Aircraft Balance Calc.
Basic Model Calc.
Unit Conversion Calc.
Gas / Oil Calc.
CG Calculator
MAC Calculator

 This web site is designed for 800 x 600 screens with 16 bit resolutions.

It's best viewed with
   Best Viewed With MSIE 3.0!
   Best Viewed With Netscape 3.0!
 Click Here To Start.

R/C Modeling Logo
On-line Calculator

 
[ General tips ] [ Construction Tips ][ Engine Tips ]
[ Alternative Materials ][ Calculators ] [ Check Lists ] [ Charts ] 


{short description of image}

I can be reached at rcmodeling@gmail.com. Please feel free to contact me so we can talk about one of our favorite hobbies!

{short description of image}
Many times it is difficult to find the proper conversion routines to build your aircraft correctly. This area will be used as a glossary as well as a link to different calculation routines!
{short description of image}
Servo Torque Calculator

This is neat little calculator to assist in determining servo torque requirements for various sized planes. It allows you to determine simple servo torque calculations, to complex calculations in situations where there are offsets, differential, unusual control geometry, etc. The parameters you can use and modify allow you to calculate very precise torque requirements if you had the time. Once you input your parameters, it will print a detailed table of the torque requirements at various airspeeds and control surface deflections. The simple calculations are, well, simple, and meet most peoples needs. However, for the possessed, you won't be disappointed either.

You can download it here. Its a Excel 5.0 worksheet.
Created by Craig Tenney

This spreadsheet predicts required servo torques
using the following assumptions:
  1. The angle of attack of the wing, stab, or fuse is zero (relative to the airflow).*
  2. Angular velocity and acceleration of the aircraft is zero.
  3. Air flow may be modelled using the concept of dynamic pressure.
  4. Conditions are: sea level, zero humidity, moderate (~55 F) temperature.
  5. Control linkages have zero offset at hingeline and are perpendicular to horns at neutral.**
  6. Control mechanisms are frictionless and surfaces are mass-balanced.
  7. The wing, stab, fuse, and control surfaces are thin, flat slabs.
  8. No aerodynamic counterbalances are used. (Account for these manually, if desired.)
  9. The pushrods are significantly longer than the servo and control horns.*


    10. * This assumption dropped in "ServoPlus" worksheet.
    ** This assumption dropped in "Offset & Differential" and "ServoPlus" worksheets.
Please note:
  • The calculations are completely theoretical. No empirical "tweaking" has been done.
  • The assumptions (except #6) should generally yield conservative (high) predicted torques.
  • Extreme control throws are probably not practical at high speeds.
  • This model is best used for comparisons.
  • No guarantees are made of its validity.
  • Maximum required servo torque may occur at LESS than maximum throw.
The mathematical model: "t = (AMPC2LV2) / (4RT)" where:
t = servo torque
A = sin(S) * tan(S) / tan(s)
      S = control surface angle from neutral
      s = servo arm angle from neutral
M = molecular weight of air (~28.6 g/mol)
P = air pressure (1 atm)
C = average chord length of control surface
L = average length of control surface
V = airspeed
T = air temperature (~290 K)
R = ideal gas constant (82.056 atm cm3 / mol K)
{short description of image}

Developed by Geistware of Indiana© ., 1999.
Updated October 1, 2006

Top