Would a YS 140 be ok??

Also what do you think of those servos? (They are not metal gear)

2xNES 4131 (6Kg) Elevator
2xNES 4131 Ailerons
1xNES 4721 (8.6Kg) Rudder

Rgrds,

Nik

a ys 140 would be ok, but it would be way overkill. something like a ys 110, saito 1.20, or os 1.20 would suffice. i have no experiance with those servos, but for something with such alrge control surfaces, digitals really shine. they are not necessary however. while the plane is obviouysly physically capable of flight without metal gears, they are highly reccomended.

You will snap those servos and plant a balsa tree.. I broke an HS-635 on an aileron 2nd flight.. I use HS-625's and they are the best non-digital servo for the plane.. Chris will not stand behind you unless you use metal gears.. A YS-140 is overkill but I guess if you have one lying around you could use it.. If not go with Clam's recommendation.. 90% of us use YS 1.10's with it.. If I had to do it all over again I would use a small RCS 140 gasser as I am getting out of glow engines..

you should definatly not use one of those servos if you want to use a ys 1.40

I have a Saito 150 in mine and it is great. More than enough power for everything I want it to do. As others recommended though, the YS 110 is the perfect match, I thought I heard the plane was designed for this engine. As for servos, I have all digital on mine.

the plane is designed aroudn the engine. the 110 weighs less than any engine in it's power class by several ounces, and all the measurements for the engine mounting are for the 110 as well.

How did you come to that conclusion? Not long ago, before digitals were around, this was the set up of choice for everything up to 30% planes with gassers. I personally had the exact same set up on a Byron 27% Sukhoi with a G-62 and they were plenty strong. Regardless of the type of flying you do, these servos will hold up. Remember, this is only a 90 size plane and the elevators on my Sukhoi were bigger than the rudder on the Yak. I saw one of these fly today with a Saito 180 and it was more than what was needed. Unless you've already got the 140, I'd recommend the 110, if you can find one.

Hm, I think I will have to go for QQ's YAK because it is designed for the 140. The issue here is that there's no availability in Europe till Feb 2005, the distributor is Sebart. If I finally get the EF YAK what kind of modifications would they be required to support the 140?

Also I would agree, the servo set up I'm refering to, was the high end JR servo set up before digitals came out. It has been used in larger planes than 68"" and patternships, but at that time 3D was nearly non existent.

i am not saying that because they cant hold up. i think they probably could. i am saying that because if you want good support from EF than i suggest you use metal gear. no modifications are necessary to mount the 1.40, just split the difference in extra width of the mounting lugs between the engine mounts and you wil be fine. you could ask pugsley-rcu, he had a 1.40 on his EF yak.

rcmigpilot, I too am beginning to wonder at some of these recommendations. 4131s and 4721s have been used in 3D 60 size helicopters for many years, with good results; and you cannot convince me that a nine-pound plank, regardless of what engine it has or how violently it is flown, is going to be harder on those servos than a ten-pound helicopter being thrashed by some of the heli community 3D hotdogs.

The JR 4131 servo has a record of quality and service that some of the recently popular (such as Hi-Tec) can only wish for; ditto the 4721. and if you think 120 oz./in. isn't enough rudder servo for a light, 120-size airplane, just what IS "enough"?????

Have you seen output shafts snap off, not a pretty sight........

Spaceclam,

Sorry but I find difficult to understand what you exactly mean.... You're saying that If I want to have good support from EF, I must use metal gear servos???!!!! Your way of thinking seems a bit complicated to me mate...

EF can not guarantee a structural failure if I use the 140, the same exists for the servos. If someone employs good throtle management, I think there's no problem. The same exists for my 40 size Flip 3D, it is highlighted in the manual that someone must never use full throtle during horizontal flight. I think this is the case for every 3D plane, which by definition, is overpowered.

Regarding the servos, has anybody faced a plastic gear failure? If yes, under what circumstances? The only I can imagine are: High G blender, violent snap at full throtle and knife edge (loop).

Nik

I reckon that servo should be ok but not if you are putting a YS 140 in it. You need a JR 8511. They are bullet proof in planes way overpowered like this.

You need a JR 8511.

You mean only one? Should I use this everywhere?

Nickolas, there are 2 Somenzini importers in the UK, not sure if they will ship outside the UK though, and i dont think they habve any in stock..... As far as i'm concerned the EF yak is a lot better for the money, and they are readily available in Europe from www.freestyle-rc.com .

Hi Welsh 3D,

First of all congratulations to you and the guys of 3DRC for your web site and your really serious efforts with aerobatics.

Can you please give me the details of QQ's distributors in the UK? I've heard that QQ's YAK has some structural drawbacks and a refined version will come out after Christmas in Europe. If this is the case it won't be availabe in the UK either.

Anyway, what is your opinion on my potential set up, engine, servos, etc. for EF YAK?

JR 8511 is quite heavy and expensive, I think Probuild sells it for 85 GBP. If I use metal gear servos I plan to use them on the elevator halves only. If I lose the rudder or one aileron due to servo failure, there is no problem, I can land the plane.

Rgrds,

Nik

nikolas,
what i am saying is that Extreme Flight strongly reccomends metal geared servos. If you were to put a 1.40 on a 60 size airframe when they only reccomend a 60-90, and you say your wing broke off and you thought you heard flutter, they would say "maybe because your engine was much larger than the reccomended size?" same with the servos. chris is a very personable guy and it very pleasent and fair, but if you have a failure and it is possible that it is servo related and you did not follow his reccomendations, he will most likely not stand behind the product, and rightfully so. If you bought a computer with a warranty and you overclocked the processor, do you think warranty will cover it?
however, the servos will probably physically work for the yak.

I got the YS110 on mine and it is the perfect match. THe YS 140 may present some balance issues, they might be easily solved they might not without adding weight. Jeff

Thanks for your positive comments about 3DRC. For your needs I would perhaps recommend the Hitec 645MG, theyre available in the Uk for about £30 per servo... they have metal gears and very high torque ratings. For this size of model they should work fine.

I wouldnt worry too much about adding weight, the YS 1.40 is not excessively heavier and this model is so light anyway, it will not make the model fly a lot worse. One concern is that there is no real consideration for a tuned pipe tunnel so you would have to use a pitts exhaust or a standard YS exhaust.

Comparing how many negative things you hear about the somenzini yak and how few about the EF, the 'better' one is obvious. However, if you decide to take the EF Yak and YS .140 setup, do take care, it is unlikely that the manufacturer will accept responsibility for any structural failure which might occur.

The main Somenzini importer is Fusion Models http://www.members.aol.com/fusionmodels/index.html

Thanks for that. I have a pitts style Slimline muffler on my YS which will add some weight. Also I use a Gator mount which will add some too. I don't really know whether the Hyde mount is much lighter than the Gator. Any opinions?

Now with regards to responsibility. EF can not guarantee a structural failure if I use the 140, the same exists for the servos. If someone employs good throtle management, I think there's no problem. The same exists for my 40 size Flip 3D, it is highlighted in the manual that someone must never use full throtle during horizontal flight. I think this is the case for every 3D plane, which by definition, is overpowered.


Rgrds,

Nik

it is true that you will be fine if you excersize good throttle management, but as good of a guy as chris is, he can't tell whether you are telling the truth or not, or whether your definition of throttle management is "lower your throttle when landing, full throttle when not". dont get the wrong impression though. chris is one of the most honest and personable guys in the rc industry that i have yet met.