Replies

1. 
   JohnWW | Sep 12, 2003 11:44pm | #1

   gsg,

   Assuming there are no mechanical problems, the blades are sharp, and the tables are flat and coplanar, the most likely problem is that the outfeed table isn't set at exactly the correct height.  Setting the outfeed height is a simple procedure, so I'd start out trying to adjust it before trying anything else.

   To set up the outfeed table height, you'll need two test boards, each about 2/3 as long as the overall length of the jointer, these boards should be close to perfectly flat on their wide faces with no large knots.  If you primarily plane hardwoods, the adjustment will be more accurate if the test boards are also a hardwood. 

   Start by dropping the outfeed table so that it is slightly lower than the highest point in the path of the knives on the cutting head.  In this position, the outfeed table will definitely be too low.  Take a pass with each of the test boards and place them together, planed edge to planed edge.  With the table too low, you should find that the planed edges are concave when placed together and each board's trailing edge will have a small snipe over the last inch or so.  The test cut should be fairly shallow, removing no more than a 1/16th of an inch from each board. 

   Next start to raise the outfeed table by small increments, taking test cuts on both boards after each adjustment.  As you bring the test boards together after each height adjustment, you should see the midpoint gap diminish and the trailing snipe disappear.  Keep adjusting the outfeed table upward by small amounts until the edges mate perfectly and you'll be all set. 

   If you overshoot the setting, the boards will be touching in the middle and gapping at the ends of the joint.  If this happens, drop the table to below the correct height and try again to get the correct setting by raising the table. 

   If this procedure doesn't solve your problem, I'd replace the knives with a freshly sharpened set, and repeat the above adjustments on the outfeed table.  If you are still having problems after that, then it is likely you have some problems with the alignment of the tables with each other, which will be harder to diagnose and fix.

   John W.