31, it depends on how short the arm on the control surface is, but I have found that the 1 & 1/4 arms on elevator and aileron will give you the maximum throws you want. 1" may be to short. But I have 5945's on mine and it is performing flawlessly. If you don't want to go with the new thick Hitec arms, give SWB's site a look. they have some nice aluminum arms tapped for 4-40 ball links. PS: I have tapped the XHD Hitec arms for 4-40 ball links and they are working great, look cool also. They are only coming in the newest releses, so you may not have gotten them.