What size servo do I Need?

This video answers more e-mails I have received from fans. How big does my servo need to be?
The torque calculator mentioned in this video was created from the formulas located in the AMA LMA program document 520-A.

[@Scairborne66]

You're the best!

[@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.

[@Yogenh]

You give us so much information that is so helpful

[@dcabrick]

Fantastic servo math! Thanks!

[@dagtheaviator]

Very welcome! Rock ON!

[@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.

[@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

[@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 .

[@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.

[@chiragjadhav8819]

Hello sir. From where can I get the spreadheet ?

[@dagtheaviator]

[e-mail]