To get your 3D "throws" you need 1-1/8 inch from center of shaft to clevis pin hole. The SWB and AirWild 1-1/4" metal arms both do the job very well. Set your servo travel to have reached full servo travel with the flight surface in the 3D position at high rate. Try to keep the distance from the center of the flight surface hinge line to the clevis hole on the flight surface arm be the same as the distance from the servo shaft center to clevis pin hole distance on the servo arm.

I probably didn't explain that as well as I should have, but you likely get the picture.