rotary switches yet again!

hi there,I was reading through the 737ng.co.uk site which is full of very informative and inovative stuff on cockpit building.Anyway one can make rotary encoders from much cheaper rotary switches which I'm going to try.Has anyone else tried this,if so do you use type make before break or break before make to achieve this and also if using these switches for there intended use( simple rotary switches) which type do you use when let's say interfacing through the buo836x card to fs .anyone,john.