Futaba GY240 in 50 size heli

[ladingterbang]

I am new in flying heli. I have at the moment a stock hirobo shuttle plus with os32 sxh engine and futaba 3003 servo with futaba gy240 gyro. I intend to move up to a 50 size heli and my simple question is wheather this Futaba GY240 servo can be used in a 50 size heli. And for added information, I do not intend to fly 3D or aggresive, but rather a smooth scale like flying. Thanks for any help....

['roboRon]

Hi, we had a local with a raptor 30, gy240 and nes537 servo. It worked really well, but then he converted it to a 50 and it couldn't handle it imho. It had a tail wag, consistently, even through fff. He tried changing out for a digital ds811 and a few other things, but i doesn't have digital mode so it just couldn't handle the 50 size. a Gy401 and 9254 fixed it right up. Futaba only rate the 240 up to 30 class, seems to me for a reason.

Sorry its not what you wanted to hear :oops:

[ladingterbang]

Still looking for friendly advise on wheather I can use GY240 in a standard 50 heli. This is just for normal flying/circuits with no 3D. Appreciate any advise on it.

[Shoopy]

Uh.....? ^
You have the 240, give it a shot and see if it works for you, if it doesn't, then you can always upgrade later.

[ShawnK]

The only practical difference between a GY240 and a GY401 is that the 240 doesn't have remote gain adjustment. As far as the sensor and programming go, they are identical units.

[BarracudaHockey]

Well that and high frame rate compatibility for digital servos.

[ShawnK]

You can use a digital servo on normal frame rate, just not the opposite way around (you can't use a normal servo on digital frame rate).

[BarracudaHockey]

You said the only difference is the remote gain. The differences are remote gain, limit adjustment and digital servo support.


Also Futaba, for reasons I don't completely understand, says digital servos aren't reccomended for the 240, I don't know if that means it would be a waste of money or if there's a compatibilty issue.

[ShawnK]

Alright, fine... you win. I was wrong, and you were right. Nevermind that I used the word practical.

If Futaba says you can't use a digital servo on a GY240, then I guess that's all there is to it.

I'm wrong on all counts.

[BarracudaHockey]

BK have a happy 4th! :hug:

Not too sure what the reasoning is but this is from the Tower Tech Notes

This gyro performs best when used with non-digital servos.

[ShawnK]

I'll let you in on a little secret... Tower Tech Notes are written by people who spend all their time writing tech notes... i.e., not flying helicopters.

A GY240 works just fine with a digital servo. You can run high frame rate digital servos on a standard frame rate all day, and the only "harm" in it is that your fancy high frame rate digital servo just isn't being used to it's fullest.

However, if you use a normal frame rate servo (i.e. analog) on a high frame rate gyro (for example, a 401 with the DS switch on), you'll beat the electronic crap out of the control circuitry in the servo, and it'll die on you in fairly short order.

I'm being cranky (rained all day), but trust me... a GY240 will work just fine for what the guy wants to do, I don't care what Futaba or Tower's Tech Notes say. Futaba says that the 9251 servo that comes with the 601 gyro is supposed to be used at only 4.8 volts, but you can't swing a dead cat without hitting someone who uses them on a 5.3 volt regulated Duralite system without so much as a hiccup (myself included).

There is such a thing as "safety margin" when it comes to reading what manufacturers and non compus mentis retailers say. :wink:

Where's my coffee...

[Alfred]

My Rappy30 with GY240/S3003 servo does: Loops, rolls, 540 Stall turns, inverted with no issues.
All done through a GV1 at 1650rpm in idle2.

[ladingterbang]

Wow!!! Alfred, you are flying with that set up? GY240 and 3003 and yet still doing loops, rolls and etc. That's beyond my expectation from this sort of gyro. I thought gy240 is only good for a 'scale like' flyin. If you dont mind, whats the servo setup for your aileron , elevator and pitch - is it still using the s3003? Thanks for all whom have been very kind in giving inputs to my initial inquiry with regard to the use of gy240 in 50 size heli.

[Alfred]

Sorry
I double checked..it's a S3001 servo, the only difference is that it has got a single bearing on the output shaft which you can do without as the tail doesn't create a lot of load.
It's speed and torque is exactly the same as the S3003.

so:

Futaba:
Tail/Rudder: S3001
Throttle: S3401 controlled by GV1

JR:
Aileron/LR cyclic: NES507
Elevator/FR cyclic: L8001 (12year old coreless servo)
Collective: L8001 (same as above)

It's the heli on the LHS of my Avatare.

[ladingterbang]

Hi Alfred,

From your specs, you are using a GV1 governor. What is the most practical reason/advantage of using a governor in a 30 size or what ever size heli. Does it really help a newbie like me or it make even worse my learning curve as the throttle management has some sort being taken over by the governor. Appreciate your or any one's comment on the practical reason of using a governor. Thanks

[ShawnK]

Personally, I don't see it as being much of an issue either way (whether you use a governor or not). However, I do think there's a lot of merit to a period of self-imposed discipline in learning how to properly set up a throttle and pitch curve on your own.

Additionally, I have found in my experience that governors can sometimes "mask" an engine tuning problem and make it a little more difficult to tell how your engine is reacting. When you're running curves alone, it makes it a little easier to see what the engine is doing, because you don't have a governor artificially trying to compensate for your mixture settings.

[Alfred]

I believe a Governor has an advantage in the small 30 helies as they are prone to be a bit all over the place due to their limited power and torque.
With their limited power and the 39TT having a bit of a too rich characteristic in the midrange, the Governor will steady the rpm once the engine is tuned properly.
You don't need it until you start doing advanced aerobatics (or mild 3D).
My 30 will now happily do vertical tail slides without the tail braking out on the pullout.

My R50SE has a Governor in it but isn't used as it's power to weight makes it easy to get an excellent pitch/throttle mix..it just doesn't need it.

It's not something you NEED, but does help (and also adds complication/weight..it's all a trade off).
A gyro will work far better if the engine rpm doesn't change.
The danger is that a Governor can cover up bad engine tuning and it will bite you when you least expect it, unless you know how to tune an engine.
IF you are going to install one, then make sure that you are able to turn OFF the Governor from the TX for proper engine tuning.

[ladingterbang]

Its seems too complicated for me a newbie in heli. I think I would be better off with my present set up with out the governor and happy with it. I must agree with buddykitchen that I am not good with setting throttle or pitch curve yet so better learn to master the curve principle and how to set it up first. some more Alfred also mentioned that governor can cover up bad engine! Thats very bad as I am most worried if the engine quit mid air as I am new and no nothing about auto rotation. Might as well concentrate on learning to set the pitch and throtle curve first. Thanks for all your valuable advise.

[Rockohaulic]

There is one other difference between a GY240 and a GY401 that no one talks about.

With a 401, when you move the rudder stick from one max position (let's say left for example) to the other, the servo moves all the way to the other position at max rate. So from full left to full right your tail blades quickly turn from max left to max right. Sounds reasonable.

But with the 240 it doesn't do this. If you move from max left to max right position with the stick, the servo moves quickly (max rate) to about the center position, then it slows down very noticably as it makes its way to the full right position. Piros are very slow with a 240 because of this.

I've shown this to several people at the field I'm flying at, and they have never heard of it. I've demonstrated this with 2 different 240 gyros and 2 different TXs and RXs. It's a characteristic of the 240 that is not well advertised or well known. CHeck it out. It's pretty interesting! :mrgreen:

Just getting the info out!!!

Rockohaulc

[Alfred]

Rockohaulc

Correct
I'ts just fast around the centre.

[Rockohaulic]

I just replaced my 240 on my EVO 30 with a 401/9243.

Different bird now!!! So much more tail control.