Hi Dennis
I use various servos in all my models from £100 to £10.00 cost per servo. I had a very interesting talk with some of the display pilots at this years British nationals on the subject of what servos to use in models, The pilots where of the opinion that in high performance jets and Imac models (50% and up models) the use of top brand servos where used.(JR, Furtaba HiTec etc) due to the high loads on the control surfaces.we all agreed,
One pilot commented on the fact that many model suppliers push the point that you need digi servos in all models 10kg etc, however he said that before the age of digi servo he flew many models at displays on standard servos, e.g. JR 591's and never had any problems,he said that in many cases, the cause of a crash was due to the load on the batterys from big powerful servos and not failure of the servo, digi servos are power hungry!!
I buy servos to handle the loads from the control surfaces e.g is the control surface large, is the model fast, is there large amounts of movement on the control surface, etc all elements add to the load on the servo. A slow flying model with a small elevator does not need a super strong expensive digi servo.
The small B52 uses standard servos JR 591's and on the elevators i used two 16g MG servos which cost £12.00 each, great little servos and very strong and light.The big b52 will use a selection of standard servos(JR 591's) and 10kg Hitec's on the very large main control surfaces. Ali's hobbies has a good sale, at the moment,on HiTec servos e.g. 10kg digi MG servo £32.00, that's cheap!!
I also got some servo's last year from Richard at Expressfly, they where from a USA company, MG 19g servos, one the the best servos I ever used, perfect for gliders I think!!
A few ideas hope this helps
johnp
