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[tassie48]

Hi Crew my new PROJECT PCS WW2 has twin rudders a new experience for new my question is in the set up of the linkages to the servo ,both are linked together then a single arm to the rudder cable to  the servo , having not done this before is the arm in board ie tween the rudders or out board I have plenty of room trying to get the most throw area , rudders are in full bearing collars oil filled way over size in side the hull 8 mm shaft with a bottlescrew adjuster between the rudders  should I need to adjuster etc in the future, any and all help much appreciated tassie48

[RST]

Hi Tassie, have you looked at any model build blogs with twin rudders?
...when I see it written like you did it seems very compicated to how it should be in reality. It should be pretty simple unless you can share some pics that make it it akward and explain the difficulty?
Rich

[BrianB6]

2 different ways I have done it.   Both work well   

[Circlip]

Oh the joy of ball couplers for slop free linkages. And don't forget closed loop.


  Regards  Ian.

[Stan]

This my rendition of twin rudders. Brass niples from SLEC model supplies

[John W E]

hi there


Here is a closed loop system for just for good measure.


John

[tassie48]

Thanks Crew get the idea now lots of great ideas to help me out much much appreciated, now will work out what will work the best for me , absolutely great getting help on a new project again many thanks for the input regards tassie48

[derekwarner]

From a mechanical aspect, the closed loop 'push-pull - double arm on the servo' as John WE shows has balanced moments and is superior to the open loop 

[JimG]

With the normal sized rudders we use and the limited movement the closed loop linkage has little actual advantage over the usual single link, especially if good sized rods are used (at least 2mm ) with good linkages to the servo arm.(Clevices or ball links). It can also have a disadvantage if you don't make sure the servo arms and the rudder horn are the same length as if they are different it can cause strain on one of the rods when at full deflection. I regularly use a closed loop linkage on aircraft using flexible cable, in some cases it has been known for one of the wires to become slack at full deflection even though they are both tight when centered. Not a problem as aerodynamic force keeps one tight when the rudder is deflected although it could cause rudder flutter in disturbed air.
Jim