What happens inside a servo that makes two servos with the same dimensions produce different amounts of torque? An HS-475 and an HS-645 both are 1.6" x 0.8" x 1.4", yet the 475 weighs 1.52 oz and produces 76 oz/in while the 645 weighs 1.94 oz and produces 133 oz/in. Is it the amount of turns…more wire means more power?
Also, what is the difference between an analog and a digital servo? Are they manufactured differently? They both receive the same voltages and the same pulses, right? In Jim’s servo tutorial he states that a digital servo has to be programmed to get the same amount of travel as an analog, but it can be done. But he also says a Hitec digital does not need to be continually updated with pulses to hold a position. So what is the difference.
Also, I’m assuming analog servos do not need to be programmed because the DSP-01 is a digital programmer. And after a digital servo is prgrammed for it’s travel limits, both types of servos react the same way to an SSC-32?
Well, I think for the most part it plays with the motor that you are using in the Servo. I believe taht servos with the same motor, a digital one can produce more torque (that’s waht I’ve heard… but don’t quite get why.)
In the motor, the main factors :
-diameter of the wire
-Lengh of wire around the core of the motor
-amout of current (amps)
-amout of tension (voltage)
-The magnets around the core.
-If it’s brushless or not (creates more friction, so I guess that it MAY cause less torque)
The difference between analog and digital is quite simple : the digital one has a chip inside that basicly control the servo. An analog you would have to send the position to the servo every 1-2 ms and a digital, once he gets his position he keeps it (don’t need to send it each mili second). Some digital servos will send back information on inside temperature, load, shaft position, they will clsoe down if it’s two hot. Stuff like this will give you the possibility to know where all the limbs of your robot are.
Another thing that factors into torque is the gearing the servo has.
You could have the same motor in two servos. One will have gearing for higher torque which will give it the power but as a result you would lose some speed. And if you went the other way gear the servo for speed you get a faster servo but at the the expense of torgue.
As you up the motor strength these get better but thats when the cost start to go up.
