Jointer Blades How accurate?

[Stoutman]

I just sharpened and reset my jointer blades. I checked (dial caliper) that the blades were level with the outfeed table and one blade is 0.001" above and one is 0.002" below (the other is level).

Obviously having all at 0.000" above or below would be ideal, but I still want to keep the little hair I have left on my head.

Do you think this is acceptable? Will I notice this when jointing?

I assume the highest blades will wear the fastest and maybe "catch-up" with the low blades with use as they dull.

[Stoutman]

I am referring to measurements at 'top-dead-center'. -Just in case there is confusion.

[Joe Wells]

I dunno nothin' 'bout settin no blades. But this guy does:

[CW]

I don't mean any offense by this so please don't take it that way. I am responsible for training new hires at work (machine shop). I have been machining for over twenty years. I am also told that I am a rather good teacher but, it is the rare individual that I would trust to take a measurement with dial calipers to that kind of accuracy. There are too many things working against you in that situation. I would say that it is probably closer than you can measure which is very well close enough. The blades will wear .003 in very short order and they will even themselves up. To set them any closer, I would recommend a dial indicator. Not totally goof proof but, I don't see you as a goof either.

[Stoutman]

Darn it. I meant to say DIAL INDICATOR, not dial caliper!!!

Uggghhh!

[Stoutman]

Thats what I thought regarding the wear. Thanks!

Yep, I used a dial indicator, not a dial caliper like I wrote!

Thank you!

[CW]

[Stoutman]

Not to beat this to death, but at what point would you consider the error to large and re-set the knife?

Thanks!

[CW]

[Stoutman]

Thanks Joe!

That guy sure is rough with his jointer! I'm not sure I would smack my jointer knife with a wooden block while it was in the cutter head, but thats just me!

I enjoyed his presentation though! Thank you.

[Mike M]

Just to confuse the issue is that on both sides or in the middle.

Mike M

[Stoutman]

Nope, doesn't confuse anything.

I set my knives using a magnetic jig like this one:

ensures (in theory) that the blade is parallel with the outfeed table. Therefore, the blade measurements should be (and usually are) the same down the length of the blade.

[Peter Huebner]

In my experience you start getting chatter somewhere between .05 and .15 mm. Depends on the width and hardness of the wood.

-Peter

[George E. Cawthon]

Check here:

I think the "low-tech" type of setting that measures cutter height by measuring how far a blade moves a stick is pretty good, but I'm no professional.

[barry]

> It ensures (in theory) that the blade is parallel with the outfeed table.

In fact, that's not possible. There will always be some error, however slight. And ... I'd not presume that any blade is precisely straight. Meaning: within zero tolerance.

This is not metalworking. Being within .005- .10" and being consistent is excellent.

Fussing about a blade measured radially off by .001" is obsessive. IMHO.

TTFN, J