What size servo do I Need?

[@axelsmith209]

I don’t think I actually thought about the ratio when I set up my control rods to my control horns in consideration to how much more the servo could put into torque. This is awesome man I would never have even the slightest thought about it 😂

[@rzxhandsome]

Hello there! I was wondering if you could tell me where I can find these formulas, since I didn't find it in the AMA LMA program document 520-A.

[@dagtheaviator]

Its on page 19 Section 3: Servo Torque part a) Minimum torque = A *Chord *Span * Chord/3 * Servo Arm/Control Arm. A = Airspeed Factor (see Table 2.1) Chord = average control surface chord (root chord + tip chord) / 2 Span = control surface span Servo Arm: the distance from the center of the servo arm to the control linkage attachment. Control Arm: the distance from the hinge line to the control linkage attachment.

[@Scairborne66]

You're the best!

[@Yogenh]

You give us so much information that is so helpful

[@dcabrick]

Fantastic servo math! Thanks!

[@dagtheaviator]

Very welcome! Rock ON!

[@charlesmyers9765]

Hey Dag, id like to have that calculator!!

[@RC-Flight]

Thanks for the great video and info! Would you be so kind to forward the spread sheet I do t know how too contact you other then with a comment.

[@dagtheaviator]

Hello, send a e-mail here- [e-mail]

[@anarpearls9785]

So helpful. Thank you. Please also help understand the impact of receiver to servo cable length on servo performance for giant rc airplanes. When you get to like 2meter+ on cable length, does it result in significant voltage drop that the servos may not work. If you address this any of your videos, please do share the link. Would help a lot as I can't seem to find this anywhere. Much appreciated

[@Desertduleler_88]

I was thinking about this when l begin to start building my 1/3 Lazer from Lanier, which according to them l require 70oz servos. I feel that this isn’t enough by modern standards as this kit was from the late 1980’s early 1990’s.

[@vishalanreddy4333]

HI there, great video!!! Just wanted to know if you would be able to say what simulation software you used ?

[@dagtheaviator]

Its a excel spread sheet I made.

[@chrismanning1171]

I am new at building RC airplanes. I am building a twin 90mm SU37. It has a wingspan of 1200mm and a length of approx 1700mm. It weighs about 13lbs to 15lbs with lipos. I am using spare parts to build it. The elevators each have a servo that I got out of a Freewing Stinger. Seeing the size, weight, and speed I don't think these servos can handle it. Can some please make a suggestion of what servos I should use? Thanks

[@dagtheaviator]

Can you tell me the length and cord of the right elevator? Width and length? And what you think the max speed would be of the aircraft? I can figure it out. Thanks.

[@chrismanning1171]

@@dagtheaviator Thanks for the response. I did a little research and I ordered 30g servos. These servos are used on a Freewing twin 80mm edf MIG 29. It is about the same size and weight of the twin 90mm plane I am building from scratch.

[@BrainDeadEngineering]

This outstanding brain food ! Helped me . Are you a quantum mechanic ? I always wonder how the China built big scale foam planes get away with always using 9 g servo all over . Agree ..what are they thinking .

[@chiragjadhav8819]

Hello sir. From where can I get the spreadheet ?

[@dagtheaviator]

[e-mail]