Servo
 

Well... you can get a partial listing by going to www.towerhobbies.com and typing servo in thier search box.

You'll find probably over 100 different servos by several manufacturers... and then there's more manufacturers which Tower doesn't carry.

A nice feature of thier site is you can get the technical specs of each product, and read up on the basic info they place in each product's description. (you don't have to buy from them to read the info... ;) )

The 3003 and 3004 are "standard" size and power servos, with the main difference being the 3004 is ball bearing. One note... the Tower TS-53 is a relabeled Futaba S-3003. Peel the label, and the Futaba designation is molded in the case. The TS-53 is close to $9, the S-3000 is close to $14... and the only difference is a label has been stuck on the CHEAPER servo.

There's a kit available with 4 case tops that upgrades S-3003 to ball bearing, and the case tops are a stronger material than the S-3004 tops. I use this kit to replace case tops that have had the mounting lugs broken off. Appx $14 for the kit. (which combined with 4 new TS-53's is cheaper than 3 S-3004's. ;) )

Servo
 

Let's kinda divide the world of servos into 4 basic categories.


Sport off brand
Sport brand name
High performance
Digital




Now, let us agree that your control system is only as good as its weakest link. Repeat in your mind for full effect.


Sport off brand servos are fine for trainers up to .60 sized engines. Resolution, power and speed are not important. Cost is also a factor so they make a good choice. Generally in the 40 to 45 inch/ounce range with a transition time of .20 to 25 second.


Sport Brand Name Servos generally are an improvement in performance and service at a small cost. Generally in the 40 to 45 inch/ounce range with a transition time of .20 to 25 second.


High Performance servos vary a lot, but generally you have a choice of speed with lower torque or torque at a lower speed. I consider a minimum of 70 inch/ounces at .15 second to 120 inch ounces at .22 second with a coreless motor and ball bearing supported output shaft to be high performance. There are a few that have both power and speed such as the Futaba 9402 and are quite expensive.


Digital are better, but not by much. Generally offer the same speed and power, but in specialized situations can provide a slightly tighter feel. Most expensive.
Now here comes the rub, you almost cannot have too fast or too powerful a servo. Please repeat!

I know this comes as expensive news to some, but if you really want a precise model that performs, you need to pull out that Visa and invest in at least #3 for all control surfaces.



I got this info from Dave Patrick

Servo
 

I'll agree that the S-3003/4 servos aren't what you need for planes larger than .60 size. In fact, on many .60 size planes using these servos for rudder isn't a good idea.

Typically, the rudder will have the highest load on the servo, especially when you are flying a taildragger with dual aileron servos. The tailwheel places more shock loads on the servo than a nsegear typically will. Spring loaded "servo savers" are highly recommended on nosewheels or a springy connection of tailwheel to rudder is a very good idea no matter what servo you use.

There is a difference between off-brand servos and relabeled name-brand... The Tower TS-53 is a relabeled Futaba. The GWS servos are not relabeled. (and they are getting pretty good....)

Also, some of the "off brand" servos are getting to be as good or better than some of the "major name brand" servos... HiTech for example used to be a low end off-brand maker of Futaba compatible servos. They have developed into a major name brand R/C equiment maker, with as good average quality as Futaba.

Yes, you do get better quality and precision by getting a higher priced servo in most cases. The Futaba 9000 series servos are worth the extra cost for thier improved precision and power. I know Competition Pattern fliers who will use nothing else.... Not much need for these in a trainer though.

Without knowing what was desired except some info on the S-3003/4.... Ithought that pointing out a cheaper way to get the same servo was a good idea.