It’s true that understanding how a servo works is a good starting point. Though I must say that some things about servos still don’t make sense to me, ahaha.
An example, why on most website selling servos, the specs rarely mention what is the maximum degree rotation a servo can achieve. It seems to be something you should discover once you bought it. Some servos can achieve 180 degrees, some others 120, or 90 to even only 60 degrees.
The HK15298B and HK15298 can rotate 90 degrees.
The MG996R can achieve approximately 120 degrees.
The MG946R can achieve 180 degrees if I recall correctly.
Here is a standard specs data sheet for the MG946R:
Basic Information
Modulation: Digital
Torque: 4.8V: 145.8 oz-in (10.50 kg-cm)
6.0V: 180.5 oz-in (13.00 kg-cm)
Speed: 4.8V: 0.20 sec/60°
6.0V: 0.17 sec/60°
Weight: 1.94 oz (55.0 g)
Dimensions:
Length:
1.60 in (40.7 mm)
Width:
0.78 in (19.7 mm)
Height:
1.69 in (42.9 mm)
Motor Type: 3-pole
Gear Type: Metal
Rotation/Support: ? (add)
Additional Specifications
Rotational Range: ? (add)
Pulse Cycle: 1 ms
Pulse Width: ? (add)
Connector Type: JR