I'm back and most importantly, still have all my fingers.
I wish I'd read the tip to face the miter gauge with sandpaper before this evening; it really would've helped! The workpiece wanted to slide around on the miter gauge something fierce. By the way, the magic number was 64. As in the miter gauge needed to be at a 64-degree angle left/right to make the "reduction cut" from 12 1/8" to 8.0".
This was a brain-busting, nerve-wracking exercise for SURE, but I learned so much. Next time I have to do this, I will just say "Oh, this....I know how to that!"
I do not like my fingers anywhere near the blade. I use push sticks for everything and the guard is always on the blade, but for this there was no way to go but "bareback" for this operation. I did have the riving knife installed though. Stupid, I'm not.
Not the best pics, but at least there's pics. I don't know where the burns came from. Some of the pieces were binding as I slide them through the blade. I did all 8 the exact same way. Is that from the workpiece moving? Yeah, the sandpaper trick would've helped. Not sure if the workpiece moved as all the cuts look straight to me. Long sides are at 45, short at 26.
I'd be very interested in seeing what a jig for these types of parts looks like. While I'm aware of the useful, time-saving benefits of jigs, I'm not real smart on them. I'm a visual learner...helps if I see the object in question.
I'm pretty impressed with the miter gauge that came with my Grizzly 0690 TS. It only has snap detents at 45, 30 and 90 degrees, but the twist knob locks down securely at any angle in between and the markings on the gauge are easy to see. That said, an Incra with a positive detent at every degree b/t 0 and 90 is definitely in my future.
I can't thank all of you enough; I would not have been able to do this without all of your help. I learn from each and every one of you. Thanks, guys.