First I cut what I thought was right and ended up with 30 degree bevels and found I would need 6 sides
Then I tried using the SS tendoning jig to cut the 60 degree. That is when I found my Tendoning jig was not set up right, after using it for 15-20 years. The miter bar can be adjusted to the metal plate. WHO KNEW????? Fix that but even very fine tuned it still left a lot to be desired.
Finally I figure it would be easier to rip cut the 60 degree bevels in a 36 inch board and then cut the 3 12" pieces from it. Did that and it worked.
I set my table to 60 degrees and then using my rip fence placed the board vertically on the rip fence with bottom corner just be cut off by the blade.
With the table tilted gravity held the board against the fence so it was actually easier to cut this bevel with a tilting table than it would be for a tilting arbor.
I really enjoyed playing with the tendoning jig, which I rarely do. Now thinking about past projects I think I now know what some of the joints were just slightly off. When I cut the bevel using the jig it was real noticable in fact I even cut a vertical to verify the problem with the jig and not my table trunnions that I have played around with in the past. It was the jig.