RE: Do I need a servo programmer for digital servos
There are many factors here and the statement that all digital will do this unless you use PCM is not even close to being true. Also the statement that switching to JR will make all your problems go away is a stretch as well... that is one mans opinion. JR does not even offer a servo to compete against the 5645 so you will have to spend twice the money on their servos. Hitec offers high end servos for higher prices too that will inprove performance. The 5955TG servo costs the same as the JR servos and is now being touted as the best of the best by giant scale pilots who are just looking for the best their money will buy. Do a search on this to see for yourself. The 5645's are one of the most popular servos on the market for a reason... they offer good bang for the buck.
Now... let's try to solve your problem instead of just assuming the servos are junk.
How is your linkage set up?
How long is the horn and where is the linkage attached?
How much travel do the surfaces have and where are your EPA's and Dual Rates set?
These are factors that will affect the servos ability to center the surface. Yes some servos center better than others but these servos should work for you as the do for many thousands of others.
If you have a long control horn of the servo mounted on the outside hole, even a small amount of movement will move the surface a long way... if you then use the EPA to reduce this throw you will affect the resolution. You need to utilize the entire throw of the servo to get the desired movement. This is where 3D throws will have an affect on the centering and it is best to go with a coreless motor servo for more precision.
If you want to talk about this in person, give me a call; I'll help you get it set up right.
Mike Mayberry
Hitec RCD Inc.
(858) 748-6948 x 302