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View Full Version : Jointer fences: how flat is "flat enough"?


Dan Mitchell
05-21-2009, 9:41 PM
I bought a PM 60B 8" jointer last year, which I really haven't had a lot of time to use as of yet. I was out in the shop today checking on the alignment of the tool's various surfaces, using a feeler gauge and my Veritas 50" aluminum straight edge. The jointer seems reasonably true as delivered, except that there is a pronounced dip in the middle of the fence. Beginning about 3" from each end of the fence, a .005" feeler guage slides easily under the straight edge over the entire mid-section (a .006" one does not). Is this excessive, or of any practical concern?

Thanks

Dan
John Jendro
05-21-2009, 11:06 PM
I guess it's just me, but I wouldn't consider .005 a big deal. The wood you are working with is going to move a lot more then that by itself.

The attached is a tolance guide for a local macine shop. You will see you are well within their tolerances.

http://www.northernim.com/tolerance_guide.htm

John
Thomas S Stockton
05-21-2009, 11:37 PM
Not being flat is not that big a deal with a jointer fence, what causes problems is if there is a twist in it. If you think about it your fence could be really bowed and it would not cause any problems in getting a cut that is square but if it is twisted it will cause all sorts of problems.
Tom
Phil Thien
05-21-2009, 11:39 PM
(1) .005" is fine.

(2) For squaring stock, it could be out 2" and it wouldn't matter.

(3) Out of flat could be a problem for beveling stock (where the fence is angled at other than 90-degrees to the table), but .005" would still be inconsequential.

In other words, you're fine.
John Thompson
05-22-2009, 10:45 AM
WW'ing isn't science... You are well within acceptance with .005.

Sarge..
Clifford Mescher
05-22-2009, 11:39 AM
I guess it's just me, but I wouldn't consider .005 a big deal. The wood you are working with is going to move a lot more then that by itself.

The attached is a tolance guide for a local macine shop. You will see you are well within their tolerances.

http://www.northernim.com/tolerance_guide.htm

John
I showed that print to my brother and he said they look more like carpenter tolerances. It is obviously mold not machining tolerances. Clifford.