Jointer alignment question

[bogydave]

I just got the blades back for my jointer & read the book on installing them.
The book says the height of the blade should be .003 above the outfeed table. In some of the jointer discussions, someone mentioned that the blade should be level or even with the outfeed table. Craftsman 6" (Tiawan).
After several tries I got it .003 above outfeed table.
Which is right? Even or a hair above?
I won't mention the amount of time it took to get the infeed table aligned!!!

[Don]

Hey, Bogy. We're talking about a super small amount here, 3 thousandths. The theory is correct. Infeed and Outfeed tables should be exactly parallel, the outfeed should be exactly inline the cutterhead. That's a perfect world though. Unfortunately in woodworking we can't achieve the precise cuts that metal guys can so there are a few "tricks" that we can use to compensate for it. Calling for the cutterhead to be above the outfeed by .003" allows for some "springback" of the wood, regardless of how sharp the cutters are the wood is compressed slightly. Plus, the very first piece of wood you run begins to reduce the cutting diameter. Plus, it gives you just a touch of "overcut" and keeps the wood from "bumping" the outfeed table - maybe just a bit of a safety and convenience feature.

Now with all things being perfect from there, the theory dictates that your jointer will now cut your wood concave instead of being straight. You will not notice that though with the lengths that you will typically run on a jointer. It takes a real good mechanic and a long bed jointer to joint anything "perfectly" straight over eighth feet long. Set it up as the book suggests, I don't think you will notice any issues, and that will be a good thing.

Setting up a jointer properly is one of the toughest jobs in the small woodworking shop. Once understood and done though you will be golden.

All the best, Don