Saw blade runout

[rlah]

I just bought a new Ridge TS2000 TK blade (10" x 40T), a premium blade.

I thought to check the runout with a dial indicator before using the first time and am a little puzzled... see the attached pics. Within 10 teeth of each other there is .005" runout ... seemed a bit high. Could it be runout on the arbor? Maybe a bent arbor? I had a kickback experience about 2 weeks ago, but since then, it seemed to make smooth cuts with a new Hitachi 10x40 blade.
You'll notice I am measuring on the teeth, not the blade body, for the best measurement. If anyone might question my methods, I duplicated the results many times after turning the blade over several times... and the measured teeth are both right cutting teeth, not the left-cutting or raker teeth, within 10 teeth (or 1/4 turn) of each other. ( I know the magnetic base for the indicator doesn't stick to the aluminum surface but it is heavy enough to show repeatable results.)

When I installed this new blade, I made sure to wipe any debris off of all mating surfaces so there would be no grit to throw this off.

When I made these measurements in the past, I think I observed maybe .003" runout on the saw blade bodies (Freud 10x50, Hitachi 10x40 blades). This is the first time I decided to measure the actual tooth runout.

Comments appreciated.

rlah

[SARGE..g-47]

IMO.. .005 is acceptable. Look at .005 on a feeler gauge and you get a better picture of just what .005 is. Your working with wood and a mitre gauge. Do you suppose your BT 3 slide can hold a .000 tolerance wth you pushing it forward with perfect body-hand alignment?

I just purchased a reco Uni-saw (new to me) and wish it had a .005 arbor run-out. The Uni-saw if notorios for having more.. but on the other hand there are a zillion cabinet shops.. WW'ers and pros that have one and build perfectly acceptable furniture.

I would lighten up in the worry department with your saw riah and go cut some wood. You will be glad you did!

Have fun with that very sufficeint saw...

Regards...

[cgallery]

This is the first time I decided to measure the actual tooth runout.

Comments appreciated.

rlah

Hard to compare results when two different methods of measurement have been used. I think most of us measure the blade body, not the teeth. It is possible (likely?) that the side-tolerance of the teeth isn't held as tight as the blade body.

I'd check the body. Then I'd toss another blade on there and check the runout at the teeth and compare.

[Knottscott]

I'd cut with it and not worry about the runout. If it's cutting well and accurately, (and it should) no worries....

[rlah]

I'd cut with it and not worry about the runout. If it's cutting well and accurately, (and it should) no worries....

It is cutting nicely... super smooth edge on 3/4" birch plywood and 1" walnut. The corner edges of the walnut (after ripping it) are so sharp, I have to handle it carefully or they will cut my hand!

(But I do wonder what runout would be unacceptable?)

Thanks to all.

rlah

[scorrpio]

A few thoughts:
1. Measuring runout on teeth, the dial gauge is not in constant contact with material. If you set the gauge against one tooth, zero it, then rotate blade to where stylus does not rest against a tooth, next tooth pushing against a stylus might push it enough to move the whole thing. I would clamp something flat made of iron to BT3 so magnetic base holds better. Or, I would measure against blade body.

2. Unless you want to invest in a master plate (Grizzly got on for $50) you might want to try to compare it for a few other blades, also measuring body runout.

3. Try measuring arbor runout directly. Not going to be easy to do because of the flats on the arbor.

[Knottscott]

The sides of the teeth aren't necessarly flat. Many have a side relief angle and it's likely you're not getting an accurate read.

[SARGE..g-47]

The run-out will exaggarate as you move farther away from the center bore. You cannot measure the blade body and expect the outer perimeter to be the equal, much less smaller!

Regards...

[MBG]

I don't think blade runout will cause kick-back. Runout will cause your saw to work harder creating a larger kerf. I think I read somewhere that a well known blade manufacturer allows 0.007" max. runout.

As far as the kick-back, check your blade to fence alignment and make sure you are using the riving knife.


Mike

[LCHIEN]

There's arbor runout and blade runout - two related but different things.
IMO a blade wobble of .005 is nothing to worry about. Are you satisfied with the cut?

I have all the tools but I have never measured mine never felt the need to).
Your technique is OK except for two things.
Just the weight of the stand on the table (no mag base function) is too precarious-easy to move slightly.
I'd be careful measuring on the tooth, some may have a relief angle as someone stated. Thae blade body may be more reproducile.

And just remember that you are measuring combined arbor and blade runout.

[rlah]

There's arbor runout and blade runout - two related but different things.
IMO a blade wobble of .005 is nothing to worry about. Are you satisfied with the cut?

I have all the tools but I have never measured mine never felt the need to).
Your technique is OK except for two things.
Just the weight of the stand on the table (no mag base function) is too precarious-easy to move slightly.
I'd be careful measuring on the tooth, some may have a relief angle as someone stated. Thae blade body may be more reproducile.

And just remember that you are measuring combined arbor and blade runout.

Yes, I'm satisfied with the cut... and the reassurances from this group gives me added confidence... I just wanted some idea from experienced people on this kind of runout.

Although there were cautions about my measurements, I was able to get repeatability... I set the gauge so that the tip depressed only about .006" with each tooth contact. This small amount did not cause the indicator to move. It seems to me this is the actual point of contact for measurement although the blade body is probably sufficient for woodworking (not machine shop) machinery.

Thx again for all comments. rlah