Hi,

I have been flying a GP Reactor Bipe for a couple of months now. Last week we noticed that in a hover the aileron servos seemed to be reacting late- a bit slowly. Even the best 3D pilots noted that. I was using Futaba 3010s on ailerons and elevators, so I replaced them with Hitec 5625MGs. I also dropped the aileron side clevis to a lower horn. I am using Dubro heavy duty horns, not the stock horns, so the push rod was not level with the surface in the earlier setup. Even when dropped to a lower hole it is not level but its closer. I dont want to go to the inner most hole where it may magnify any linkage slop

However with this change, I have to reduce the ATVs to 25% to get the manual specified throws. When I did this on a earlier airplane, it changed the way the airplane flew- the elevators on that airplane stopped being linear in response and took on a sort of on-off snappy response. It made the airplane very difficult to fly. Those were 3010s servos on that airplane and I was flying of a 9CAP wherein the sticks were very stiff and I had to make them loose to allow for more comfortable flying, so I am not sure whether the snappyness was radio or TX related

So my question is, does reducing the ATV (AFR in Futaba 12FG) to such a extent make the servo resolution poor and hence snappy?

Ameyam

Yes adjusting the atv will do nothing to affect servo speeds but can make it twitchy if ATV is short and the mechanics are poor

You always want to use the shortest horn on the servo and the longest on the control surface you can get away with and max the ATV when possible, this takes full advantage of both the servo's resolution and torque.

Adding to the problem, I think your new "Snappyness" might be due to installing a higher speed servo also, try adding some negative exponential in the TX to smooth it out around center. I recommend you start around -40% and adjust to your liking from there.

And if slop is an issue, loose the crappy clevises and invest in better linkages,, like good quality ball links

good luck

That snappiness is on another airplane, not this one. I will know tomorrow

The sloppinessin linkage is more due to the z-bend servo side. W.r.t horn size, I used the recommended GP horns servo side, only replaced the stock white nylon horn surface side with the Dubro black he horns, then aligned the pushrod to be parallel to servo body. Lets see what happens tomm. I currently have 5% negative expo on low rates, 10% on high & 20% on 3d & will take it from there

Ameyam

ZBends on a gas aerobatic plane??

No, its a OS 110FS. If it were gas I would have used ball links- it would have come with ball lings in the first place

Actually, I didnt use the stock pushrods either. The ailerons are fill thread SS 4-40 Sullivan. The rudder and elevator are 4-40 one side threaded. The manual requires you to solder the other side, which I have never done, hence z-bends. I didnt use the 4-40 full threaded on the rudder and elevator as threaded pushrods have a lower cross section than one side threaded, so they are likely to fail earlier from corrosion. The clevis I have used are Dubro spring steel clevices

http://www3.towerhobbies.com/cgi-bin...?&I=LXD937&P=7

http://www3.towerhobbies.com/cgi-bin...?&I=LXD885&P=7

Ameyam

IMO 5,10 & 20% is hardly noticeable, expecially if you have the ATVs down to 25% and *****g out the throw mecanically, that's why for an aerobatic plane I'll start at -40%