probably is mahogany (recycled end table), a 2 1/2" thick glued up piece.

I'm thinking about getting the full kerf 40T WWII from woodcraft for fathers day. They've got a version with a #1 grind for flat bottomed cuts. I'll probably pick up a stabilizer too.

As has already been discussed trim cuts are always the ones most likely to have issues and the blade, saw power, alignment and runout will all play part of the equation that creates the end result.

Given the elements that come into play there is always going to be the potential to have a less than perfect cut (i.e deadon angle in both axes, smooth and clean on all edges/faces). For most cuts absolute perfection is not needed. In the cases were you want it as close as you can get, the TS is rather a "blunt instrument." I have for quite a while been considering making a couple of quality, tuned, shooting boards for joints that I really care about.

A good shooting board and a nice sharp plane will get you much closer to "perfect" with much greater consistency than a TS and is probably just as quick, if not quicker, when you want to shave a 1/16 or so and have a close to guaranteed end result.