Espritmodel.com Telemetry Radio
Reply
Thread Tools
Old Jan 09, 2013, 11:19 AM
"RC ADDICT" in Toronto!
wollins's Avatar
Toronto Canada
Joined Aug 2004
1,688 Posts
Discussion
Elevator servo torque vs rudder servo torque

Everything else being equal ... what requires more torque in a plane? The rudder or the elevator? My gut says that the answer would depend on the "type" of flying in question, (eg 3D flying vs a warbird?) so since I'm building a warbird, let me put it this way ... what requires more servo torque in a warbird? The rudder or the elevator?

Thanks!

Colin
wollins is online now Find More Posts by wollins
Reply With Quote
Sign up now
to remove ads between posts
Old Jan 09, 2013, 11:36 AM
Registered User
richard hanson's Avatar
United States, UT, Salt Lake City
Joined Oct 2007
6,491 Posts
If you are keeping everything to scale and you know how to make the surfaces hinge freely with no resistance to movement - yet no slop- then use same size servos unles you are steering the tailwheel with another servo.
Don't skimp!
I build scale/warbird/IMAC and little stuff and the only cases where a really heavier duty servo is necessary is on the 3D stuff with big rudders.
Lots of 3D flyers are constantly wagging the rudder and the highest load on a servo is during quick direction reversals -- You can proove this with a meter in the circuit. You are effectively stalling the servo over and over
richard hanson is offline Find More Posts by richard hanson
Reply With Quote
Old Jan 09, 2013, 12:40 PM
"RC ADDICT" in Toronto!
wollins's Avatar
Toronto Canada
Joined Aug 2004
1,688 Posts
Thanks Richard, I guess the reason for my question is that in this particular application that I'm using it on, (20lb Typhoon) I have the two servos that are both basically overkill for either rudder OR elevator.

However one of them does produce more torque than the other so I just wanted to know which surface I should use the more powerful one on ... rudder or elevator?

Colin
wollins is online now Find More Posts by wollins
Reply With Quote
Old Jan 09, 2013, 01:38 PM
Registered User
richard hanson's Avatar
United States, UT, Salt Lake City
Joined Oct 2007
6,491 Posts
On that size model - I would want std size servos - to have min 90 in oz - speed not important.
This size servo typically has stronger gears -and if all works smoothly the servo will never be taxed - which means it should not overheat or fail
Last year, a DA50 powered P51 with retract/flaps etc., that size, for a friend - used 140 in oz at 6 volt servos on everything.
battery power was A123 2300ma -
the idea is to have lots of overhead - that is the servos and batteries are never taxed . This was a model using a 2.4 radio system- - Lots of work in a good scale project - skimping on radio and power just isn't worth it.
richard hanson is offline Find More Posts by richard hanson
Reply With Quote
Old Jan 10, 2013, 06:01 AM
Proud to eat Kraut ;-)
Julez's Avatar
Germany
Joined Dec 2003
5,195 Posts
I would always put the stronger Servo on the elevator. If this one stalls, you have a problem. As stalled rudder is no problem.
Julez is online now Find More Posts by Julez
Reply With Quote
Old Jan 10, 2013, 07:54 AM
Red Merle ALES
Curtis Suter's Avatar
United States, Mt, Helena
Joined Apr 2002
5,294 Posts
This link may be of interest to you.
http://www.mnbigbirds.com/Servo%20To...0Caculator.htm

Curtis
Curtis Suter is online now Find More Posts by Curtis Suter
RCG Plus Member
Reply With Quote
Old Jan 10, 2013, 08:46 AM
Detroit 2-stroke junkie
1320fastback's Avatar
USA, CA, Oceanside
Joined Jul 2008
3,168 Posts
Does the rudder also have a steering linkage?
1320fastback is offline Find More Posts by 1320fastback
Reply With Quote
Old Jan 10, 2013, 11:27 AM
Ascended Master
Sparky Paul's Avatar
Palmdale, CA
Joined Oct 2000
13,353 Posts
Quote:
Originally Posted by Julez View Post
I would always put the stronger Servo on the elevator. If this one stalls, you have a problem. As stalled rudder is no problem.
.
If the plane has ailerons....
Had a rudder servo strip while it was way up there.. and only elevator and motor on the plane. Careful stalling and motor running got it back to land at my feet.
Sparky Paul is offline Find More Posts by Sparky Paul
RCG Plus Member
Old Jan 10, 2013, 10:48 PM
"RC ADDICT" in Toronto!
wollins's Avatar
Toronto Canada
Joined Aug 2004
1,688 Posts
Quote:
Originally Posted by 1320fastback View Post
Does the rudder also have a steering linkage?
Yup
wollins is online now Find More Posts by wollins
Reply With Quote
Old Jan 11, 2013, 04:00 AM
Registered User
Joined Oct 2004
2,713 Posts
Is the steering linkage spring limuited? A rough landing with the rudder deflected could well strip the servo or linkage if it was not allowed to deflect somewhat.
Brandano is online now Find More Posts by Brandano
Reply With Quote
Reply


Thread Tools

Similar Threads
Category Thread Thread Starter Forum Replies Last Post
Help! Bixler Servo rudder elevator problems svenvwier Beginner Training Area (Aircraft-Electric) 6 Sep 26, 2012 08:44 AM
Discussion Extreme flight elevator/rudder/rudder mix 7oneWo1f 3D Flying 2 Aug 10, 2012 01:11 PM
Sold Cox / Nine Eagles 2.4ghx 3 or 4 Channel Micro RX with rudder and Elevator Servos ShokWaveRider Aircraft - General - Radio Equipment (FS/W) 0 Jul 31, 2012 01:07 PM
Rudder / Elevator / Aileron VS Elevator / Aileron control GliderGuider Electric Sailplanes 6 Jan 11, 2002 06:30 PM