sillyness

My Feedback: (25)

I'm still trying to figure out what I want to do for a rudder servo setup on my 35% Extra... what are you using?

1: I have an 8611A that puts out 290oz... I can set it up with a mechanical advantage to get about 350 ozs of torque. 2.5 oz total weight.

2: I can add a second with a heavy(???) SWB rudder tray and get more torque. 5 oz + ??? for tray.

3: I can eat the 10 ozs for a Seiko Giant servo and have 1800 ozs of torque.

What should I do?

flyinrazrback

My Feedback: (69)

Hitec 5955, unless you dont like hitec. I wouldnt do the seiko, thats too much for a 35% plane (not the power, the weight), or 2 in a tray, extra weight wont hurt.

Diablo-RCU

My Feedback: (1)

I've been using the Hitec 5735 on a 35% Wildhare Extra, plenty of rudder authority for knife edge loops, very durable servo, about 500 flights, no gear slop. It's low tech at $70, but works fine. No bell cranks, 3 inch Airwild servo arm and Dubro giant rudder horns, using 60 lb nylon coated stainless steel fishing leader. Simple and no maintenance.

extratorker

My Feedback: (8)

Your putting too much thought into this. Stop worrying yourself to death about mechanical advatage,lever arm,moment etc,etc,etc. A single 8611 is enough using a 4 inch bellcrank and a 4 inch control horn,even though you wont have bevel to bevel you wont need it. Unless your flying very,very hardcore 3-D or unlimited imac you wont feel the difference. That being said I'm running 2 8611's with a tray and 4 inch bellcrank and control horn and can definitley feel the difference between mine and my buddies that only has a single 8611.

DENNIS C

My Feedback: (99)

Sillyness, i was just reading on the radio forumn that there is a mistake on the out put of the 8611a. it actually puts out 330 oz's at 6 volt's.

here's a link to the forumn.

http://www.rcuniverse.com/forum/m_3112076/tm.htm

mglavin

My Feedback: (31)

The announcement referenced in the link above will be interesting.

The retooled/re-geared/reconfigured 8611A’s may really be as powerful as Hitec’s 5955’s.

Ask someone in the know where the motor came from??? Ask about the potentiometers too...

Smokey

My Feedback: (16)

Sillyness......Your still not done? Get that thing in the air already.. 5735 with 4" arm worked for me.

Smokey

3DEXTRA

With 2 S9152 futabas I can do Knife Ed Loops.,on my 35% DA 100

sillyness

My Feedback: (25)

No... I've been out of town, and when I'm in town I spend most of my time flying my 33% Edge... too much fun.

southern_touch9

My Feedback: (3)

One poster mentioned the 5735 on the plane. I had this same setup on my 35% WH Extra ran to a larger SWB bell crank. Though it holds Knife edge fine you can begin to see the servo stall as you add power. EX: put it on its side in KE flight at 1/4 throttle and it holds great, gradually add power and watch the blowback happen right before your eyes.

sillyness

My Feedback: (25)

OK... from what I've been reading there is a difference in the power of the rudder at differing power settings and speeds. I think I'm going to go with the SWB self-adjusting tray with 2 8611s for the following reasons...

1. I want the ultimate in rudder power at all speeds and throttle settings.
2. I want redundancy... using this tray I can plug the rudder servos into opposite RXs... if one craps I keep 1 aileron, 1 elevator, and at least 1/2 of the rudder throw.
3. If a servo goes out I can at least get the rudder to center.
4. I don't have to mix servos or worry about them fighting each other.
5. I want longer servo life... if they aren't being pushed to their limits (i.e. blowing back... if you can feel the difference they are blowing back) then they should develope less heat and last longer.
6. I've heard that using 2 will actually lower current draw... they use more current to get the last bit of their power than they do to get the first bit...
7. I still don't trust some other brands.
8. I can use standard 8611s and use the 8611As I have on ailerons where they're power could be used more effectively
9. I've never used a bellcrank before... sounds like fun

Thanks for all your input.

Diablo-RCU

My Feedback: (1)

I can think of two possibilities why your plane had blowback and mine doesn't.
1. large SWB bell crank - reduces servo torque depending on your lever ratios. I used pull-pull cables with 1:1 ratio that delivered the rated servo torque to the rudder.

2. Your batteries delivered less voltage/current to the servo. I used two 5-cell 2700 NiMH packs in parallel without a regulator and using HD wiring.

If I roll my plane to knife edge at 1/4 throttle and hold the rudder and throttle up it does a knife edge loop.