Thanks for all the replies!
I hadn't made the taper connection. It makes sense! I'll try Al Drew.
Much like Yamaha Tom Arms. Do you ever wonder why a Yamaha tom arm is tapered at the very end? I found this out the hard way.
I had installed a RIMS mount on an older Yamaha tom, so I needed the shorter hex rod "YESS" arm (otherwise the longer hex arm was hitting the drum instead of being able to go through it). I didn't have a YESS arm, so I just cut a standard hex arm shorter. I couldn't get the tom onto the hex arm and I couldn't figure out why. It turns out, inside the Yamaha Tom Bracket that mounts on the shell (or the RIMS mount), it has a little plastic piece that keeps it tight on the hex rod when tightening down the wing screw. The taper at the very end of a Yamaha hex arm gradually "lifts" the plastic piece out of the way so the bracket will slide onto the hex arm. Without the taper being there, the plastic piece won't move out of the way, so in order for me to mount that tom on the arm, I had to put the tom upside down on the floor and put the hex arm in upside down, so that gravity would lifting the plastic piece out of the way.
Moral of the story, the taper is there for a reason! (And don't cut a Yamaha hex arm shorter unless you want to attach the drum upside down each time)!