After about 4 days of figuring out how to model trusses, I can sleep now. My ultimate goal: model a fully parametric truss where the overhangs are different slopes from the main part of the truss. I wanted to be able to place it like a beam with out it automatically connecting itself to centers of bearing walls, enter in the slopes, and adjust the overhangs. See image, "Goal picture".
I've seen posts where ppl edit a wall profile (which I thought was a genius workaround, but not a good solution for me at this time) but most people just can't seem to get trusses to work well. I know others of you may have better or different successes than what I've done. But I wanted to share my discovery incase it's helpful to anyone.
I tried to re-create trusses with truss family templates (overhangs didn't come out well).
I tried to fake it with beam-based family templates (the span edges of the trusses would embed itsself into the wall centerline & the bottom of the trusses would not line up with the reference planes that I wanted)
After hours of re-creation...I used a line-based family template. I don't know why I didn't think of it before. You can see what I've done for a simplified truss in the images. I still have to put in vertical and diagonal webs - but that's a breeze once the chords are in.