I am flyng an Ace 4-60, with a Saito 80. The plane has developed a constant wing rock.I checked all the linkages,everything is O.K. Any suggestions ?

Sounds like aileron flutter. My combat planes wiggle back in forth in roll when flutter starts, it's usually my first warning to fix it before something goes really wrong. Check your linkages and servo mounting. If it just started out of nowhere, I'd take a close look at the aileron servo mounts and give them a good wiggle by hand to see if anything moves.

A friend of mine had that same problem and found the gap at the ailerons were not the same so he tightned up the gap and that fixed it.

Thanks guys, I will certainly give it a try

JDAn, another area that is generally overlooked by most is servos! I have had this happen and have seen it happen to others. When using a standard servos on a large aileron the gears can wear down, or the servo strength can decay from age. This can be especially true if you are doing some really hard aerobatic flights. The servo is only a small electric motor that moves gears to turn the linkage arm. You may want to check your servos to see if they are still producing enough torque. This can be quickly and easily done. Turn everything except the engine on. Turn the ailerons and see if they can be moved easily with hand pressure. If they can be easily moved, you may want to invest in new, or stronger servos. Now we are talking about doing this by feel so the amount of pressure you feel is right is totally up to you.

If the servos are still strong, I agree with the others, it is probably flutter.

Thanks,

Reg