Poor cuts on the table saw. Getting frustrated.

[Glen Butler]

I have a PM2000, 5hp, cabinet saw. I have recently trued the table to the blade and the fence to the table. I used my Freud industrial glue line blade to line it up and every tooth gauged true both front and rear. Sometimes I get glass smooth cuts, but sometimes I do not. Most of the time it runs, like a saw should, with a high pitched whir. But sometimes and suddenly, it will start buzzing. My first thought is the arbour bearing may be a little worn and this may cause the buzzing and vibration in the blade resulting in a poor cut. Any way to diagnose this? What is the likelyhood of the arbour going bad like that?

[Roger Bullock]

I always try to look at the simple first. I too installed a new glue line blade a couple of years ago. It cut like a dream and like you every once in a while I would start to get a poor cut or a little burn on cherry or hickory.

Here are 4 things to check before you get into the mechanics of the machine. Check for pitch on the blade. I know you just adjusted your fence but check it again. It slides in a dusty environment, the smallest wood chip caught under the slide can cause this problem. Same thing can happen with the tilt so check that too. Once you have the blade square to the table and the height adjusted, lock down both adjustment wheels. If it is a thin blade are you using a stabilizer?

[Jeffrey Makiel]

That's a qualilty saw. I suspect the blade.

I'd try another blade, and use a full kerf blade as Roger recommended. There really is no reason to spin a thin kerf blade with a PM2000. My experience is that they flutter a little more than standard kerf. I'm not sure a blade stabilizer alleviates the inherent flutter to any significant degree either.

-Jeff :)

[Glen Blanchard]

What did you use to confirm that everything on the table saw is square, and how much out of square is the blade to fence?

[Myk Rian]

The Glue Line blade is for stock up to 1". Were you cutting thicker at any times?

[Glen Butler]

Let me preface by saying this saw was purchased used. I don't know much of its history except that the original owner purchased it from a dealer perhaps as early as 2004. When did powermatic start integrating casters into the base? That may be a good indicator.

I suspect that the dealer may have fabricated the fence from some 2x3 tube steel for these reasons:

The exposed steel where the fence glides run is black, like how you would find raw cold rolled material. I thought they were typically the brushed silver color.

The end of the fence looked typical of how length would come from the foundry, like a blunt shear cut.

And the masking for the paint veers off at the end.

It would be nice if other PM owners could chime in about thier fence and whether this is typical. If the dealer did have the fence fabricated who knows what else they pulled? If the fence is just cold rolled stock is it possible that the fence can vary in parallelness cause the fence isn't straight?


What did you use to confirm that everything on the table saw is square, and how much out of square is the blade to fence? I used my combo square in the miter slot, and used the same tooth of the blade front and back. From what I can tell the fence is right on.


That's a qualilty saw. I suspect the blade.

I'd try another blade, and use a full kerf blade as Roger recommended. There really is no reason to spin a thin kerf blade with a PM2000. My experience is that they flutter a little more than standard kerf. I'm not sure a blade stabilizer alleviates the inherent flutter to any significant degree either.

-Jeff :)I have been using a full kerf blade. It is the freud LM74M010 found here. http://www.freudtools.com/p-34-glue-line-rippingbr-nbsp.aspx Like I said sometimes it cuts perfectly. Other times not.


I always try to look at the simple first. I too installed a new glue line blade a couple of years ago. It cut like a dream and like you every once in a while I would start to get a poor cut or a little burn on cherry or hickory.

Here are 4 things to check before you get into the mechanics of the machine. Check for pitch on the blade. I know you just adjusted your fence but check it again. It slides in a dusty environment, the smallest wood chip caught under the slide can cause this problem. Same thing can happen with the tilt so check that too. Once you have the blade square to the table and the height adjusted, lock down both adjustment wheels. If it is a thin blade are you using a stabilizer? The blade was just barely sharpened and cleaned up by perhaps the best place in Utah. There is no pitch. I will check my fence again and make sure it is perfect to the blade and see if the problem fixes.


The Glue Line blade is for stock up to 1". Were you cutting thicker at any times?
No, the material was only 3/4.

My problem lies with the fact that sometimes I get great cuts and sometimes not. I noticed all my freud blade vibrate at startup except for the glue line rip. I think that blade stability might have something to do with the poor cut, especially after I put on a tenryu blade that stays stiff at startup and it gave me a glass smooth cut, but this tenryu is the mel-pro, so I don't want to use it for everyday cutting. None of the post above address the buzzing noise that happens intermittently with the saw. It seems that this is causing blade vibration. I will do a series of tests for you. I will try each of my blades and hope I can do a cut with each blade, with and with out the buzzing and we can go from there to a better diagnosis.

[Lee Schierer]

I used my combo square in the miter slot, and used the same tooth of the blade front and back. From what I can tell the fence is right on.

I have been using a full kerf blade. It is the freud LM74M010 found here. http://www.freudtools.com/p-34-glue-line-rippingbr-nbsp.aspx Like I said sometimes it cuts perfectly. Other times not.


The Glue Line rip LM74 has only a .118 kerf so it is a thin kerf blade. I use an LU73M or LU82M and get glass smooth cuts on a craftsman saw.

If the vibration comes and goes, I would suspect the bearings or the belts or possibly sawdust build up in the motor fan causing an out of balance condition.

[Glen Butler]

The Glue Line rip LM74 has only a .118 kerf so it is a thin kerf blade. I use an LU73M or LU82M and get glass smooth cuts on a craftsman saw.

If the vibration comes and goes, I would suspect the bearings or the belts or possibly sawdust build up in the motor fan causing an out of balance condition.

You will notice the plate on both blades you mention is only .087 whereas the plate on the LM74 has a .98 plate thickness. LM74 will be a stiffer blade. The carbide thickness doesn't determine stiffness. I will check the motor fan for build up, but the buzzing just turns on suddenly not slowly. How do you check the arbour bearing? I am guessing that the play required to cause the buzzing is so minor a wouldn't be able to detect it.

[Lee Schierer]

You will notice the plate on both blades you mention is only .087 whereas the plate on the LM74 has a .98 plate thickness. LM74 will be a stiffer blade. The carbide thickness doesn't determine stiffness. I will check the motor fan for build up, but the buzzing just turns on suddenly not slowly. How do you check the arbour bearing? I am guessing that the play required to cause the buzzing is so minor a wouldn't be able to detect it.

We just rebuilt a powermatic saw where I work. The bearings were shot. With the belt tension released you cold feel side play in the arbor shaft. You can place a dial indicator against the arbor at two place 90 degrees apart and wiggle the arbor. The indicator should only show a couple of thousandths if any movement.

[Glen Butler]

We just rebuilt a powermatic saw where I work. The bearings were shot. With the belt tension released you cold feel side play in the arbor shaft. You can place a dial indicator against the arbor at two place 90 degrees apart and wiggle the arbor. The indicator should only show a couple of thousandths if any movement.

Can I perform this operation without breaking down the saw? I am not familiar with dial indicators and how they function. I know there was a recent thread about them. If you could break this down for dummies it would help.

[Lee Schierer]

1.You need a dial indicator.

2. You can pick one up at harbor freight for under $20.

3. Mount the indicator so it is perpendicular to the arbor so the tip touches the arbor.

4. With the dial indicator in place, wiggle the arbor shaft and watch the indicator.

5. Repeat steps 3 through 5 with the indicator mount 90 degrees to the first position relative to the axis of rotation of the arbor.

6. If it moves a lot,replace the bearings.

[Glen Butler]

You didn't really give any new information over your previous post except put numbers in front of everything.:D I guess I should have been more clear on the questions I still had. Should remove the belt? I assume I need a magnetic base also to mount the indicator? Is the pic below the orientation the indicator should have to the arbor?

[Glen Butler]

Lee hasn't been on for a while and I don't want this to get lost. Can someone answer the final questions here?

[Myk Rian]

Is the pic below the orientation the indicator should have to the arbor?
Yes, it is.

[Lee Schierer]

You didn't really give any new information over your previous post except put numbers in front of everything.:D I guess I should have been more clear on the questions I still had. Should remove the belt? I assume I need a magnetic base also to mount the indicator? Is the pic below the orientation the indicator should have to the arbor?

Actually you want the dial perpendicular to the threaded area then try to move the arbor away from and toward the dial indicator. The pictured setup will check for end play only, which should me minimal as well.

[Thomas love]

Glen I have had two of thesesaws in the past, I now have one of which I have changed the bearings twice in 15 years, it is my main saw for ripping, I have a dial indicator although I have never used it to check for blade runout.

Try this, unplug the saw, raise the blade up and from the side of the blade grip it tight with your thumb and index fingers while keeping your wrists on the table.
Using your fingers push and pull the blade from side to side, if you can feel any movement, I am going to say its the bearings. Make sure the tilt and depth adjustment wheels are tightened.

Bearings on these saws are fairly easy to change out.
Tom

[Glen Butler]

I understsand they are pressed in. Does this need to be done by someone who has a press or can I accomplish this feat by other means?

[Doug Shepard]

Are you using a Zero Clearance insert by any chance? Once that might have been cut with a different blade and might be causing some buzzing as it wears against glue-line rip blade? Or maybe not sitting exactly in the same spot in the insert opening every time?

[Charlie Barnes]

Glen,

I have a PM2000, but it's the 3 HP model. I've only had it 2 years and bought it new, so I haven't had too much of a chance to wear it out yet. Your comments regarding the fence interest me since mine sounds very different. Can you post a photo? Maybe you are correct that the fence has been modified or fabricated and is not the factory version. (I know this doesn't address the vibration issue.)

Regarding the vibration, I used to have a Craftsman contractor saw that would occasionally get a vibration in the blade. I think it was due to harmonics though since it would go through a cycle of vibration for a few seconds and seemingly cancel itself out. It definitely did this when slowing down after shutting off the power, but sometimes at speed too. My first step would be to talk to the previous owner if possible and see if they know anything about this. They might be able to give you some useful history. Then it seems to make sense and follow the advice given here to check the play in the bearings since you say this issue occurs intermittently.

Anyway, good luck on solving this.

Charlie

[Don Jarvie]

If you don't have a dial indicator, get a combination sq and with the blade off and the arbor at 90 deg. Place the short part of the sq on the table and place the long part so it touches the top and bottom of the arbor washer (what the blade would rest against).

Turn the saw on and if the arbor is off it will hit the square at some point.

It's not the most exact way of doing this but will give you an idea if the arbor is out.

[Glen Butler]

Ok, so I bought a dial indicator today. The arbor washer runs perfect, there is no slop in the bearings, but the arbor has .0075 of runout. Now this shouldn't affect a single blade but it would affect a dado. I should clarify that the dial indicator needle varied by .0075, so would that only be +/- .00375 of runout from perfectly parallel to the axis? Or maybe I should ask, how do you quantify runout?

So I think part of it is less expensive blades, and I learned from here http://www.newwoodworker.com/basic/tsalign.html that the fence should be tailed out to the blade a thou or so. This may in affect get rid of all the tooth marks I am seeing in the cut. Agree or Disagree?

[Brian Gumpper]

I agree with the fence being out a thousandth or two on the back side. You need room for the wood to clear the blade so the fence does't try to push it into the back of the blade.

Could that noise your heard be from slight binding?

[Chip Lindley]

A Point I don't think has been mentioned yet:

It is hard to *crowd* a rip blade, but feeding too fast can cause sawdust in the blade gullets to bind the blade in the kerf. Binding can cause the saw plate to flex and set up a side-to-side vibration as you discribe.

Many assume that a big 3hp cabinet saw will cut anything at any rate of feed. Not necessisarily true. Any given blade has it's optimum feed rate. Too slow; burning results. Too fast; crowding and vibration. Harder woods feed slower than soft woods. A 60T blade must feed slower than a 30T rip blade. AND, thin kerf blade plates are much more flexible than standard kerf blades.

Sounds like you may have gotten a shop-made fence with your saw. PM AccuFences are powder coated, mustard yellow all over. Some sellers feel no obligation to disclose all, unless asked point-blank.

The .0075" runout of your arbor cannot possibly help the saw's quality of cut, even if it is at the extreme threaded end. As you said, it should affect a dado stack more than a single blade. But, a new arbor should not set you back too much. Install new bearings during the change-out and enjoy your Powermatic for posterity. Best of Luck!

[Glen Butler]

Finally, I was starting to go through withdrawals not being able to post. I changed my e-mail address and didn't realize I had to verify before I could post, and I didn't know where my spam folder was.

So, I am no longer worried to much about the vibration, since I verified there is no excess play in the arbor. There are several things that could vibrate on and off inside the cabinet. I am more concerned now with the runout in the arbor and I would like to know if runout is measured only one direction from the axis, if so then my arbor is only out .00375. Not sure how bad this is and whether a new one will surely be better though. I guess I should contact powermatic and see what they say.

[Glen Butler]

This thread would not be complete with out a thank you to all who participated and a posting of my resolution.

I have not heard the vibration/buzzing noise in a while and I have been locking down the height adjustment everytime.

The poor cut was caused by the fence being perfectly parallel to the blade. I found that once I kicked out the outfeed end ~.002 my cuts were acceptable. I guess it just allows room for runout in the blade.

[Dan Forman]

Glen---I don't think arbor runout should be more that .001 in a cabinet saw. Consider that the arbor runout will be considerably greater at the outer edge of the blade. If you add an additional 2 to 4 thousandths of runout that the blade might bring to the equation, you could have a pretty substantial figure. My guess is thats why you had to kick the fence out, which shouldn't actually be necessary.

Dan

[Glen Butler]

Dan the arbor washers are perfect. So where a single blade is installed shouldn't hurt me. The run out is on the threaded end of the arbor. So that will only affect dado's. I will replace it someday.