Jointer acting very strange. Trying to diagnose.

[bradleyheathhays]

Basically out of nowhere my little Craftsman jointer starts doing something I've not only never heard of but am struggling to understand. Right now when I joint a board putting the correct back pressure against the fence the jointer makes wedges out of whatever I run over it. By that I mean it takes a lot out of the front end of the board and virtually nothing from the rear, gradually making the front of the board into a point. This picture illustrates what I'm talking about. I ran these 2x4s over the jointer maybe about 25 times with the depth properly set (table adjusted downward first then brought up to the position and locked) between 1/16 and 1/32 and it did the same thing both times. I jointed the top board with the wide side to the fence first so I would have good flat side part of the 2x4 to push up against the fence. I checked the back fence for 90 deg and it's just a gnats hair off with the top leaning in just a little.


Any idea what's causing this egregious behavior?

 

[Mortalis]

Sounds like you outfeed table may be low or the piece you are trying to joint is too long and the jointer cannot remove the bow correctly.

 

[maxwell_smart007]

Sounds like you outfeed table may be low or the piece you are trying to joint is too long and the jointer cannot remove the bow correctly.

My thoughts exactly - it's going from low to high, so that's why it tapers...it cuts deep, and then travels to the high side, and that makes a taper.

 

[GaryMGg]

Test again using a board which is true and square.
See if it joints properly and maintains true and square.