I wrote a rather detailed description of how to do pull-pull in the May 1993 issue of Model Airplane News. That item was also reprinted in their "Radio Control Airplane How To's Vol 2". The technique is still very appropriate and I think the Volume 2 How To is still available and well worth it as it has many good articles in it such as "21 ways to mount servos", "Biplane Secrets", "Flutter - - Causes and Cures" plus much more, well worth the price. If you build large models, you will get your monies worth even if you do not use the Pull-Pull information.