Marcelo Assis

My Feedback: (3)

Hello Guys,
How are you?
I have one more question to discuss with you:

How many servos would you suggest for each aileron and elevator on the Aerotech 126"wingspan 40% YAK?
I am planning to use 1 JR8611A on each elevator and 2 JR8611A on each aileron, but a friend of mine who has a good flight skills is advising me to use 3 X JR 8611A on each aileron and 2 X JR 8611A on each elevator.
His concerned is about flutter at higher speeds than in 3D maneuvers.He thinks that these servos are weak at center and can cause flutter.
Is he correct?
What do you think about it?
Regards,
Marcelo
PS: I am not discussing about JR or Hitec, I am just lookin for a better choice regarding the number of servos,ok!!!!

btomlinson

My Feedback: (58)

Hi Marcelo, I would take your friends reccomendations. Two 8611a's on each elevator and three on each aileron will be perfect.
What are you planning for the rudder ?


Brian

Marcelo Assis

My Feedback: (3)

Hello Brian,
Thanks for your reply.
For Rudder i am palnnig to use the Seiko PS050.
Regards,
Marcelo

Badge

My Feedback: (21)

On Wood airplanes I always use 3 on aileron not because it gives me more power but because unlike composite airframes the ailerons will flex and if you have 2 servos 40" or so apart it leaves a lot of room for flexing in wild maneuvers. 3 gives you support in the middle. I always run 2 on elevator but that is just for my piece of mind.

40%plane

My Feedback: (1)

i AM PLANNING ON RUNNING TWO 9152 ON EACH AILERON AND 1 9253 ON EACH ELEVATOR. I DONT PLAN ON HAVING ANY TROUBLE WITH THESE AT ALL, THEY SHOULD WORK GREAT.

jsm77777

My Feedback: (4)

I am planning to use 8611a's on mine with 2 on each aileron, 2 on each elevator, and four on the rudder. I don't see the need for 3 on the aileron, but it couldn't hurt either. I alway's taper my ailerons, and on my C-Arf SuperExtra, I have 2 8611's on each aileron with no problems at all. Wingspan for both planes is almost the same, so I feel 2 is plenty, and also the 8611a's have even a little more torque than what I have on my SuperExtra. Scott

Marcelo Assis

My Feedback: (3)

Dear Scott,
Thanks for your tips.
What engine will you use on your YAK?
Marcelo

Marcelo Assis

My Feedback: (3)

Hello Badge,
Thanks for you tips.
Badge,couldn't you lend me your Russian Scheme to me?
I am thinking in cover my YAK with your very nice creation, do you mind if i use it?
Is it possible to you e-mail me this scheme?
Thank you very much.
Marcelo.
My e-mail is: [email protected]

jsm77777

My Feedback: (4)

Marcelo, I was planning a 3W-157 on tuned pipes. I have been hearing that these Yaks come out very tail heavy. Read on the other posts that with a 3W-200 it balanced just right. With the 157 being 3 or 4 pounds lighter, I would need to end up with a lot of lead needed for balance. I am now thinking of the 3W-212. If I need weight in the front, might as well have the power. I heard of the 3W-200's having crankshaft problems, so I think I will stay clear of that engine. I also was thinking of the DA-200, but it's not that powerful. So, it's still up in the air. Scott

Aerotech

Hello,

So far our Yaks have not been overly tail heavy. Our prototype wasnt with a 150 with Pefa cannisters. The customer on our site with the Red Bull YAK is running a 150 on cannisters without additional weight.

Thanks

John

www.aerotech-rcmodels.com

jsm77777

My Feedback: (4)

Sounds ok John. Just wondering on the one built in California with a 3W-200, and it balanced on the wing tube. That is a heavier engine than the 150, so I am figuring it was very tail heavy. My C-Arf 3.1 SuperExtra came out tail heavy too, and I needed to add almost 2 pounds to the front of the cowl to get it to balance. I don't want to do that again. Although it's still just under 40 pounds with cannisters. I know this Yak will weigh more, and if I need nose weight, I'd rather add engine than lead. Scott

Marcelo Assis

My Feedback: (3)

Dear Scott,
I have one 3W 200 B2 TS and it is the best engine that I had until now.
I think that you should call Gerhard from Aircraft international and ask him about the crakshaft problems that you have heard.
I will fly mine with the 3W 200 and incowl mufflers.
Regards,
Marcelo

Badge

My Feedback: (21)

Those alleged problems came out like 3 years ago and nothing ever came of it. I wouldn't hesitate to buy that engine if its what you want.

jsm77777

My Feedback: (4)

Well, this is good news. I did talk to one fellow that had 4 of the 3W-200's, and no problems also. I guess sometimes the things that happen in the past, get blown out of proportion. For me the 3W-200 would be ideal for this Yak, and now I will look into it further. I will have to decide on what type mufflers to use. I do want to keep noise down, and I have not been totally happy with the cannisters on my QS 150, so I am leaning to tuned pipes. The extra power wouldn't hurt either. In cowl mufflers would be simpler, and lighter, but noise will be an issue at my field, (and at all), in the future. Looks like the 3W-200 on pipes, and I am leaning towards three servo's on each aileron now. Scott

newshoundaussie

My yak actually balances about 3/4 of an inch ahead of the tube, with da 150 and Dalton cannisters. I have 2 8611's on the elev's total, one per half. The 2200 Duralite is on the engine box for the ignition. The plane John and Tony built is not tail heavy! Using 3 8611's in the new SWB tray with the cable system in the back bay. Also power box and receiver just behind the wing tube on a tray. Two 4000 duralite packs are over the wing tube. Also two 8611's per aileron. It's a floater compared to my 27% extra and 27% cap232 both with DA 50's. Also using one inch standoffs from Litepilots on the DA, this could be a factor, plus 6 inch p51 spinner with light backplate from Tru Turn.

Marcelo Assis

My Feedback: (3)

Hello Newshoundaussie,
How is the flight carecteristics of your Yak?
Aren't you concerned about flutter on elevators, using just one 8611 per each elvator half?
How is your flight style do you perform 3D or just precison flight?
I am just asking these question to decide how many servos on elevators and ailerons I should use on mine.
Thanks a lot.
Hope to hear from you soon.
Marcelo

jsm77777

My Feedback: (4)

That is good news to hear. Adding 2 extra servo's on the stabs would add about 6 more ounces in the tail, which will mean another pound or so in the nose. After hearing that, I am planning to go back to the 3W-157 twin spark on tuned pipes. I think I will be able to shift things around to get it to balance without needing nose weight. I will also lighten the rudder before sheeting to save a little there. Every ounce in the tail is around 4 ounces in the nose. I am thinking 3 8611a servo's in each wing, and 2 8611a servo's for each stab half, and four on the rudder. I know several guys flying 40% planes with just one elevator servo with no problems. I still use 2 as it makes me feel safe, and is makes the elevator feel much more solid. Scott

Marcelo Assis

My Feedback: (3)

Dear Scott,
I haven´t sen any 3W 157B2 Ts running yet, but my 3W 200 B2TS runs extremely well, it is very powerfull and as I have told before is the best engine that I have owned until now.
Another issue to think is about the price, I think that the 3W200B2 is cheaper than the 3W157.
In your position I would go for the 3W 200 B2 TS, you can´t imagine its power.
Take your time.
Marcelo

jsm77777

My Feedback: (4)

I am still thinking about it. There seems to be still some reliability issues with some users. It may not be wide spread, but it is something I think about. The 157 is turning in some real great power numbers. It may end up being just as strong as the 200, which I hear isn't as powerful as it should be for a 200cc engine,(and neither is the DA200 for that matter). If I hear more people telling me that they are not having ANY problems with the 200, I may end up going with that. But for now, I am leaning toward the 157, as it would be useful for me to use on future projects also. If I need that kind of extra power the 212 seems to be the engine, albeit it's almost 2 pounds heavier. I know this plane is going to end up near the 44 pound mark, so engine choice on this one is tougher. Scott

newshoundaussie

This was the setup suggested by John. Can't see it being a problem for IMAC flying. Don't think flutter will be a problem! Just make sure of slop free linkages and sealed hinge lines.

flyinrazrback

My Feedback: (69)

jsm, what about the zdz 210, it has real 200cc power, but the new 157 is no slouch.

Aerotech

Hello,

If I was going to buy a 3W from Cactus. The 157 would be my first choice. I had a 200 and they have power but I think the 157 will the best deal with MTW cannisters or Dalton cannisters. The Yak is draggy due to the cowl/front end, but with the wings and stabs we did the plane floats or creates lift so at 40lbs or 44lbs with 200's or 210's it flies equally as well. I can't wait to see the pics as you guys get them done.

Take Care

John

www.aerotech-rcmodels.com

flyinrazrback

My Feedback: (69)

I do not like the 3ws on the MTW cans, they seem to have a flat spot in the middle of the power band, the 3Ws thrive on the KS 1090s, another pipe to consider I hear great things about are the BMB pipes from Germany. They claim a bit more power than the KS system, and a better top to bottom throttle response, 3oz lighter than the KS, and a little cheaper, I may try them on another project since I already have 1090s for my 157 TS.

Supermod56

My Feedback: (36)

The 200's did originally come out with weak cranks, but they came out with a new beefier crank and AI installed it in mine N/C under warranty. There has been reports of it not having the power it should, but mine runs great, get right around 6000 RPM with both a 34X12 2 blade and a 31X12 Triple on PEFA Cans. It weighs exactly 10 pounds, so if my Comp ARF Super Extra is tailheavy like I am hearing they are, the 200 will go in there, but I don't know yet. If it isn't, the 157 will go in the cowl, and the 200 on a big Yak or Bipe. To answer the original question, I would run 3 servos on the ailerons and 2 on each elevator.

Tom

jsm77777

My Feedback: (4)

I have thought about the ZDZ, but I would like to stick with 3W. I have had great luck with all 10 I've had over the last 10 years. The 157 will be my first choice with KS 1090 pipes, as I'm not a real fan of the flat spot in the cannisters. I am also looking at the 3W-200 also, as I think it would be ideal on this plane. I am still leary of it's reliability, but the more I hear others using it with no problems, the more I am considering it. I would also run that engine on pipes if I can. On my Comp-Arf 3.1 SuperExtra, the 200 would have solved my tail heavy condition, so if nose weight is needed, and it will be with 4 elevator servo's, the 200 is a good choice. This is a good forum with good information being passed along by all. Scott