I just got a UNI-T fence from Peachtree woodworking. I set it up, tried to get It parallel and noticed ever time I fed a long length of wood (30" or so) that the back end (operater side) of the board would pull away just before the blade and through the cut. I repeated four more rips and same scenario (even with board buddies). I whipped out the digital calipers to measure test pieces and was getting a narrower measurement at the front of the board than rear (or maybe I have it backwards) either way I'm not getting parallel rips.

I decided to take a 24" framing square and test the UHMW fence face for flatness. I put one edge of the framing square just before the beginning of the blade. I was able to see a gap at the front edge of the fence and also able to rock the framing square back and forth. I didn't measure the gap, but from aligning the fence to fence to miter slot with a dial indicator I was getting a hump in the middle of the fence from .008-.013 (8 to 13 lines on the dial indicator, if I didn't list the decimals correctly). When I moved the dial indicator to the very back of the fence (rear of table) it would right itself / zero out.

Peachtree list that UHMW varies in thickness and that the UHMW may not be perfectly flat with the top part of the aluminum extrusion. But they do not list anything about the UHMW face not being flat along it's length.

1) Is too much deviation in the middle of the fence? (The OEM unifence extrusion has some slight deviation along it's length but only like .002-.003 at most)

2)if yes to above and Peachtree doesn't see it as a issue, how could I accurately shim behind the UHMW to get the fence flat along it's 43" length or should I make a new face out of hardwood?

Thanks in advance
Michael