I'm building a goldberg ultimate biplane from the kit, and I am wondering what servos everyone recommends. I will have two servos in the wing, one for throttle, preferably one for elevator, and one for rudder. I have a feeling I should use something with more torque than a standard Futaba 3003 or 148 servo, especially on the elevator, but not enough experience with planes of this type to know for sure. I'm also curious to see any photos of how people have mounted them.

I am just about to the covering portion on my CG Bipe. And it is my first kit but I got some good help with my local hobby store. I only have one servo for the ailerons but it is the biggest one they recommended. and of course one servo for throttle, elevator and rudder. Your local hobby store can give you good rec. on what servoes to use.
I mounted the three servos by taking to pieces of 1/2" x 1/2" balsa and attaching the servos with elevator on the left, rudder in the middle as it is a pull-pull and throttle on the right. Then these were attached just behind the landing gear supports at the top of the plane.

Hope that helps, it seems to work well so far.

One 605BB for rudder and one for elevator. Two 425BB for aileron, 3003 for throttle.

That's my set-up, but I'm cheap and don't have 3d throws.

Oops, I just read the last part of your message. I started with a 3003 on elevator, and it was very loose after eight flights.

My set-up is exactly the same as ilikeplanes.
These are Hitec servos.
605's have 77in.oz. of torque, about 30 bucks..croz

To Parkerspop:
Are you sure you want to attach those servos to 1/2" x 1/2" BALSA? I suggest you use aircraft ply or spruce.

the kit contains 1/2" x 1/2" hardwood servo mounting rails. They may be spruce or some other wood, but they're definitely not balsa. Thanks for the recommendations on the servos. Those look like great suggestions.

waagbuck:

fundamental question! what engine are u going to use?

hs-475hb all around... 76 oz of torque at 6v and they cost about $18

I'm building for a friend. He as an os 91 four stroke, but may be upgrading to the 120.

If going to a 120, Then replace the 2-56 push-rod wires for elev & rudder for 4-40 first, regarding the servos standart ones are o.k. although a 605 for rudder & elev will be a nice up-grade!

with a magnum 120 i'm using 2, 425bb for ailerons 2, 425bb for elevator 625bb for rudder and 422 for throttle. mounted rudder and elevator servos to 1/2 inch spruce toward rear of cockpit to help with balance

I use 2-56 on everything except the aileron to aileron link. I keep all unsupported control rods to a bare minimum length to prevent buckling. I see no reason to go 4-40 unless you have a buckling problem (like the aileron link I already mentioned). A 4-40 rod can easily pull a servo completely off its rails (unnecessary overkill in my opinion).

I have close to 100 flights on a CGM Sukhoi with all 2-56 controls. I have hardly any wear, much less a failure. It's your choice though.

Hi,

I run JR 911's at 6 volts (through a regulator) in my ultimate. Plenty of power, but then, I don't really 3D it. I am flying the sportsman pattern with this plane though.

while you're at it, I hope you've strengthened the undercarriage mounts and thrown away the wire u/c that comes with the kit. I ended up fabricating a kevlar/carbon u/c that's been great. I also laid up a new cowl as the plastic one didn't last long.

Its my favourite flying plane, the Ultimate.

Steve

ilikiplanes:
I already lost a nice plane to 2-56, this after a year worth of flights, since them I use 4-40 when I am looking for strong aerobatics in 120+ planes!!

I've got hs645 on the rudder-605 on the elevator and hs-77's (low profile) on the ailerons. 4-40 rods on the upper ailerons. FZ120 for power.