Most light plane control systems use cables, fairleads and sometimes blocks (nautical term for pulleys) to route the cable to the flight control surface. I competition model yacht racing, friction is a big factor considered when routing sheet lines from the winch to the sail. Here's a sample source for these items; sometimes applications in one area can be used in another. http://www.midwestmodelyachting.com/...ckFittings.asp. For example: blocks and fairleads can be installed to route cables in line to the control surface without having to "cross the streams". Proctor Enterprises is another source for similar items.