Hi Cassandra, I'm back,
So, the jointing is getting better, but still not there. I'm using the rockler split fence, and 040 shim on the outfeed. Things improved when I got the insert aluminum plate flush to the table, there was a little skip there. And, things got better when I brought the fences in close, about 1/8 to each side of the bit (3/4 straight bit, 1/2 shank). It's almost perfect now, except, right at the end of the cut, it seems to cut deeper. This makes no sense to me, since by that time its almost all riding on the outfeed fence. But the last 1/2 or 3/4 inch gets a deeper cut (thus ruining the edge). It seems to happen when the piece leaves contact with the infeed fence. Which shouldn't matter. Any idea what's wrong? thx.
I usually find that trailing end snipe (the effect that you described) is usually caused by misalignment of the fences to the bit. That is, the outfeed fence is still not tangential to the bit's cutting circle or the infeed fence is not parallel to the outfeed fence.
As a test of the setup, joint half-way along a test piece. Then stop everything. Drop the bit to just below the table surface. Place the test piece in the position where the bit would be cutting the piece, if it was still up. Is the test piece making good contact with the fences along its entire length? Or is there a gap between the test piece and one of the fences near either end of the test piece? If there's a gap, then something is misaligned -- either the fences with respect to each other or one of the fence to the bit.
If there's no gap, then the outfeed fence is not still tangential (sorry, Richard) to the bit's cutting circle.
I had the same problem at first, but after installing the Incra LS positioner, I have been able to accurately position the fences to the bit and to each other. This ended the snipes.