This is the clockwise rotor hub for my gyro.
http://www.netlabs.net/hp/soarrich/hub.jpg
The view on the left is the top view, if you look you can see the bevel that I put on the blade holders so the can flex up maybe 15*. There is a scribed line on the left side of the rotor that shows up clearly, from that you can see I have put in about 20* of angle on the blade hinge, I'm assuming that is the delta angle that gives the hub it's name.
On the right is the bottom of the hub. See the differance on the hinge line? It's much tighter so the blade can't go down.
I've put two flanged bearings in the hub one on the top plate one on the bottom plate. I'm using a 10-32 allen bolt for the axle. It spins very freely, but it is heavier that expected. Maybe gyronut is right I should look in to trains!