Just recently purchased a super FMT and had a few hours to try it out today - left my shop after 3 hours with not a single joint created. The issue is pretty simple to describe - the tenon is to big for the mortise - no amount of adjustment up or down on the brass pin fixes the issue. Using the supplied 5/16 spiral bit and a 5/16 x 1 1/2 guide, with 3/4 cherry test boards. I also made sure that when I cut the mortise that I followed the inside of the left guide, although that did not make any difference then just going left to right in the slot.
im sure I am missing something obvious as most reviews I read say they get a "piston" fit out of the box.
Any suggestions would be greatly appreciated.
TomD