Use this balancer to balance spinners outboard the balancer. That is not between the stands. The Unique Over/Under Set-Up Option allows this. Also you can balance the 16-6 props outboard like this.
http://www3.towerhobbies.com/cgi-bin...&I=LXD712&P=ML
As long as the back of the propeller is not pressed against the back plate - it will be OK