Hi
I had a 1/3 busa sopwith for several years it flew on the standard JR servos(5kg torque I think at 6v) since then ive built a 1/3 GTM fokker dr1 flown on standard servos again (but rudder did strip so upgraded it) and bought a friends 1/3 Camel which actually had those towerpro 15kg metal geared jobs. (Reviews of these say vibration will eventually kill them as the wires inside are not secured - I looked and it was true - whipped them out)
My two penneth on WW1 biplanes being flown in a scale powered manner ( i.e. your not sticking a 150cc petrol engine into a 1/3 sopwith pup and prop hanging etc )
I always use 6v batteries (for the extra torque it gives on the servos) and I use two 6v batteries each with seperate switch (so one fails the other is failsafe)
These days, I worry unless the servos have a minimum of 6kg of torque at 6v. So to be 'safe' i go for Hitec HS645MG High Torque, Metal Gear (9kg torque at 6v) More expensive but if I sell the model the servos stay with me for the next one.
I think its a good investment to go with the HitecHS645 or futaba equivalents. Almost certainly overkill but worth it for the peace of mind.
Last edited by Alistair; 09-29-2016 at 03:02 AM.