Swept Back Rudder Control Linkage Best Practice

[Capt Kremen]

Couldn't find my good old 'Radio Modeller' books illustrating installations to look this up or find a suitable thread on here ...

Scenario: A swept back rudder control installation

e.g. a Red Arrows Hawk jet has an angled rudder hinge line like ' / '

If using a push-rod connection from the rudder servo:

(A) What sort of control horn would be best to fit to the rudder, a '90 degree' or 'swept forward' one and in which orientation?

(B) Servo Arm or Disc with a conventional clevis or is a ball-link clevis better - see 'C'

(C) How to allow for the 'rise' in push rod travel as the rudder deflects?

Would a ball-link be best?

(A closed-loop set up or installing the servo at an angle in the tail is not an option in this case).

[Geoff S]

The RM book recommends three possible solutions:

1: Use a snake angled to be normal to the rudder pivot. They actually say a tube/cable pushrod rather than a snake and didn't seem very keen on the idea. Perhaps snakes weren't available in 1975 when my secondhand copy was touchingly gifted to 'My dear Arthur' at Christmas.

2. A nylon horn scewed onto a through bolt which is free enough to turn as the control is applied.

3. A ball joint but it points out that the exit slot needs to allow for the rise and fall of the push rod which will be at rightangles to the hinge.

I picked my copy up at a local secondhand bookshop in Cromford several years ago for £2. Despite its age there's still a lot of useful information and it's interesting to read about older radio systems and reflect how lucky we are now with modern computer sets.

Geoff

[Former Member]

[This posting has been removed]