SD MODELS 33% YAK RUDDER ???? AGAIN

[mikel7099]

Has anyone experienced with the SD models 33% Yak under almost full power at level flight then go do knife edge it seems 1 servo is not enough holding power ? I am running a brand new Hitec 5955 i just bought from TBM . If under half throttle no problems at all. Also the engine i have installed is a ZDZ 80 rj-v . If anyone else noticed this and is running multiple servos please post pics too.

[zzw26n]

I'm not Flying that Plane, but I'm Flying a 33% Suhkoi with two 5955's and they hold.
IMHO you need at least 300 oz. on the Rudder and when the 5955 gets heated up, your only at 250 oz. which is marginal for 33%, that's why I run two. 30% , yes one.

just my .02 cents

[Extra260]

I think this servo has less torque but it has a bigger gear train. But I know what you are talking about, mine still lacks in power. I think this is because the 33% rudder is almost out of proportion. The servos a 5745

[jeroli27]

I have just swapped out a 5955 for a 8611 on the rudder in my 34% extra and I noticed a big difference in the performance. It is crisper and has more holding power on maneuvers like knife edge loops.

[mikel7099]

	Quote: Originally Posted by Extra260
	I think this servo has less torque but it has a bigger gear train. But I know what you are talking about, mine still lacks in power. I think this is because the 33% rudder is almost out of proportion. The servos a 5745

I was also gonna use that same servo but the Yak has such a big rudder i would try the 5955 but that seems to be a little weak to handle that rudder alone. I am going to try to gang two of them up now. I think that will cure my problem. Just don't want to over work the one servo and have it fail!! Also if someone has already ganged them together to get ideas on how they did it.

[mikel7099]

	Quote: Originally Posted by zzw26n
	I'm not Flying that Plane, but I'm Flying a 33% Suhkoi with two 5955's and they hold. IMHO you need at least 300 oz. on the Rudder and when the 5955 gets heated up, your only at 250 oz. which is marginal for 33%, that's why I run two. 30% , yes one. just my .02 cents

I tend to agree with you especially now!!! I was hopeing to get away with using just the one.

[plaster93]

More torque you could go JR 8711

[2leftthumbs]

I started with the same set up as you and had the same issue. In my opinion one 5955 is not enough. Now that I have two 5955's on the rudder knife edge flight takes a lot less pressure on the stick. At full power on low rates the plane easily starts to pull into a climb when I push the stick all the way over. It would not do this with one 5955.

[mikel7099]

	Quote: Originally Posted by 2leftthumbs
	I started with the same set up as you and had the same issue. In my opinion one 5955 is not enough. Now that I have two 5955's on the rudder knife edge flight takes a lot less pressure on the stick. At full power on low rates the plane easily starts to pull into a climb when I push the stick all the way over. It would not do this with one 5955.

Can you post pics? I like to get an idea of how you did it .

[2leftthumbs]

I can post a pick for you but, it will be a few days as I don't have the plane in front of me. I just used two short H9 turnbuckles between two SWB straight servo arms. Epoxy in some hardwood to screw the servo's to and used the provided offset servo arm in the 3inch holes (or whatever the distance is between the holes that are closes in). The cables stay snug thru full 3d travel and mechanical setup seems to be good.

Another thing this did was help the tail wag. I also put a strip of carbon on the edge of the rudder in an effort to improve this prior to the second servo. Not sure if it is needed now but, it fly’s so good now, I am not touching anything.

[Dan J]

	Quote: Originally Posted by plaster93
	More torque you could go JR 8711

Yep.

[mikel7099]

	Quote: Originally Posted by 2leftthumbs
	I can post a pick for you but, it will be a few days as I don't have the plane in front of me. I just used two short H9 turnbuckles between two SWB straight servo arms. Epoxy in some hardwood to screw the servo's to and used the provided offset servo arm in the 3inch holes (or whatever the distance is between the holes that are closes in). The cables stay snug thru full 3d travel and mechanical setup seems to be good. Another thing this did was help the tail wag. I also put a strip of carbon on the edge of the rudder in an effort to improve this prior to the second servo. Not sure if it is needed now but, it fly’s so good now, I am not touching anything.

Thanks . I did have tail wag but was able to correct without putting anything down the rudder. Just seems one servo is not enough power to handle that rudder .

[mikel7099]

	Quote: Originally Posted by plaster93
	More torque you could go JR 8711

Probably still not enough .

[plaster93]

403 oz torque????

[flying skunks]

I am running a single Hitec 5745 at 6.5v and do not have any lack of rudder authority to pull off a knife edge loop.
Donnie