ORIGINAL: siclick33
if you use half you only have half the strenght!
Is that true?My servo specs only give one torque figure, not one for half travel and one for full travel.
If you can get full flap travel with the linkage on the inner servohornhole then,IMO,reducing travel doesn't reduce strength. If you are notusing the inner hole,and increasing travel enables you to useto do so,then Iagree there is a strength benefit.
EDIT: This assumes that your control surface horn is a fixed length or already on the outer hole.
Keith, you're perfectly right and I would like to add a small thing.
The quote above is just to outline a small misconception:
The torque given for a digital servo is independant of the position of the servo arm. HOWEVER what is important for us is the torque LEFT AT THECONTROLSURFACE.
A servo torque of say 110 oz/in can become 30 oz/in at the control if the mechanical advantage law is not observed as explained above by Keith. So taking the best servos on the market is totally useless if a proper setup is not done.
This point has been already largely discussed on the FEJ F-18F thread where the elevator system is far from optimal.
It resulted in a very interresting "non mechanical" setup that optimizes the mechanical advantage on a pull-pull system. Look at Idleup1 posts on this page:
http://www.rcuniverse.com/forum/m_77...40/key_/tm.htm
http://www.modelaircraft.org/files/520-a.pdf
page 3 and 4
Here is a fantastic spreadsheet to compute leverage, servo torque required and much more by Craig Tenney ( once again, hat down to you Craig ):
http://www.geohei.lu/olin/data/model...calculator.xls