It's not quite
Ackermann steering, because the geometry is not set up quite right (notice the line from the spindle pivot to the tie rod pivot is parallel to the wheel), but it should work ok, since the wheels can't steer very far because of the frame being in the way.
Might want to see about using some smaller wheels like 4" Colsons? then it might steer more sharply.
I like the simple spindle!