are 61 oz of torque servos enough for the Funtana 90. if not whats the recommended amount of torque

AHHHHH NOOOOO.....90 OZ more better...METAL GEAR !! DON'T HAVE TO HAVE DIGITALS

Don't forget the only thing keeping those big control surfaces from blowing back or fluttering are the servos !! they are the muscle of the plane

Per instruction manual yes but many people believe that the Funtana needs to have much more than that. As for my Funtana it has about that with FMA direct metal gear digitals. I believe it is more important to have no slop linkages and good holding power on the servos. as long as you don't plan on ripping your Funtana through the sky at WOT then I wouldn't worry about it to much. Plus my Funtana is way over powered carrying 3.5 horse and I have not had a problem with flutter yet just watch your speed the Funtana does not need to be going fast to perform any aerobatic maneuver. The only thing I can say is that it could use just a little more on the rudder.

Photo taken by Greg Cardillo at the NEAT Fair 2005.

Funny thing is look at the H9 instruction manual for the Showtime 3D--they are recommending a lot more servo now.

If you set it up with true 3D rates and want to slam it around make sure you have MG servos with at least 90oz. (no minis)

My F90 will KE loop clockwise, but not counter clockwise. It is no where as strong on its side as the Yak or Fliton 330. It is a ton of fun to fly though and I don't mind going low with it. [sm=lol.gif]

I've been using nylon HS545's (61 oz @4.8v) everywhere but the rudder for several months with no problems. I went with a 635HB (karbonite, 69oz) on the rudder because of the added stress of the tail wheel vibration. Although I just upgraded my electrical to 6v LiPo so the 545's now deliver 76oz.

We went through this repeatedly on the Funtana main thread. Nobody that said you need more was ever able to back up their statements with real data. Maybe someone can here...

Clark

Had 90 oz on my U Can do 60, hovered and knife edged ok. Had a spare JR8411 280 oz and stuck it on for grins. Yiiips. Yea, now knife edge loops and a fun part, knife edge hovers. A real crowd pleaser. Now if i could just get it to torque roll!

Hmmm.... That's getting closer to "real" data I suppose. Still very subjective...
Clark

I agree 60 oz. is not enough. There is a lot of force when you are using full 3D throw and engine running wide open. I say .90oz or above. Be on the safe side.

As a matter of fact right now I have a elevator servo that is failing on me power wise and it is rated at .94oz. I first noticed when I was on ground and ran engine to full throttle and pull full elevator. I seen that my right elevator half was laying down. I would back off throttle and it would raise up to normal position. I dont think it should of done this, so guessing I just got a hold of a bad servo because it is not all that old.

Not that I fly full speed and yank it around. But doing 3D flying slow there is still a lot of strain on the servos depending on what you are doing. Especially those short burst of full throttle can be hard on them.

That's not enough. I'd go double that. Also you need to set up the linkage properly. You want to have the best mechanical advantage possible while still having enough throw and speed.

IMO, the best route is hitec 5625's all around, 5645 on rudder, PLENTY of torque for this plane, and they can be had very cheap over at www.servocity.com ... the best part about the digitals, is that if you get your hands on a programmer (someone around is bound to have one you can borrow once) you can fully maximize the endpoints, which allows you to achieve maximum throw, while maintaining good mechanical advantage...

This is soooooo funny. Does anyone have real data to back up these recommendations???

How do we actually measure the forces on these control surfaces? Until someone does that...

Clark

FallingWithStyle,

It depends how you fly in my opinion. Also what type of engine you are using, with a Saito 100 on it is not really strong enough to do much harm I think. Thats a pretty mild engine for that plane. As for me I am rough and have put a beating on my servos. Some people like to fly with the bare minimum and say it works fine. I rather be on safe side. This is our hobby so why take chances on something you enjoy so much. I would like to pack my plane up at end of day and take home in one piece, well 3.

I tell you what I will send you that servo that is failing and you put it in your plane and fly with it. When you crash take nice pictures of it for real data and post on here. From here we can see how funny it is.

agreed...with a Saito 100... standard servos are enough... but anything more and you are going to get flutter and definite blowback...

example...

I had a .60 size plane that just would not KE....... I upgraded the rudder servo to a 5645.....and now the plane will HAKE the length of the field...
I thought it was the plane, but it was the servo not able to hold the forces....
not "hard" data... just my real world experience

My dad had a cap 232 with an os 120 supercharged that would hold knife edge ok and after replacing the servo in the rudder he could almost knife edge loop it... Although it was a cap and would snap unless you where really moving. now it has been replaced by the QQ yak 54 and that is one sweet flying airplane!!

Cute

OK, so KE ability is being used as a yardstick... I can do a KE over the field OK, in fact I have trouble not tipping it over the top when I do it. KE loop? I'll need a stiff drink before I try that but I can get back to you maybe after the weekend. Should I take "before" pictures?

BTW, do we all agree that it seems like the rudder servo is the one being the most stressed for this plane?

Clark

I agree with rudder servo being stressed out a bit. That is only one control surface to control entire plane. On mine I removed the stock rudder and replaced with a longer one with more surface area. So far so good. We shall see what goes first, the servo or rudder.

As for the ailerons you really don't need a ton of torque out there. Once you give input it goes in that direction. Unless you are in a flat spin. Now for the rudder and elevator they need strong holding power and torque. Digitals work well there because of the better holding power but not a must have. Just something nice have the get the most out of your plane. Mainly the rudder then elevators next. Flying normal the elevators are not really under much stress. But doing waterfalls where you hit throttle wide open for a second to get tail over then again to repeat there is some torque needed. Snap rolls or tumbles on 3D rates can be stressful also. A good reason why there is a carbon fiber rod in tail. Without them the horizontals would break.

My Funtana does pretty good knife edge with the servos I have got in it right now I would say it could be a little better but it climes out knife edge. have not done a KE loop with it yet though to much coupling in every direction I think that is partially due to the large TnT graphite landing gear I have on it for prop clearance on the 20x11 lol It makes it tuck to the gear really bad and it rolls out as well... its partially because the Funtana does not had allot of side area.

Take some pictures before and after so we know if it worked or not .... the pictures will speak for themselves ( one piece = it worked ... pile = things didn't go as planned)

I agree the rudder servo is the most stressed on the Funtana

Heck the F90 can be flown with servos like the Airtronic 102 or Futaba 3003s even. The again you will be flying it like a trainer! I used 645s and 6545s in mine and its more than enough. If it will be full 3D flying then you will need MG servos for sure. That is a must.

Yea, the rudder is fairly large and only gets 1 servo, i'm running a 5645, and it feels like I'm getting a little blowback, something to do with my pull-pull setup, I need to work on that I think this servo @ 180oz on 6v has PLENTY of torque and holding power

Regaurding your last post, When I was first looking for servos, I was looking for the same thing, who really knows exactly what we need? But when I saw the prices on the 56X5 hitecs, roughly 40-45 in a big flight pack while they were on sale, nothing else comes close for bang/buck, they have way more torque than H9's requirements, and there is no reason to go to a lesser servo, prices don't go down that much...

edit, my error, 5645's are 168oz @ 6v

It's true you don't need a lot of torque to move the ailerons, especially if you are flying slow and gentle. But these are the scarest servos to me. Because that is where all the flutter on the F90 starts. If you happen to overspeed somehow (like give it some throttle or go down) the standard servos are in danger. The servos on the ailerons are not just for control but for reduction/prevention of flutter...loss of parts...loss of control...Loss of plane.

I think this plane needs at least 90 oz servo. Over a 100 up to 125 is better. It begs to have better servos.

Thanks
Barry

Everything here about sums it up; don't skimp on servos! Although linkage geometry and just plain airframe failure (older version Funtanas) can cause flutter, the servo can also be where it starts, ie, sloppy servo gears, output arms, etc. If you do get the mechanical advantage right with a lower torque servo, chances are that you will not flutter, but you will instead have blowback and will likely not have enough throw for true 3D.

One example would be my 27% Edge. When I had a 120 oz. in. servo on the rudder, authority was marginal at best. If you let it come out of a torque roll in a slight K/E attitude, it was impossible to bring it back. Knife edge was marginal and it did not lock into rollers very well at all. That servo eventually stripped on takeoff (it was even metal gear) and I almost lost the plane to it. (I'm repairing the servo now to put it in something else)

But, once I installed a 180 oz. in. servo, it is a totally diffrent plane. It locks into K/E very well (except for the bad coupling), locks into any kind of roller very well, and will even pull off a double hammerhead. (Two consecutive stall turns)

So, the lesson learned is, do not skimp on servos; they do not have to be digital-although that is a big plus- just a good amount of torque and metal gear if you can.

Hope this helps,
Brandon

I have 2 Funtana 90's. Both are overpowered, one has a Saito 1.50, the other has the Saito 1.80. The one with the 1.50 has Hitec 5475 servo's with karbonite gears, the other has 5625's with metal gears. Neither has ever given me the least bit of trouble & flutter has never been an issue. Both will do knife edge loops so I don't think blowback is an issue & I have never stripped a gear in either one & both have had gallons & gallons of fuel through 'em. Whatever power the 5475's are, it's enough.

What I did do though is replace the cheap nylon control horns with some dubro's with ball joint ends. Having ZERO Slop I think is far more important then having $100.00 servos in your plane.

You are exactly right about that. I forgot all about the flutter issue. Good point!

I never had that happen but have seen it many of times before. A brand new plane go down because of cheaper servos in wings without metal or carbonite gears. Even though they argue the servos have toque in wings the right gear combination in them are a must.

Exactly right!

I think the most important thing about servos in the F90 is to get MG ones, we had one guy maiden his F90 and the nylon geared servos on both ailerons stripped. Guess he was pushing the plane a little hard and it was not caused by flutter, MG gives you some peace of mind. Like everyone else says, you don't need 350 oz servos for this baby.