ORIGINAL: agexpert
The plastic arms are strong enough for a .90 size plane, but I would not go much bigger.
can't speak for the HiTec servos, i only use JR equipment, but the stock 'plastic' horns included with JR servos are plenty strong enough for any installation. I've used them on all surfaces of 200+ mph turbine jets with absolutely no problems and even Bob Violet (another JR flier) recommends them for all his jets.
kc