Jointer help needed possibly

[Anthony Yakonick]

I face jointed some cherry today and it seems that a few boards rock (high on the ends and low in the middle) after I was finished, my short boards (2') were dead flat but the 4' boards rocked. Any thoughts or sites on jointer use? This flat stuff aint as easy as I thought

[Dick Parr]

I found that if you put to much downward pressure on the board when you pass it over the blades, it can cause this on longer boards. I learned to use just enough pressure to get the board from the in feed table to the out feed table safely. I try to just feed the board by putting pressure on the out feed table once I get it over it. If you are going to do a lot of face surfacing on the jointer, you might want to add a little hook to the back side of you paddle to help push the board over the blades without having to use all the downward pressure. I found this true with edge jointing also. I was always causing the boards to have gaps that I couldn’t get out when jointing to make wide boards. A friend was over one day and saw me doing it and he told me to let up on all the pressure I was putting on the board over the blades. When I did this, it worked and it made life easier for me after that.

Good luck.

[Scott Post]

Are your edge jointed boards also convex? I've found two things to cause this: having one of the tables dip near the cutterhead or having the knives too low. The latter is easier to fix and is more common.

The knives need to be just a hair higher than the outfeed (NOT dead even with it) or you'll get convex edges. On two of the jointers I've owned they need to be about 0.003-0.005" higher. You can check it with a dial indicator, but I've found that if you lay a straightedge on the outfeed overhanging the knives and turn the cutterhead by hand if you hear a faint "snick" as a knife contacts the straightedge but the straightedge doesn't move then you've got it right.

Another way to set the outfeed height is to lower the outfeed and joint a piece of scrap. You'll get snipe at the end of the cut. Alternately raise the outfeed a little and test until the snipe just disappears.

If one of the tables is high at the end farthest from the cutterhead you need to shim the ways, in this case fitting a piece of shim stock (or an old feeler gage) between the ways and the errant table near the cutterhead until the convex edge goes away.

[Anthony Yakonick]

Thanks folks, I'll give it a try.