Thanks for the advice guys. I figured out that the correct approach was to put a standard servo in late last night... and it works fine... now to get the MDS 2.18 running properly or replace it. Bought it on advice from an owner of a local hobby shop. Wish I had gotten better advice!! Thanks again for your help. The retracts operate very smoothly. Will a 1/8th" wheel collar really slow down the operation of the retracts? Is there anyway to incorporate one of the robarts switches with the spring airs?