Hello. Just bought my first heli, a Sceadu Evo. The only guy in the local club that has helis says I need a high dollar digital servo for the collective. I know I need one for the the tail rotor, but I didn't know one was needed for the collective. Do any of the others need to be digital, high torque, high speed, etc? Thanks.

Hi

I don't know whether you will be flying JR or Futaba but I'll give you an idea on Futaba servos.The order of importance of the servos is as follows:1)Tail rotor 2)Collective 3)Aileron/Elevator 4)Throttle.
The tail doesn't have to have a digital servo but if you get a gyro i.e Futaba GY401 with heading-lock it is going to allow it to run at its best.One can buy the gyro with its servo S9254 which is a very good combination.
Regarding the collective servo you don't have to have a digital servo, a standard S3001 or S-148 will work but it does lack a bit of torque.I reckon you should have at least a 5kg.cm servo for the collective especially if it is the 50 size heli.The servo doesn't have to be digital or coreless but they will more precise and responsive.If you're a beginner it is not always good to start with fast servos but it will save you from having to change them as you become more experienced.The problem with putting a high speed digital servo on the collective is that if the throttle one is not equally fast it will lag behind the collective but this you won't notice unless you are doing extreme 3D.The Aileron/Elevator servo can also be standard servos.It all depends on how much you can spend and whether you think you're going to fly 3D,if you're never going to fly 3D and just fly around a do a few loops and rolls etc. then standard servos will be fine.

Here is an ideal setup:

Aileron/Cyclic:Futaba S9202 coreless servos or S9252 digital
Collective:S9252
Throttle:S3001 or 9001 coreless
Tail rotor:S9253 or S9254(the newer one) used in conjunction with a GY401(very good gyro).

Don't use standard servos that don't have bearings on the output shaft as the vibrations on heli can damage the servo leading to which may cause a crash.One such servo is the S3004 that's why I recommend the S3001 if you're going to use standard servos.

Hope this helps!

I have heard reports about blade flutter problems with Sceadu under some conditions. For this reason I selected 3 x S9252 to have some extra strengthness over the minimum demand. Besides there are nice offers, for example helihut and therefore the servo bundle is possibly the best update to improve your heli from the standard level.

I have s3001 servos in my wing plane. After I got used to see S9252 moving I was quite surpriced to see how slow the standard servos actually are!!! I think I need to update those as well.

The flutter problem was confined to the original Sceadu; it hasn't been an issue with the Evo. However, you still want the best servo you can get on collective, as it has the highest loads and is worked the hardest in "normal" flying. The tail servo is equally important if you're going going to be thrashing around doing 3D, as are the cyclic servos. There is no real "most important" servo in a helicopter; if any one of them fails you're coming down RIGHT NOW. A tail rotor or throttle servo failure is survivable; a cyclic or collective servo failure, 99% of the time, is not.

Having said that, you will find that putting a digital on collective makes a huge difference in the way it feels. Much smoother and more precise; your hovering will improve drastically. I have a 9252 on my Evo 50's collective; I have good analogs everywhere else. I do have all-digitals on my X-Cell, but just cannot see putting them all around on a plastic helicopter.

Regarding the tail servo; you will be told that one MUST have a fast digital, etc., etc. Nonsense. If you're an accomplished flip-flopper (3D), then yes, you'll need one. If you're learning, or just flying around, a good analog will do just fine. My Evo has a 9402 hooked to the 401 gyro, and I have all the tail authority I can stand.

Digital servos do indeed perform better, due to their zero dead band and near-perfect centering. That comes at a price; higher cost and heavier battery drain. My advice for a novice with a plastic 30 machine is to use standard servos until one becomes accomplished at flying around and is ready to try aerobatics. Then is the time to upgrade servos and battery pack. If you want to spend the bucks on all digitals, by all means go for it. You will certainly be able to tell the difference in performance. But, if I was just flying around and doing mild aerobatics (which is the way I fly), and this was my "beater" machine (which the Evo is), I would put a digital on collective for the enhanced performance there and save my bucks by using good analogs everywhere else. The Evo flies very well on good analog servos, especially the 50 with its closed-loop collective and cyclics. I think it is the hands-down best ship going in the 30-50 plastic market today.

But you're still talking about a plastic helicopter. There is BUILT-IN slop on plastic helicopters. Unless you need the strength of digitals to withstand the thrashing that hard 3D produces, there simply isn't any sense in putting $500 worth of servos on a $300 machine.

Opinions vary... that's mine.

BTW, the advice to NOT use Futaba 3004 servos on a helicopter is sound, but the reason is because of the indirect drive potentiometer on the 3004; not the output shaft being weak, or whatever. The 3001 is nothing more than an S148 with a bearing on the output shaft; a good, solid bread'n'butter servo, suitable for a plastic 30 helicopter; but NO MORE. If you get an Evo 50, use 9001s at the very least.

Im using a JR 9x and Im running JR DS 811 all round except throttle (standard), and tailrotor( S9254 with gy401). The reason im running a standard servo on the throttle is that digital servos like to chew the juice, so im running a 2600mah nicad (an my evo is a little tail heavy too).I also turned the u/c legs back to front to get the skids further back to help the tail sit higher when flying off the grass.


Rhyno

Sceadu Evo 50 vs Jr Venture 3D 50 , Has anyone flown both these helis? , Which one is a better heli?


Thanks

"Better" is a relative term. I prefer the Evo. I have built and flown three JR machines (Ergo 60 Sport, Ergo 30 SS, Vigor), and until looking at their newest offerings always held JR helicopters in high regard. I was a bit underwhelmed with the Venture. That said, it is an okay machine and flies fine.

The Venture is CCPM, which will complicate your life if you're using an entry-level radio. You also need a better grade of servo when using CCPM, to avoid interaction.

IMO, the Sceadu is the best deal going for a plastic mid-sized helicopter these days. The 30 makes an excellent first machine/trainer, and is easily upgradeable to a 50. The 50, with the right engine and servos, will hang with the best of them at the ever-popular flip-flopping.

I heard a credible rumor that Horizon (the US importer of JR stuff) is considering getting out of the helicopter business. They have lost the commanding spot in the market they once enjoyed, and, as with any business, the bottom line is everything. Something to consider for later support, etc. Horizon does have excellent product support, but if they drop the line... just ask the guys who need parts for some of their Hangar 9 ARF planks. One or two production runs, and that one is gone and we're off to the next latest/greatest.

Get an Evo or a Raptor. Either is "better" than a Venture, for several reasons.

Thanks for the info.

Rich D

Hey Guys
Had an "interesting" fly today after accidently over speeding the headone of the paddles had come loose and rotated about 20Degrees which made for a hurried landing ,sorted that out and then had one blade go horribly out of track[sm=eek.gif] Found a slightly (bout 4 thou)bent spindle shaft(the one the blades are on) and a few screws loose on the collective servo[sm=eek.gif][sm=eek.gif] This is after about 15 lts of fuel through so im hoping that ive got it sorted cos i aged about 5 yrs and gave my mate a work out (running away)

Just a thought.

Try add up the cost of all the equipment using standard or lower priced servos and then do the same using quality digital servos. In both cases the heli will cost quite a bit.
Looking at the relative cost difference the digital setup is not that much more expensive. Now ask yourself the question: What is the value of the extra security of going digital
(here I assume that for example F9252 servos wont break or fail as easily as standard servos)?

Personally I will rather spend around $1800 than $1600 (13% more) and then know that a servo failure is unlikely. Of course if the whole setup where only $400 (which unfortunately it is not) the
story will be different.


/RCfun

Buying *first heli* or first car, first camera... or anything first... is difficult. When i bought my first (rc) plane, I was not sure at all if it will become my hobby. But it did.. So the first kit went to trash bin and the second one was more pricey.

Now when I started playing with helis, I was very confident that yes, this hobby will and the kit is not going to collect dust on a book shelf

..And so I bought what ever I thought would serve me well in long term.