logo
Thread Tools
Old 07-27-2019, 10:49 AM
SBrock is offline
Find More Posts by SBrock
Registered User
United States, TX, Frisco
Joined Nov 2007
4 Posts
Discussion
Control Surface/Servo Resolution

Guys, setting up a new plane for IMAC (no 3D at all) and have a question on surface throws/servo resolution. Have programmed the Hitec servos for end points and centering, also happy with the mechanical setup (short servo arm, longer control arm). Also set the DX9 TX at about 140 for initial travel setup. Iím getting about twice the control surface throw that I want and using the dual rate function its taking about 50% to reduce it to what I want and Iím not clear if Iím losing servo resolution doing it that way. Could get a little reduction by changing the mechanical setup but not near enough.

So the question is, what is the correct/best way to solve this and keep servo resolution high? Reset the servo end points with the programmer? Use the TX end point function and reduce the throw that way? Thanks in advance for feedback.
SBrock is offline Find More Posts by SBrock
Reply With Quote Quick reply to this message
Sign up now
to remove ads between posts
Old 07-27-2019, 11:56 AM
BarracudaHockey is offline
Find More Posts by BarracudaHockey
Multi Platform Pilot
BarracudaHockey's Avatar
United States, FL, Jacksonville
Joined Dec 2007
9,673 Posts
Shorten the servo and control arms
BarracudaHockey is offline Find More Posts by BarracudaHockey
Reply With Quote Quick reply to this message
Old 07-27-2019, 12:00 PM
Festivus is offline
Find More Posts by Festivus
I fly 12 months a year
Festivus's Avatar
United States, TX
Joined Jul 2017
923 Posts
I think it's shorten the servo arm and length to control arm will reduce how much surface deflection you get which will add resolution to give precise flying control
Festivus is offline Find More Posts by Festivus
Reply With Quote Quick reply to this message
Old Yesterday, 04:04 PM
wingtwister is offline
Find More Posts by wingtwister
Registered User
United States, NC, Greensboro
Joined Jun 2013
4 Posts
Shorten the servo arm as short as possible (I use 1/2") and then lengthen the surface distance from the hinge line if necessary. Usually that gets me in the ballpark for elev, ail take 3/4" servo arm, 5/8" for rudder. I shoot for a minimum of 3:1 mechanical advantage on the linkage geometry. I run servos in the 120% range max. The only reason for the larger ail and rudder deflections are to accommodate snaps and such. For regular sequence flying I use in the 70%-80% range with lots of expo.
wingtwister is offline Find More Posts by wingtwister
Reply With Quote Quick reply to this message


Quick Reply
Message:


Currently Active Users Viewing This Thread: 3 (1 members and 2 guests)
crfabbro
Thread Tools