New tail servo + Carbon blades

[Chris True]

I've started flying my Eco again after a long layoff, installed a couple upgrades such as aluminum pulleys and aluminum boom mounts. I was having a lot of performance problems with the tail, it was very loose - almost uncontrollable and would wag at anything over about 45% gain on a GY240 gyro.

Eventually I figured out that the pitch change arm was extremely tight. I had taken the boom + tail gearbox + HS-81 servo off a parts bird I had bought without checking it over carefully. Turns out the screw in the pillar was a bit too big which caused a big bind. I fixed that after fiddling with it a couple times but still the tail peformance was not totally right. It was flyable now but would still wag at over 55% gain which made the tail still too loose. I decided the HS-81 was probably no good, I know a lot of guys use em but this one had been abused and had to go.

The LHS had a JR DS-368 for $60 so I decided to try that. The speed rating is a little slow but it is digital which means the update rate is higher and you can run a long arm so I figure it would all balance out. So far it is working great, I have the gain cranked up to 80%+ so far without a hint of wag yet. I need to try it in forward flight but so far this servo is working well, not as well as the GY401+ 9253 I had in it a long time ago but getting closer.

The other upgrade I can recommend is the MS Composite carbon tail rotor blades. You should be beyond digging furrows in the grass with your T/R of course but they perform great and are perfectly balanced out of the package. At least the ones I got were! These blades took the last little vibration which was showing up as a buzz in the base loaded antenna out of the machine.

[Erez]

Chris, I have had the same opinion as you, where I thought that servo would work out. I'm hoping that someone will find a way to get the graupner 9g digital servo over to the states. Let us know how that combo works out.

From what I understand the 401 is a good bit better than the 240, so I'd be inclined to think performance difference would be due to the gyro more than the servo.

[Chris True]

Will do, I had another 11 minute hovering flight today in a confined area. Todays it felt better than yesterday because the wind wasn't howling. Feels pretty good so far, the couple times I blasted off into forward flight I noticed I needed to move the rudder stick much more than I'm used too. I'm not sure if that is the different servo or the different tail blades or the gain is too high so I may swap the blades out for a flight or two to see. I think the gain is actually a bit too high at the moment, the tail is locked very well but it takes a fair amount of stick movement to rotate the heli.

Also, the 240 kind of drifts a couple clicks in trim every so often. It won't rotate but will want to lock on a different heading 10-20 degrees from where it was. Very strange, the 30 degree temps probably aren't helping!

Waiting for some warmer days to wring it out some more.

One thing is for sure, the Eco has never been this smooth. I'll have to tach it to see what I am hovering at on the low speed idle up. I dialed back my midstick throttle setting to 53% today to really slow the headspeed. I had it slow enough it was taking aprox. 8-9 degrees to hover. Only when I got it that slow did the base loaded antenna start to vibrate at all. I should probably make up a plastic framed, plastic headed hacker for aerobatics. The Super Eco is running so nice I almost hate to risk a crash trying aerobatics! There aren't too many plastic parts left, couple boom clamps, tail gearbox - pitch plate - tail lever and blade holders, landing gear, anti rotation fitting, washout base, and the dome bearing housing.

[Chris True]

Success! I've been happy with the hold of the 240+DS368 but definately not happy with the responsiveness in forward flight. I was using the normal long arm that comes with the servo, gain set at 80-85% in heading hold mode and ATV's set at 140. Despite that, to execute a simple turn in forward flight required FULL rudder throw! Less gain just loosened up the tail hold unacceptably.

I consulted with a heli guru (Gary Wright) who recommended a REALLY long arm and much less gain. So I installed the longest Dubro arm available which has the last hole 20mm from the pivot point and dialed the gain down a touch below 50%. Problem solved, tail hold is now excellent and the response is back. It feels much the same as my 401 + 9253 combo did with the old stock Eco tail blades. Keep in mind, I'm not doing serious stuff like piro'ing backward loops or anything like that. Just basic hovering, forward flight and I do do some loops and stall turns but haven't with this combo yet. I suspect the fix of using a super long arm probably only works with the digital servo due to better bandwidth.

[Luxor]

Bump. This is good info.